孔结构对水泥混凝土抗冻性的影响

摘要

The paper researches the hardened cement paste and the macrostructure and microstructure of concrete by adopting the pressure pumping method and the scanning election microscope,proves by the results that the porosity of hardened cement paste and mortar of concrete increased and especially the capillary pores volume,which are larger than 50 nm,and the microcracks also increased,indicates this can lead to the hardened cement paste will turn from the compression structure to loose structure,and finally the separation of the coarse aggregate and mortar will be caused.%用压汞法和扫描电子显微镜研究了冻融循环作用下硬化水泥浆体和混凝土宏观与细观结构的变化。结果表明,冻融以后硬化水泥浆体和混凝土中砂浆的孔隙率,特别是大于50 nm的毛细孔体积和微裂纹增加较多,导致硬化水泥浆体由密实结构向松散结构发展,最后导致粗骨料与砂浆分离。