（北京工业大学城市与工程安全减灾教育部重点实验室， 北京 100124）

［摘要］为研究半预制HRB600级钢筋钢纤维高强混凝土梁（简称半预制梁）的受弯性能，设计了5根半预制梁进行了三分点单调加载试验，分析了预制外壳混凝土强度、钢纤维掺量以及键槽间距等因素对半预制梁承载力、挠度、裂缝发展变化规律的影响，并与现浇HRB600级钢筋高强混凝土梁（简称现浇梁）进行了比较。结果表明，半预制梁与现浇梁表现出相同的受力特点和变形特征；预制外壳加入钢纤维可提高试验梁的开裂荷载，改善延性，减小裂缝宽度；提高预制外壳混凝土强度可提高试验梁的极限承载力；设置键槽，可提高梁的极限承载力，延缓刚度退化，改善延性；设置键槽的半预制梁在受弯荷载下的承载力、裂缝宽度、挠度可按《纤维混凝土结构技术规程》（CECS 38∶2004） 计算。

［关键词］半预制；钢纤维； 高强混凝土；受弯性能；键槽

中图分类号：TU375-1文献标识码：A文章编号：1002-848X(2021)05-0048-06

Experimental study on flexural behavior of semi-precast steel fiber reinforced high-strength concrete beams with HRB600 steel bars

ZHANG Jianwei, LIU Jiao, CAI Ruxing, ZHANG Deli

（Key Laboratory of Urban and Engineering Security Disaster of China Ministry of Education, Beijing University of Technology, Beijing 100124, China）

Abstract:In order to study the flexural behavior of semi-precast steel fiber reinforced high-strength concrete beams with HRB600 steel bars(semi-precast beams), five semi-precast beams were designed and the three-point monotonic load test were carried out. The effects of precast shell concrete strength, steel fiber content and keyway spacing on the bearing capacity, deflection and crack development of semi-precast beams were analyzed, and the test results were compared with cast-in-place high-strength concrete beams with HRB600 steel bars (cast-in-place beams). The results show that the semi-precast beams exhibite the same mechanical performance and deformation characteristics as the cast-in-place beams; the addition of steel fiber  to the prefabricated shell can  increase the cracking load of test beams, improve ductility and reduce cracks width; the increasing of strength of precast shell concrete can improv the ultimate bearing capacity of test beams; the setting of keyway can improve the ultimate bearing capacity, slow the stiffness degradation, and imprve the ductility of the beam; the bearing capacity, crack width and deflection of semi-precast beams with keyways under bending load can be calculated according to Technical specification for fiber reinforced concrete(CECS 38∶2004).

Keywords:simi-precast;steel fiber; high-strength concrete;flexural performance;monotonic load test; keyway

*国家自然科学基金项目资助（51678009），北京市教委科技重点项目资助（KZ201710005003）。

作者简介：张建伟，博士，教授，博士生导师，Email: zhangjw@bjut.edu.cn。