EFFECTS OF DIFFERENT FIBERS ON MECHANICAL PROPERTIES OF REACTIVE POWDER CONCRETE (RPC)

Abstract

An example of an ultra-high-performance cement-based composite is reactive powder concrete (RPC). Its engineering characteristics are achieved due to a dense and homogenous microstructure. Usually, RPC is reinforced with steel fibers (SF) to improve ductility and fire-resistance. In the case of RPC, studies must be conducted using lightweight and durable fibers because of the concerns regarding high density, low durability, and high conductivity. This study focuses on the RPC’s mechanical properties that use a single and hybrid fiber mixture of carbon fiber (CF) and conventional SF. The effects of performing high temperatures of 200^oC, 400^oC, 600^oC, and 800^oC for two hours, on the mechanical properties of plain RPC and fiber reinforced RPC were evaluated. It was observed that CFRPC performs mechanically up to 85-90% of SFRPC’s conventional value. Mechanical property hybridization of SF 1.5% and CF 0.5% synergized at higher and normal temperatures. Compared to plain RPC, CFRPC showed, after 800ºC exposure, around two, four, and five times more residual compressive, tensile, and flexural strengths, respectively. Moreover, valued less than SFRPC, the compressive strength-per-unit weight of CFRPC was significantly improved.