预制NC板现浇UHPC接缝的抗弯性能有限元分析研究

Finite Element Analysis Research on Flexural Performance of Prefabricated NC Panels with UHPC Joints

预制拼装混凝土结构已经成为我国最为广泛使用的一种结构形式,但现有的普通混凝土(NC)湿接缝处发生大量病害。其根本原因在于接缝材料的力学性能较差,加之现浇接缝混凝土与原有混凝土界面粘接强度不高,而超高性能混凝土(UHPC)有优异的力学性能且与原有混凝土的界面粘接强度较高。因此,预制拼装混凝土结构中现浇UHPC接缝已被大量应用。目前不同的UHPC接缝构造型式对预制拼装混凝土结构的抗弯性能具体影响研究很少,设计5组常见接缝构造型式,并使用有限元分析软件Abaqus分析不同接缝型式有限元模型的受力特点,与试验结果比较验证。结果表明:有限元分析较好地符合试验结果;不同接缝构造型式的接缝板抗弯拉性能都优于完整NC板,UHPC接缝并未影响模型的力学性能;凿孔、密配筋接缝型式能较大地提高接缝板抗弯拉性能,楔形接缝型式与菱形接缝型式次之,矩形接缝型式效果最差。

Prefabricated concrete structure has become one of the most widely used structural forms in our country,while in normal concrete joints a lot of diseases occurred.The basic reason is that the joint material has bad mechanical properties and poor bond strength with precast normal concrete.Ultra-high performance concrete has excellent mechanical properties and good bond strength with precast normal concrete.Therefore,prefabricated concrete structure with UHPC joint has been widely used.Nowadays there are few researches on flexural performance of prefabricated concrete structure with UHPC joint.This study designed five groups of common joint shapes,and used finite element analysis software Abaqus to analysis their mechanical characteristics in models of different UHPC joint shapes,comparing to the test result.The results indicated that(1)Finite element analysis accorded well with the test result;(2)No matter what joint shape was,the flexural performance of the joint panels was better than that of the monolithic NC panel,and UHPC joint didn’t affect panel performance;(3)The joint shape of drilling hole and dense reinforcement greatly improved flexural performance of the jointed panels,the joint shape of cuniform and diamond took the second place,while the joint shape of rectangular was the worst.