Corrosion durability of reinforcing steel in cracked high performance fibre-reinforced cementitious composite beams

Abstract

This paper reports test results on the corrosion durability of reinforcing steel in three series of precracked beams of ordinary mortar; a high-performance fiber-reinforced cementitious composite (HPFRCC) containing polyethylene (PE) fibers, referred as mono HPFRCC; and hybrid combinations of steel cord (SC) and PE fibers, referred as hybrid HPFRCC. In each series three precracked beams with a maximum crack width of 0.1–0.5 mm were tested. All beams were subjected to an accelerated corrosion regime consisting of applying constant 3-V DC potential across rebar (anode) and cathode and cyclic wetting and drying cycles. The durability performance of the specimens was examined through regular monitoring of corrosion current—hence, the calculated steel loss, the corrosion-induced damage measured by the longitudinal crack width and through visual inspection. At the end of the corrosion tests, the reinforcing bars in all specimens were exposed to observe the corrosion depth, corroded area, actual amount of steel loss, and residual tensile strength. Results showed that the hybrid HPFRCC specimens exhibited better performance than did the mortar and mono HPFRCC specimens. Relationships of maximum crack width with actual steel loss, maximum corrosion depth, and residual tensile strength were observed in mono and hybrid HPFRCC beams. However, no correlation between maximum crack width and corroded area was observed in all series. The relationship of maximum corrosion depth and actual amount of corrosion in the hybrid and mono HPFRCC series was also observed in this study.