Experimental study on mechanical anchoring performance of steel bars with enlarged sleeves

steel bars with enlarged sleeves;  mechanical anchoring;  anchorage strength;  Experimental studies

The extraction test of 36 hot-rolled ribbed steel bars and concrete bonding specimens using the anchoring form of enlarged sleeve was carried out, and the main parameters were concrete strength, steel bar diameter, anchoring length, protective layer thickness, transverse reinforcement ratio and enlarged sleeve size. The bonding anchorage strength, failure form and main factors affecting the bonding and anchoring performance of ribbed steel bars and concrete using this mechanical anchoring method are systematically analyzed. The experimental results show that this anchoring method can significantly improve the ultimate bonding anchoring strength of ribbed steel bar and concrete, reduce the amount of bonding slip, and effectively reduce the anchorage length. Finally, on the basis of statistical regression, the calculation formula of the bonding strength of the steel bar with enlarged sleeve is given, which provides a reference for the inclusion of mechanical anchoring method in the further revision of the design code of concrete structure in China.