LOSS OF CONCRETE-STEEL BOND STRENGTH UNDER MONOTONIC AND CYCLIC LOADING OF LIGHTWEIGHT AND ORDINARY CONCRETES*

Abstract – In this study, loss of concrete-steel bond strength of lightweight and ordinary concrete under monotonic and cyclic loading is examined for plain and deformed steel bars. Here, lightweight and ordinary concrete-steel bond strength is determined by pull-out test for a variety of specimens in various configurations. For each specimen, a bond strength-slip curve is obtained through monotonic loading. Following this process, an identical specimen is subjected to cyclic loading under similar conditions using the same test setup. These examinations reveal several insights. Lightweight concrete-steel bond strength is greater than the ordinary concrete-steel bond strength for plain steel bars under monotonic loading. Ordinary concrete-steel bond strength is greater than lightweight concrete-steel bond strength under both monotonic and cyclic loading for deformed steel bars. The loss of concrete-steel bond strength is greater in plain bars than in deformed bars