Fracture energy regularization for the numerical modelling of concrete structures with recycled aggregate: An application with an UMAT user subroutine for ABAQUS

Abstract

This paper investigates the application of a new concrete damage model for the numerical simulation of recycled aggregate concrete (RAC) structures. The proposed model incorporates fracture energy regularization for tensile and compressive behaviour in Mode I, addressing mesh dependency issues common in finite element (FE) analyses. Using the ABAQUS FE software, the damage model was implemented via a UMAT user subroutine developed in Fortran 90. The accuracy of the numerical model was evaluated by comparing its results with experimental data from previous studies, focusing on structural responses, cracking patterns, and the estimation of tensile and compressive fracture energy for concrete with recycled aggregates in structural members. The findings from the simulation of two classical concrete benchmark tests, conducted on concretes with different percentages of recycled aggregates, validate the adopted material properties for future applications.