大直径钢筋套筒锚固拉拔性能研究

Research on the Drawing Behavior of Large Diameter Steel Sleeve

研究目的:钢套筒锚接技术广泛应用于加固建筑结构、连接混凝土结构的工程实践中,但是锚筋直径一般小于40 mm。为研究大直径钢筋与钢套筒的锚固性能,本文采用拉拔试验和数值模拟研究不同锚固形式的破坏形式和锚固性能,从而为工程中确定锚固长度、锚固形式及计算锚固力提供依据和方法。研究结论:(1)采用圆钢筋、锥形钢筋试件的破坏形式是钢筋与植筋胶滑移破坏,采用倒锥形钢筋的破坏形式是钢筋的断裂破坏,得到了两种破坏形式下钢筋的应力分布情况;(2)试件钢筋与植筋胶之间滑移破坏前,钢筋已达到屈服强度,表明长度为10D的锚固长度可以提供足够的锚固力使钢筋、植筋胶的强度相匹配;(3)采用内聚力模型模拟钢筋锚固拉拔试验与模型试验的结果相近,验证了模型试验的正确性,同时表明这种模拟方法是可行的,可应用于实际工程,对受力较大的预制混凝土装配式结构具有一定的参考价值。

Research purposes: Steel sleeve anchoring technology is widely used in the engineering of strengthening building structure and connecting concrete structure. However, the diameter of steel bar is generally less than 40 mm.In order to study the anchoring behavior of large diameter steel bar and steel sleeve, the failure modes and anchoring properties of different anchoring forms are studied by pull-out test and numerical simulation method in this paper. It provides the basis and method for determining anchoring length, anchoring form and calculating anchoring force in engineering.Research conclusions :(1) The failure form of tapered steel bar is the slip of steel bar and gluing, and the failure form of inverted cone steel bar is the fracture of steel bar. The stress distribution of steel bar under two kinds of failure forms is obtained.(2) When the steel bar slips between the steel bar and the gluing glue, the yield strength of the steel bar has been reached, indicating that the anchoring length of 10D can provide sufficient anchoring force to match the strength of the reinforcing bar and gluing glue.(3) The results of the cohesion model are similar to those of the model test, and the correctness of the model test is verified. It is also shown that this simulation method is feasible and can be used in practical engineering. It has certain reference value for prefabricated concrete assembly structure.