采用UHDC的钢筋不接触式搭接节点的受弯试验研究  

Bending Test Research on Non-contact Overlap Joints of Steel Bars Using UHDC

作　　者：邹勇[1,2] 朱宇锋 曹淑上 杨若愚[1] Zou Yong;Zhu Yufeng;Cao Shushang;Yang Ruoyu

机构地区：[1]重庆市建筑科学研究院有限公司,重庆400042 [2]重庆大学土木工程学院,重庆400044 [3]镇江市房屋安全和抗震技术指导中心,江苏镇江212141

出　　处：《重庆建筑》2022年第7期42-46,共5页Chongqing Architecture

摘　　要：UHDC是一种基于断裂力学设计的纤维增强混凝土,在拉伸时具有超高的延性、应变硬化及多裂缝稳定开裂特征。通过采用UHDC连接的预制拼装节点四点弯曲试验,对UHDC连接预制拼装节点的抗弯性能进行研究。与现浇节点相比,预制拼装节点应力与应变水平均较低,裂缝较少且集中在UHDC段及交界面处,基于此提出了试件受弯承载力公式;预制拼装节点的变形能力更强,且UHDC搭接长度越长,变形能力越强,钢筋的应力和应变水平也越高,基于此提出了钢筋利用系数公式。研究表明:UHDC具备良好的预制构件拼接性能,但要达到“等同现浇”的效果,还必须对此类新型节点进行更全面、深入的研究。UHDC is a fiber-reinforced concrete designed based on fracture mechanics,with ultra-high ductility,strain hardening and stable cracking characteristics when stretched.Through the four-point bending test,the bending performance of non-contact steel rebar joints were studied.The test results showed that compared with the cast-in-place joint,the precast joint has lower stress and strain levels,and fewer cracks,which are concentrated in the UHDC zone and the interface.On this basis,the formula to calculate the bending capacity of the specimen was derived.As the UHDC overlapping length is increasing,the strength and deformability of the precast joint is therefore enhanced,as well as the stress and strain levels of the steel bars.Also,the formula for the utilization factor of steel bars was obtained.The test results indicated that UHDC has prefabricated components with remarkable splicing performance,but to achieve"the effects equivalent to cast-in-place",more comprehensive and in-depth research must be carried out on this new type of joint.

关 键 词：超高延性水泥基复合材料(UHDC) 搭接长度 拟静力试验 受弯承载力 延性 

分 类 号：TU528.572[建筑科学—建筑技术科学]