预制夹芯墙体中新型复合式连接件受力性能试验研究

Experimental study on mechanical performance of composite connector for prefabricated concrete sandwich panels

为使预制混凝土夹芯墙体的内叶与外叶之间通过连接件具有良好的整体工作性能,针对新型复合式连接件,对其抗拉、抗剪性能开展试验研究,通过15个抗拉试验和12个剪切试验,获得了该连接件的抗拉及抗剪能力、破坏过程与现象,分析了墙体中分布钢筋与连接件位置关系及混凝土强度等级对连接件抗拉性能及剪切性能的影响。结果表明：复合式连接件的受拉破坏形式为混凝土的锥形体破坏,而剪切试验呈现连接件穿心钢筋的弯剪破坏;复合式连接件的抗拉承载力及抗剪承载力与实际工程中连接件所受的拉力及剪力实测值相比,具有较大的安全储备,可在实际工程中应用推广;墙体内分布钢筋与连接件的位置关系对极限承载力大小及破坏现象基本没有影响,但外叶墙中的钢筋网片以及十字形钢筋能够延缓连接件的拔出过程;混凝土强度对连接件的抗拉承载力有显著影响,而对抗剪承载力无影响;最后,基于试验现象及分析,提出了新型复合式连接件抗拉承载力计算方法。

In order to study the cooperative work between inner panel and outer panel for prefabricated concrete sandwich panels,the mechanical performance including tensile performance and shear performance of a new composite connector was investigated through the experiment of 15 tensile specimens and 12 shear specimens. The connector’ s tensile capacity and shear capacity,the tensile and shear failure process of all specimens were obtained. Moreover,the experiments gained the effect rule on mechanical performance of the composite connector from concrete strength and positional relation of the connector and distribution reinforcement. The results from tests and analysis show that the composite connector provides an enough safety reserve for its application in practical engineering. The tensile failure model is cone body damage of concrete and the shear failure model is bending shear failure of the connector’s reinforcing steel bar,both of which are brittle. The relative position of the connector and distribution reinforcement has no influence on the unltimate bear capacity but can delay the connector pulling out from the outer panel. The tensile strength is signifigently effected by concrete strength which has no impact on the shear strength. Finally,the approach of calculating tensile bearing capacity for composite connector is proposed based on experimental phenomena and analysis.