偏高岭土对SHCC力学性能的影响研究

关键字：偏高岭土,SHCC,力学性能,影响,研究

（1.武汉理工大学 理学院 工程结构与力学系，湖北 武汉  430070；
2.武汉理工大学 硅酸盐建筑材料国家重点实验室，湖北 武汉  430070）

    摘要：用偏高岭土（MK）取代0、5%、10%、15%水泥的配制应变硬化水泥基复合材料（SHCC），以研究MK对SHCC基本力学性能的影响。结果表明，MK作为掺合料能使SHCC的初裂强度、极限拉伸强度、极限拉伸应变、弹性模量和抗压强度等有不同程度的提高，较佳的MK掺量为10%。掺入适量的MK能改善SHCC的多缝开裂特性，细裂纹（宽度为几十微米）数量增加，裂纹平均宽度降低。MK的掺入还能改善PVA纤维与水泥基体的界面粘结性能，界面粘结强度得到提高。
    关键词：偏高岭土；SHCC；拉伸性能；单丝拔出
    中图分类号：TU528.041        文献标识码：A        文章编号：1001-702X（2017）10-0004-04

Investigation of mechanical properties of SHCC incorporating metakaolin  
LIU Zhengchao1，WANG Yingjun1，WEI Yunpang1，SUN Mingqing1，SHUI Zhonghe2
（1.Department of Engineering Structures and Mechanics，School of Science，Wuhan University of Technology，Wuhan 430070，China；
2.State Key Laboratory of Silicate Materials for Architectures，Wuhan University of Technology，Wuhan 430070，China）

Abstract：Strain hardening cement-based composites（SHCC） is prepared using metakaolin（MK） to replace cement with re-
placement rates such as 0，5%，10% and 15%，respectively. The influence of MK on the basic mechanical properties of SHCC is investigated. Results show that the MK as admixture can obviously improve the mechanical properties of SHCC，namely，initial crack strength，ultimate tensile strength，ultimate tensile strain，elastic modulus and compressive strength of SHCC has been improved with different degrees，and the optimal dosage of MK is 10%. The addition of MK induces the improvement of the number of fine crack（the width of crack is tens microns） and decreasing of the average width of crack. MK can also improve the interfacial bonding properties of PVA fiber and cement matrix，and the interface bond strength improved.
    Key words：metakaolin，SHCC，tensile properties，monofil pull-out