Implementation of thermomechanical coupling to the study of recycled aggregate concrete in mesoscale

Abstract

The employment of recycled aggregate concrete (RAC) presents a series of environmental and economic benefits to the construction industry. Therefore, one of the main concerns in the researches about this topic is to determine how the employment of recycled aggregate would affect the mechanical properties of concrete such as tensile and compressive strength as well as failure mechanisms at normal and elevated temperatures.In the numeric simulation context, as the particularities of the recycled aggregate concrete happen at the mesoscopic domain, a more refined scale numerical approach should be given to the analysis. Mesoscale models allow the representation of the material different phases and therefore are able to consider particular thermomechanical properties and constitutive laws to aggregate, matrix and interfacial transition zones (ITZ). In this context, an implementation of the thermomechanical coupling to the study of recycled aggregate concrete in mesoscale is proposed. Once the formulation is implemented, basic tests (benchmarks) will be developed and analyses performed to validate the model. Finally, more specific simulations with regard to heat transfer and thermal cracking in mesoscale RAC will be carried out using the developed tool. These results will be compared quantitatively and qualitatively with experimental results and also with natural aggregate concrete in order to better evaluate RAC as an engineering material. (AU)