Confinement effects on the steel–concrete bond strength and pull-out failure

In this contribution, an experimental campaign based on unconfined and actively confined pull-out tests is presented to investigate the bond stress–slip behavior. This campaign aims at underlining passive (concrete cover) and active (external pressure) confinement effects on the maximal bond stress. Experimental results are associated to a numerical approach in order to predict the evolution of the bond strength. Equations are finally proposed that distinguish splitting failure (function of the concrete tensile properties) and pull-out failure (function of the compressive concrete properties).

► It presents experimental and numerical results on steel–concrete bond strengths.
► It studies the active and passive confinement effects on the bond strength.
► A bilinear law for bond strength in splitting and pull-out failures is proposed.