【摘要】 利用四电极法研究了内掺CCCW(水泥基渗透结晶防水材料)的石墨水泥砂浆试样的导电特性及在循环荷载作用下的压敏特性,讨论了材料的体积电阻率随石墨掺量的变化规律及压敏机理,并分析了在不同石墨掺量下试样压敏性能差异产生的原因。试验结果表明:添加CCCW的石墨砂浆试样的体积电阻率随石墨掺量的增加而迅速下降,并存在渗滤现象,渗滤阈值为20%左右。在循环荷载作用下,不同石墨掺量试样的电阻和应力存在一定的对应关系,石墨掺量为水泥质量的50%时,石墨砂浆试样的压敏性最好。更多还原

【Abstract】 CCCW(cementitious capillary crystalline waterproofing materials) involves special chemical substances that can hydrate as moisture permeate through concrete so as to repair cracks.The electrical conductivity and pressure-sensitivity of graphite cement based composites samples(40 mm×40 mm×40 mm) containing CCCW were measured by four-probe method and Instron 5882 system.The variation trend of volume resistivity with graphite contents and pressure sensitivity mechanism were discussed.The experimental results showed that the resistivity of graphite cement based composites containing CCCW versus the concentration of carbon fiber curves had typical features of percolation phenomena.The percolation threshold was 20%(by the weight of cement).The corresponding relationship between stress and resistance existed with different content of graphite,and it came to the conclusion that when the content of graphite was up to the amount of 20% cement,the pressure sensitivity was the best.更多还原