PP纤维及冷却方式对C60 HPC高温损伤红外热像的影响  

Effect of polypropylene fiber and cooling mode on infrared thermal image of C60 HPC exposed to the damage of high temperature

作　　者：张茂林 杜红秀[1] 陈尧 徐瑶瑶 ZHANG Maolin;DU Hongxiu;CHEN Yao;XU Yaoyao(Building Materials and Disaster Prevention and Mitigation Institute,College of Architecture and Civil Engineering,Taiyuan University of Technology,Taiyuan 030024,China)

机构地区：[1]太原理工大学建筑与土木工程学院建筑材料与防灾减灾所

出　　处：《混凝土》2019年第8期43-46,53,共5页Concrete

基　　金：国家自然科学基金资助(51278325);国家自然科学基金资助(51478290)

摘　　要：对聚丙烯(PP)纤维体积掺量为0、0.2%、0.3%(编号为P0、P2、P3)的C60高性能混凝土(简称HPC)进行模拟火灾试验,采用自然冷却和喷水冷却方式分别将试件冷却至常温。利用红外热像仪检测HPC平均温升,测试HPC抗压强度,分析不同冷却方式及PP纤维掺量对经受不同受火温度后的C60 HPC红外温升和抗压强度的影响。结果表明:随受火温度的提高,HPC的红外热像平均温升均呈上升趋势,其中P3红外热像平均温升最大、P0最小,喷水冷却下试件的红外热像平均温升均大于自然冷却的红外热像平均温升;抗压强度总体呈下降趋势,但300℃后自然冷却下的抗压强度有反弹现象,喷水冷却下作用温度小于300℃的混凝土抗压强度下降幅度较小,其中两种冷却方式下,P3抗压强度始终最小,受火温度200、300℃时,P2抗压强度大于P0。作用温度高于300℃后,喷水冷却下试件的抗压强度均小于自然冷却的抗压强度。总体,PP纤维适宜掺量为0.2%,喷水冷却对混凝土火灾损伤趋于严重;300℃之前,PP纤维融化可降低混凝土内部蒸汽压,改善HPC的高温性能。C60 high performance concrete(HPC)added polypropylene fiber(PP)was simulated fire experiment,the PP volume content is 0,0.2%,0.3%(Number as P0,P2,P3).Specimens were cooled to roomtemperature by using natural cooling and spray cooling respectively.Average temperature rise of HPC were test by using infrared thermal imager,compressive strength of HPC were test.The influence of different cooling modes and PP fiber content on infrared temperature rise and compressive strength of C60 HPC after different temperature were analyzed.Results showed that the average infrared temperature rise of concrete were on the rise with the temperature rise,the P3 infrared average temperature rise was maximal but P0's was minimal,specimens of spray cooling infrared average temperature rise were larger than of infrared average temperature rise in the natural cooling.Compressive strength was decline generally.But compressive strength appeared the phenomenon of rebound after 300℃ in natural cooling,compressive strength of concrete dropped slower before 300℃ in spray cooling.Two kinds of cooling modes,compressive strength of P3 is always the minimum.compressive strength of P2 were larger than the P0's at the temperature of 200℃ and 300℃.Compressive strength of the specimens in spray cooling were less than the compressive strength of natural cooling at the temperature of higher than 300℃.In general,the optimum content of PP is 0.2%,and concrete was damaged worse in the spray cooling after the high temperature.Before 300℃,melt of PP can reduce internal vapor pressure of the concrete and improve the high temperature properties of HPC.

关 键 词：聚丙烯纤维 冷却方式 高性能混凝土 高温 红外热像 抗压强度 

分 类 号：TU528.01[建筑科学—建筑技术科学]