（1 江苏大学土木工程与力学学院， 镇江 212013；  2 河海大学土木与交通学院， 南京 210098;3 盐城工学院土木工程学院， 盐城 224051）

［摘要］通过对单掺和复掺碳酸钙晶须及PVA纤维的高性能细骨料混凝土分别进行抗压、抗折和劈拉试验，研究不同尺度纤维对高性能细骨料混凝土力学性能的影响，并采用扫描电镜对纤维混凝土微观结构进行观测，分析纤维对混凝土性能的影响机理。结果表明，掺入适量碳酸钙晶须或PVA纤维均可提高细骨料混凝土的力学性能，但提高幅度不同； 单掺PVA纤维混凝土强度提高较明显，其抗压、抗折和劈拉强度提高可达11%，20%和35%。碳酸钙晶须和PVA纤维混掺后可进一步改善混凝土的力学性能，混凝土抗压、抗折和劈拉强度的提高幅度分别增至14%，44%和48%。微观结构观测结果显示，碳酸钙晶须和PVA两种纤维可在不同尺度上发挥对混凝土的增强作用。

［关键词］复合增强； 高性能细骨料混凝土； 力学性能； 碳酸钙晶须； PVA纤维

中图分类号：TU528-572文献标识码：A文章编号：1002-848X(2020)22-0077-06

Experimental study on mechanical properties of high-performance fine aggregate concrete composite reinforced by fiber at different scales

ZHANG Zheng1, ZHANG Qin2, LIU Ronghao1, XUN Yong1,3

（1 Faculty of Civil Engineering and Mechanics, Jiangsu University, Zhenjiang 212013, China;2 College of Civil and Transportation Engineering, Hohai University, Nanjing 210098, China;3 School of Civil Engineering, Yancheng Institute of Technology, Yancheng 224051, China)

Abstract:The compressive, flexural and split tensile tests were conducted respectively on high-performance fine aggregate concrete  with single mixing and compound mixing calcium carbonate whisker and PVA fiber to study the influences of fiber at different scales  on mechanical properties of high-performance fine aggregate concrete. The microstructure of fiber reinforced concrete was observed by scanning electron microscope, and the influence mechanism of fiber on concrete performance was analyzed. The results show that the mechanical properties of fine aggregate concrete can be improved by adding calcium carbonate whisker or PVA fiber, but the improvement range is different; the strength of concrete mixed with PVA fiber increases obviously, and its compressive, flexural and split tensile strength increase up to 11%, 20% and 35% respectively. The mechanical properties of concrete can be further improved by mixing calcium carbonate whisker and PVA fiber, and the compressive, flexure and split tensile strength of concrete can be increased to 14%, 44% and 48% respectively. The microstructure observation results show that calcium carbonate whisker and PVA fiber could enhance concrete at different scales.

Keywords:composite reinforcement; high-performance fine aggregate concrete; mechanical property; calcium carbonate whisker; PVA fiber

*国家自然科学基金资助项目（51508154），江苏省自然科学基金资助项目（BK20150803），中国博士后科学基金面上项目（2015M581711），住房和城乡建设部科技项目（2015K4012），江苏省建设系统科技项目（2014ZD08）。

作者简介：张正，硕士研究生，Email:2653874556@qq.com；通信作者：张勤,博士，副教授，Email:zhangqin8190@163.com。