Steel Fiber-Reinforced Recycled Coarse Aggregate Shotcrete Flexural Performance：Investigation

Abstract: In order to investigate sprayed steel fiber-reinforced recycled concrete (SSFRRC) beam flexural performance, this research performed four points bending tests on 10 different SSFRRC beam parameters. Then, flexural performance variations were analyzed focusing on concrete compressive strength, replacement rate of recycled aggregate (RA), and flexural performance volume fraction. Research findings: By keeping replacement rate of RA and volume fraction of Steel Fiber (SF) unchanged, increase of compressive strength increased flexural performance index of SSFRRC. Also, SF volume fraction (VOF) remained constant and increase of RA replacement rate significantly increased mid span deflection value. When VOF of SF was less than 0.5%, SSFRRC flexural performance was not significantly enhanced. However, increase of the VOF of SF from 0.5% to 1% significantly improved reinforcement effect, and when VOF of SF was greater than 1%, further increase of VOF significantly decreased flexural resistance. This research proposed an evaluation index suitable for SSFRRC flexural performance. Furthermore, this research also derived equations for the calculation of SSFRRC tensile and flexural strength. Calculation equations of tensile and flexural strength were found to be consistent with experimental results for compressive strengths of less than 30 MPa and VOF of SF values of less than 1.5%.