辅助胶凝材料对C80混凝土高温后抗压强度及孔结构的影响  

Effect of auxiliary cementing materials on the compressive strength and pore structure of C80 concrete experiencing high temperature

作　　者：樊祺 杜红秀[1] FAN Qi;DU Hongxiu(College 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,太原030024

出　　处：《中国科技论文》2022年第10期1072-1077,共6页China Sciencepaper

基　　金：山西省重点研发计划项目(201903D321113)。

摘　　要：为了研究不同辅助胶凝材料对C80混凝土高温后抗压强度及孔结构的影响,以4种硅铝质辅助胶凝材料(原状硅灰、加密硅灰、高钙硅灰、煤系偏高岭土)等质量5%取代水泥制作混凝土试块,使用箱式电阻炉模拟高温火灾试验,测定其抗压强度和红外温升,并通过CT重建技术研究孔结构随温度的变化规律。结果表明:各类辅助胶凝材料均可提升C80混凝土高温后的抗压强度,加密硅灰的效果最好,当试块受火温度为600℃时,相对抗压强度提升了34%;随着受火温度的上升,C80混凝土红外温升增加,加密硅灰可降低C80混凝土红外温升;掺加加密硅灰的C80混凝土在400℃后,孔隙劣化较快,孔隙体积增长76%,孔隙表面积增长94%。In order to study the effect of different auxiliary cementing materials on the compressive strength and pore structure of C80 concrete experiencing high temperature,four kinds of silico-alumina auxiliary cementing materials were used for raw silica fume,dense silica fume,high calcium silica fume,coal series metakaolin and other qualities.The test concrete blocks were made by 5% replaced cementing materials to simulate fire experiments.The compressive strength and infrared temperature rise were measured,and the change of pore structure with temperature were studied through CT reconstruction technology.The results show that all kinds of auxiliary cementing materials can increase the compressive strength of C80 concrete experiencing high temperature,and the effect of densification of silica fume is the best.When the temperature of the test block is 600℃,the relative compressive strength is increased by 34%.When the temperature raises,the infrared temperature of C80 concrete is increased,and the density of silica fume can reduce the infrared temperature rise of C80 concrete.C80 concrete mixed with densified silica fume is deteriorated rapidly after experiencing 400℃,with the pore volume increasing by 76% and the pore surface area by 94%.

关 键 词：高强混凝土 高温 硅灰 红外温升 CT重建 

分 类 号：TU528[建筑科学—建筑技术科学]