Experimental study on the bond behavior of deformed bars embedded in concrete subjected to lateral tension

The bond behavior of steel bars embedded in concrete, including the anchorage capacity and bond stress-slip relationship, is highly concerned owing to its importance in the design and checking calculation of reinforced concrete structures. The purpose of this paper is to present an experimental study on the bond behavior of deformed bars embedded in concrete subjected to lateral tension. In the experiment, a total of 237 pull-out specimens are tested. It is shown that the failure mode is influenced by the strength of concrete, ratio of the cover depth to bar diameter, and unfavorable lateral tension. The bond strength and the slip at the peak stress decreases with the increase of the unfavorable lateral tension for specimens in pull-out and splitting failures, but the ratio of the residual to ultimate bond strength almost keeps constant for specimens in pull-out failure. Based on the experimental results, an empirical formula for the bond stress-slip relationship is proposed. The empirical formula is in good agreement with the experimental results for specimens with different strengths of concrete, bar diameters, and combinations of lateral tensions.