500 MPa级钢筋套筒灌浆连接力学性能研究

Study on the Mechanical Properties of Grouted Sleeve Connection With 500 MPa Rebar

套筒灌浆连接是装配式混凝土结构中预制构件的主要连接方式之一,并向着高强钢筋的方向发展。文中基于500 MPa级钢筋,设计了4个不同钢筋强度、锚固长度、灌浆料强度的套筒灌浆试件,进行单向拉伸试验研究,以明确各试件的破坏模式、荷载-位移曲线等。结果表明,增大灌浆料强度可减少灌浆料内部裂缝,并增强钢筋与灌浆料的黏结,降低二者之间的滑移;将钢筋锚固长度由6 d增大至8 d,能显著提升钢筋的机械咬合力,减少残余变形。另外,建议锚固长度至少为8 d,并匹配使用120 MPa高强灌浆料,以充分发挥其极限承载力。

Sleeve grouting connection technology is one of the main connection methods in the prefabricated concrete structures,which is developing towards to the high-strength steel bars.In this paper,four grouted sleeve connections with different rebar strengths,anchorage lengths,and grout material strengths are designed and analyzed which are based on 500 MPa grade rebars,so the failure modes and load-displacement curves of the specimens can be obtained.The results show that increasing the grout strength can reduce the internal concrete cracks and enhance the adhesion force between the rebar and grouting material.The mechanical interlocking of the rebar and steel grouting material can be also improved by increasing the anchorage length of rebar from 6 d to 8 d,while the residual deformation of the sleeve grouting connection will be effectively decreased.In addition,the 120 MPa grouting materials and anchorage length of 8 d are recommended to use in the 500 MPa rebar grouted sleeve connection.