Corrosion of steel rebars across UHPC joint interface under chloride attack

Abstract

Corrosion of steel rebars across ultra-high-performance concrete (UHPC) joint interface under chloride attack is experimental investigated in the present study. The cases of concrete joint interface with normal concrete (NC) and high-performance concrete (HPC) are also investigated as the contrast. Twelve specimens are prepared and subjected to corrosion test. The corrosion potential and corrosion current density are measured to monitor the corrosion evolution of steel rebars. The effects of chloride concentration and cracking on the corrosion of steel rebar across the concrete joint interface are clarified. And the corrosion characteristic of steel rebars with a high corrosion loss are further investigated through the accelerated corrosion method. Results show that steel rebars across joint interface trend easily to be corroded for all the three cases with NC, HPC and UHPC. Corrosion of steel rebar across UHPC joint interface is just a little slower or slighter than the other cases across NC and HPC joint interface. The corrosion of steel rebars is highly centralized and localized at the joint interface for the case with UHPC, but relatively uniform without significant difference around the joint interface for the other cases with NC and HPC. Corrosion of steel rebars across concrete joint interface is sensitive to chloride concentration and interface cracking, especially for the case with UHPC.