Calibration of Viscoelastic Chain using the PSO algorithm to match various Creep Models

Abstract

This paper employs an optimization algorithm to approximate the creep-induced behavior of a concrete material as predicted by various well-established models of concrete that exist in the literature. The models in question are i) the B3 Model ii) the CEB-FIB 2010 model code and iii) the model in the current AASHTO LRFD specifications. The topic of concrete creep is of utmost significance for the maintenance of infrastructure such as highway bridges, where the Dead Load is much larger than the live loads originating from traffic. Recent studies have shown that simplified, design-oriented equations may not always yield conservative predictions of long-term deformations. The economic effects of this shortcoming are enormous, while in some cases the structural integrity of the structure may be compromised. The present study used a finite element analysis of a simple model through which the long-term deformation of a uniaxial element was analyzed based on the constitutive law provided by the above-mentioned model codes. The constitutive law used in the analyses consists of a solidifying viscoelastic chain, calibrated to match the creep curves generated by the three different models.