Experimental and Numerical Study of Grout Effectiveness and Force-Transfer Mechanism in Socket Connections
Zeng Zeng, Zhigang Wang, Zhiqiang Wang, Yan Xu
Abstract
This study aims to investigate the effectiveness of grout and the mechanism of force transfer in socket connections. In doing so, it proposes a new transfer mode called integral transfer mode (ITM), as opposed to the conventional separate transfer mode (STM). The proposed ITM suggests that, in a reinforced concrete socket connection, if there is a strong bond between the column, grouting material, and receiving member, the socket connection will function as an integral structure, deforming together as a whole rather than as separate components. Consequently, the grouting material does not need to provide a significant lateral bearing force, and the interface shear stresses become the key focus in designing a socket connection. To explore this concept, quasi-static tests and numerical analyses using solid elements were conducted on three half-scale specimens with varying grout strengths. The results demonstrated that the performance of specimens with normal-strength grout was comparable to that of the specimen with high-strength grout. And the proposed ITM was better than STM at predicting failure modes, force–displacement relationships, the stress states of reinforcements, and grout stresses.