Effects of waste rubber powder and resin content on the free shrinkage of polymer concrete

Abstract

In this study, the effects of waste rubber powder (WRP) and resin content on the free shrinkage of vinyl resin polymer concrete (PC) were investigated for use in corrosive environments, such as wet flue gas desulfurization (WFGD). The mechanical properties, free shrinkage performance, microstructure, and pore structure of PC were examined with varying levels of WRP (0%, 2.5%, 5.0%, and 7.5% of binder volume) and resin content (23.1%, 24.7%, and 26.2% of total volume). The results indicated that increasing the proportion of resin in the PC material led to an enhancement in the strength of the samples. However, it was observed that high resin contents resulted in a significant increase in shrinkage. Specifically, when the resin content was elevated, the volume of the resin increased by 3% and shrinkage increased by more than 14%. Conversely, the inclusion of WRP had a negative effect on the mechanical strength but significantly reduced the shrinkage rate and exothermic peak during the curing process by over 50%. The primary factors found to be responsible for the reduction in shrinkage of PC is that the inclusion of WRP resulted in the formation of an appropriate air void system and the stress relaxation owing to the retardation of resin curing. Overall, the study revealed that WRP is a promising and sustainable filler for shrinkage reduction in PC, particularly in corrosive environments.