Bond behavior of steel bar embedded in recycled coarse aggregate concrete under lateral compression load

Steel bars and concrete in practical engineering is served under a complex stress state, the bond behavior of steel bar embedded in concrete, inevitably, was affected by the stress state. So, the center pull out tests were conducted to investigate the bond strength and the bond stress-slip curves of steel bar embedded in recycled coarse aggregate concrete under the action of lateral compression load. For recycled coarse aggregate concrete, the replacement percentage of recycled coarse aggregate to the sum of natural coarse aggregates and recycled coarse aggregates was 30%. The variables of two types of steel bars (deformed steel bars with diameter 14 mm, 18 mm, 22 mm and plain steel bars with diameter 12 mm), four levels of lateral compressive load (0 kN, 200 kN, 320 kN and 450 kN) were considered in the experimental study. The failure modes of center pull out specimen were observed and recorded. Based on the test results, the influences of lateral compressive stress, type of steel bars and diameter of deformed steel bars on the bond behavior of steel bar embedded in recycled aggregate concrete were studied and analysed. It was found that the pull out force and bond strength for deformed steel bar are larger than that for plain steel bar under the same lateral compressive load, the bond strength increases with the increase of lateral compressive load.