A Software Tool to Estimate the Time-dependent Deformation in RC Walls and Columns

Abstract

Tall reinforced concrete (RC) buildings are sensitive to time-dependent effects which arise due to creep and shrinkage. In this study, a software tool has been developed to estimate the time-dependent deformations in RC walls and columns. The program can invoke the ACI 209, EC 2, IS 1343 and fib MC 10 models to determine the creep and shrinkage in plain concrete. In order to include the effects of longitudinal reinforcement, two alternative methods have been explored: (i) effective modulus method and (ii) one-dimensional boundary value problem method. The effect of variable environment is included using the principle of superposition, which is valid within the linear creep domain. The program is written on the Python platform and can be used on any Windows machine. The program is validated using tests reported in the literature. The program is capable of accepting input of a linear elastic one-step-analysis from standard commercial software like ETABS and StaadPro. This program requires minimal input from the user, such as the grade of concrete, rate of loading and time at which the deformations are to be evaluated. The time-dependent deformations are evaluated for each column or wall and the super-elevation levels for each story are presented in a chart form, which serves as a design aid for the engineers and can be readily used by the site construction team.