Analysis and Experimental Study on Mechanical Properties of Large-Diameter Grouted Sleeve Connections

The mechanical properties of a connection are essential for the structural performance of a prefabricated bridge pier because the connection is located in the weakest part of the pier structure. Among different types of connections, a large-diameter grouted sleeve connection with a connection bar of 40 mm diameter has been widely exploited in recent years. However, past experimental researches and the latest corresponding industrial standards barely pay much attention to the mechanical properties of this large-diameter grouted sleeve connection. Therefore, a series of experiments and numerical simulations were conducted to address the critical issue. First, the static tension tests were carried out on fabricated specimens considering the eccentricity of the bar, and then the internal conditions of the sleeve were detected using industrial computed tomography. Experiment-based tests showed that the bearing capacity of all connections exceeds the standard value of the tensile strength of connection bars and mainly depends on the bearing capacity of connection bars. The eccentricity of the bar could increase the local stress of the sleeve, which must be addressed during the design and construction progress. The inner bonding interface between the bar and the grouting material was destroyed when the bar was fractured or pulled out. Moreover, the results of experiments and numerical simulations revealed that some geometry-related parameters about the sleeve and the bar could be properly optimized for further design. The sleeve design parameters considering the eccentricity of the bar was recommended as 1.27, and a new sleeve structure with variable thickness was proposed.