Mechanical properties of half grouted sleeve connections with insufficient grouting and bar eccentricity defects

For the structural integrity of precast concrete structures, the connections between concrete members are of utmost importance. In order to investigate the effects of insufficient grouting and rebar eccentricity defects on the structural performance of semi-grouted sleeve connections (HGSCs), 27 semi-grouted carbon steel sleeve specimens were designed and fabricated in this study. The test results showed that the coupling effect of insufficient grouting and eccentricity of the spliced reinforcement reduced the bond performance of the HGSC, changed the damage mode of the HGSC, and made the bond-slip damage more likely to occur. In addition, the coupling effect reduced the load resistance of the HGSC more significantly than the independent defects of rebar eccentricity and insufficient grout, and the impact of the coupling effect on the strength degradation became more pronounced as the grout fullness decreased. Moreover, a database of bond-slip failures of sleeve connections was established based on bond-slip failure test data for the 195 existing sleeve connections. Existing models for calculating the load-carrying capacity of grouted splice sleeve connections (GSSCs) were applied to the database for comparison. Ultimately, through a comprehensive regression analysis of the existing models, a more accurate analysis model for the load-carrying capacity of GSSCs was proposed. Based on the prediction model, a new method is proposed to avoid bond-slip failure of GSSCs.