碳纤维/ 水泥基复合材料微观结构及机敏特性

以普通硅酸盐水泥为基体材料, 以碳纤维为功能组分, 采用压力成型法制备了碳纤维增强水泥基复合材料(CFRC) 。用SEM 和孔结构分析仪对复合材料的微观结构进行了分析, 同时研究了其机敏特性。结果表明:较大成型压力制备的复合材料孔隙率明显低于较小成型压力制备的复合材料。不同成型压力制备的复合材料电阻率均随温度升高而呈先增大后减小的趋势。较小成型压力制备的CFRC , 其临界温度为75～100 ℃; 较大成型压力制备的CFRC , 其临界温度为100～120 ℃。循环载荷下, 碳纤维水泥基复合材料电阻的相对变化与载荷之间呈现明显的一一对应关系, 较大成型压力制备的CFRC 在每个循环过程中电阻相对变化的幅度明显大于较小成型压力制备的CFRC , 更适合应用于结构的实时、动态的健康监测和损伤评估。

Microcosmic and smart properties of carbon f iber cement-based composites

Portland cement and carbon fiber were used to fabricate carbon fiber reinforced cement-based composites(CFRC) by compressing. The microcosmic properties were analyzed by SEM and Poremaster Analyzer , and thesmart properties were also studied. The result s show that the porosities of the specimens formed under larger pressures are obviously lower than those of the specimens formed under smaller pressures. With the temperatureincreasing , the resistivities of the composites formed under different pressures show the t rend of increase anddecrease. The critical temperature zones of the specimens formed under the smaller and the larger pressures arebetween 75～100 ℃and 100～120 ℃, respectively. Under the low cyclic load , the f ractional change in resistivity ofCFRC changes reversibly with the cyclic load. The amplitude of the f ractional change in resistance of the compositesformed under the larger pressure is obviously larger than that of the composites formed under the smaller pressure ,which is more suitable for the real-time , dynamic and health monitoring and damage assessment of st ructures.