Experimental Study and In-depth Tensile Mechanism Analysis of Grouted Sleeve Lapping Conectors

Qiong Yu,Liang Zhang,Ling-Zhi Li,Xingkui Zhang,Baoxiu Fan,Zhenhai Chen,Peiyan Tang,Zhi Zhang

doi:10.1590/1679-78256935

Abstract

To study the failure modes, bearing capacity, ductility, and sleeve strain of grouted sleeve lapping connectors, 36 specimens were tested under uniaxial tensile load. The test results show that the sleeves are under longitudinal tension at the beginning, which changes to longitudinal compression in the late stage of loading, and the changing load increases gradually with the lap length. The force transmission path and mechanical mechanism of the connectors are analyzed. The distribution and development process of longitudinal sleeve stress is analyzed based on the constitutive model stress, and it is found that the sleeve changes from longitudinal tension to longitudinal compression at the late loading stage, which is consistent with the test results. Based on the test, the calculation formulas of the ultimate bond strength and critical lap length of the grouted sleeve lapping connector are proposed. The research results lay a theoretical foundation for the application of grouted sleeve lapping connectors.

Highlights

Steel bar pull-out failure occurred for specimens with lap length L of 8d, and most with lap length 10d, but unlike specimens with L = 6d, the steel bar would yield and strengthen before the specimen reached the ultimate state of bearing capacity
When the steel bar diameter remains the same and slip failure occurs, the bearing capacity of the specimen increases with the lap length
When the diameter of the steel bar remains the same, when slip failure occurs, the bearing capacity of the specimen increases with the lap length

Summary

Introduction

Cast-in-situ reinforced concrete is the most common method of construction for structural systems. The connection between precast components plays a decisive role in whether a precast structure can perform its prescribed function. Ever since their invention by Alfred A. Yee (1968) in the late 1960s, grout-filled sleeves have been used to splice the reinforcing bars of adjacent components (Ling et al, 2008a; Ling et al, 2008b; Sayadi et al, 2014; Ling et al, 2014; Ameli et al, 2015; Popa et al, 2015; Lin and Wu, 2016; Wang et al, 2018; Liu et al, 2018; Xu et al, 2019; Lu et al, 2017). A grouted spliced sleeve, as shown, is pre-embedded in one component around the rebar requiring connection during fabrication.

Methods

Results

Conclusion