摘要
运用SEM高温疲劳实验系统、环境扫描电镜和压汞仪等对高温作用后水泥基材料的微观结构进行了试验研究.研究表明:随着温度升高,水泥基材料内部致密的水泥浆体结构逐渐被破坏,300℃后尤为严重,并且由表及里逐步深化;孔隙率明显增加,阀值孔径不断增大,"孔粗大化"严重;高温对水泥砂浆的劣化影响比水泥净浆更为严重.材料微观结构的劣化意味着与材料渗透性有关的耐久性降低.
The microstructure of cement-based composite material after high temperatures was investigated with SEM-high temperature fatigue experimental system and environmental scanning electron microscopy （ESEM） and mercury intrusion porosimetry（MIP）. The research shows that a series of physical and chemical changes which happened because of high temperatures in the cement-based composite material led to the deterioration of microstructure. With the increase of temperature, dense hardened cement paste in the materials is being destroyed gradually, particularly serious after 300 ℃ and the damage of surface is more serious than the inside. Meanwhile, porosity increases significantly and threshold pore diameter becomes larger and larger. Effects of high temperatures on the deterioration of mierostructure of mortar are more serious than that of cement paste. And the deterioration of microstructure in the materials after high temperatures means the reduction of durability which is related to permeability.
出处
《建筑材料学报》
EI
CAS
CSCD
北大核心
2009年第3期318-322,共5页
Journal of Building Materials
基金
国家自然科学基金资助项目(50408029,50778084)
教育部新世纪优秀人才支持计划(NCET-06-201)
关键词
水泥基材料
环境扫描电镜
压汞
微观结构
劣化
cement-based composite material
environmental scanning electron microscopy（ESEM）
mercury intrusion porosimetry（MIP）
microstructure
deterioration
