Heated Rebar Efects on Corrosion Performance of Reinforced Concrete

Defects of steel-concrete interface (SCI), such as those caused by “top bar” effect, are believed to induce corrosion-related problems of reinforced concrete. This paper first attempts to explore the “hot bar” effect on concrete durability. The high temperature of rebar cast in summer is simulated by elevating the temperature of rebars prior to cast in laboratory conditions. Accelerated carbonation and cyclic wet-dry cycle corrosion tests were conducted to study the heated rebar effects on the corrosion rate, corrosion potential and concrete conductivity of carbonated RC specimens. Another group of specimens with different rebar casting temperatures were cast to study the heated rebar effect on the Ca/Si ratio around SCI by using scanning electron microscope (SEM). The test results are presented to illustrate the “hot bar” effects on reinforced concrete structures.