Thermal conductivity, abrasion resistance and compressive strength of end-of-life tire aggregate incorporated concrete

Abstract
Recycling end-of-life tires is a global problem that requires an urgent solution. Storing and preserving these tires is a challenge that delays facing potential problems instead of solving the problem. In this context, recycling waste tires without harming the environment and at low costs has been the focus of many researchers. For several decades, the possibility of grinding these tires to aggregate size for concrete and substituting them with natural aggregate has been the subject of research by scientists working in this field. In this regard, this study aims to experimentally investigate the influence of waste rubber aggregate on some engineering properties of concrete, such as ultrasonic pulse velocity-based quality assessment, abrasion resistance, thermal conductivity characteristics, and mechanical performance, namely, compressive strength. Another significant side of the study was establishing a statistical relationship and correlation between the w/c ratio and substitution level of waste rubber aggregate and the experimental outputs. The experimental study indicated that the waste rubber aggregate decreased the concretes' compressive strength, but it improved the thermal conductivity characteristics and abrasion resistance of the concretes manufactured in this study. On the other hand, the statistical analysis revealed that the input parameters have meaningful effects on the engineering properties of the concretes, and there is a strong correlation between these properties.