Study on the Compressive Properties of RPC Restrained by CFRP Sheet under Low-Temperature Curing

To address the problem of significant degradation of compressive properties of reactive powder concrete (RPC) after freezing during the curing period in a low-temperature environment, carbon fiber-reinforced polymer (CFRP) was used to restrain RPC specimens with carbon fiber filament content of 0 or 1 %, and axial compression tests were performed after low-temperature curing (20 degrees C, -5 degrees C, -15 degrees C, and-25 degrees C). The effects of temperature, restraint, and carbon fiber filament content on the compression properties of the RPC were analyzed. Results of the analysis showed that the mechanical properties of RPC under compression decreased with decreasing curing temperature. The use of CFRP sheets for the restraint of RPC specimens and the addition of carbon fiber filaments can both increase the ultimate load capacity of RPC specimens at each curing temperature, and the specimens were relatively intact after damage. With the addition of carbon fiber filaments, which can slow down the rate of decay of load capacity as curing temperature decreases, the degree of load capacity improvement is greater the lower the temperature. The degree of load capacity increase of the CFRP sheet decreases with decreasing temperature because of the weakening of the epoxy resin adhesive bond strength in the CFRP sheet at low temperatures. Both CFRP sheets and carbon fiber filament can increase the compressive pre-crack energy absorbed by RPC at each of the temperatures and can increase the toughness of RPC at low temperatures.

Automated summary

This study investigated the effects of carbon fiber-reinforced polymer (CFRP) on the compressive properties of reactive powder concrete (RPC) during freezing and found that low-temperature curing resulted in a significant degradation of RPC's mechanical properties. The use of CFRP and carbon fiber filaments can increase the ultimate load capacity and improve the toughness of RPC at low temperatures.