摘要
采用四电极法研究了内掺水泥基渗透结晶防水材料(CCCW)的石墨水泥基复合材料(GCC)的压敏性.结果表明,电阻率随石墨掺量的变化呈现渗流特征,渗流阈值为20%.渗流区和超过渗流区的GCC的电阻率具有明显的压力依赖性.石墨掺量为水泥质量分数20%和50%的试样,在压应力幅值6.25 MPa循环荷载作用下的应变灵敏度系数(单位应变的电阻变化率)分别约为37和22,远高于电阻应变片的2.
The piezoresistivity of graphite cement-matrix composites（GCC）with graphite powder contents and CCCW（cementitious capillary crystalline waterproofing materials,4% mass fraction of cement） were studied by four-probe method.The results show that the resistivity of GCC containing CCCW versus the concentration of graphite curve had typical features of percolation phenomena.The percolation threshold was 20 %（mass fraction of cement）.A clear piezo-resistive effect of electrical resistance dependence on uniaxial compression deformation was observed in composites with 20% and 50%（mass fraction of cement） of graphite powder,indicating that this type of smart composites is a promising candidate for strain sensing.The measured gage factor（defined as the fractional change in resistance per unit strain） of cement-based composites with graphite content of 20 % and 50 %（mass fraction of cement）under 6.25 MPa compressive stress cyclic loading are 37 and 22 respectively,which are higher than gage factor 2 of resistance-strain gauge.
出处
《华中科技大学学报（自然科学版）》
EI
CAS
CSCD
北大核心
2010年第2期72-75,共4页
Journal of Huazhong University of Science and Technology(Natural Science Edition)
基金
国家自然科学基金资助项目(50878170
10672128)
关键词
石墨水泥基复合材料
水泥基渗透结晶防水材料
电阻率
压敏性
四电极法
graphite cement-based composites cementitious capillary crystalline waterproofing materials electrical resistivity piezoresistivity four-probe method
