Study on shear resistance of precast concrete sleeve grouting joint with double-interface
In this paper,direct shear tests were conducted on 22 Z-shaped specimens to analyze the shear performance of the concrete-grout-concrete double interface in the grouted sleeve connection of precast components.The failure modes,shear strength,shear stiffness,and shear-slip curve variations of the shear interface were examined.Several parameters such as interface roughness,reinforcement ratio,fullness of sleeve grouting,and grout layer thickness were considered in the tests.It is shown that the double-interface shear cracks start at the bonding interface,develop along the interface regularly and run through the grout layer after cutting the keyway.In the elastic and elastoplastic stages,the shear force is balanced by the cohesion force,the bar friction force and the pin force,and only the bars provide the shear resistance after the cracks penetrates.The ultimate shear and shear stiffness of the double interface are improved by increasing the interface roughness,reinforcement ratio and grouting thickness.The ultimate shear strength,residual shear strength,and shear stiffness are reduced by about 10％,15％and 20％with the absence of 65％sleeve grouting material,respectively.Based on the performance parameters of the characteristic points of the shear-slip curve,a two-interface shear-slip constitutive model was established.The cohesive force and friction coefficient affected by different interface roughnesses were determined.Based on the theory of beams on elastic foundation,the expression of pin force influenced by the thickness of the grout layer was derived.Finally,the calculation formula for double-interface shear bearing capacity under different factors was established,and the calculated results matched well with the experimental data.
万方数据
维普
