Modeling of mechanical bond–slip for steel-reinforced concrete under thermal loads

The mechanical bond–slip relationship for steel-reinforced concrete at elevated temperatures is investigated by using an analytical model based on the smear crack theory and the thick-wall cylinder theory. By considering the concrete cover in its partially cracked elastic stage and the splitting failure as the primary failure mode, a correlation between the slip of the steel rebar and the inner crack radius of the concrete cover can be established. Simplified equations for estimating the bond stress–slip relationship at a designated temperature are derived for practical use. Parametric studies are also conducted to investigate the effect of the variation of compressive strength of concrete, concrete cover and temperature on the prediction of the bond stress–slip relationship obtained by the proposed model.

► The mechanical bond–slip relationship for RC at elevated temperatures is investigated.
► The model is based on the smear crack theory and the thick-wall cylinder theory.
► A correlation between the slip and the inner crack radius is established.
► The simplified bond stress–slip relationship is derived for practical use.
► Parametric studies of the predicted bond stress–slip relationship are conducted.