预制装配式混凝土框架高效延性节点试验研究

Experimental study on high ductile joints for precast RC frame

介绍国内外关于装配式混凝土框架延性节点的研究成果,在此基础上,设计一种新型装配式混凝土框架高效延性节点并开展足尺试验研究。试验包括3个装配式节点和1个现浇对比节点,采用低周反复加载方法。试验结果表明:装配式高效延性节点的承载力高于现浇对比节点;在节点核心区预埋低屈服高延性连杆并通过中间翼缘有效锚固后,节点正负向加载位移延性系数比现浇对比节点有大幅提高,延性性能明显改善;在整个加载过程中,连杆首先屈服并发生充分的塑性变形,梁柱基本保持弹性状态,达到延性连接设计目的;加载后期节点核芯区剪切变形增大,有限元分析表明节点核芯区箍筋加密后可有效抵抗剪切变形。最后,结合本文研究成果对相关装配式延性节点的抗震性能作总结分析。

The research results from home and abroad about ductile joints for precast RC frame were introduced. Based on these previous researches, one new type of high ductile joints for precast RC frame was designed. The specimens including three precast joints and one monolithic joint were all full-scale and were tested by low reversed cyclic loading. Test results indicate that the load-beating capacity of the high ductile precast joint was greater than that of the monolithic one; after the low yield and high ductile rods were embedded and anchored by the middle flanges in the core area, the displacement ductility coefficients of the pecast joint corresponding to both the positive loading and the negative loading were increased greatly, and therefore the ductility behavior of the precast joint was improved obviously; during the whole loading, the rods were yielded first and then generated full plastic deformation, but both the prefabricated beams and the prefabricated column were kept in the elasticity state, which proved that the ductile connection design was attained; the ultimate shear deformation of the core area was increased, but the analysis by FEM indicated that the shear deformation could be resisted efficiently by reducing stirrup spacing in the core area. Finally, combined with the research of this paper, the seismic behaviors of the related type of ductile precast joints were summarized.