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, xAVER, 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 xAVER/r0, where r0=rebar radiusr0=rebar radius; and (4) PITMAX, not the xAVER/r0 ratio, was the most important parameter affecting flexural load capacity reduction in corroded beams.