(1 扬州大学建筑科学与工程学院,扬州 225127;2 江苏邗建集团有限公司,扬州 225127)

摘要: 为研究预应力、弦杆及腹杆配钢率对预制预应力桁架式钢骨混凝土梁正截面受弯性能的影响,设计制作了6 根预制预应力桁架式钢骨混凝土梁和 1 根非预应力桁架式钢骨混凝土梁进行静力受弯性能试验,研究试件的开裂荷载、极限荷载、裂缝形态及其发展规律、破坏形态等.结果表明:下部受拉区角钢屈服后,试件挠度不断增大,最终受压区混凝土压碎,呈典型的适筋破坏形态;预应力筋的配置对试件的开裂荷载有明显的提高作用;试件正截面抗弯承载力随钢骨桁架弦杆角钢截面尺寸的增大而明显提高.推导了预制预应力桁架式钢骨混凝土梁的短期刚度以及正截面抗弯承载力计算公式,与试验结果较为吻合,可供工程实际参考.

关键词: 预制预应力桁架式钢骨混凝土梁;预应力筋;受弯性能;短期刚度;抗弯承载力

中图分类号:TU375.1 文献标志码:A 文章编号:1002-848X(2022)18-0078-08

DOI:10.19701 / j.jzjg.LS202044

Experimental study on flexural behavior of precast prestressed steel-truss-reinforced concrete beams

LIU Jiaqi1,CAO Dafu1,GE Wenjie1,WANG Jiajun2

(1 College of Civil Science and Engineering,Yangzhou University,Yangzhou 225127,China;2 Jiangsu Hanjian Group Co. ,Ltd. ,Yangzhou 225127,China)

Abstract: In order to study the influence of prestress,the chord and steel distribution ratio of web rod on the flexuralbehavior of precast prestressed steel-truss-reinforced concrete (STRC) beam,six precast prestressed STRC beams and onenormal STRC beams were designed and fabricated to conduct static flexural behavior tests. The cracking load,ultimateload,crack morphology,development law and failure mode of the specimens were studied. The results show that thedeflection of lower chord angle steel increases continuously after yield,and concrete is crushed in the compression zone,and finally the concrete in the compression zone is crushed,showing a typical failure mode of reinforcement. Theconfiguration of prestressing reinforcement can significantly improve the cracking load of specimens. The flexural bearingcapacity of the normal section of the specimen increases significantly with the increase of the section size of the steel trusschord angle. The short-term stiffness of precast prestressed STRC beams and the formulas for calculating the flexuralbearing capacity of the normal section were deduced,which are in good agreement with the test results and can be used forpractical engineering reference.

Keywords: precast prestressed steel-truss-reinforced concrete beam;prestressing reinforcement;flexural behavior;short-term stiffness;flexural bearing capacity

∗国家自然科学基金资助项目(51578478、51678514),江苏省自然科学基金面上项目( SBK2020020197),中国博士后基金面上项目(2018M642335),江苏省住建厅建设系统科技项目(2018ZD047),江苏高校“青蓝工程”资助项目(中青年学术带头人,苏教师函〔2020〕10 号).

第一作者:刘嘉琪,博士研究生,主要从事结构工程研究,Email:1090934386@ qq. com.

[引用本文] 刘嘉琪,曹大富,葛文杰,等. 预制预应力桁架式钢骨混凝土梁受弯性能试验研究[ J]. 建筑结构,2022,52 ( 18): 78-85. LIU Jiaqi,CAO Dafu,GE Wenjie,et al. Experimental study on flexural behavior of precastprestressed steel-truss-reinforced concrete beams[J]. Building Structure,2022,52(18):78-85.