箍筋约束ECC轴心受压性能试验研究  

Experimental study on axial compression performance of ECC confined with stirrups

作　　者：李艳[1] 刘泽军[1] 王伟伟[1] 王焕芳[1] 

机构地区：[1]河南理工大学土木工程学院,河南焦作454003

出　　处：《建筑结构学报》2017年第7期164-173,共10页Journal of Building Structures

基　　金：国家自然科学基金项目(51208183);河南省科技攻关项目(132102310312);河南省高等学校青年骨干教师资助项目(2014GGJS-043);河南省高等学校重点科研项目(17A560005)

摘　　要：为研究箍筋约束工程纤维增强水泥基复合材料(ECC)的受压性能,对12组共36个箍筋约束的配筋ECC圆形截面短柱进行了轴心受压试验,分析了箍筋屈服强度和间距、ECC强度与PVA纤维体积掺量对约束ECC应力-应变曲线的影响。结果表明:试件的破坏形态均为纵筋压屈、核心ECC压碎,由于PVA纤维的桥接作用,提高了柱的整体性,保护层ECC外鼓但并未剥落;提高箍筋屈服强度、减小约束箍筋间距、采用低强度ECC及增加PVA纤维体积掺量,约束ECC应力-应变曲线的下降段较为平缓,短柱的延性得到改善,相对于较强的箍筋约束作用,PVA纤维对约束ECC变形的影响则较小。基于试验结果的分析,提出了考虑有效约束指标与PVA纤维体积掺量的箍筋约束ECC峰值应力及其对应应变计算式,建立了约束ECC应力-应变全曲线方程,计算曲线与实测曲线吻合较好。In order to investigate the compressive performance of ECC confined with stirrups, 12 groups of totally 36 short ECC circular section columns confined with stirrups were tested under axial compressive loading. The influences of stirrup yield strength, stirrup spacing, ECC strength and PVA fiber content by volume on stress-strain curve were analyzed. Test results show that similar failure modes are buckling of longitudial reinforcements and crushing of ECC. Because of bridging effect of PVA fiber, the integrity of specimens increase and ECC covers don ＇ t peel off. If improving stirrup strength, reducing stirrup spacing or ECC strength and increasing PVA fiber content, the descending section of stress-strain curve can become more gentle and the ductility of short columns has been improved. Compared with the stronger effects of stirrups confinement, PVA fiber content has the smaller effects on deformation performance of ECC. Based on test results, the equations for calculating the peak stress and strain of confined ECC are proposed and the stress-strain model is suggested. The comparisons show that theoretical results are in good agreement with experimental results.

关 键 词：圆形截面短柱 纤维增强水泥基复合材料 PVA 箍筋约束 轴心受压试验 应力-应变曲线 

分 类 号：TU525.9[建筑科学—建筑技术科学] TU502