Bond Slip of High Relative Rib Area Bars under Cyclic Loading

The load-slip behavior of high relative rib area and conventional reinforcing bars subjected to reversed cyclic loading is compared. No. 8 (No. 25) production reinforcing bars with relative rib areas of 0.119 and 0.085 are subjected to reversed tension-tension cyclic loading to evaluate the effect of relative rib area on slip and bond deterioration. The tests demonstrate that the high relative rib area bars exhibit 50 to 70% less unloaded end slip, and 30 to 40% less loaded end slip than the conventional bars under multiple cycles of loading. The results suggest that high relative rib area bars could be used to improve the behavior of reinforced concrete members and frame joints that are affected by bond deterioration, such as caused by seismic loading.