Experimental study on bond behavior for ribbed steel bars and grout

Abstract:

To provide theoretical data for the grout used in prefabricated structures and reinforcement reconstruction field. Pull-out tests were conducted on 27 specimens having grout with ribbed reinforced bars, and the failure mode and the variation of bond strength were studied. According to a typical bond-slip curve, the cracking, crushing and shearing process were analyzed. Based on the experimental data, the bond strength formula, the slip formula and the bond-slip formula were fitted. The empirical value of anchorage length of reinforcement in grout was presented. The result shows that the average bond strength increases with the increase of the cover thickness. While thickening the cover thickness, the increasing rate of bond strength is lower than that of concrete. In addition, increasing the bar diameter, the average bond strength decreases. Further-more, with the increase of the anchorage length, average bond strength decreases. The increase of anchorage length results in higher increment rate of the bond strength of grout compared to the self-compacting concrete. With the same compressive strength grade, the bond strength of grout is higher than that of ordinary concrete. In conclusion, the bond-slip behavior between ribbed steel bar and grout is different from that of concrete.