Fatigue performance of basalt fibre-reinforced polymer bar-reinforced sea sand concrete slabs

Abstract

Combining both Fibre-reinforced polymer (FRP) and sea sand concrete (SSC), the new composite structure of FRP bar-reinforced SSC can not only solve the issue related to reinforcement corrosion but also alleviate the problem of river sand shortage. Here, four-point bending tests were performed to investigate the fatigue performance of basalt FRP (BFRP) bar-reinforced SSC slabs. Results revealed that fatigue life decreased significantly with the increasing load levels. The average reduction of fatigue life was about 28% when the load levels increased by 0.05. The main fatigue failure mode of BFRP bar-reinforced SSC slabs was the BFRP bar rupture, which occurred at the mid-span or loading point. The load levels had no evident effect on the attenuation rate of bending rigidity. The critical value for the fatigue deflection growth rate could be set at 35%. An equation for the mid-span deflection at upper loads was established. Herein, considering the growth rate of fatigue deflection, insights to detect the deflection of BFRP bar-reinforced SCC slabs were presented. Meanwhile, based on the S–N curve, Miner rule, and axle load frequency spectrum, a fatigue life prediction method was proposed.