超低离子渗透性水泥基材料的抗氯离子渗透性能研究

Study on chloride ion penetration resistance of ultra low ion permeability cementitious materials

通过优化超低离子渗透性水泥基材料(ULIPCM)的孔结构以及细化其界面过渡区,减少由于毛细孔或界面过渡区相互贯通而形成的逾渗路径,提高了其抗氯离子渗透性能。28 d时,ULIPCM的6 h导电量小于300 C,为一般高性能混凝土的1/10～1/7;90d时,ULIPCM的6 h导电量小于100 C。28 d时,ULIPCM的Cl-扩散系数小于1.0×10-13 m2/s,为一般高性能混凝土的1/20～1/10,且蒸养条件下ULIPCM的Cl-扩散系数稍低于标养条件下的。ULIPCM的界面过渡区厚度细化为30μm以下,界面过渡区内充满了水化产物,结构致密,C-S-H凝胶非常多,CH晶体很少且取向性差;ULIPCM的水化产物中CH含量大幅下降。

By optimizing pore structure of ultra low ion permeability cementitious materials （abbr. ULIPCM） and reducing its interfacial transition zone,percolation paths in capillary pore and interfacial transition zone were decreased and the ability to resist chloride ion penetration was improved. At the age of 28 days,conductive charge for 6 hours of ULIPCM is lower than 300 coulombs,and which was equivalent to 1/10-1/7 of that of normal high-performance concrete. At the age of 90 days,conductive charge for 6 hours of ULIPCM is lower than 100 coulombs. Furthermore,at the age of 28 days,chloride diffusion coefficient of ULIPCM is lower than 1.0×10^-13 m^2/s which was equivalent to 1/20-1/10 of that of normal high-performance concrete. In addition, chloride diffusion coefficient of ULIPCM under steam curing system is lower than that of standard curing system. Interracial transition zone of ULIPCM is dense,and its thickness is below 30 μm. The main hydration product of interfacial transition zone in ULIPCM is C-S-H gel,but few is Ca（OH）, erystal and the orientation of Ca（OH）2 crystal isn＇t very distinct. The content of Ca（OH）2 crystal in hydration product of ULIPCM is obviously decreased.