考虑箍筋约束的630MPa高强钢筋抗压强度发挥水平研究  

Research on the compressive strength of 630 MPa high strength steel bar considering the influence of stirrup constraints

作　　者：田桥罗 王毅红[1] 权登州[1] 张俊旗 TIAN Qiaoluo;WANG Yihong;QUAN Dengzhou;ZHANG Junqi(School of Civil Engineering,Chang an University,710061 Xi'an,China)

机构地区：[1]长安大学建筑工程学院,西安710061

出　　处：《应用力学学报》2024年第5期1042-1051,共10页Chinese Journal of Applied Mechanics

基　　金：国家自然科学基金资助项目(No.42172302);陕西省自然科学基金资助项目(No.2020JM-234);西安市建设科技计划项目(No.SZJJ2019-19)。

摘　　要：在高强钢筋混凝土大偏心受压构件设计计算中纵筋抗压强度发挥水平会影响其抗压强度取值,而现行《混凝土结构设计规范》尚未对此做出明确规定。基于现行规范对630 MPa级高强钢筋混凝土大偏心受压柱的受压纵筋强度发挥水平进行了理论分析;同时设计制作了8个630 MPa级高强钢筋混凝土大偏心受压柱试件,开展单调等偏心距加载试验测得混凝土构件表面应变和高强纵筋应变,研究高强钢筋混凝土大偏心受压构件中受压纵筋实际强度发挥水平;对比分析理论计算结果与试验研究结果的差异及其产生原因,最终提出了采用箍筋约束混凝土本构模型分析高强钢筋混凝土大偏心受压柱受压纵筋强度发挥水平的新思路。研究结果表明:高强受压纵筋在试验中均发生屈服,抗压强度能够充分发挥;构件受压区应变分布仍符合平截面假定,现行规范公式的形式仍满足要求,但混凝土极限压应变的规范取值偏小导致理论计算得到的高强受压纵筋抗压强度发挥水平低;引入箍筋约束混凝土本构模型可较好地反映混凝土大偏心受压构件中高强受压纵筋抗压强度实际发挥水平,基于MANDER模型的高强受压纵筋应变计算值与试验实测值比值的平均值为1.044,标准差为0.148,变异系数为0.142,精度最高、预测结果最优。研究将为高强钢筋纳入现行规范理论分析体系,加快高强钢筋大规模推广应用提供参考和依据。In the design and calculation of high-strength reinforced concrete members with large eccentric compression,the compressive strength of longitudinal bars will affect the value of compressive strength,but the current Code for the Design of Concrete Structures has not made a clear regulation on this.Based on the current code,the strength level of compression longitudinal reinforcement of 630 MPa high strength reinforced concrete column with large eccentric compression is analyzed theoretically.At the same time,eight specimens of 630 MPa high strength reinforced concrete columns with large eccentric compression were designed and manufactured,the surface strain of concrete members and the strain of high-strength longitudinal reinforcement were measured by monotonic equal eccentric loading test,and the actual strength of compressive longitudinal reinforcement in high-strength reinforced concrete members with large eccentric compression was studied.The differences between the theoretical calculation results and the experimental results and their causes are analyzed.The results show that the high-strength compressive longitudinal bars yield in the test,and that the compressive strength can be fully utilized.The strain distribution in the compression area of the member still conforms to the plane section assumption,and the form of the current code formula still meets the requirements.However,the value of the ultimate compressive strain of concrete in the code is too small,which leads to the low level of the compressive strength of the high-strength compressive longitudinal reinforcement calculated theoretically.The introduction of stirrup confined concrete constitutive model can better reflect the actual exertion level of the compressive strength of high-strength compression longitudinal bars in concrete large eccentric compression members.The average value of the ratio of the calculated strain of high-strength compression longitudinal bars based on Mander model to the measured test value is 1.044,the standard deviation

关 键 词：630MPa高强钢筋 抗压强度 混凝土极限压应变 箍筋约束混凝土本构关系 MANDER模型 大偏心受压 

分 类 号：TU375.3[建筑科学—结构工程] TU317