高温对混掺碳-塑纤维水泥基复合材料强度及温敏性的影响  

Effect of high temperature on strength and temperature sensitivity of carbon-plastic fiber cement-based composites

作　　者：石丽娜 杜红秀[1] SHI Lina;DU Hongxiu(School of Civil Engineering,Taiyuan University of Technology,Taiyuan 030024,China)

机构地区：[1]太原理工大学土木工程学院,山西太原030024

出　　处：《混凝土》2021年第5期32-35,共4页Concrete

基　　金：国家自然科学基金资助项目(51278325);山西省研究生教育创新计划项目(2019SY173)。

摘　　要：碳纤维水泥基复合材料具有高强度及机敏性能,为研究高温对不同碳纤维掺量水泥基复合材料强度及温敏性的影响,并避免试件高温爆裂,对混掺碳纤维、聚丙烯纤维水泥基复合材料模拟高温试验,观察试件外观变化,进行质量损失率、强度、电阻率测试。试验结果表明:水泥基复合材料质量损失率随温度升高呈增大趋势,300℃时最大,混掺纤维试件质量损失率高于素水泥基复合材料;25~300℃,水泥基复合材料强度随作用温度升高明显增大,400℃高温后强度呈现下降趋势;碳纤维的掺加可提高抗折强度,而抗压强度略微降低,碳纤维体积掺量为0.4%时,抗折强度最大;混掺纤维水泥基复合材料电阻率在临界转变温度前呈现先急剧下降后缓慢下降、之后呈现先缓慢上升后急剧上升的规律,有良好的温敏性。Carbon fiber cement-based composites have high strength and alertness.In order to study the influence of high temperature on the strength and temperature sensitivity of cement-based composites with different carbon fiber content and avoid the high temperature cracking of the specimens,the high temperature test was simulated for cement-based composites mixed with carbon fiber and polypropylene fiber to observe the appearance change of the specimens,the mass loss rate,strength and resistivity were tested.The test results show that the mass loss rate of cement-based composites increases with the increase of temperature,and reaches the maximum at 300℃.The mass loss rate of specimens mixed with fiber is higher than plain cement-based composites.At 25~300℃,the strength increases obviously with the increase of temperature,and decreases after the high temperature of 400℃.The flexural strength can be improved by adding carbon fiber,but the compressive strength decreases slightly.The flexural strength is the largest when the volume content of carbon fiber is 0.4%.The resistivity of cement-based composite mixed with fiber shows the rule of first sharp decline and then slow decline before the critical transition temperature,then slow rise and then sharp rise,and has good temperature sensitivity.

关 键 词：纤维混凝土 高温 强度 温敏性 

分 类 号：TU528.572[建筑科学—建筑技术科学]