Bond–slip behavior of 1.4362 duplex stainless steel bar embedded in concrete

Abstract

Stainless steel reinforcement is widely used in reinforced concrete structures due to its good corrosion resistance and mechanical properties. In this work, a set of pullout tests on 20 types of specimens are presented. Tensile tests on stainless steel rebars with different diameters and carbon steel rebars are conducted to determine the mechanical properties of rebars. Compressive tests on cubic concrete specimens with different grades are conducted to determine the mechanical properties of concrete. The design of specimens for pullout tests considers the effects of concrete grade, rebar material, rebar diameter, specimen shape, bond length, concrete cover length, rebar position, and stirrups. The damage observation is recorded. The experimental results are compared with the models provided by the Chinese code for the design of concrete structures (GB/50010-2010). With the experimental data, the coefficients of the model are modified by linear fitting. The comparison of bond–slip curves between experimental data and the modified code model is presented. Experimental results indicate that bond strength increases with increasing concrete grades, bar diameter, bond length and concrete cover depth. However, the bond strength between stainless rebar and concrete is smaller than that of carbon steel rebar and concrete. The modified model can produce a better prediction of the bond–slip relation between stainless rebar and concrete.