The influence of fiber RC beams under flexure on the chloride-induced corrosion

Abstract

Corrosion of rebars is the main cause of the deterioration of reinforced concrete structures. In an aggressive marine environment, rebar corrosion occurs due to chloride ion penetration of the reinforced concrete (RC). This paper presents the findings of an experimental study conducted to determine the influence of fiber reinforcement on the chloride-induced corrosion and flexural behaviour of reinforced concrete beams. Uncracked and cracked reinforced concrete beams were exposed to a 16.5% chloride solution in a cyclic immersion for three years, causing them to corrode naturally. The half-cell potential test was carried out to monitor the corrosion potentials, and flexural tests were carried out in a three-point bending configuration to assess the structural performance. Gravimetric tests revealed that bars in conventional concrete had higher degrees of corrosion than those in fiber-reinforced concrete with a variation of 11 %. With increasing crack widths (max 0.2–0.3 mm), there was a tendency toward early corrosion initiation, in contrast, fiber addition delayed the process of corrosion initiation by 6 %. Regarding flexural performance, fiber-reinforced beams are significantly better than conventional concrete beams, especially steel fiber incorporated concrete beam's residual flexural strength 16 % more than the conventional concrete beams.

Keywords

• Corrosion initiation
• Conventional concrete
• Fiber reinforced concrete
• Crack width
• Half -cell potential