4
 
Volumes
 
ISSN 1983-4195
 
Vol13 - Num 3
2020
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Editorial

The IBRACON Structures and Materials Journal, published every two months, is a scientific and international journal, published by the Brazilian Concrete Institute, the largest Latin American Concrete Institute. Recently this journal has implemented some changes. The article submission now uses the Scholar One Manuscripts managing system, available at https://mc04.manuscriptcentral.com/riem-scielo. Reviewers can choose if they wish to be acknowledged in the publons website. Only papers submitted in English are now accepted and a new paper template is available. The Journal is increasing the number of published paper per year to 90, due to the high-qualified demand of paper submissions. Annually, close to 250 papers are received. Starting in the next issue, V13 n.4, the volumes will be published using the continuous flow system. This will reduce the time between submission and on-line availability of accepted articles. We would like to thank Professor José Luis Antunes de Oliveira e Souza, Editor-emeritus, who, together with other Editors, for more than 12 years, built the reputation of the IBRACON Journal.

We acknowledge the dedication of authors and reviewers, fundamental to the quality of the Journal.

The Editors

 
Vol13 - Num 2
2020
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The second 2020-number of the IBRACON Structures and Materials Journal (Volume 13 Number 2, April 2020) is published with twelve articles. The issue begins with an article on a simplified criterion to estimate second-order global effects in reinforced concrete buildings. The second article brings the analyses of the steel-concrete bond strength behavior after high-temperature exposure of a conventional 30-MPa concrete and 65-MPa high compressive strength concrete. The objective of the third article is to evaluate the influence of the cement type, curing period, shape, and humidity concrete specimens on the ultrasonic pulse velocity. The fourth article discusses the interference of the soil-structure interaction on small buildings reinforced concrete structures with deep foundations. The objective of the fifth article is the evaluation of the Ground Penetrating Radar (GPR) technique with a 1.2 GHz antenna in the determination of material thickness and discontinuities in the masonry shells of the Theatro Municipal do Rio de Janeiro, an early 20th-century heritage building, with high historical and cultural value. The sixth article discusses the use of geopolymer cement to repair cracks in concrete specimens, focusing on mechanical performance and fracture modes. The seventh article brings an experimental investigation on semi-rigid interior beam-column connections with negative bending moment continuity reinforcement. The eighth article presents a numerical approach for the simulation of the nonlinear structural behavior of composite connection between a partially encased composite beam and a concrete infilled steel tube column. The ninth article discusses the annual reliability indexes of a prestressed precast beam bridge at the serviceability limit state (SLS) designed according to the Brazilian standards. In the tenth article, finite element models were developed to analyze the variation of temperature to fire exposure time of shallow hollow core slabs, focusing on the presence of voids in the transversal section of the slab. The eleventh article addresses concrete mixtures produced with aggregates from ceramic block waste at high temperatures, evaluating their residual mechanical strength, axial compressive strength, and elastic modulus, and also their tendency to spalling in fire situations. An evaluation of the effects of carbon nanotubes sonication on mechanical properties of cement pastes is presented in the last article.

We acknowledge the dedication of authors and reviewers, fundamental to the quality of the Journal.

The Editors

 
Vol13 - Num 1
2020
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The first issue of the 2020 volume of the IBRACON Structures and Materials Journal (Volume 13, Number 1, February 2020) is published. Twelve articles discuss relevant topics on structural concrete. The issue begins with an evaluation of the influence of metakaolin on the mechanical properties, porosity and, in particular, on the carbonation of concrete, from the addition of 0%, 5%, 10% and 15% of metakaolin, in relation to the cement mass. The second article presents the use of numerical model techniques to identify and locate damage adopting the Modal Curvature Difference (MCD) method as reference in the analysis of concrete plates simply supported on rubber bearings. In order to analyze the influence of polymer fibers on the thermal properties of concrete, the work described in the third article assessed the thermal conductivity, the thermal expansion, and the compressive strength of concrete specimens with addition of polypropylene fibers and concrete specimens with addition of high modulus polyethylene, after exposure to 200-°C temperature. The fourth article aims to identify the modal parameters of Bridge 44 on the Carajás Railroad, using experimental on-site data obtained by monitoring the vibration caused by a group of people jumping at the deck. These data are compared with finite element modeling results. The fifth article presents a statistical analysis of reinforced concrete pipes design procedures. The sixth article presents an experimental study aiming to evaluate the relationship between the properties of four different concrete mixes produced in accordance with the specifications of EN 1992-1 and EN 206 standards and its performance during carbonation and salt spray accelerated testing. In the seventh article, numerical models are developed in order to assess the effective stiffness of elastomeric bearing pads under precast beams for the limit load of lateral instability considering combinations of the beam span length and cross-section and lateral eccentricities. The eighth article proposes a new flexural design model for reinforced concrete beams considering the ductility factor. The ninth article focuses on the physical-mechanical potential properties of wastes from glass lapping to produce mortar as partial replacement of the conventional aggregate. The purpose of tenth article is to compare the specification on the ACI 318/2014, AASHTO and ABNT NBR 6118: 2014 codes related to shear and torsion, assessing results from experimental data obtained in the literature. The eleventh article presents a study on the applicability of a concrete elastoplastic model in the analyses of a theoretical framework describing the Cutting Plane return mapping algorithm. The last article in this issue presents an analysis of the global stability of flat-slab tall buildings considering the soil-structure interaction.

We acknowledge the dedication of authors and reviewers to the quality of this issue.

The Editors

 
Vol12 - Num 6
2019
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The last issue of the 2019 Volume of the IBRACON Structures and Materials Journal is now released with twelve articles on relevant structural concrete topics. The issue begins with an article on the development of stabilized mortars for masonry using air incorporator additives and settling retardant plasticizer to compare with a conventional mortar with lime. The second article presents a study on the content of ether polycarboxylate-based superplasticizer, determined by rotational rheometry. Its effects on the environmental impacts of concretes were studied for cement and limestone filler. A reliability-based calibration of partial safety factors for Brazilian codes used in the design of concrete structures is presented in the third article. The work is based on reliability theory, which allows an explicit representation of the uncertainties involved in terms of resistances and loads. The fourth article describes an experimental test program intended to evaluate the influence of the particularities of self-consolidating concrete mixtures on the shear capacity of beams with shear reinforcement. A study on the use of parameter γz for reinforced concrete frames in fire situation is the subject of the fifth article. The sixth article presents a theoretical formula to evaluate the long-term deflections for reinforced concrete beams of normal and high strength concretes. A study on the aerodynamic behavior of a 150 m tall concrete chimney is presented in the seventh article. The eighth article aims at the evaluation of the effect of nano-silica on Portland cement matrix. The ninth article describes a study on the properties of lightweight concretes with addition of expanded polystyrene for structural walls applications. The tenth article proposes a new system to classify possible damages in piles partially reinforced considering the results of low strain integrity tests. The objective of eleventh article is the development of an algorithm for the design of steel-concrete composite beams aiming at an optimization in terms of material costs. The twelfth and last article in this issue deals with the analysis of torsional tangent rigidity of reinforced concrete waffle slabs by comparisons between results from numerical analysis and results of experimental tests.

We congratulate the authors for the quality of articles in this issue and acknowledge the dedication of the reviewers.

The Editors

 
Vol12 - Num 5
2019
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The fifth issue of the 2019 volume of the IBRACON Structures and Materials Journal (RIEM, Volume 12, Issue 6, October 2019) is released with twelve articles on structural concrete. The main objective of the first article is the implementation of a finite element model for nonlinear numerical analysis of concrete slabs with steel decking. The second article presents a nonlinear static analysis using a case study of a pile-supported wharf in a new oil tankers port. An experimental program on reinforced concrete masonry beams is described in the third article, aiming at a better understanding of the behavior of reinforced masonry beams. The work described in the fourth article investigates the influence of the instability parameter of reinforced concrete frame-braced buildings. The fifth article discusses the behavior of single-storey, single-bay reinforced concrete infilled frames with masonry panel subjected to static horizontal load. The sixth article aims at an evaluation of the reliability indexes of reinforced concrete beams designed in accordance with Brazilian Code NBR-6118:2014 with respect to the ultimate limit state. The objective of the seventh article is to analyze the influence of concrete compressive strength in columns for the design of a multi-storey building, using a CAD/TQS computational tool. In the eighth article, results of uniaxial compression tests and indirect tensile tests, using cylindrical samples, are reported. These tests confirm that both the unconfined compressive strength and the indirect tensile strength determined on cylindrical samples are influenced by the angle between the sample axis and the orientation during casting. The ninth article presents the development of a trusstype shear connector proposed for a concrete-steel composite beam. The tenth article investigates the use of semi-continuity in simply supported composite steel and concrete beams, to remove fireproof coatings for standard-fire resistance requirement of fewer than 30 minutes. The eleventh article presents a comparative analysis between two model hierarchies commonly applied in tunnel structural design: continuum ground models and bedded-beam models. The main objective of the last article is to carry out a comparative analysis between the methods and provisions of the Brazilian code ABNT NBR 15421:2006 and those of the ASCE/SEI 7 and the Eurocode 8, on the seismic design of structures.

We acknowledge the dedication of authors and reviewers for this issue

The Editors

 
Vol12 - Num 4
2019
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The fourth issue of 2019 of the IBRACON Structures and Materials Journal (RIEM, Volume 12, Number 4, August 2019) is now released with twelve articles on relevant topics of concrete structures and materials. The first article aims to evaluate the global structural stability of model concrete structures considering the eccentricity of the beam-wall connections. The flexural behavior of hybrid glass fiber reinforced polymer - concrete beams as railway sleepers, comparing to the prestressed concrete monoblock sleeper is the objective of the second article. In the third article, an experimental study is presented on the application of ultra high performance reinforced concrete (UHPRC) with sustainable materials produced in Brazil. The fourth article describes a statistical analysis of the inclusion effects of waste tire rubber and fly ash from thermoelectric plants as mortar components for coating buildings. In the fifth article, the behavior of reinforced concrete corbels strengthened with external prestressing is investigated. Nonlinear analysis of short corbels, strengthened or not, and analytical models based on the strut-and-tie model are described and results are compared with experimental results. The sixth article addresses the design of pile caps by strut-and-tie models. In the seventh article, the Laplace’s equation is solved analytically in the complex plane for the field of hydrodynamic pressures generated by the rigid body movement of a dam against a reservoir with infinite domain and incompressible fluid. The axial compressive strength at 3, 7, and 28 days, and the tensile strength at 28 days of specimens of two self-compacting concrete mixes are evaluated in the eighth article. The difference between them was the presence of the sugarcane bagasse ash in the substitution rate of 10% of the sand mass in the second mix. The ninth article addresses concrete block structural masonry beam shear design, discussing the theoretical and experimental analyses and recommendations to the Brazilian standards. The tenth article aims to implement optimization techniques for the design of reinforced concrete beams according to the precepts of Brazilian Standard ABNT NBR 6118:2014. A computational algorithm for the verification of reinforced concrete sections in fire situation is described in the eleventh article. A stress integration algorithm was implemented from the strain profile of the section according to ABNT NBR 15200:2012, linked to a finite element mesh generator and a thermal analysis algorithm. The twelfth article analyzes a single reinforced concrete building designed for the 3 SL specified by ABNT NBR 15575:2013 - a standard that determines minimum performance requisites that must be applied to housing developments to meet requirements of habitability, safety, and sustainability. The study focused on the total consumption of steel and concrete.

We would like to acknowledge the dedication of authors, reviewers and other professionals that contributed to the quality of this issue

The Editors

 
Vol12 - Num 3
2019
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We are now releasing the third issue of the twelfth volume of the IBRACON Structures and Materials Journal (Volume 12 Number 3, June 2019), with twelve articles. The issue begins with a discussion on the theoretical estimates of punching shear resistance using ACI 318, Eurocode 2 and ABNT NBR 6118 in the case of slabs without shear reinforcement. The second article aims to discuss the progressive collapse and the behavior of masonry buildings subject to abnormal loads. The third article addresses the feasibility of grinding dust, a waste generated in the clutch disc finishing process, as a retardant additive in cementitious matrices. An alternative shear connector for cold-formed steel-concrete composite beams is proposed in the fourth article. In the fifth article, the finite element method is used to model columns with square, rectangular and circular cross-sections wrapped with fiber reinforced polymers. An application of structural reliability theory to a case study of a built concrete gravity dam is illustrated in the sixth article. The research described in the seventh article investigates if the addition of rubber chips to mass concrete enhances cracking strength due to thermally induced volumetric variations. The eighth article addresses the feasibility of the pervious concrete made with electric furnace slag, discussing mechanical and hydraulic properties. The research described in the ninth article intends to analyze the potential of sugarcane bagasse ash and tire residue in pavers. The objective of the tenth article is to assess the thermal insulation capacity of concrete block masonry in fire conditions. The eleventh article presents contributions to shear strength analysis of slabs without transverse reinforcement under concentrated loads, with a focus on the accuracy level of the shear strength analytical models recommended by ABNT NBR 6118:2014. The issue closes with an article on shrinkage and porosity in concretes produced with recycled concrete aggregate and rice husk ash.

We acknowledge the contribution of authors and reviewers for the quality of this issue

The Editors

 
Vol12 - Num 2
2019
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The second issue of 2019 of the IBRACON Structures and Materials Journal (Volume 12 Number 2, April 2019) is now available, with twelve articles. The first article discusses the optimization of the replacement content of Portland cement by stone powder using particle packing methods, and analysis of the influence of the excess water on the consistency of pastes. The second article discusses the theoretical basis of ACI 440.2R: 2008 and NBR 6118: 2014 related to the analysis of reinforced concrete beams strengthened with CFRP. The third article intends to evaluate the technical viability and application of fiber-reinforced polymers with sisal fibers for strengthening reinforced concrete structures. The fourth article describes experimental research on short reinforced steel fiber concrete beams, aiming at investigating shear stresses, bending, strain energy, toughness, scale effect and fracture energy. A methodology is presented in the fifth article for dynamic analysis of structures under wind loading, considering geometric nonlinearity, vibration caused by the kinetic energy of wind gusts, and aerodynamic damping. The seventh article presents experimental and theoretical analyses of circular concrete-filled steel tube columns using bolts as shear connectors. The eighth article aims to evaluate the effects of superplasticizer admixture with nanosilica in colloidal suspension on the consistency and mechanical strength of the concrete. In the ninth article, the improved version of the lumped damage model is coupled to the Monte Carlo simulation method to represent the mechanicalprobabilistic behavior of reinforced concrete structures. The effect of temperature gradients on the behavior of jointed plain concrete pavements is the topic for the tenth article. In the eleventh article, numerical analyses are conducted on nine models with different patterns of irregularity in terms of geometry and stiffness. The objective is to evaluate the applicability of the χT parameter in structures that have asymmetric geometries and that can present torsional as the fundamental mode of vibration. This issue closes with an article intended to evaluate, through experimental and finite element analyses, the effects of specimen shape and size on uniaxial compression tests.

We congratulate authors and reviews for the quality of this issue.

The Editors

 
Vol12 - Num 1
2019
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The first issue of 2019 of the IBRACON Structures and Materials Journal (Volume 12 Number 1, February 2019) is now available online. The first article aims at an appropriate support to decision-making for maintenance, rehabilitation and repair strategies under constraint of limited budgets. An analytical study on the design of cylindrical liquid storage tanks resting on deformable foundations is the subject of the second article. The third article discusses the economic aspects of high-strength concrete associated with geometrical optimization of decks of post-tensioned multi-girder overpasses. The fourth article brings an evaluation of the influence of Bacillus subtilis AP91 spores addition on the mechanical properties of mortars. The fifth article presents a study on the loop joint behavior in reinforced concrete structures under tension. The sixth article discusses experimental results related to load capacity of beams with steel fiber reinforcement on the compression face. The seventh article has the objective of presenting the application of the linear and non-linear strut-and-tie models on some typical structural elements, using the Evolutionary Topological Optimization Method. The eighth article presents a study of dosage and addition of polypropylene fibers for pervious concrete. The ninth article presents a numerical study on the explosive breaching of a concrete wall using an optimized contact explosive charge with cylindrical shape. In the tenth article, a comparative analysis is presented among standards of transversal reinforcement computation for high strength reinforced concrete beams subjected to shear action. The eleventh article investigates the behavior of the self-compacting mortars with sugarcane bagasse ash in fresh and hardened state. The goal of the twelfth is the evaluation of the widening and strengthening procedures used in reinforced concrete highway bridges.

We acknowledge the dedication of authors and reviewers to the quality of this issue.

The Editors.

 
Vol11 - Num 6
2018
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Editorial

We acknowledge the dedication of authors and reviewers, responsible for the good quality of the articles presented

Américo Campos Filho, Eduardo N. B. Santos Júlio, José Luiz Antunes de Oliveira e Sousa, José Márcio Fonseca Calixto, Leandro Francisco Moretti Sanchez, Mauro Vasconcellos Real, Osvaldo Luís Manzoli, Paulo César Correia Gomes, Rafael Giuliano Pileggi, Roberto Caldas de Andrade Pinto, Ronaldo Barros Gomes and Túlio Nogueira Bittencourt, Editors

 
Vol11 - Num 5
2018
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In the fifth issue of 2018 of the IBRACON Structures and Materials Journal (RIEM Volume 11 Number 5, October 2018), we are publishing twelve articles on concrete structures and materials. The first article presents a study on the reliability of internal column-slab connection under punching according to the Brazilian Standard NBR 6118:2014. The reliability index β is compared with the reliability index recommended by fib Model Code 2010. The second article reports a research conducted to evaluate the hardening phenomenon of pastes formulated with Portland cements blended with limestone filler, ground blast furnace slag or pozzolan. The third article presents an experimental study with numerical modeling of Crestbond shear connectors in concrete-filled tube columns. The fourth article presents an experimental and computational study on ribbed slabs with wide-beam, one-way and two-way slabs, with variable depths for evaluating resistance to punching and shear. The fifth article discusses the design of reinforced concrete beams with steel fibers according to fib Model Code 2010 (MC 2010) procedures. In the sixth article, a composite footbridge is analyzed by means of experimental tests and computational modeling. The focus is the determination of natural frequencies and mode shapes. The seventh article reports an experimental study on the interference produced by neighboring buildings in the wind action on a tall building. The objective of the eighth article is to evaluate the influence of sodium and magnesium sulfates on physical properties of mortars composed by SR cement (CP V - ARI RS), as commercially sold in Brazil. The ninth article discusses effects caused by soil-structure interaction in reinforced concrete wall building on shallow foundation. The focus is the influence of displacements of supports on the redistribution of internal forces in the structural walls and in the redistribution of loads on the foundation. The objective of the tenth article is to present an experimental evaluation of punching shear strength of reinforced concrete flat slab with steel fibers and punching shear reinforcement. Eight square slabs, size 1800 mm by 1800 mm by 130mm, were loaded until failure by punching shear around the column. The eleventh article describes the parametric analysis applied to assess the influence of column anchorage-reinforcement length on concrete two-pile caps under uniform compression. The twelfth and last article discusses best practices for pervious concrete mix design and laboratory tests.

We acknowledge the dedication of authors and reviewers, responsible for the good quality of the articles presented

Américo Campos Filho, Eduardo N. B. Santos Júlio, José Luiz Antunes de Oliveira e Sousa, José Márcio Fonseca Calixto, Leandro Francisco Moretti Sanchez, Mauro Vasconcellos Real, Osvaldo Luís Manzoli, Paulo César Correia Gomes, Rafael Giuliano Pileggi, Roberto Caldas de Andrade Pinto, Ronaldo Barros Gomes and Túlio Nogueira Bittencourt, Editors

 
Vol11 - Num 4
2018
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Editorial
This issue of the IBRACON Structures and Materials Journal (Volume 11 Number 4, August 2018) brings twelve articles on relevant topics related to concrete. The issue starts with a study on the conformity of structural concrete blocks used in masonry construction in Brazil. The second article presents a numerical analysis of the mechanical behavior of structural masonry panels submitted to horizontal and vertical stresses. The effects of unilateral suspension on the cable-stayed curved deck are the topic for the third article. The fourth article presents an adaptation of an incremental algorithm, developed by Bažant and Prasannan, to account for creep in a finite element commercial software, according to the CEB-FIP Model Code 1990. Numerical models are described in the fifth article to implement the analytical formulations prescribed by ABNT NBR 8800:2008 for lateral-distortional buckling of continuous steel and concrete composite beams. The objective of the sixth article is to evaluate the influence of partial interaction in the effective width of composite beams formed by a concrete slab connected to a steel beam with a deformable connection. An investigation of the correlation between compressive tests and sclerometry tests is the objective of the seventh article. The eighth article presents an experimental study of reinforced concrete beams strengthened for bending by reinforced grout layer and connectors. The ninth article reports an investigation on the influence of the beam-column connections stiffness on the structural behavior of reinforced concrete buildings. The tenth article presents an experimental analysis of the spalling phenomenon in precast reinforced concrete columns exposed to high temperatures. The eleventh article aims at the thermo-structural performance of steel and steel-concrete composite columns on fire. The last article addresses the influence of crusher type in the shape of fine aggregate grains.

We acknowledge authors and reviewers for their contributions to this issue

Américo Campos Filho, Eduardo N. B. Santos Júlio, José Luiz Antunes de Oliveira e Sousa, José Márcio Fonseca Calixto, Leandro Francisco Moretti Sanchez, Mauro Vasconcellos Real, Osvaldo Luís Manzoli, Paulo César Correia Gomes, Rafael Giuliano Pileggi, Roberto Caldas de Andrade Pinto, Ronaldo Barros Gomes and Túlio Nogueira Bittencourt, Editors

 

Vol11 - Num 3
2018

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We are now publishing the third issue of 2018 of the IBRACON Structures and Materials Journal (Volume 11 Number 3, June 2018) with eleven articles on materials and concrete structures. The first article brings a comparison between load contour diagrams generated for rectangular RC cross-sections under combined axial compression and biaxial bending obtained according to the two options allowed by NBR 6118:2014: the first using the parabolicrectangular stress-strain diagram and the second using the rectangular diagram. Evaluation of the influence of the corrosion degree on mechanical properties of reinforcements buried for 60 years is the objective of the second article. The third article reports a study on the influence of the placement rate on the lateral pressure of fresh concrete using theoretical models from the literature and international codes. The objective is the evaluation of the lateral pressure of fresh concrete at high rates according to actual data from current practice. The fourth article presents a nonlinear analysis of concrete structures using GFEM enrichment strategy with a microplane constitutive model. The fifth article describes an experimental evaluation of the mechanical behavior of a geopolymer concrete beam with a comparison with a Finite Element nonlinear numerical model. The sixth article reports an evaluation of chloride penetration and life cycle of self-healing concretes activated by crystalline admixture. The objective of the seventh article is the effect of creep and shrinkage of the concrete in soil-structure interaction, analyzing a 17-story building on shallow foundation, in the central part of the construction, and steel piles, on the boundary. A computational tool for preliminary tunnel design using Bernaud & Rousset’s New Implicit Method is described in the eighth article, and validated with a finite element analysis. The ninth article presents experimental results from confined pullout tests, comparing the performance of cast steel reinforcement bars with that of bars bonded to concrete with epoxy resin. The tenth article presents an evaluation of the influence of transverse rebars on bond between steel reinforcement and cellular concrete with very low compressive strength. The subject of the eleventh article is the analysis of creep strains on reinforced concrete thin-walled columns, emphasizing the fresh concrete consistency effect. We acknowledge the contributions of authors and reviewers to this issue.

Américo Campos Filho, Eduardo N. B. Santos Júlio, José Luiz Antunes de Oliveira e Sousa, José Márcio Fonseca Calixto, Leandro Francisco Moretti Sanchez, Mauro Vasconcellos Real, Osvaldo Luís Manzoli, Paulo César Correia Gomes, Rafael Giuliano Pileggi, Roberto Caldas de Andrade Pinto, Ronaldo Barros Gomes and Túlio Nogueira Bittencourt, Editors

 

Vol11 - Num 2
2018

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We are publishing the second issue of volume 11 of the IBRACON Structures and Materials Journal with ten articles. The issue begins with an article on modelling of fracture problems in quasi-brittle materials by the E-FEM. The second article presents an experimental study on solid reinforced concrete slabs strengthened on the upper surface. The third article discusses experimental results to assess stiffness plasticity degradation of masonry mortar under compression. The fourth article draws on the use of semi-continuity to remove fireproof coatings in simply supported composite steel and concrete beams. In the fifth article, computational routines, based on the Brazilian Norm ABNT NBR 6118:2014, are used to analyze the ultimate flexural strength of prestressed concrete beams. Lateral-torsional buckling of cellular composite beams is addressed in the sixth article. The seventh article analyzes the Real Class building collapse, a residential building with reinforced concrete structural system and located in the urban area of the city of Belem / PA, occurred in 2011. The eighth article proposes a standardized solution for the application of Tuned-Mass Dampers to the control of floor vibrations based on the characteristics of the acting loads associated to human usage and the characteristics of the most common structures of the contemporary engineering practice. The ninth article evaluates the effect of the mixing method on the mini-slump spread of Portland cement pastes. An evaluation of international design codes on punching resistance of reinforced concrete footings is presented in the last article.

Américo Campos Filho, Eduardo N. B. Santos Júlio, José Luiz Antunes de Oliveira e Sousa, José Márcio Fonseca Calixto, Leandro Francisco Moretti Sanchez, Mauro Vasconcellos Real, Osvaldo Luís Manzoli, Paulo César Correia Gomes, Rafael Giuliano Pileggi, Roberto Caldas de Andrade Pinto, Ronaldo Barros Gomes and Túlio Nogueira Bittencourt, Editors

 

Vol11 - Num 1
2018

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Editorial

We are now releasing the first issue of the eleventh volume of IBRACON Structures and Materials Journal (Volume 11, Number 1, February 2018). This issue begins with a material nonlinear approach to analyze the global stability of buildings with less than four floors. In the second article, a mechanical model is presented involving material nonlinearities and corrosion effects to predict the loss of resistance of reinforced concrete beams. The third article describes ambient vibration tests performed with the objective of obtaining the natural frequencies of a heritage construction from the nineteenth century. The objective of the fourth article is to analyze self-compacting concretes using lightweight and recycled aggregates. The fifth article discusses an experimental modal analysis procedure for vibratory responses through impulsive excitations to determine the natural frequencies and the location of points suitable for attachment of dynamic vibration absorbers to a reinforced concrete beam. The sixth article reports an investigation on the influence of the thickness of the mortar-laying joint in the resistance of masonry structures. The seventh article aims to evaluate emissions and CO2 uptake in concretes produced with different cement content and type. The eigth article presents ultimate limit state curves for short reinforced concrete columns in fire situation. The ninth article describes numerical evaluation of concrete beams with geometric imperfections on elastomeric supports. A discussion is presented on the influence exerted by the concrete parameters, physical non-linearity and the compression stiffness of the bearing pads. In the last article, two design methodologies are presented considering the uniform and triangular pressure distribution between base plate and concrete.

We acknowledge the dedication of authors and reviewers in assuring the quality of this issue.

Américo Campos Filho, Eduardo N. B. Santos Júlio, José Luiz Antunes de Oliveira e Sousa, José Márcio Fonseca Calixto, Leandro Francisco Moretti Sanchez, Mauro Vasconcellos Real, Paulo César Correia Gomes, Rafael Giuliano Pileggi, Roberto Caldas de Andrade Pinto, Ronaldo Barros Gomes and Túlio Nogueira Bittencourt, Editors

 

Vol10 - Num 6
2017

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Editorial

The last issue of 2017 of the IBRACON Structures and Materials Journal is now published (Volume 10 Number 6, December 2017), with ten articles focusing relevant topics on concrete structures and material are presented. The first article examines the live load statistics for Brazilian concrete bridges. The analysis was conducted using monitoring data corresponding to thirteen months of a High Speed Weigh-In-Motion station (HS-WIM), in a resolution of one hundredth of a second, currently operating on the Fernão Dias highway (BR 381). Results show that, except in the side-by-side case, the span length has significant effect on the frequency of multiple truck presence. The second article addresses the effect of alkali concentration and curing temperature regime on fly ash-based geopolymer pastes using NaOH solutions. The third article describes the use of technology based on low frequency ultrasonic tomography for evaluating concrete pavement parameters. The equipment was applied in three experimental sections with different concrete pavements at the University of São Paulo campus. The fourth article presents a parametric study to evaluate the rollover instability of beams supported exclusively by elastomeric bearing pads during construction of precast girder bridges. A finite element model was calibrated with experimental results through a nonlinear geometrical analysis. The fifth article presents a model for penetration of chloride by diffusion in reinforced concrete structures based on the solution of the 2nd Fick’s Law, using a two-dimensional finite element model to predict the time, in a given situation to reach a limit of chlorides for depassivation of reinforcement. The sixth article presents a study on the behavior under cyclic loading of reinforced concrete beams strengthened in bending by the addition of concrete and steel on their tension side and expansion bolts as shear connectors at the interface beamjacket. The seventh article addresses the behavior of high strength structural masonry. The compressive strength and the modulus of elasticity of concrete block walls tested under axial load were evaluated. The specimens included grouted and ungrouted walls and walls with a mid-height bond beam. The eighth article aims at the pozzolanic activity of fly ash from coal burning, from the aluminum manufacturing process, such as mineral admixture in mortars and conventional concrete. The ninth article presents the results of a B-WIM system applied on a bridge. The weighin-motion technique is based on Moses’ Algorithm, which obtains influence lines directly from traffic loads.

The tenth and last article discusses results of tests on self-supporting lattice joists subject to negative bending. As this is the last issue of Volume 10, we present a list of reviewers that contributed during 2017. We acknowledge their dedication to ensuring the high level of the IBRACON Structures and Materials Journal.

Américo Campos Filho, Eduardo N. B. Santos Júlio, José Luiz Antunes de Oliveira e Sousa, José Márcio Fonseca Calixto, Leandro Francisco Moretti Sanchez, Mauro Vasconcellos Real, Paulo César Correia Gomes, Rafael Giuliano Pileggi, Roberto Caldas de Andrade Pinto, Ronaldo Barros Gomes and Túlio Nogueira Bittencourt, Editors

 

Vol10 - Num 5
2017

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Editorial

We are now releasing the fifth issue of 2017 of the IBRACON Structures and Materials Journal (Volume 10, Number 5, October 2017), with ten articles approaching relevant topics on concrete structures and materials. The first article addresses the dispersions of the compressive strength of concretes mixtures, focusing on the influence of the workers team. The second article describes the optimization of the bending stiffness of beam-to-column and column-to-foundation connections in precast concrete structures, modelled with finite elements. The third article discusses the influence of packing and particles dispersion on the cement content of concrete. For the fourth article, axial compression tests were performed on specimens of reduced size. The total porosity was assessed by an apparent density and solid fraction density ratio, obtained, respectively, by means of mercury and helium pycnometry and µ-CT microtomoghaphy techniques. The fifth article reports an investigation on the influence of the transverse reinforcement detailing on the ductility of the reinforced concrete column. The sixth article aims to correlate the results of pull-out bond tests with its variables applying artificial neural networks. The seventh article aims at assessing the behavior of composite slabs, considering the influence of friction at the sheeting-concrete interface in the support region. The eighth article proposes a model for the numerical simulation of the mechanical behavior of quasi-brittle materials. Numerical examples involving the microcracking process are provided to illustrate the performance of the proposed modeling. The ninth article is intended to evaluate the efficiency of the γz coefficient as a global stability parameter. A comparative analysis was performed in several idealized structures, from which an approximate equation was obtained for computing the critical load factor based on the γz coefficient. This equation was validated by numerical analysis of actual reinforced concrete buildings. The purpose of the last article in this issue is to discuss the equivalent time method, a procedure for decreasing the required time for fire resistance of the multistory buildings detailed in the Brazilian standard ABNT NBR 15200: 2012.

We acknowledge the dedication of authors and reviewers, responsible for the quality of this issue.

Américo Campos Filho, Eduardo N. B. Santos Júlio, José Luiz Antunes de Oliveira e Sousa, José Márcio Fonseca Calixto, Leandro Francisco Moretti Sanchez, Mauro Vasconcellos Real, Rafael Giuliano Pileggi, Roberto Caldas de Andrade Pinto, Ronaldo Barros Gomes and Túlio Nogueira Bittencourt, Editors

 

Vol10 - Num 4
2017

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A new issue of the IBRACON Structures and Materials Journal (Volume 10 Number 4, August 2017) is now available, with ten articles approaching relevant topics on structural concrete. The issue begins with a paper on punching shear in prestressed slabs with unbonded tendons, designed according to Brazilian, European and American codes. Results according to four design codes show advantages in favor of European EC2:2004 and Brazilian NBR 6118:2014. The second paper describes ultrasonic pulse velocity experiments to evaluate effects of thermal and mechanical loading on the degradation of mortar mechanical properties. The next article presents a critical review of microstructural changes in concrete exposed to high temperature. In the fourth article, the corrosion potential technique is used as an electrochemical method to support monitoring of reinforcement corrosion in reinforced concrete structures. The aim is to evaluate some of the possible factors that influence corrosion potential measures, such as concrete moisture content, water-cement ratio, cover thickness and degree of chloride contamination. The fifth article summarizes experimental studies on the shear strength of reinforced slender self-compacted concrete beams, comparing with the shear strength of the corresponding vibrated concrete beams. The sixth article presents a series of test results of large-scale rectangular concrete-filled steel tubular beams to assess their performance under pure bending. Test results show that the concrete infilling enhanced flexural behavior and performance of the steel tubes. The seventh paper presents an evaluation of the strength compliance of concretes produced in Brazil. Results from more than twenty-seven thousand concrete samples, from different parts of the country, show that a significant part does not reach the characteristic strength specified in the design and that the percentage of nonconforming samples tends to be above 5%. The behavior of the block-grout interface for concrete and clay block masonry is the objective of the eighth article. The ninth paper proposes a simplified dynamic analysis methodology for studying vibrations in railway bridges produced by a typical passenger train. In the last paper, a literature survey examines material and mechanical properties of ultra high-performance fiber-reinforced concrete, a material with unique properties (high ductility, low permeability, very high strength capacity in compression, higher toughness) in comparison to conventional concrete.

We congratulate authors and reviewers for the quality of the articles published in this issue.

Américo Campos Filho, Eduardo N. B. Santos Júlio, José Luiz Antunes de Oliveira e Sousa, José Márcio Fonseca Calixto, Leandro Francisco Moretti Sanchez, Mauro Vasconcellos Real, Rafael Giuliano Pileggi, Roberto Caldas de Andrade Pinto, Ronaldo Barros Gomes and Túlio Nogueira Bittencourt, Editors

 

Vol10 - Num 3
2017

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We are now releasing the third issue of the 2017 volume of the IBRACON Structures and Materials Journal (Volume 10 Number 3, June 2017), with ten articles on interesting topics related to structural concrete applications. The first article brings a discussion on a methodology prescribed by the Brazilian Standard ABNT NBR 8522:2008 for determining the stress-strain behavior of cylindrical samples of concrete, presenting considerations on possible enhancements related to the application to concretes with recycled aggregates. The second article is intended to evaluate the influence of different regularization methods for concrete cylindrical specimens in simple compression test. The third article describes an analytical and experimental study on the behavior of shear connectors in composite columns with concrete-filled hollow section. A structural bolt was selected as a shear connector in order to validate analytical expressions provided by ABNT NBR 16239: 2014. A study on the design loads due to mooring and berthing of vessels is presented in the fourth article, regarding the design of port structures. The fifth article describes a research project intended to monitor the carbonation front progress and the pH variation on the surface of the cementitious composite, in compliance with the European standard EN 14630. The structure of voids in the matrix was assessed with the µ-CT imaging technique. The sixth article discusses an evaluation of blast wave overpressures using a computational fluid dynamics software. The seventh article discusses the effect of the failure of a steel roof on the facade concrete columns of a warehouse in fire. A procedure a based on British literature, which considers the horizontal load on the columns is adapted to Brazilian standards and applied to a case study. The next article proposes a simplified methodology for the dynamic analysis of curved road bridges under the effect of a heavy vehicle. In the ninth article, physical nonlinearities and fundamentals of fracture mechanics for quasi-brittle materials are considered for determining the fracture energy and the fracture process zone length, as well as the modulus of elasticity, the tensile strength and the compressive strength, to characterize the mechanical behavior of self-compacting concrete. The last article studies the effect of the variability of the geometric section of square and rectangular columns, with different longitudinal reinforcement rates, in the main reinforcement of two pile caps.

We congratulate the authors for the quality of the published and acknowledge the dedication of the reviewers, fundamental for the consolidation of our Journal.

Américo Campos Filho, Eduardo N. B. Santos Júlio, José Luiz Antunes de Oliveira e Sousa, José Márcio Fonseca Calixto, Leandro Francisco Moretti Sanchez, Mauro Vasconcellos Real, Rafael Giuliano Pileggi, Roberto Caldas de Andrade Pinto, Ronaldo Barros Gomes and Túlio Nogueira Bittencourt, Editors

 

Vol10 - Num 2
2017

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The second issue of 2017 volume of the IBRACON Structures and Materials (Volume 10 Number 2, April 2017) is now published, with 10 interesting articles on concrete applications. The issue starts with an article on the reliability of punching shear of flat slabs without shear reinforcement. Reliability theory concepts are applied to evaluate safety based on the formulation established by NBR6118: 2014. A second article presents a study of the reliability of partially encased steel-concrete composite columns, subject to compression and bending. Literature statistics are used to quantify uncertainty in strength of structural materials and in loads. Reliability indexes are evaluated and a discussion is presented on the prescriptions of the Brazilian Norm NBR8800:2008 with respect to the safety levels. The third article describes a LITS (Load Induced Thermal Strain) semi empirical model and two practical applications in simple and reinforced concrete members. A comparison between the described model and experimental values is presented aiming at an evaluation of reliability of the semi-empirical model. In the fourth article the simplified method to evaluate final efforts using gz coefficient is discussed considering the variation of the second order effects with the height of the buildings. The fifth article focuses the influence of technological variables on the results obtained through Ultrasonic Pulse Velocity tests, aiming at the adequate choice of test parameters. The sixth article describes concepts, development and validation of a two-dimensional finite element model for physical and geometric nonlinear analysis of reinforced concrete beams and plane frames. The seventh article presents a comparative study of different simplified methods and nonlinear finite element models used for calculating short-term deflections (vertical displacements of the longitudinal axis) in continuous reinforced concrete beams, under service loads. The next article intends to show that a correlation is possible between the ultimate limit state in fire conditions, and ultimate limit state at room temperature, for square cross sections under fire. The ninth article describes the development of experimental tests and numerical models able to represent the mechanical behavior of prisms made of ordinary and high strength concrete blocks. The last article presents analytical and numerical analysis of concrete corbels in different stages of columns, comparing results with experimental tests performed on five specimens.

Thanks to the dedication of authors, reviewers and all the IBRACON community, our Journal is reaching a status of an important scientific vehicle for the researchers in concrete structures and materials. In the past year, our Journal received higher grades from the CAPES/QUALIS evaluation: B1 from the Engineering I committee and A2 from the Architecture and Urbanism Committee.

Américo Campos Filho, Eduardo N. B. Santos Júlio, José Luiz Antunes de Oliveira e Sousa, José Márcio Fonseca Calixto, Leandro Francisco Moretti Sanchez, Mauro Vasconcellos Real, Rafael Giuliano Pileggi, Roberto Caldas de Andrade Pinto and Túlio Nogueira Bittencourt, Editors

 

Vol10 - Num 1
2017

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With this issue (Volume 10, Number 1) we are opening the tenth volume of the IBRACON Structures and Materials Journal, with ten articles on concrete structures and materials. The first article discusses the economic viability of ultra-high performance fiber reinforced concrete applied to a wind tower for a 5 MW turbine. The second article deals with the influence of coarse aggregate on shear resistance of self-consolidating concrete beams. A numerical analysis of steel-concrete composite structures with nonlinear behavior is the topic of the third article. Tools to evaluate damage in concrete affected by alkaliaggregate reaction are described in the fourth article. The next article draws on the thermal insulation capacity of blocks with EVA waste for green roofs. Adherence between steel bars and lightweight concrete with EPS beads is analyzed in the sixth article. The seventh article presents an experimental analysis to evaluate the concrete contribution to the shear strength in beams without shear reinforcement. The eighth article reports an investigation on reinforced concrete plates and shells with skew reinforcement whose directions are not aligned with the principal internal forces. The ninth article is a compendium on intumescent paint and its main features regarding chemical composition, thermophysical properties and performance as a fire-retardant material. This issue closes with an article on recommendations for the calculation of the column-base connection by socket according to ABNT NBR 9062:2006.

All articles in this issue result from original researches, and were evaluated by reviewers with recognized competence in the corresponding areas.

We are pleased to announce that the IBRACON Structures and Materials Journal has been classified as B1 by CAPES/QUALIS. We acknowledge the dedication of all the community, authors, reviewers and readers, for this important achievement.

Américo Campos Filho, Eduardo N. B. Santos Júlio, José Luiz Antunes de Oliveira e Sousa, José Márcio Fonseca Calixto, Leandro Francisco Moretti Sanchez, Mauro Vasconcellos Real, Rafael Giuliano Pileggi, Roberto Caldas de Andrade Pinto and Túlio Nogueira Bittencourt, Editors

 

Vol9 - Num 6
2016

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We are publishing the last number of the 2016 Volume of IBRACON Structures and Materials Journal (Volume 9 Number 6, December 2016), with eight articles on relevant topics related to concrete. In the first article, the amount and the distribution of fibers are examined with 3D microtomography, using scanning electron microscopy to analyze the interaction of fibers with the cement composite. The influence of the flexibility of beams and slabs in the static response and dynamic properties is the topic for the second article. The third article analyzes two pile caps with partially embedded sockets. The fourth article discusses a parametric study to quantify how far errors in the design stage related to the wind action may compromise the response and safety of reinforced concrete buildings. Another article presents a study on the performance of plastic spacers and their influence on the durability of reinforced concrete structures. The risk of cracks originated from thermal effects related to cement hydration is analyzed in the sixth article. A case study of an 800 m3 spread footing illustrates the procedures and problems involved. The seventh article evaluates the applicability of rheometry in steel fiber reinforced self-compacting concretes. The last article in this issue deals with characterization and application of sewage sludge ash to be used, after a calcination process, as partial replacement of Portland cement in the production of high performance concrete.

This issue closes the Volume 9 of our Journal. As usual, in this issue we acknowledge the contribution of the reviewers that donated part of their time in assuring the good quality of the published articles.

Américo Campos Filho, José Luiz Antunes de Oliveira e Sousa, Leandro Francisco Moretti Sanchez, Rafael Giuliano Pileggi, Roberto Caldas de Andrade Pinto and Túlio Nogueira Bittencourt
Editors

 

Vol9 - Num 5
2016

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We are now releasing the October 2016 issue of the IBRACON Structures and Materials Journal (Volume 9 Number 5, October 2016). This issue brings eight articles on concrete structures and materials. The first article deals with an evaluation of the interaction between strength concrete block walls under vertical loads. Experimental analysis was performed on full-scale H-shaped flanged walls. The next article presents a study on safety of reinforced concrete beams subjected to bending moment and designed with the partial safety factors proposed by ABNT NBR 6118:2014. The third article discusses the behavior of deep beams using short straight bars anchorages. Results from tests performed on 12 deep beams using three different shear span-to-depth ratios, indicated that short bar anchorages did not seem to influence significantly the shear strength of the deep beams tested. The fourth article aims to study the structural concrete dosage in construction sites. In another article, results of an experimental research on bond stress-slipping in Brazilian reinforced concrete, using five different concrete strengths (20, 40, 60, 80 and 100 MPa) and two different rebar diameters (16 and 20 mm). The sixth article reports a study on Mortar modified with sulfonated polystyrene produced from waste plastic cups. The influence of polystyrene in the mortar properties was evaluated by consistency index, water retention, water absorption, porosity, elasticity modulus, compressive strength, flexural strength, and bond tensile strength. The sevenths article discusses the influence of the cable shape on the shearing resistance of prestressed concrete beams. The issue closes with an article on an experimental study of column reinforcement using anchor bolts and self-compacting concrete.

All the articles were reviewed by specialists from many Institutions in Brazil and abroad. Their contribution, fundamental for the quality of our Journal

Américo Campos Filho, José Luiz Antunes de Oliveira e Sousa, Rafael Giuliano Pileggi, Roberto Caldas de Andrade Pinto and Túlio Nogueira Bittencourt, Editors

 

Vol9 - Num 4
2016

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The fourth issue of volume nine of the IBRACON Structures and Materials Journal (Volume 9 Number 4, August 2016) is now released. The issue begins with a global stability analysis of a reinforced concrete plane frame aiming at an evaluation of the Gama Z coefficient from the Brazilian Norm NBR 6118:2014. In the second article an hourglass-shaped specimen is proposed for determining the compressive resistance of mortar and concrete. Numerical results are presented, showing that the highest stress occurs at the center of the specimen. Experimental results indicate advantages with respect to the cylindrical specimen. Another article deals with the determination of water retention curves for mortars and concrete using the filter paper method. The fourth article describes an automatic procedure for geometry definition and analysis of axisymmetric domes by the membrane theory. An example shows the differences between a spherical dome with constant thickness and a dome subjected to constant stress. The fifth article addresses the effects of electric arc furnace slag on the expansion of mortars subjected to alkali-aggregate reaction, evaluating its effectiveness as a partial replacement of cement according to NBR 15577:2008. In the next article, a digital image correlation procedure is applied for evaluating the concrete modulus of elasticity. The seventh article presents an analysis on corrosion parameters of reinforcing steel bars. Tests confirmed the better performance obtained from the coated bars. The last article presents an experimental study on the partial replacement of fine aggregates in mortar by sugarcane bagasse ash to evaluate the effects on cement hydration at early ages.

We acknowledge the dedication of authors and reviewers, responsible for the high quality of the published articles. Palavras-chave: cinza do bagaço da cana-de-açúcar, argamassa, ultrassom, sustentabilidade

Américo Campos Filho, José Luiz Antunes de Oliveira e Sousa, Rafael Giuliano Pileggi, Roberto Caldas de Andrade Pinto and Túlio Nogueira Bittencourt, Editors

 

Vol9 - Num 3
2016

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The March 2016 issue of the IBRACON Structures and Materials Journal (Volume 9 Number 3) is now released with eight articles related to engineering applications of concrete structures and materials. This issue begins with an integrated slab/column approach for the numerical simulation of reinforced concrete flat slabs. The second article brings a risk analysis of delayed ettringite formation in pile caps foundation in the Metropolitan Region of Recife. The next article addresses an ultrasonic pulse velocity approach to estimate compressive strength of concrete. The fourth article presents a tridimensional finite element approach to model a tunnel with shotcrete and precast concrete. The objective of the fifth article is to evaluate the modified mortar pad behavior in the transfer of compressive stresses. In the sixth article, a comparative analysis of design models for concrete corbels is presented. The seventh article describes an adaptive procedure for camber control of forward cantilever structures. The issue closes with an article on the evaluation of pyrite and pyrrhotite in concretes.

We would like to acknowledge the dedication of authors and reviewers for the good quality of the articles in this issue.

Américo Campos Filho, José Luiz Antunes de Oliveira e Sousa, Rafael Giuliano Pileggi, Roberto Caldas de Andrade Pinto and Túlio Nogueira Bittencourt, Editors

 

Vol9 - Num 2
2016

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We are now publishing the second issue of the ninth volume of IBRACON Structures and Materials Journal (RIEM, Volume 9, Number 2, April 2016). This issue contains eight articles on relevant topics on concrete structures and materials. The first article presents a Damage Mechanics approach for the numerical analysis of steel fiber reinforced concrete beams. Concrete is assumed as an initial elastic isotropic medium presenting anisotropy, permanent strains, and bimodularity induced by damage evolution. Global stability analysis of structures and actions to control their effects is the subject of the second article. The basic concepts of the instability parameters α and γz in accordance with the Brazilian standard ABNT NBR 6118 are presented and simulation results are discussed. The study presented in the third article evaluates experimentally obtained shear strength of elements with hollow circular cross sections in comparison with values computed using the Canadian Code (CSA A23.3) and a proposed procedure based on the Brazilian standard (NBR 6118). The influence of the addition sequence of PVA-fibers and water on mixing and rheological behavior of mortars is addressed in the fourth article. Another article presents a study on the global stability of slender buildings consisting of flat slabs, with slenderness (ratio between smaller width with the height of the building) about one to six, from the modeling of a building with prestressed slabs nonadherent and waffle slabs. The sixth article presents an experimental parameterization of continuously reinforced concrete pavement using nondestructive techniques. The objective of the seventh article is to provide recommendations for structural designers to meet higher performance requirements of the Brazilian Code NBR 15575:2013 with respect to durability. The last article presents a case study on the structural reliability assessment based on optical monitoring system aiming at a forecast of the reliability of an elevated water elevated reservoir for the next 100 years.

We acknowledge the efforts of the IBRACON community that supported the development of a qualified scientific journal dedicated to concrete structures and materials. We thank the authors for the submission of high quality manuscripts, the reviewers for the dedication of their time carefully evaluating submissions, and former and current editors involved in the assurance of the quality of each issue.

Américo Campos Filho, José Luiz Antunes de Oliveira e Sousa, Rafael Giuliano Pileggi, Roberto Caldas de Andrade Pinto and Túlio Nogueira Bittencourt, Editors

 

Vol9 - Num 1
2016

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The first issue of the 2016 Volume of the IBRACON Structures and Materials Journal (Volume 9 Number 1 February 2016) is now published. The issue begins with a study of reinforced concrete columns strengthened by partial jacketing and tested in combined compression and bending. A second article presents an analytical model for evaluation of reinforced beams, based on recommendations of the Brazilian Concrete Code (NBR-6118) and a study published by the International Federation of Concrete (fib). The objective of the thrid article is to use a particle packing analytical model (Compressible Packing Model) to verify the maximum packing density of cement and silica fume, which could be associated with the optimum content of silica fume in pastes. The fourth article addresses the potential reactivity of granitic rocks to alkalis. The study involves granites collected from different regions in Portugal, from which eight samples have their test results analyzed. The tests include the petrographic analyses of the aggregates and mortar and concrete expansion tests. Another article addresses the performance of pervious concrete with aggregates from recycled constructions and demolition waste. The sixth article analyzes, through a case study, the innovative application of 3D laser scanning technology on the façade of a building to map the surface flatness and, in an unprecedented manner, to quantify the volume of mortar. The last article is intended to analyze the structural behavior of reinforced concrete beams strengthened in bending with carbon fiber reinforced polymer, without using any anchoring system for fibers, varying steel reinforcement and the amount of fiber reinforcement layers.

We acknowledge authors and reviewers for their contribution to this issue.

Américo Campos Filho, José Luiz Antunes de Oliveira e Sousa, Rafael Giuliano Pileggi and Roberto Caldas de Andrade Pinto, Editors

 

Vol8 - Num 6
2015

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The last issue of the 2015 Volume of the IBRACON Structures and Materials Journal (Volume 8 Number 6, December 2015) is now released. This number brings five articles discussing topics related to concrete applications. The development and the implementation of a numerical procedure for design of reinforced concrete columns and composite columns with fully concrete encased steel I-section is discussed in first article. Application to experimental and numerical results demonstrate the accuracy of the procedure. The second article discusses recommendations for safety check of precast beams in transitory phases, comparing results of parametric analyses with national and international code recommendations, and confronting the formulations used for assessment of buckling loads. The next article deals with nonlinear finite element analysis of the bond-slip between reinforcing steel and concrete, combining a microplane model for the concrete with an embedded reinforcement model accounting for bond-slip. The fourth article aims at the evaluation of the seismic behavior of a reinforced concrete structure with irregularities through their influence in the loss of ability to resist lateral loads and energy dissipation. Methodology for the design of cellular composite steel-concrete beams is the subject of the last article.

With this issue, we complete the eighth volume of the IBRACON Structures and Materials Journal. We acknowledge the efforts of the whole IBRACON community that supported this project during the last decade, particularly authors, reviewers, former and current editors. As usual, as this is the last issue of 2015, we present the list of reviewers who donate their precious time evaluating manuscripts to assure the good quality of our Journal.

Américo Campos Filho, José Luiz Antunes de Oliveira e Sousa, Rafael Giuliano Pileggi and Roberto Caldas de Andrade Pinto, Editors

 

Vol8 - Num 5
2015

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We are publishing the October 2015 issue of the IBRACON Structures and Materials Journal (Volume 8 Number 5, October 2015). This issue contains eight articles on concrete structures and materials, a discussion on a previously published article and the corresponding response by the authors. Image analysis for obtaining shape parameters in crushed sand grains is the subject of the first article. The work described in the second article aims at the numerical simulation of concrete wall-like columns, affected by the alkali-aggregate reaction. The third article deals with the bond strength between steel-concrete and between concretes with different ages, focusing on structural rehabilitation. The fourth article presents an evaluation of reinforcement cover in slabs using different spacer and tying distances. The motivation is durability, directly related to the cover thickness. The geometric characteristics of synthetic macrofibers, important because of their effects on the behavior of fiber reinforced concrete, are the subject of the fifth article. The sixth article describes an inverse analysis strategy for automatically determining cohesive and viscous parameters describing a fracture model for concrete under tensile stresses, using data from three-point bend tests performed at high loading rates. The next article reports an investigation on the spatial distribution of steel fibers in concrete using X-ray microtomography. The last article presents an alternative way for a bridge inspection considering dynamic parameters, using mobile phone equipment to acquire acceleration data and evaluate the structural behavior of two concrete viaducts from natural frequencies. The issue closes with a discussion on a formerly published article and the corresponding response by the authors.

All the articles describe original research and are peer-reviewed by specialists with expertise in the specific subjects. We congratulate authors and reviewers for the high level of this issue.

Américo Campos Filho, José Luiz Antunes de Oliveira e Sousa, Rafael Giuliano Pileggi and Roberto Caldas de Andrade Pinto, Editors

 

Vol8 - Num 4
2015

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We are publishing the fourth issue of the eighth volume of the IBRACON Structures and Materials Journal. In this issue, the first of eight articles presents interaction curves for concrete-encased composite columns subjected to combined compression and bending, based on the deformation domains of reinforced concrete structures defined by ABNT NBR 6118. The second article describes a numerical and experimental analysis of the behavior of structural elements composed of double lattice panels filled with cast-in-place concrete. A probabilistic failure scenarios analysis is described in the third article for the assessment of the influence of reinforcement corrosion on statically indeterminate reinforced concrete beams. In the next article the B-WIM technique is applied for weighing in motion and characterization of the railroad traffic. Finite element analysis of composite concrete-timber beams is the subject of the fifth article. The use of electrochemical impedance spectroscopy for monitoring the corrosion of reinforced concrete is approached in the sixth article. The impacts of the 2014 Revision of the Brazilian Standard ABNT NBR 6118 in the structural design are discussed in the seventh article. The issue closes with an article on the behavior of granular rubber waste tire reinforced soil for application in geosynthetic reinforced soil wall.

We congratulate the authors for the quality of their contributions. All the articles are original and were reviewed by specialists selected among the IBRACON members and other invited reviewers, whose contribution is acknowledged.

Américo Campos Filho, José Luiz Antunes de Oliveira e Sousa, Roberto Caldas de Andrade Pinto and Romilde Almeida de Oliveira, Editors

 

Vol8 - Num 3
2015

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Editorial

We are proud to note a rise in the interest of our community in publishing in the IBRACON Structures and Materials Journal. The number of submitted manuscripts has increased considerably as well as the overall quality of the published articles. We have now the entire collection, since Volume 1 (March 2008), published in the SciELO site (www.scielo.br/riem). The current issue (Volume 8 Number 3, June 2015) comprises eight articles related to concrete structures and materials. The first article presents a study on the hydraulic conductivity of pervious concrete by constant and falling head methods. The next article discusses the influence of column rectangularity index and boundary conditions on the punching resistance of slab-column connections. The third article focus on the application of active infrared thermography to detect damage in bonding between concrete and glass fiber reinforced polymer. One of the articles reports the application of Digital Image Correlation technique to measure displacements on the surface of beams aiming at the evaluation of size effect. The influence of grouting and reinforcement ratio in the compressive behavior of concrete block masonry is discussed in the fifth article. The sixth article presents a contribution to the safety assessment of existing structures. The next article addresses the serviceability limit state related to excessive lateral deformations with the consideration of the infill walls in the structural modeling. This issue closes with an article presenting an interactive graphics computational tool for the verification of pre-stressed concrete beams with post-tensioned bonded tendons to the serviceability limit state (SLS) stress check according to the Brazilian code NBR 6118:2014.

With this issue, we fulfill the objective of providing our community with a qualified vehicle for diffusion of the research and developments in concrete structures and materials, aiding our interaction with researchers worldwide. We thank all those who contribute for this achievement: authors, reviewers and readers.

Américo Campos Filho, José Luiz Antunes de Oliveira e Sousa, Roberto Caldas de Andrade Pinto and Romilde Almeida de Oliveira, Editors

 

Vol8 - Num 2
2015

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We are now releasing the second issue of the 2015 volume of IBRACON Structural and Materials Journal (Volume 8, Number 2, April 2015). Eight articles focus on relevant topics of concrete structures and materials. The objective of the first article is to evaluate the effect of binder content on bond strength of mortar-brick interface. The second article presents an analysis of the behavior of reinforced concrete columns strengthened with sleeve wedge bolts and a self-compacting concrete layer. The third article reports a study on the performance of the processing sludge of ornamental rocks and grinding after heat treatment, aiming at their potential application as partial substitute for cement. Another article discusses the results obtained in the first stages of an investigation on traffic load models for short span highway bridges. The article includes a comparison between the static effects due to the actual traffic of heavy vehicles and those generated by the live load model from the current Brazilian code NBR 7188. The fifth article draws on the structural assessment of a reinforced concrete bridge over Sororó River along the Carajás Railway. The following article presents an assessment of the structural performance of reinforced concrete flat slab-edge column connections under the effects of outward eccentricity. The seventh article discusses the global stability of tall buildings with prestressed slabs. The last article of this issue presents a numerical analysis of waffle slabs in flexure considering the effects of concrete cracking.

We would like to acknowledge authors and reviewers’ contribution to maintain the quality of our Journal

Américo Campos Filho, José Luiz Antunes de Oliveira e Sousa, Roberto Caldas de Andrade Pinto and Romilde Almeida de Oliveira, Editors

 

Vol8 - Num 1
2015

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With this issue (Volume 8 Number 1, February 2015), we open the eighth volume of the IBRACON Structures and Materials Journal. This issue contains five articles related to concrete structures and materials. The first article presents an application of Chapelle’s method for determining the reactivity of pozzolanic materials. The method is applied to evaluate lime consumption by metakaolin, silica fume, fly ash, sugar cane bagasse ash and rice husk ash, comparing the result with mass proportions - lime:pozzolan 1:1, as originally proposed by Chapelle, and 2:1 according to Brazilian and French Standards. The second article evaluates the effect of polypropylene and steel fibers on the loss of water by evaporation and shrinkage of concrete. A study was carried out to relate the loss of water from the paste and the shrinkage during the first 28 days of age, using a control mix without fiber for comparison. Another article aims to evaluate the use of coal waste to produce concrete paving blocks. A process was developed with the purpose of reducing the sulfur content of the coal waste and changing the particle size distribution to meet the specifications for fine aggregates. The fourth article discusses the implementation and validation of a software for thermal analysis of two-dimensional structures subjected to fire. The last article discusses an anisotropic damage model for analysis of reinforced concrete structures submitted to reversal loading.

We congratulate the authors for the quality of the published articles and acknowledge the dedication of the reviewers.

Américo Campos Filho, José Luiz Antunes de Oliveira e Sousa, Roberto Caldas de Andrade Pinto and Romilde Almeida de Oliveira, Editors

 

Vol7 - Num 6
2014

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WIBRACON Structures and Materials Journal is now releasing the sixth and last issue of the 2014 volume. This issue brings five articles on relevant topics on concrete structures and materials. The first article describes a study on the properties of peanut husk ashes aiming at its use in cement mortars as partial substitute of Portland cement. The next article presents a case study on challenges and solutions devised to execute an anti-flotation reinforced concrete slab for the new Sound and Image Museum, in Copacabana, Rio de Janeiro. A third article draws on the rheological properties of pumped concrete. The goal is an investigation on the effects of important Portland concrete design variables in the rheological characteristics of pumped concrete cement pastes. The fourth article describes a model to predict the flexural behavior of reinforced concrete slabs, combining Mazars damage model for simulating concrete cracking, the perfect elastoplastic model for yielding and rupture of the reinforcing steel, and the classical theory of laminates. The issue closes with an article on the development and behavior analysis of high performance fiber reinforced cement composites applied as a transition layer of reinforced beams.

In this issue, we present a list of the reviewers that contributed to our Journal during the year 2014. We congratulate the authors and reviewers for the high quality achieved by our Journal.

Américo Campos Filho, José Luiz Antunes de Oliveira e Sousa, Roberto Caldas de Andrade Pinto and Romilde Almeida de Oliveira, Editors

 

Vol7 - Num 5
2014

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Editorial

We are releasing the fifth issue of the 2014 volume of the IBRACON Structures and Materials Journal. This issue brings eight articles on relevant topics of concrete structures and materials, such as reliability, creep, progressive collapse and others, discussing the Brazilian codes with comparisons to the international codes. The first article discusses the Brazilian ABNT codes with respect to reliability indices for reinforced concrete, steel and steel-concrete composite beams. The influence of the steel reinforcement ratio in concrete columns on their properties of creep and shrinkage is the topic of the second articles, which is based on experimental tests and three-dimensional finite element-based simulations of experimental curves. The next article reports an investigation aiming at the influence of surface treatment of concrete specimens tested under compression. The fourth article presents an analysis of the mechanical behavior of a railway bridge during train braking using the Finite Eleability, creep, progressive collapse and others, discussing the Brazilian codes with comparisons to the international codes. The first article discusses the Brazilian ABNT codes with respect to reliability indices for reinforced concrete, steel and steel-concrete composite beams. The influence of the steel reinforcement ratio in concrete columns on their properties of creep and shrinkage is the topic of the second articles, which is based on experimental tests and three-dimensional finite element-based simulations of experimental curves. The next article reports an investigation aiming at the influence of surface treatment of concrete specimens tested under compression. The fourth article presents an analysis of the mechanical behavior of a railway bridge during train braking using the Finite Element Method for numerical simulation and monitoring data acquired during actual operation, with a comparison with code provisions. Another article discusses the viability of the APULOT test applied to concrete with rubber addition to evaluate bonding steel-concrete. The sixth article draws on the computational assessment of the progressive collapse of reinforced concrete planar frames using a nonlinear multilayered beam formulation, including elastic-viscoplastic effects. The investigation focused on the potential resistance of frames to progressive collapse when a column is accidentally removed. The seventh article presents the second part of an experimental investigation on the use of steel-concrete bond tests for estimating axial compressive strength of concrete. This issue closes with an article on material and geometric nonlinear analysis of reinforced concrete frames. Experimental results reported in the literature are used to validate the proposed formulation and computational. ]

We are pleased to announce that SciELO has already assigned DOI (Digital Object Identifier) codes to all the former issues, which are now available in http://www.scielo.br/riem/. This is important because it increases the visibility of our Journal, favoring the access by the international community.

We appreciate the dedication of authors and reviewers, responsible for the good quality of the content of this issue.

Américo Campos Filho, José Luiz Antunes de Oliveira e Sousa, and Roberto Caldas de Andrade Pinto, Editors

 

Vol7 - Num 4
2014

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Editorial

The fourth issue of the 2014 volume of IBRACON Structures and Materials Journal (Volume 7 Number 4) is now published. This issue brings eight articles on topics related to concrete structures and materials. The first article presents fragility curves for the evaluation of a highway bridge located in Trois-Rivières, Quebec, Canada, retrofitted with seismic isolator devices. The focus of the second article is the analysis of accidental loads used for garage floors considering the recommendations of international norms. The third article uses experimental results from two-way reinforced concrete ribbed flat slabs with rectangular holes close to the column and without shear reinforcement to evaluate estimates obtained from ACI 318 and NBR 6118. The behavior of slab-column connections in a reinforced concrete flat slab and strengthened to shear with carbon fiber reinforced polymer is discussed in the fourth article. Another article addresses the influence of the sugar cane bagasse ashes on concrete mechanical behavior. The sixth article discusses evaluation of shear strength of reinforced concrete one-way ribbed slabs without stirrups. The protective capacity of concretes produced with metakaolin with respect to transportation and penetration of chlorides is the subject of the seventh article. The issue closes with an evaluation of the physical properties of grout enriched rolled compacted concrete, replacing the conventional concrete usually employed in the face, using the same materials, labor and equipment used in the construction of the Maua Hydro Power Plant. We would like to acknowledge the contribution of authors and reviewers to this issue.

Américo Campos Filho, José Luiz Antunes de Oliveira e Sousa, and Roberto Caldas de Andrade Pinto

 

Vol7 - Num 3
2014

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Editorial

The third issue of the seventh volume of the IBRACON Structures and Materials Journal is now published, with seven articles on concrete structures and materials. Evaluation of second order moments in reinforced concrete structures is addressed in the first article, with an alternative proposal for estimating the magnification of first order moments. The second article aims at the evaluation of the quality of the concrete plant wastewater, proposing guidelines for treatment and reuse. In the third article the overlapping crack model is used to simulate concrete crushing, considering that the material in damage is simulated through surfaces that interpenetrate each other. Another article brings a structural reliability approach for evaluation of the bending moment capacity of reinforced concrete beams taking into account the influence of the reinforcement corrosion. The fifth article analyzes punching shear in reinforced flat slabs with a hole adjacent to the column. The study includes experimental tests performed on seven internal slab-column joints, analyzing ultimate loads, cracking, deflections and strains in concrete and reinforcement bars. A statistical analysis and conformity testing of concrete in the Rio Grande Port is the topic for the sixth article. The issue closes with an article on the design of cast-in-place reinforced concrete walls comparing two different strategies for numerical simulation, focusing on the maximum compressive stress.

We congratulate the authors for the quality of the articles and acknowledge reviewers and editors for their dedication, responsible for the results achieved by the IBRACON Structures and Materials Journal.

Américo Campos Filho, José Luiz Antunes de Oliveira e Sousa, and Roberto Caldas de Andrade Pinto

 

Vol7 - Num 2
2014

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Editorial

The second issue of the Volume 7 of the IBRACON Structures and Materials Journal is now released. This issue brings an article on fire design of composite ribbed slabs, a topic not covered by the Brazilian standards in fire. The second article presents comparative analysis of solutions in shallow foundations or in pile foundations for an industrial machine subject to vibrations, discussing the relevance of the dynamic analysis. Another article addresses the technical feasibility and ecological advantage of using sinter feed tailings from iron ore mining as an aggregate in the production of concrete, initially to manufacture precast concrete pavers, but with the possibility of extending its use to other applications. The fourth article approaches the soil-structure interaction in the three-dimensional analysis of frame structures. The fifth article examines the structural design aspects related to the vibrations on floors of urban buildings, induced by the human activities that can motivate some discomfort for their users. The last article addresses the use of galvanization on hot technology for rebars, using a zinc thickness supposed to be consumed before the steel enter in action, comparing with the use of rebars without zinc, aiming at an increase of the service life of reinforced concrete structures.

We congratulate the authors and acknowledge the important work developed by the reviewers.

Américo Campos Filho, José Luiz Antunes de Oliveira e Sousa, Roberto Caldas de Andrade Pinto and Romildo Dias Toledo Filho

 

Vol7 - Num 1
2014

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Editorial

We are now opening the seventh volume of the IBRACON Structures and Materials Journal. In this issue (Volume 7 Number 1 – February 2014), seven original articles on concrete materials and structures are published. In the first article numerical simulation and design by the strut and tie method are presented for reinforced concrete six-pile caps. The next article approaches the rheological behavior of plastic shrinkage and cracking of self-compacting concrete mortars. An algorithm for automatic design of concrete shell reinforcement is described, with results showing its robustness and capability of application on large-scale structures. In another article, the topic is the evaluation of deflections in reinforced concrete structures using continuous damage mechanics. The fifth article, also an application of the continuous damage theory, presents a simplified modeling of the cracking and collapse process on frames and arches of reinforced concrete. The sixth article draws on the computational simulation of pull-out tests and APULOT using the program ATENA. The last article deals with slim floor beams in fire, with emphasis on the concrete constitutive models.

As our Journal is in the Scientific Electronic Library Online (SciELO), with the inclusion of the SciELO Citation Index in the Web of Science platform, an important step for the access to the international community has been achieved. We acknowledge the dedication of our authors and reviewers, responsible for these nice results we are experiencing.

Américo Campos Filho, José Luiz Antunes de Oliveira e Sousa, Roberto Caldas de Andrade Pinto and Romildo Dias Toledo Filho

 

Vol6 - Num 6
2013

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Editorial

We are now releasing the last number of the sixth volume of the IBRACON Structures and Materials Journal (Volume 6 Number 6, December 2013). With this number we have six volumes completed without interruption. This number contains five articles addressing relevant topics on concrete materials and structures. The influence of service life, strength and cement type on life cycle environmental performance of concrete is evaluated in the first article. The second article discusses relations between indirect tensile and flexural strengths for dry and plastic concretes. The next article compares prediction models available in codes with test data for shear strength. The fourth article proposes a way to determine the reinforcement bars to be used in tests of hollow core slabs with continuity provided by a structural topping. The fifth and last article addresses the interpretation of strength loss in dry concretes with addition of milled asphalt through microscopic analysis.

In this number we acknowledge the reviewers who donate, during this year, part of their time to support the editors in the task of deciding which articles should be published or not. Their contribution has also an impact on the quality of the articles, with comments that help significantly the authors.

Américo Campos Filho, José Luiz Antunes de Oliveira e Sousa, Roberto Caldas de Andrade Pinto and Romildo Dias Toledo Filho

 

Vol6 - Num 5
2013

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Editorial

The number 5 of the sixth volume of the IBRACON Structures and Materials Journal (October 2013) is now released. Seven articles on relevant topics related to concrete materials and structures are published. The first article draws on the punching resistance of internal slab-column connections with double-headed shear studs. Experimental results of 36 tests are compared with theoretical results using recommendations presented by ACI 318, NBR6118, Eurocode 2 and also the Critical Shear Crack Theory. The second article presents the first part of an experimental investigation on the use of steel-concrete bond tests for estimating axial compressive strength of concrete. An experimental study on reinforced concrete pile caps with external, embedded and partially embedded socket with smooth interface is the topic addressed by the third article. Another article brings an experimental evaluation of prevention methods for the interface between masonry infill walls and concrete columns. The fifth article presents a study on the influence of the number of floors on the instability parameter of reinforced wall- or core-braced buildings. The next article analyzes the impact strength and abrasion resistance of high strength concrete with rice husk ash and rubber tires.
This number finishes with an article that explores life cycle-based sustainability indicators for building structural frames in concrete. These articles are results of original and unpublished research, and have been reviewed by members of our community with recognized expertise in the corresponding areas. We acknowledge the authors’ and reviewers’ efforts to maintain the high level of our journal.

Américo Campos Filho, José Luiz Antunes de Oliveira e Sousa, Roberto Caldas de Andrade Pinto, and Romildo Dias Toledo Filho

 

Vol6 - Num 4
2013

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Editorial

The IBRACON Structures and Materials Journal is releasing the fourth issue of the sixth volume. In this issue, eight articles are being published on significant topics of concrete structures and materials. The first article draws on graphical means for fire design of concrete beams. Creep strains on reinforced concrete columns are addressed in the second article. Chloride accelerated tests are the topic for the next article, focusing on the influence of silica fume, water/binder ratio and concrete cover thickness. The fourth article discusses the use of X-ray microtomography for evaluation of the effects of varying the workability of the fresh concrete, produced by the use of additives, on concrete pore structure and compression strength. Another article approaches the post-cracking behavior of blocks, prisms and mini-concrete walls reinforced with vegetal fibers. The sixth article presents a numerical analysis of prestressed hollow core slabs under long term loading. Numerical results are compared with experimental tests performed on two series of prestressed hollow core slabs. The objective of the seventh article is the analysis of the spacing between supports in the assemblage of lattice slabs. The issue closes with an article on replacement of Portland cement by stone cutting waste and ground waste clay brick, focusing on the hydration and packing density of cement pastes. We would like to acknowledge the dedication of authors and reviewers, responsible for the significant results achieved by the IBRACON Structures and Materials Journal. We are glad to welcome Prof. Dr. Roberto Caldas de Andrade Pinto, from the Federal University of Santa Catarina, who is participating as a new Associated Editor.

Américo Campos Filho, José Luiz Antunes de Oliveira e Sousa, Roberto Caldas de Andrade Pinto, and Romildo Dias Toledo Filho

 

Vol6 - Num 3
2013

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Editorial

We are now releasing the June 2013 issue of IBRACON Structures and Materials Journal (Volume 6, Number 3). This issue contains eight articles on remarkable topics of concrete materials and structures. The flexibility modeling of reinforced concrete frame joints is the topic for the first article. The second article discusses numerical and experimental study of a waffle slab designed to serve as a tennis court floor. The next article addresses the evaluation of nonconventional concrete hollow blocks by destructive and non-destructive testing. The fourth article draws on the influential factors on the rheological behavior of adhesive mortar available in the market. An Image-based method for monitoring of crack opening on masonry and concrete using mobile platform is presented in the fifth article. The sixth article presents a numerical analysis of two-pile caps with embedded sockets, subject to eccentric compression. The seventh article describes an application of photogrammetry in the analysis of plastic rotation and tension stiffening effect in beams. The issue closes with an article on a numerical approach of the bond stress behavior of steel bars embedded in self-compacting concrete and in ordinary concrete using beam models We acknowledge the authors’ and reviewers’ contribution to this issue.

Américo Campos Filho, José Luiz Antunes de Oliveira e Sousa, Luiz Carlos Pinto da Silva Filho and Romildo Dias Toledo Filho
Editors

 

Vol6 - Num 2
2013

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Editorial

The April 2013 issue of the IBRACON Structures and Materials Journal (Volume 6 Number 2) is now released. In this issue, the first article discusses cathodic protection methods for both preventing premature corrosion as well as reducing an ongoing corrosion process. The variability analysis of the compressive strength and physical properties of ready mixed concrete along the unloading of the truck mixer is discussed in the next article. Numerical analysis of reinforced concrete beams strengthened with high strength cement-based composite materials is discussed in the third article. The fourth article approaches the influence of environment and loading age on SCC drying creep. The application of the ultrasonic pulse velocity method for internal flaw identification in concrete members is the topic addressed in the fifth article. Another article has the purpose of discussing important aspects of the historical development of mushroom slabs and also presents experimental analysis of tests in mushroom slabs with circular column capitals. The seventh paper deals with the influence of steel fibers on the reinforcement bond of straight steel bars. The last paper has the objective of assessing changes in the compressive strength of concrete when used after exceeding the time limit for mixing and transport specified by standard NBR7212.
We would like to acknowledge the contributions of authors and reviewers, responsible for the nice results achieved by the IBRACON Structures and Materilals Journal.

Américo Campos Filho, José Luiz Antunes de Oliveira e Sousa, Luiz Carlos Pinto da Silva Filho and Romildo Dias Toledo Filho
Editors

 

Vol6 - Num 1
2013

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Editorial

We are now opening the volume six of the IBRACON Structures and Materials Journal (Volume 6 Number 1 – February 2013). In this issue, eight articles approaching interesting topics on concrete structures and materials are being published. The first article presents experimental analysis on the behavior of reinforced concrete beams strengthened to shear with carbon fiber composites. Results were used to evaluate the Cracking Sliding Model, showing good agreement. The next article presents a suggestion for automatizing procedures for design of bonded and unbonded prestressed concrete flexural members, according to the Brazilian (NBR 6118:2007) and French (Règles BPEL 91) code specifications. The third article describes preliminary studies, design and construction of a platform for dynamic tests. A study of the gamma z coefficient used to evaluate global second order effects in reinforced concrete structures is addressed in the fourth article. Numerical-computational analysis of reinforced concrete structures considering damage, fracture and failure criteria is discussed in the fifth article. Another article has the purpose of creating a short-term monitoring plan to check the structural behavior of a curved highway concrete bridge, based on a case study. The seventh paper deals with strut-and-tie models and the performance index of the structure. In the last paper a numerical analysis of three-pile caps is developed to study the influence of concrete compressive characteristic strength on load bearing capacity. We would like to acknowledge the efforts of all the IBRACON community, that contributed for the results achieved by our Journal.

Américo Campos Filho, José Luiz Antunes de Oliveira e Sousa, Luiz Carlos Pinto da Silva Filho and Romildo Dias Toledo Filho
Editors

 

Vol5 - Num 6
2012

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Editorial

We are now releasing the December 2012 issue of the IBRACON Structures and Materials Journal (Volume 5 Number 6). The first article focuses on the analysis of the mechanical performance of concrete deep beams, with a non linear orthotropic model using the finite element method. The next article describes the application of the Pull Off Test to evaluate the compressive strength of concrete as an alternative to Brazilian standard techniques. The shear strength of reinforced concrete beams with circular cross section is addressed in the third article. The fourth article approaches the concrete behavior when time for casting exceeds the limits specified by Brazilian standard NBR 7212. A comparative study of codes for the seismic design of structures is presented in the fifth article, where a simple building structure is analyzed considering the criteria from several standards. Another article discusses the design of compression reinforcement in reinforced concrete membrane. And the issue closes with an experimental study on the behavior of beam-column connections in precast concrete structures. During the last five years RIEM has experienced important steps towards the recognition as a relevant International Journal in the area of concrete structures and materials. RIEM started in 2008 publishing 20 articles per year and gradually increased this number to comply with the minimum of 40 required by SciELO (Scientific Electronic Library Online). This minimum was reached by RIEM after June 2011, when we started publishing bimonthly, and is expected to be maintained from now on. We would like to acknowledge the efforts of all the IBRACON community: authors, reviewers, readers and editors for the acceptance of RIEM as a member of SciELO.

Américo Campos Filho, José Luiz Antunes de Oliveira e Sousa, Luiz Carlos Pinto da Silva Filho and Romildo Dias Toledo Filho
Editors

 

Vol5 - Num 5
2012

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Editorial

We are now releasing the October 2012 issue of IBRACON Structures and Materials Journal (Volume 5, Number 5). Seven articles on relevant topics of concrete materials and structures are being published. The issue starts with a comparative analysis on the static modulus of elasticity tests of plain concrete cylindrical specimens. The second article discusses models for combined shear and torsion, aiming at the evaluation of the required transverse reinforcement, according to the Brazilian Standard Code ABNT NBR 6118:2007. The next article presents the development of an innovative strengthening method for RC beams, based on a high performance cement-based composite of steel fibers (macro + microfibers), applied in a transition layer intended to better control the cracking of concrete and to avoid the premature detachment of the strengthening. The fourth article draws on the fatigue structural safety assessment of a reinforced concrete bridge in the Carajás Railroad. Relevant aspects related to punching strength of reinforced concrete flat slabs without shear reinforcement are discussed in the fifth article, with experimental results organized in a database with 74 slabs with results according to recommendations of ACI 318, EUROCODE 2 and NBR 6118 and also through the Critical Shear Crack Theory, incorporated in the new Fib Model Code. The sixth article presents the analysis of the mechanical and durable properties of recycled aggregate concrete, using construction and demolition wastes. The issue closes with an article presenting experimental results of a research program with ceramic block masonry under compression. We would like to congratulate the authors for the quality of their contributions and acknowledge the voluntary support provided by our reviewers. We are pleased to announce that the IBRACON Structures and Materials Journal is now a member of the Scientific Electronic Library Online - SciELO (http://www.scielo.br/riem).

Américo Campos Filho, José Luiz Antunes de Oliveira e Sousa, Luiz Carlos Pinto da Silva Filho and Romildo Dias Toledo Filho
Editors

 

Vol5 - Num 4
2012

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Editorial

The fourth issue of volume five of the IBRACON Structures and Materials Journal is being published. This number contains seven articles addressing interesting topics on concrete structures and materials. In the previous issue the first part of a work on post-strengthening of reinforced concrete beams with prestressed strips of carbon fibers embedded in epoxy matrices (CFRP) has been published, focusing on analysis under static loading. This issue starts with the second part of such work, addressing analysis under cycling loading. The second article deals with the application of reliability algorithms for assessment of reinforced concrete durability. Another article presents a study on the effect of red mud addition on the corrosion parameters of reinforced concrete by electrochemical methods. The behavior of bolted connections of concrete filled steel tubes is the topic of the fourth article. The fifth presents a comparative study using different dosage methods with respect to requirements such as self-compactability, strength and durability. The sixth article presents experimental results for short steel-and-concrete composite columns subjected to high temperatures, comparing with temperature distributions obtained from numerical simulations. The issue closes with an article on the approximate methods for the design of slender reinforced concrete rectangular columns subjected to eccentric loads. We would like to congratulate the authors for the quality of the work presented in this issue and thank the reviewers for the support in the evaluation of manuscripts.

Américo Campos Filho, José Luiz Antunes de Oliveira e Sousa, Luiz Carlos Pinto da Silva Filho and Romildo Dias Toledo Filho
Editors

 

Vol5 - Num 3
2012

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Editorial

The third issue of the fifth volume of the IBRACON Structures and Materials Journal is being released. Important topics related to concrete structures and materials are addressed in seven articles, which were reviewed by specialists selected among IBRACON associates and members of the Editorial Board. The first article presents experimental results involving nanoindentation measurements and prediction of macroscale elastic properties of high performance cementitious composites. The development of behavior prediction models using multiple regression and control charts for the safety control of concrete dams is the topic of the second article. Another article describes an experimental analysis program on the strengthening of reinforced concrete columns with self-compacting concrete and connectors. The fourth article deals with reduction of the stiffness in precast concrete structural elements of multi-storey buildings to analyze global stability. The next article is intended to analyze the effects of the composite prestressing in the performance of the CFRP post strengthening technique. The sixth article applies a methodology based on the probe penetration test to investigate the compressive strength of the shotcrete layer of a small hydro power plant tunnel. The last article addresses effects due to corrosion and concrete Young’s modulus variation on reinforced concrete bridges. We congratulate the authors for the quality of the articles in this issue, contributing for the consolidation of our Journal.

Américo Campos Filho, José Luiz Antunes de Oliveira e Sousa, Luiz Carlos Pinto da Silva Filho and Romildo Dias Toledo Filho
Editors

 

Vol5 - Num 2
2012

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Editorial

We are now releasing the second issue of the fifth volume of the IBRACON Structures and Materials Journal (Volume 5, Number 2, April 2012). In this issue seven articles cover relevant topics related to concrete materials and structures. Chloride diffusivity in red mud-ordinary Portland cement concrete is focused in the first article. Another article addresses the application of iron ore mud in powder form in Portland cement presence. The use of construction residues in substitution to the natural aggregates in the production of concrete based materials is discussed in the third article. The next one discusses a design model and recommendations of column-foundation connection through socket with rough interfaces. Based on mathematical modeling, experimental work and specifications adopted by other countries, the fifth article proposes guidelines for the development of concrete performance-based specifications in Brazil. The sixth one presents an evaluation of partial clinker replacement by sugar cane bagasse ash: CO2 emission reductions and potential for carbon credits. The closing article compares results from non-linear three-dimensional finite-element analysis of two-pile caps with experimental observations. These articles present original results and were carefully reviewed by experts from our community. We congratulate authors and reviewers for the high quality of this issue

Américo Campos Filho, José Luiz Antunes de Oliveira e Sousa, Luiz Carlos Pinto da Silva Filho and Romildo Dias Toledo Filho
Editors

 
 

Vol5 - Num 1
2012

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Editorial

The first issue of the fifth volume of the IBRACON Structures and Materials Journal is now released (Volume 5, Number 1, February 2012). The seven articles published in this issue cover relevant topics on concrete structures and materials. The first two address steel fiber reinforced concrete pipes: part 1 discusses technological analysis of the mechanical behavior and part 2 presents a numerical model to simulate the crushing test. Simplified damage models applied in the numerical analysis of reinforced concrete structures are presented in the third article. The fourth one reports studies on cement-base bearing pads for connections in precast concrete, focusing on the surface roughness. The influence of low temperature on the evolution of concrete strength is discussed in the fifth article. The sixth addresses reliability of buildings in service limit state for maximum horizontal displacements. The closing article presents a discussion on a variable limit for the instability parameter of wall-frame or core-frame bracing structures. We appreciate the interest and dedication of authors and reviewers, responsible for the consolidation of our journal. Thanks to them we are opening the fifth volume without interruptions or delays

Américo Campos Filho, José Luiz Antunes de Oliveira e Sousa, Luiz Carlos Pinto da Silva Filho and Romildo Dias Toledo Filho
Editors

 

Vol4 - Num 5
2011

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Editorial

The IBRACON Structures and Materials Journal is now releasing this year's last issue (Volume 4, Number 5, December 2011). With these eight articles, our goal of publishing 40 items in 2011 has been reached. All the articles in this issue address relevant topics on concrete structures and materials. The first one addresses the possibility of intercalation of organic compounds within C-S-H nanostructure, aimed at the synthesis of nanocomposites with atypical properties. The second one discusses the structural behavior of reinforced concrete beams subjected to cyclic loadings through numerical and experimental analysis. The main objective is to quantify the increase in deflections of the beams subjected to repeated loading cycles. The third article compares different models to predict the compressive strength of reinforced masonry. The fourth presents a study on the use of solid waste as alternative aggregates for concrete manufacturing. The fifth discusses the shear strength of steel fiber-reinforced concrete beams. The sixth article reports an experimental investigation on the use of acoustic emissions to evaluate the modulus of elasticity of concrete. The development of artificial neural networks for interpreting ultrasonic pulse velocity of concrete is described in the seventh article. And finally, the last one presents a contribution to the obtainment of elastic modulus of concrete using micromechanics modeling. Thereby, the fourth volume of RIEM is closed. In four years a total of 105 articles and one technical note were published through 17 issues. With an ever increasing number of manuscript submissions, since June 2011 the periodicity of the releases began to change. Thenceforth, the issues that were previously quarterly became bimonthly, thus indicating a considerable growth in the importance of our journal in the concrete community. The dedication of our reviewers must also be noted, for they willingly donate their time to the voluntary task of maintaining the high standards of our Journal. In this issue, the last in volume 4, we acknowledge by name all the reviewers that collaborated with the Journal throughout the year of 2011.

Américo Campos Filho, José Luiz Antunes de Oliveira e Sousa, Luiz Carlos Pinto da Silva Filho and Romildo Dias Toledo Filho Editors

 
 
Vol4 - Num 4
2011
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Editorial

A new issue of RIEM, the IBRACON Structures and Materials Journal (Volume 4, Number 4, October 2011), is now being released with eight articles and a technical note, addressing relevant themes on engineering applications of concrete. The first article presents a finite element model for simulating the three-dimensional behavior of reinforced concrete structures under monotonic loading. Nanoindentation techniques are exploited in the second article to analyze elastic modulus and hardness of cement paste. The third article introduces a proposal of a new and accelerated concrete prism test for evaluation of the potential reactivity of aggregates in the laboratory. A pull-out bond test for on-site quality control of structural concrete is described in the fourth article. The early-age behavior of high-strength concrete made with high initial strength cement and exposed to an environment with vibrations is addressed in the fifth article. The sixth article reports an experimental investigation conducted on 8 twoway reinforced concrete waffle flat slabs under centered load, focusing on the shear behavior of the ribs. An experimental study to evaluate the influence of the use of foundry sand residues on concrete properties is described in the seventh article. The eighth article presents a study of Brazilian concrete strength (non-) compliance and its effects on reliability of short columns. During these almost four years of RIEM, only the section articles has been active. However, other communication channels are open: technical notes and technical discussions on published articles. Technical notes are short communications of three or four pages on topics of general interest. In this issue, for the first time, a technical note is being published. In addition to eight articles, this issue brings a technical note on the implementation of a Levenberg-Marquardt algorithm to fit a softening curve to data from fracture tests on concrete specimens. We would like to thank the authors and reviewers for their involvement in maintaining the high level of RIEM. Their efforts are a fundamental contribution to our attempts towards the admission of our Journal in SciELO collection and other relevant scientific searching databases.

Américo Campos Filho, José Luiz Antunes de Oliveira e Sousa, Luiz Carlos Pinto da Silva Filho e Romildo Dias Toledo Filho - Editores

 
Vol4 - Num3
2011
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Editorial

We are pleased to release the third issue of 2011 of the IBRACON Structures and Materials Journal (Volume 4, Number 3, August 2011), with eight articles discussing relevant themes related to concrete structures and materials. The first article in this issue addresses the compressive strength of concrete block prisms, using a finite element package in a nonlinear analysis to compare numerical results
to experimental observations. The second article presents a performance evaluation of mechanical properties of self-compacting concrete prepared with different cements types submitted to steam curing.
Environmental variables in the concrete saturation degree modeling are discussed in the third article. The fourth article addresses effects of temperature changes on load transfer in plain concrete pavement joints. The fifth article focuses on the determination of rheological parameters of mortar and concrete by alternative techniques. An educational tool for design and detailing of reinforced concrete
columns is described in the sixth article. Stability of reinforced concrete buildings with flat slabs is discussed in the seventh article, focusing on the influence of frames with flat slab layers and inverted edge beams. The last article presents an efficiency evaluation of Branson’s equivalent inertia to consider physical nonlinearity of beams.
We would like to acknowledge authors and reviewers for the important contribution to this issue.
Thanks to your efforts we are maintaining the periodicity and punctuality, important for indexing our Journal.

Américo Campos Filho, José Luiz Antunes de Oliveira e Sousa, Luiz Carlos Pinto da Silva Filho and Romildo Dias Toledo Filho - Editors

 
Vol4 - Num2
2011
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Editorial

We are very glad to release the second issue of 2011 (Volume 4 Number 2) of the IBRACON Structures and Materials Journal (RIEM). Eight articles are being published addressing relevant and upto-date themes in the area of concrete structures and materials. The first article is related with the design optimization of concrete structures using a fully probabilistic approach. In their contribution the authors compare the fully probabilistic approach applied in agreement with Eurocode 2 and the partial reliability factor method of the same standard, showing that the former can satisfy the design requirements even when the latter does not. The second article presents a multi-phase model to account for concrete cracking based on a smeared crack approach, emphasizing its advantages in terms of reduced computational cost. In the third article, digital image processing was used to determine the aspect ratio, sphericity, flakiness ratio and shape factor of fine aggregates and how such geometrical aggregate characteristics affect mortar and concrete performance. In the fourth article the authors use MATLAB® programming for stress analysis in concrete gravity dams considering earthquake and silts. The fifth article presents a comparison of the use of pozolanic and non-pozolanic fine materials such as fly ash and fine sand in self-compacting concrete (SCC). The results presented indicated that the final cost of the fly ash-SCC was lower than that of the fine sand-SCC for similar strength levels. The objective of the sixth article is to perform thermal and structural analyzes of reinforced concrete beams and propose alternatives to the Eurocode recommendations in order to standardize them in view of the revision of the Brazilian standard ABNT NBR 15200. In the seventh article the authors compare experimental and theoretical results of a new strut-and-tie formulation for the design of precast column bases embedded in socket foundations with smooth interfaces. The last paper of this issue presents a probabilistic analysis of the strength data of the fiber reinforced concrete used in the construction of the Estaleiro Rio Grande Dry Dock. A correlation model between the concrete tensile and compressive strengths is also proposed by the authors. This issue is a result of the efforts of authors and reviewers from many national and international institutions. We would like to congratulate and thank all of you for your participation in the publication of this issue of RIEM.

Américo Campos Filho, José Luiz Antunes de Oliveira e Sousa, Luiz Carlos Pinto da Silva Filho
and Romildo Dias Toledo Filho - Editors

 
Vol4 - Num1
2011
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Editorial

We are pleased to release the first issue of a new volume (Volume 4 Number 1) of the IBRACON Structures and Materials Journal (RIEM). Professor Paulo Helene, who has been collaborating as Editor since RIEM´s first volume, is now being replaced by Prof. Romildo Dias Toledo Filho in the Editorial team. We thank Prof. Paulo Helene for his important contribution to RIEM. As a Former Editor, Prof. Paulo Helene will continue collaborating with our Journal as a member of the Editorial Board. We would also like to thank Prof. Romildo for accepting our invitation to join the Editorial team. In this issue seven articles are presented, dealing with interesting and up-to-date themes. The first article is related with the use of CFRP (carbon fiber reinforced polymer) as external reinforcement of beams. In the study the strengthening behavior of regular concrete beams is analyzed and compared with that of beams molded with cement mortar and short steel fibers. The second article presents a proposal of thermal performance evaluation of a one-storey housing typology, considering the use of cast-in-place monolithic panels of concrete, varying panel thickness and concrete density. The third paper reports an investigation about the flexural behavior of steel fibers reinforced self-compacting concrete beams. The fourth paper reports the consequences of erosions on concrete structures of urban stormwater channels, based on inspections in over 180 km of channels in the drainage system of Belo Horizonte city (Brazil). The fifth article presents the development of a mechanical model to reinforced concrete analysis based on the finite element method, taking into account the non-linear material behavior with shear strength mechanisms. The sixth article discusses the design, manufacture and constructions issues related to precast lattice-reinforced joist slabs in reinforced concrete structures. Motivated by reports on damage and collapse of existing RC building structures after recent earthquakes, the seventh article presents a comparative analysis, with special attention to the influence of bond-slip mechanisms on the cyclic behavior of structural elements reinforced with plain bars (poor bond properties) and deformed bars (good bond properties). Our journal, created in 2008 as a result of a successful combination of the former IBRACON Structural Journal and IBRACON Materials Journal, completed three years of publication without interruption. In the beginning, twenty articles were published per year. This number is increasing and our target is to publish forty articles per year in the near future. We know that this goal can only be reached with the interest of our members in submitting good quality papers and with the collaboration of our reviewers. We thank all of you for the efforts in making RIEM a relevant publication in the area of concrete structures and materials in the national and international scenario.

Américo Campos Filho, José Luiz Antunes de Oliveira e Sousa, Luiz Carlos Pinto da Silva Filho and Romildo Dias Toledo Filho , Editors

 
Vol3 - Num 4
2010
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Editorial

We are now releasing the fourth and last issue of the third volume of RIEM, closing the third year of this Journal, which resulted from the combination of IBRACON Structural Journal and IBRACON Materials Journal. In this period RIEM experienced a significant development. Articles published in RIEM can be accessed through the search engine in the ACI site. We have reached the concept B2 in the QUALIS/CAPES system, which classifies articles published in RIEM in a significantly favorable level for Post-Graduate Programs. In this issue two articles deal with the application of concrete to floors: one addresses the influences of porosity and cure procedures on the flexural strength of paving concrete, and the other focuses on the addition of granite residue to tactile-floor alert strips for sight impaired people. Two articles evaluate the behavior of concrete when subjected to fire. Another article presents a panorama of international specifications and discusses the implementation of performance specifications in the industry of concrete. Numerical modeling of steel-concrete composite beams is discussed in the fifth article of this number, with emphasis on the structural behavior in the interface between steel and concrete. The last article deals with the application of the ultrasonic method to assess behavior of high performance concrete. In this issue we acknowledge the colleagues who acted as reviewers during the year 2010, a demanding and voluntary task of crucial importance to the development of our journal.

Américo Campos Filho, José Luiz Antunes de O. e Sousa, Luiz Carlos Pinto da Silva Filho e Paulo Helene , Editors

 
Vol3 - Num 3
2010
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Editorial

The area of structures and constructions in plain, reinforced and pre-stressed concrete is developing very fast in Brazil in recent years, with a great technical development and strong investment in the upgrade and expansion of the country infrastructure.
At the same time it is comforting to observe that academic programs and associated research centers have also received generous funding and support from the public sector and, in some cases, established strong cooperation links with the industry. Today, there are 131 research groups related to concrete registered in the country, 22% of which are considered of excellence, with a demand to produce
and publish at an international level.

The subjects under study are the most varied, starting with materials science, conducted by researchers from Materials, Chemical and Civil Engineering, passing by Structural Engineering and reaching the systemic point of view from researches in Architecture and Urbanism. The IBRACON journal of scientific dissemination, classified in the system CAPES QUALIS as B2, was created and maintained with focus on these researchers. It is open to all visions and contributions aligned with improvement of the quality of life, economy of resources and energy, safety, robustness and sustainability of civil construction, in concrete and related materials.
In this issue seven articles of great interest are published: two of them reporting major studies regarding the interaction of the concrete structure with complementary systems. One examines the influence of foundation settlements, while the other deals with the influence of end conditions when composite cold-formed steel-concrete beams are connected to masonry in fire situations. In the field of structural rehabilitation there are two important contributions: one about the reinforcement of columns using self consolidating concrete, and the other focused on the comparison of compressive strength of mortars from laboratory tests with effective values observed in loco. An interesting and up-to-date article in the field of Materials treats the influence of lithium nitrate in the alkali-silica reaction. Finally, two articles are presented on the behavior of structures in use, one focusing on the monitoring of a 600m railway bridge and another on the seismic activity of the Northeastern Region of Brazil, recently affected by earthquakes. With this number, IBRACON believes to achieving one of the most important objectives of this vehicle, which is to provide researchers with qualified means for the dissemination of research and technical developments related to structures and materials for civil construction, enriching the Brazilian engineering and promoting knowledge exchange with researchers worldwide..

Américo Campos Filho (UFRGS, Porto Alegre, RS, Brazil), José Luiz Antunes de O. e Sousa (UNICAMP, Campinas, SP, Brazil), Luiz Carlos Pinto da Silva Filho (UFRGS, Porto Alegre, RS, Brazil) e Paulo Helene (São Paulo, SP, Brazil) , Editors

 
 
Vol3 - Num 2
2010
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Editorial

We are now releasing the second issue of the third volume of our IBRACON Structures and Materials Journal (Vol. 3 Num. 2). In this issue an investigation on the ductility of reinforced concrete beams is reported in the first article. Material nonlinearity of concrete structures is the subject of the second article, in which design procedures based on lumped dissipation models are compared with simplified procedures recommended by the Brazilian code NBR 6118. In a third article, monitoring techniques are employed to compare design assumptions to actual behavior of reinforced concrete columns of tall buildings The fourth article presents mechanical properties of lightweight concrete, with a comparison to the corresponding properties of normal concretes. A teaching tool for studying skew bending
for general concrete cross-sections is described in the fifth article. The following article presents an attempt to classify environmental aggressiveness in the city of Salvador, BA. The issue closes with an article addressing the aerodynamic behavior of cable stayed bridges under simultaneous action of rain and wind.


The articles have been carefully reviewed by the Editorial Board and highly qualified reviewers from Brazil and from abroad. We deeply acknowledge their contribution, fundamental for the ever improving quality and regularity of our Journal. We would also like to thank all the authors that submitted articles for publication in our Journal, and renew the invitation to the whole concrete community, in Brazil and
abroad, to actively participate in the life of the IBRACON Structures and Materials Journal, as frequent readers or as contributors.

Américo Campos Filho, José Luiz Antunes de O. e Sousa and Paulo Roberto do Lago Helene, Editors

 
Vol3 - Num 1
2010
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Editorial

We are now releasing the first issue of the third volume of our IBRACON Structures and Materials Journal (Vol. 3 Num. 1). This issue begins with an experimental study on Shrinkage modeling for recycled aggregate concretes. The second article brings the second part of “Design models for reinforced concrete strengthening in bending with Carbon Fiber Reinforced Polymers (CFRP)”, addressing
shear models. The third article describes the characterization of sugar cane bagasse ashes produced by controlled burning and ultrafine grinding. Computational modeling of steel fiber reinforced concrete beams subjected to shear is the subject of the fourth article. Aspects related to the evaluation of safety conditions of buildings during the structural repair of columns are discussed in the fifth
article of this issue.

We are now releasing the first issue of the third volume of our IBRACON Structures and Materials Journal (Vol. 3 Num. 1). This issue begins with an experimental study on Shrinkage modeling for recycled aggregate concretes. The second article brings the second part of “Design models for reinforced concrete strengthening in bending with Carbon Fiber Reinforced Polymers (CFRP)”, addressing
shear models. The third article describes the characterization of sugar cane bagasse ashes produced by controlled burning and ultrafine grinding. Computational modeling of steel fiber reinforced concrete beams subjected to shear is the subject of the fourth article. Aspects related to the evaluation of safety conditions of buildings during the structural repair of columns are discussed in the fifth
article of this issue.

Américo Campos Filho, José Luiz Antunes de O. e Sousa and Paulo Roberto do Lago Helene, Editors

 
Vol2 - Num 4
2009
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Editorial

We are now releasing the fourth issue, closing the second volume of our IBRACON Structures and Materials Journal (Vol. 2 Num. 4). The first article of this issue addresses the behavior of fresh high performance concrete using a rheometer. The influence of the column cross section on the structural behavior of pile caps is discussed in a second article, based on experimental tests performed on two pile caps analyzed using the strut and tie model. Design models for reinforced concrete strengthening in bending with Carbon Fiber.

Reinforced Polymers (CFRP) are evaluated in a third article. Experimental tests performed by the authors are analyzed under ACI and fib guidelines, besides other models available in the literature. A fourth article shows results of experimental tests in reinforced concrete beam connections, in which the influences of concrete compressive strength and the amount of joint transversal reinforcement on
the relative rotations were investigated. The last article analyzes adequacy of a design method widely used to model waffle slabs in representing the slab behavior.

The articles have been carefully reviewed by the Editorial Board and highly qualified reviewers from Brazil and from abroad. In this issue we are pleased to nominate the IBRACON experts who participated as reviewers during 2009. We deeply acknowledge their contribution, fundamental for the ever improving quality and regularity of our Journal. We would also like to thank all the authors that submitted
articles for this second volume and renew the invitation to the whole concrete community, in Brazil and abroad, to actively participate in the life of the IBRACON Structures and Materials Journal.

Américo Campos Filho, José Luiz Antunes de O. e Sousa and Paulo Roberto do Lago Helene, Editors

 
Vol2 - Num 3
2009
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Editorial

We are now releasing the second issue of the second volume of our IBRACON Structures and Materials Journal (Vol. 2 Num. 2). In this issue the use of non-destructive tests for the assessment of concrete properties is addressed, and correlation curves are proposed, based on specimens cast in several construction sites and laboratories in Rio de Janeiro. A second paper discusses criteria prescribed
by ABNT NBR 8800:2008 for design of composite slabs with respect to the prediction of ultimate strength, based on laboratory test results. The influence of steel fibers and mineral additions on cracking behavior of reinforced concrete tension members is evaluated in a third paper. Finite element simulation of reinforced concrete structures is focused in the fourth paper, comparing implementations
of the Multidirectional Smeared Crack Model and the Disturbed Stress Field Model. In the last paper, the grain size optimization of the raw meal for energy saving cement production is discussed, aiming at reduction of energy consumption.


The papers have been carefully reviewed by the Editorial Board and highly qualified reviewers from Brazil and from abroad. We acknowledge the reviewers’ contribution, fundamental for the publication of our Journal. We congratulate the authors of the papers presented in this issue. Again we invite all the concrete community in Brazil and abroad to participate in the activities of the IBRACON Structures and Materials Journal, as a frequent reader or as a contributor.

Américo Campos Filho, José Luiz Antunes de O. e Sousa and Paulo Roberto do Lago Helene, Editors

 
Vol2 - Num 1
2009
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Editorial

We are now releasing the first issue of the second volume of our IBRACON Structures and Materials Journal (Vol. 2 Num. 1). In this issue a preliminary study to define the minimum shear reinforcement of flat slabs is presented in the first article. Properties of hardened SCC and similar conventional concrete in full-scale tests are compared in the second article. The third article brings a finite element based model to simulate the early age concrete behavior, aiming at the cracking risk assessment. Techniques to monitor the crack width and neutral axis position of steel fiber reinforced concrete beams are addressed in the fourth article. The fifth article presents correlations among mechanical properties of hollow blocks and those of the concrete used in its production.

The papers have been carefully reviewed by the Editorial Board and highly qualified reviewers from Brazil and from abroad. We acknowledge the reviewers’ contribution, fundamental for the publication of our Journal. We congratulate the authors of the papers presented in this issue. Again we invite all the concrete community in Brazil and abroad to participate in the activities of the IBRACON Structures and Materials Journal, as a frequent reader or as a contributor.

Américo Campos Filho, José Luiz Antunes de O. and Sousa e Paulo Roberto do Lago Helene, Editors

 
Vol1 - Num 4
2008
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Editorial

We are now releasing the fourth issue of our IBRACON Structures and Materials Journal (Vol. 1 Num. 4), closing the first volume. Formulations, for estimating crack width in reinforced concrete pipes, available in the Brazilian Code for design of concrete structures (NBR 6118:2003), are discussed in the first article. A second article approaches the load capacity of pre-stressed concrete structures. The theory behind a tabular method for the fire design of concrete columns of the Brazilian Code for fire design of concrete
structures (NBR 15200:2004) is discussed in a third article, aiming at a contribution for a future edition of this code. The fourth article approaches the application of heat-activated films as a new generation of adhesives used for bonding fiber reinforced polymers and concrete. And the last article discusses the performance of bridges under DER-SP jurisdiction using the reliability index β and obtains truck weight limits in order to guarantee its structural integrity.
The papers have been carefully reviewed by the Editorial Board and highly qualified reviewers from Brazil and from abroad. In this issue we list the members who participate as reviewers for the current volume and for the papers in the reviewing process for the issues to come. We acknowledge their contribution, fundamental for the publication of our Journal. We congratulate the authors of the papers presented in this first volume. Again we invite all the concrete community in Brazil and abroad to participate in the activities of the IBRACON Structures and Materials Journal, as a frequent reader or as a contributor.

Américo Campos Filho, José Luiz Antunes de O. e Sousa and Paulo Roberto do Lago Helene, Editors

 
Vol1 - Num3
2008
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Editorial

We are now releasing the third issue of our IBRACON Structures and Materials Journal (Vol. 1 Num. 3). This issue brings a paper discussing safety of concrete-filled steel tubular columns according to Brazilian code NBR 8800:2008. Based on a reliability analysis for these columns, the authors suggest changes to the proposed text for updating this code. A second article addresses in situ evaluation of stress losses in unbonded tendons of post tensioned flat slabs of a sixteen-floor building in Belo Horizonte. The influence
of compression bars spacing on the behavior of contact and noncontact lap compression splices is evaluated in a third paper. An experimental analysis on the performance of reinforced concrete beams reinforced with GFRP bars is addressed in a fourth paper. The last paper presents a study of the optimum struts and ties angles for the models recommended by NBR 6118:2003, aiming at minimum steel consumption in reinforced concrete beams.
The papers have been carefully reviewed by the Editorial Board and highly qualified reviewers from Brazil and from abroad. We thank them for their support. We congratulate the authors of the papers presented in this issue. Again we invite all the concrete community in Brazil and abroad to participate in the activities of the IBRACON Structures and Materials Journal, as a frequent reader or as a contributor.

Américo Campos Filho, José Luiz Antunes de O. e Sousa and Paulo Roberto do Lago Helene, Editors

 
Vol1 - Num2
2008
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Editorial

We are pleased to release the second issue of the first volume of the IBRACON Structures and Materials Journal. This issue brings two articles on the recycling of residues: the first discusses the influence of surface treatment of tire rubber residues on mortars, and the other on the effect of the type of recycled aggregate from construction residues on the module of deformation of the concrete. Another article applies the strut-and-tie model to the study of deformations on the compressive diagonals in two-pile caps. A fourth article focuses on the compression in concrete masonry wallettes with cement mortar overlays. The last article analyzes the distribution of bending moments in RC buildings. All these topics are relevant and up-to-date, and certainly will raise the interest of our community. As usual, the papers have been reviewed by the Editorial Board, and by reviewers selected among IBRACON members, from Brazil and from abroad, with acknowledged competence in the specific areas. We thank the effort and dedication of the reviewers who have been collaborating for the consolidation of our Journal as a vehicle of recognized quality. We reiterate our invitation to the IBRACON members and other readers to submit their contributions to the IBRACON Structures and Materials Journal.

Américo Campos Filho, José Luiz Antunes de O. e Sousa and Paulo Roberto do Lago Helene, Editors

 
Vol1 - Num1
2008
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Editorial

We are pleased to release the first issue of the IBRACON Structures and Materials Journal, result of the combination between the IBRACON Structural Journal and the IBRACON Materials Journal. This new Journal will cover distinct topics of material concrete and its structural applications. We plan from 4 to 6 issues per year, each containing 5 to 8 articles, technical notes and technical discussions. These will be peer-to-peer reviewed by an Editorial Board and by reviewers chosen among IBRACON´s member with acknowledged competence in the specific areas. Articles will be published in English, in order to aid the diffusion of the national technology and its interaction with our international counterparts, with an option to publish also a version in Portuguese or Spanish. The review process may be conducted in English, Portuguese or Spanish, and, when necessary, translated into English after the manuscript is approved. Publication in Portuguese or Spanish is optional. Articles previously submitted to RIEst or RIMat, and not yet published, are automatically considered for publication in this new Journal. The Internet access to this new journal uses a public domain management and publishing system, made available by the PKP- Public Knowledge Project (http://pkp.sfu.ca/ojs/). A link to the online system is available in IBRACON´s web site (http://www.ibracon.org.br/).

We thank and congratulate the authors of the papers selected for this first issue. We hope that their pioneer work will be remembered in the future as a symbol of national concrete engineering. We would like also to thank the Board of Directors of IBRACON, for their trust and continuous support towards the achievement of this mission.

In this opportunity we invite all the concrete community to participate in the activities of IBRACON Structures and Materials Journal, as a frequent reader or as a contributor. This is a victory of all the Brazilian concrete community. Therefore, we extend our congratulations to all the participants of IBRACON for this accomplishment that clearly demonstrates the strength and capacity of our country.

Américo Campos Filho, José Luiz Antunes de Oliveira e Sousa and Paulo Roberto do Lago Helene, Editors