Mechanical properties of recycled fine aggregate concrete incorporating different types of fibers

Abstract

In this paper, the mechanical properties of fiber reinforced recycled fine aggregate concrete (RFAC) were investigated. Natural fine aggregate was replaced by recycled fine aggregate, and experimental parameters included the fiber type and fiber volume fraction. Two types of steel fibers, namely hooked end steel fiber (ESF) and micro-fine steel fiber (MSF), and two types of flexible fibers, namely polypropylene fiber (PPF) and basalt fiber (BF) were selected. The slump, compressive strength, splitting tensile strength, load-deformation curve under splitting tensile loading and failure mode of the fiber reinforced RFAC were examined. Results showed that the slump of RFAC decreased with the increase in fiber volume fraction, while the compressive and splitting tensile strength of RFAC increased with the addition of fibers. The ductility and toughness of RFAC increased with the increase in fiber volume fraction. Compared with flexible fibers, the effects of steel fibers on the mechanical properties of RFAC were more pronounced. Among the four types of fibers, the MSF showed the most significant improvement for the mechanical properties of RFAC. Finally, the model to predict the splitting tensile strength of steel fiber reinforced RFAC was proposed and validated by the experimental results.