Repeated impact behavior of one-part high performance geopolymer composites at ambient and extremely low temperatures

One-part geopolymer (OPG), as an eco-friendly cementitious material with comparable mechanical performance compared to ordinary Portland cement (OPC), is now gathering increasing attention globally. In recent years, composite materials with excellent impact resistance have been developed based on OPG. The current study was intended to investigate the effect of extremely low temperatures on the behaviors of one-part high performance composite (OP-HPGC) under repeated impacts. The static compressive and tensile behaviors of OP-HPGC with different steel fiber contents were firstly evaluated. Then, the dynamic impact behaviors of OP-HPGCs with different steel fiber contents at ambient temperature were tested and analyzed. Furthermore, the dynamic impact behaviors of OP-HPGC-2% exposed to various temperatures (i.e., -196°C, -78.5°C, and ambient temperature) were examined. The dynamic impact behaviors of OP-HPGC-2% which firstly exposed to -196°C and then recovered to ambient temperature were also tested to investigate the influence of a single cryogenic freeze-thaw cycle. To quantify the damage evolutions of OP-HPGCs under repeated impacts, a fractural dimension approach was employed. Experimental results demonstrated that OP-HPGCs exhibited similar repeated impact performance under both ambient and extremely low temperatures, indicating low sensitivity to cryogenic conditions. Moreover, a single cryogenic freeze-thaw cycle did not significantly affect their impact resistance. This study provides a reference for understanding the repeated impact resistance of OP-HPGC at different environmental temperatures.