Stress assessment in reinforcement for columns with concrete creep and shrinkage through Brazilian technical normative

Abstract

In this paper, the induced stress in longitudinal reinforcement bars with cross sections subjected to concrete creep and shrinkage was evaluated. The study was performed for a reinforced concrete column, with loading varying from zero-in which the structure is exclusively subjected to self-weight-to forces close to the loss of stability by bifurcation of equilibrium. A real precast concrete pole, extremely slender, with geometry varying lengthwise, was the structure chosen for the analysis. The aspects related to the material nonlinearity, as well as creep, shrinkage and the development of characteristic concrete strength, were taken into account following Brazilian normative recommendations in NBR 6118:2014 (Design of structural concrete-Procedure) by the Brazilian Association of Technical Standards (ABNT). The critical buckling load was defined according to the structural frequency by using particularly nonlinear formulations. The results were obtained for different instants without exceeding the expected time for convergence of results. The maximum relative value found for the reinforcement stress was 1.24% of the steel yield strength, eliminating the possibility of yielding material.

Stability, Stress and Strain Analysis of Very Slender Pinned Thin-Walled Box Columns according to FEM, Euler and TSTh

“…Wahrhaftig (2020c) did a time-dependent analysis of slender, tapered reinforced concrete columns. Wahrhaftig et al (2021) made a stress assessment in reinforcement for columns with concrete creep. Ismail (2011) evaluated the dynamical behavior and stability of pipes conveying fluid.…”

Technical Buckling, Stress and Strain Simplified Analysis of Semi-Slender Thin-Walled Cylindrical Pinned Column

“…Wahrhaftig (2020) did a time-dependent analysis of slender, tapered reinforced concrete columns. Wahrhaftig et al (2021) made a stress assessment in reinforcement for columns with concrete creep and shrinkage through Brazilian technical normative. Ismail (2011) provided an analysis of the dynamical behavior and stability of pipes conveying fluid.…”