Experimental study on freeze-thaw failure of concrete incorporating waste tire crumb rubber and analytical evaluation of frost resistance

Abstract

The incorporation of waste tire crumb rubber into concrete in appropriate size and content not only facilitates the recycling and safe disposal of waste tires but also enhances concrete frost resistance. The exploration of the frost resistance of rubberized concrete is necessary to fill the major gap of standard evaluation guidelines for rubberized concrete. Through rigorous testing and analysis of parameters such as Wn, Pn, and XEdtn of the rubberized concrete incorporating waste tire crumb rubber ranged from 1.0 % to 5.0 % during rapid freeze-thaw cycles, the study clarified the mechanisms by which crumb rubber affects concrete frost resistance. An increase in durability life was noted as rubber content increased, but a decline occurred when rubber content exceeded 3.0 %. Additionally, pretreating crumb rubber further enhanced frost resistance. The durability life of concrete samples with 3.0 % rubber content reached 275 freeze-thaw cycles. Rubberized concrete containing 2.0–4.0 % crumb rubber saw at least a 25-cycle increase by pretreating crumb rubber, and 5.9–17.9 % increase for Pn compared to that of the concrete with untreated crumb rubber reaching the failure state. The inclusion of crumb rubber altered concrete mesoscopic pore structure and the bonding performance of concrete matrix interface, thereby affecting its frost resistance and failure state. A new set of evaluation equations was developed to quantify the frost resistance of rubberized concrete, providing a robust method for assessing the freeze-thaw response of concrete integrated with waste tire crumb rubber. The DFM proposed in this study proves to be more advanced and effective than existing methods for evaluating frost resistance of rubberized concrete.