Experimental study on bond performance between engineered cementitious composite and corroded rebars

This study investigates the bond failure mechanism between engineered cementitious composite (ECC) and corroded rebars through pull-out experiments. The effects of corrosion rate, bond anchorage length, rebar diameter, and fiber content on bond performance are analyzed. The results show that the bond stress-slip curve can be divided into: micro-slip, slip, failure and residual phases. All specimens exhibit shear pull-out failure as the primary failure mode. The bond strength initially increases and then decreases with the corrosion rate and there is a critical corrosion rate resulting in the warimized bond strength. For rebars with a 10% corrosion rate, bond strength decreases as anchorage length and rebar diameter increase. Additionally, increasing the fiber content enhances the bond toughness index and bond strength initially, followed by a decline. The optimum performance, including maximum toughness and crack resistance, is observed at a fiber content of 2%.