Cracking Resistance of Reinforced SFRFLC Superposed Beams with Partial Ordinary Concrete in Compression Zone

摘要

A new reinforced SFRFLC (abbr. steel fiber reinforced full-lightweight concrete) superposed beam was proposed to sufficiently utilize the good peculiarities of ordinary concrete in compression and SFRFLC in tension, and reduce its self-weight. Experimental study was carried out on the flexural behaviors of reinforced SFRFLC superposed beams compared with reinforced concrete beams and reinforced SFRFLC beams, the effects of such factors as sectional depth of SFRFLC, volume fraction of steel fiber, longitudinal tensile reinforcement ratio and strength of ordinary concrete were analyzed. Based on the composite principle, formulas are proposed for calculating the cracking resistance of reinforced SFRFLC superposed beam and the reasonable sectional depth of SFRFLC. The results showed that there was the optimal sectional depth of SFRFLC, steel fiber was the main factor while high-strength ordinary concrete and proper reinforcement ratio were beneficial to enhance the cracking resistance of reinforced SFRFLC superposed beam.