钢–聚丙烯混杂纤维增强超高性能混凝土单轴循环受压力学性能  

Compressive Mechanical Properties of Steel-polypropylene Hybrid Fiber Reinforced Ultrahigh-Perfromance Concrete under Cyclic Compression

作　　者：池寅[1] 尹从儒 徐礼华[1] 王淑楠 陈子甲 CHI Yin;YIN Congru;XU Lihua;WANG Shunan;CHEN Zijia(School of Civil Engineering,Wuhan University,Wuhan 430070,China)

机构地区：[1]武汉大学土木建筑工程学院,武汉430000

出　　处：《硅酸盐学报》2021年第11期2331-2345,共15页Journal of The Chinese Ceramic Society

基　　金：国家自然科学基金项目(51878519,51738011)。

摘　　要：对钢-聚丙烯混杂纤维超高性能混凝土(SP-UHPC)开展受压力学性能研究,通过单调和循环受压加载试验,分析纤维种类、长径比和体积掺量对SP-UHPC关键力学性能指标的影响,并基于扫描电子显微镜结果揭示钢-聚丙烯混杂纤维增强机理。结果表明:钢-聚丙烯混杂纤维可以显著提高SP-UHPC受压力学性能;与未掺入纤维的UHPC相比,SP-UHPC表现出明显的延性破坏特征,峰值强度、峰值应变和韧性明显提高,刚度退化速率减缓。建立了SP-UHPC单轴循环受压应力-应变关系数学表达式,能够准确预测含有不同纤维特征参数的SP-UHPC在单轴受压条件下的力学响应。Compressive mechanical behavior of the steel-polypropylene hybrid fiber reinforced ultra-high performance concrete(SP-UHPC) with respect to the impacts of fiber types, fiber aspect ratio and volume fraction was investigated. The monotonic and cyclic compression tests were both conducted. Besides, the fiber reinforcing mechanism was analyzed by scanning electron microscopy. The results demonstrate that the inclusion of steel-polypropylene hybrid fiber can enhance the compressive mechanical properties of UHPC. Compared to the UHPC without fiber addition, the SP-UHPC shows a ductile failure mode with improved peak stress, peak strain, toughness and alleviated stiffness degradation process. Based on the experimental data, a constitutive model was proposed for SP-UHPC subjected to cyclic compression, which could be used to predict the mechanical response of the SP-UHPC at various fiber parameters.

关 键 词：超高性能混凝土 混杂纤维 循环受压试验 力学性能 应力-应变关系 

分 类 号：TU528[建筑科学—建筑技术科学]