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 γ_z 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 γ_z 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.

Publication Dates

• Publication in this collection
  Sept 2017