采用直流四端电极法测试炭纤维水泥基材料在不同烘干和泡水时问的电阻率,研究了炭纤维水泥基材料内部含水量对其电阻率的影响。结果表明:炭纤维水泥基材料的电阻率随烘干时间的增加而减少,随泡水时间的增加而增加。炭纤维水泥基材料的电阻率对材料内部含水量的变化较敏感:在温度为20℃、相对湿度为25%的情况下,烘干6d,电阻率变化率约为25%;而在温度为20℃的情况下,泡水4.5h,电阻率变化率约为100%。亦即炭纤维水泥基材料具有良好的湿敏性。
The electrical resistivity of cements with additions of carbon fibers or carbon black (CACs) at different drying times and soaking times was measured by a direct-current four-pole method. The influence of water content in the CACs on their electrical resistivity was studied. It was found that the electrical resistivity of the CACs decreases with drying time and increases with soaking time. The electrical resistivity of CACs is sensitive to the change of their inner water content and they have a good humidity sensing property.