Three-dimensional aggregate modelling method and damage analysis of recycled aggregate concrete

Abstract

A new aggregate placement algorithm has been developed that can automatically identify the remaining space after the aggregate is placed, and only new aggregates are placed in these spaces. This results in a reduction in the number of overlaps with existing aggregates, and the more aggregates placed, the higher the efficiency. This method is suitable for various types of concrete, such as ordinary aggregate concrete, recycled aggregate concrete (RAC), and fiber-reinforced concrete. Finite element analysis is applied to simulate stress and damage evolution in mesoscale models of concrete, taking into account the effects of actual aggregate slenderness ratio, concavity, flatness, asymmetry ratio, and compaction degree. The study reveals that tensile damage is the primary factor in concrete damage evolution up to peak stress, with both tensile and compressive damages influencing the post-peak behavior. In RAC, older Interfacial Transition Zones (ITZs) are found to be more susceptible to early damage than newer ones. Moreover, the model effectively illustrates the influence of recycled aggregate content and concavity on concrete’s mechanical properties. This mesoscale concrete modeling method, as developed in this study, holds potential for future research on various types of concrete.