Experimental investigation of mechanical-performance deterioration of HFRC segment under combined effect of sustained loading and chloride-induced corrosion

•Established a corrosion-loading system according to one-sided corrosion of segments.•Incorporated steel fibers prolong initial rust time and slow down corrosion rate of steel bars during RC segment corroding.•Incorporated steel fibers convert the failure mode of the corroded RC segment from brittle to ductile failure. To study the influence of steel fibers on the mechanical-performance deterioration of reinforced concrete (RC) segments, a series of cofferdam-type electrochemically accelerated corrosion tests of RC and hybrid fiber reinforced concrete (HFRC) segment specimens are conducted. First, the effects of the steel fibers on the initial rust time, reinforcement strain, and segment deformation are determined; then, the crack propagation and failure pattern of each specimen are recorded and analyzed. The results indicate that 1) the steel fibers improve the internal structure of concrete, prolong the initial rust time of the reinforcements, resists the reinforcement-corrosion-induced expansion force and slow down the corrosion rate of the main reinforcement in corroded segments; 2) the steel fibers improve the overall deformation performance and reduce the strain increment of the steel fiber specimen under the same loading and corrosion environment; 3) the steel fibers improve the tensile strength of concrete members and enable the HFRC specimen to maintain a certain residual strength after cracking, which inhibits the initiation and development of segment cracks in the corrosion and damage stage; and 4) the incorporated steel fibers not only improve the ultimate bearing capacity of the HFRC specimen, but also enhance its deformation ability, which converts the failure mode of the corroded RC specimen from brittle to ductile failure.