高强箍筋约束高强混凝土本构模型研究  

Study on the constitutive model of high-strength concrete confined by high-strength stirrups

作　　者：杨坤[1] 史庆轩[2] 赵均海[1] 姜维山[2] 孟和[3] 

机构地区：[1]长安大学,陕西西安710061 [2]西安建筑科技大学,陕西西安710055 [3]西安工业大学,陕西西安710032

出　　处：《土木工程学报》2013年第1期34-41,共8页China Civil Engineering Journal

基　　金：国家自然科学基金(51178380;50978215);教育部高等学校博士学科点专项科研基金(20116120110004);中央高校基本科研业务费专项资金(CHD2010JC120)

摘　　要：通过31根高强箍筋约束高强混凝土棱柱体试件的轴心受压试验,对约束高强混凝土的应力-应变本构关系进行了研究。结果表明,采用高强箍筋约束是防止高强混凝土应力-应变曲线陡然下降的有效措施;箍筋间距较小、强度较高、形式较复杂的约束混凝土试件,具有较高的箍筋侧向约束力,其应力-应变曲线的下降段较为平缓,显示出良好的延性性能;对于高强箍筋约束高强混凝土试件,当其达到峰值强度时,高强箍筋不一定屈服,即取箍筋屈服强度计算有可能高估约束混凝土峰值强度的提高程度。在试验的基础上,提出一种计算约束混凝土达到峰值强度时相应高强箍筋应力大小的迭代方法;通过对试验结果的回归分析,得到高强箍筋约束高强混凝土峰值强度、峰值应变及极限应变的计算公式;提出一种适合于高强箍筋约束高强混凝土轴心受压的应力-应变关系本构模型,并结合试验结果与国内外几种典型本构模型进行对比,结果表明该模型与试验曲线吻合较好。Based on the axial compression tests of 31 high-strength concrete cylinders confined by high-strength stirrups, the stress-strain constitutive model for the confined high-strength concrete （HSC） was studied. The results show that using high-strength stirrups is an effective measure to prevent the stress-strain curve from descending sharply; the columns with closely spaced, high-strength and complex constraint may lead to a higher confinement as well as a smooth stress-strain curve, and also lead to a higher load-carrying capacity and ductility improvement; For the high-strength concrete columns confined by high-strength stirrups, the stirrup may not yield at the peak strength, indicating that using the yield strength of stirrups in calculation may overestimate the peak strength of cot,fined concrete. Based on the test results, an iterative procedure for calculating the stress in the transverse reinforcement at the peak strength was given, and the formulas for peak strength, peak strain and ultimate strain were derived from a regression analysis. Additionally, a stress-strain constitutive model, applicable to the high-strength concrete confined by high-strength stirrups, was proposed. Compared to other typical models, the new model may lead to better agreement with the stress-strain curves obtained experimentally.

关 键 词：高强箍筋 高强混凝土 约束混凝土 延性 本构模型 

分 类 号：TU375.4[建筑科学—结构工程]