装配式混凝土槽式灌浆连接抗拉性能试验研究

Experimental Study on Tensile Properties of Groove Grouting Connection in Prefabricated Concrete Structures

针对当前装配整体式混凝土结构预制构件之间连接构造复杂、施工精度要求高等问题,提出了一种由预埋C型钢卡槽、带锚头的连接钢筋以及后灌高强砂浆组成装配式混凝土槽式灌浆连接技术。该新型连接利用C型钢卡槽对灌浆料的三向围压,大幅提高带有锚头的连接钢筋的连接性能;对于梁柱节点可将连接区域置于梁柱核心区外的梁端位置,避免了核心区钢筋密集、混凝土浇筑困难等问题;C型钢卡槽内较大空间可有效降低现场安装精度要求,提高施工效率。在此基础上,开展了新型连接节点抗拉性能试验。试验结果表明:由C型灌浆钢卡槽和带锚头的连接钢筋组成的锚固构造性能可靠,试件均为连接区外钢筋被拉断,试件抗拉承载力远大于C型钢卡槽和连接钢筋锚头之间所填灌砂浆的抗压设计值,砂浆三向受压未出现压溃破坏,始终保持良好的传力性能。

Aiming at the problems of complex connection structure and high construction precision between the prefabricated components of the present prefabricated concrete structures,a new method of prefabricated concrete groove grouting consisting of embedded C-shaped steel groove,connecting steel bar with anchor head and post-grouting high-strength mortar connection technology is proposed. This new connection uses the C-shaped steel groove to provide the grouting material three-direction confining pressure and greatly improves the connection performance of the connecting reinforcement with the anchor head. For the beam-column joint,the connection area can be placed at the beam end position,avoid the core area of intensive steel,as well as the concrete pouring difficulties and other issues; C-shaped steel groove within the larger space can effectively reduce the on-site installation accuracy requirements and improve construction efficiency. On this basis,the tensile strength test of the new type connection joint is carried out. The test results show that the anchorage structure consisting of C-grouting steel groove and connecting reinforcement with anchor head is reliable,the test pieces are all pulled away from the connecting zone,and the tensile load capacity of the specimen is much larger than the compressive design value of the mortar filled between the C-shaped groove and connecting reinforcement anchor head,the mortar three-way compression does not appear crushing damage,and always maintains a good force transmission performance.