Concrete–reinforcement bond in different concrete classes

In this study, the effect of the depth of concrete cover and the curing time on the concrete–reinforcement bond strength in concretes with eighth different compressive strength levels was investigated. Eighth different concrete mixtures were produced. 150 mm cubic specimens were cast from these mixtures. Deformed reinforcements of 14 mm diameter were embedded at a depth of 70 mm into specimens. Three different depth of the concrete cover were selected. The pull out loads, compressive strength, splitting tensile strength and modulus of elasticity of the specimens were determined.It was found that, the bonding between concrete and steel reinforcement was increased by increasing the mechanical properties of the concrete, the thickness of concrete cover and curing time. In addition, the concrete–reinforcement bond was mathematically modeled using 28-day mechanical properties of the concrete and the thickness of concrete cover.

► The concrete–reinforcement bond was increased with the increase in the curing period.
► The concrete–reinforcement bond was increased with the increase in concrete cover depth.
► The concrete–reinforcement bond was raised with the increase in mechanical properties of concrete.