Mechanical properties and microstructure of basalt fiber-reinforced recycled concrete

摘要

This study focuses on the mechanical properties and microstructure of a new recycled-concrete incorporated with basalt fiber (BF). For the BF-reinforced recycled concrete (BFRRC), basic mechanical tests, including cubic compression, axial compression, splitting tension, and bending resistance are carried out, and an in-depth analysis of the microstructure was performed through scanning electron microscopy. Based on fiber reinforcement theory, the composite effect is first proposed. The effects of the replacement ratio of recycled coarse aggregate (RCA) and BF content on the failure mode, mechanical properties, and interface transition zone for recycled concrete (RC) are studied. The results show that when the replacement ratio of recycled aggregate is 50%, the basic mechanical properties of RC with different BF contents are better than those of ordinary concrete, thus proving the feasibility of the proposed method in preparing high-performance RC. At different BF contents, the proposed conversion relations among the strength indexes for RC with a replacement ratio of 50% are simple and feasible. The composite effect between BF and RCA can be employed to illustrate the reinforcement mechanism of BF on RC. This study provides a theoretical basis and reference for further research on BFRRC. (C) 2020 Elsevier Ltd. All rights reserved.