Effect of Low Corrosion Levels on the Bond Performance of Lap-Splices in Reinforced Concrete Beams

The Korean Highway Bridge Design Code introduced requirements for sufficient tensile lap-splice lengths in 2005. Bridge piers designed before 2005 might not have enough tensile lap-splice length. In addition to that, old structures are susceptible to corrosion due to several environmental factors. Thus, to investigate the effect of lap-splice lengths on the bending behavior of the old piers, twelve reinforced concrete (RC) beams were fabricated with sufficient and insufficient tensile lap-splice length, electrochemically corroded and tested under bending. Six of these beams, with sufficient lap-splice lengths, failed in a ductile manner after reinforcement bar (rebar) yielding occurred, whereas the remaining six, with insufficient lap-splice lengths, failed in a brittle manner owing to lap-splice bond failure before rebar yielding. The tested low-corrosion (< 4% by mass) beams exhibited significantly higher load-carrying capacities than non-corroded counterparts tested in our previous study. These results correlated with previously reported results by other researchers, indicating that low corrosion levels do not critically compromise the flexural performance of RC piers. Nevertheless, piers featuring insufficient lap-splice lengths must be rehabilitated to ensure seismically sufficient ductile flexural behavior.