Residual flexure capacity of corroded reinforced concrete beams

This work presents results from an experimental investigation which correlated flexure capacity loss with steel cross-section loss due to generalized corrosion of the embedded steel in a humid environment. Concrete beams (100×150×1500 mm) cast with chlorides were used in this investigation. Further acceleration of the corrosion process was achieved by applying a nominal 80 μA/cm2 constant anodic current for approximately 50–180 days. The specimens were subsequently tested in flexure under three-point loading. The average corrosion penetration, x AVER , the maximum concrete surface crack width, CWMAX, and the maximum rebar pit depth, PITMAX, were estimated for each corroded beam using gravimetric metal loss procedure. The results obtained showed: (1) the corrosion-induced concrete crack propagation was enhanced if dry rather than wet environment is used during the accelerated corrosion stage; (2) wet environment during corrosion acceleration enhanced pit formation at the rebar surface; (3) a decrease of as much as 60% in the flexure load capacity values was observed with only 10% of x AVER / r 0 , where r 0 = rebar radius ; and (4) PITMAX, not the x AVER / r 0 ratio, was the most important parameter affecting flexural load capacity reduction in corroded beams.