Mechanical Properties of Hybrid Steel–Glass Fiber-Reinforced Reactive Powder Concrete After Exposure to Elevated Temperatures

摘要

Due to extremely dense microstructure, reactive powder concrete (RPC) shows poor performance at elevated temperaturesowing to the development of high pore pressure that causes the deterioration of the material. By using fiber reinforcement,elevated temperature performance of RPC can be improved, as noted by many researchers. To this end, 3% volume fractionof four combinations of steel fiber (SF) and glass fiber (GF) [(3%, 0%), (2%, 1%), (1%, 2%), and (0%, 3%)] was usedin RPC to study the change in residual mechanical properties of RPC after exposure to elevated temperatures. Three mainmechanical properties, i.e., compressive strength, splitting tensile strength, and flexural strength properties, were studied.Experimental results showed that using 3% volume fraction of fibers (regardless of combination), explosive spalling of RPCwas completely prevented. Hybrid fiber RPC with 2%SF–1%GF showed the maximum best mechanical performance atboth elevated and normal temperatures. Single 3%SF–RPC performed significantly better than single 3%GF–RPC at bothnormal and elevated temperatures. A strong correlation existed between the normal temperature strength, residual strength,and exposure temperature.