磷铝酸盐水泥浆体抗碳化性能的研究

Behaviors of Carbonation Resistance of Phosphoaluminate Cement Pastes

关键词:  抗碳化特性  磷铝酸盐水泥浆体  抗碳化机理

Key words:  behavior of carbonation resistance  phosphoaluminate cement(PALC) paste  mechanism of carbonation resistance

摘要:

应用定量X射线衍射（QXRD）和电子探针微区分析技术，从微观角度考察了磷铝酸盐水泥（phosphoaluminate cement, PALC）浆体的碳化程度.通过对浆体的Ca2 +溶出浓度、离子电导、在设定条件下浸出溶液的pH值和孔结构分析，探索了浆体的抗碳化机理.将上述研究与相应的硅酸盐水泥（PC）和硫铝酸盐水泥（SALC）浆体试样进行了比较，结果表明：在CO2（质量分数）＞90%、相对湿度为（50±2）%的情况下，经碳化后的PALC浆体强度相对稳定：碳化45d时其抗压强度损失率为4.5%，而SALC和PC浆体抗压强度损失率分别达到了13.4% 和29.1%.PALC浆体的碳化系数α为0.030，PC和SALC浆体的α分别为0.092和0.118，后两者分别是前者的3.08及3.94倍.

Abstract:

Carbonation degree was analyzed by means of quantitative X ray diffraction(QXRD) and the electronic probe. The mechanisms of carbonation resistance of phosphoaluminate cement(PALC) pastes were discussed by analyzing the concentration of dissolved Ca2+, ion conductivity, pH of the extracted solution and pore structure of the pastes. The comparisons of the above investigations were conducted with the corresponding pastes of Portland cement(PC) and sulfate aluminate cement(SALC). The results reveal that the loss of the compressive strength of PALC pastes is only 4.5% at the condition of exposure in CO2 of concentration > 90%(by mass) and (50±2)% relative humidity for 45 d compared with exposure for 0 d; while the loss for the corresponding PC and SALC pastes is 13.4% and 29.1% respectively. The carbonation factor α of PALC paste is 0.030, which is 3.08 and 3.94 times lower than that of the corresponding PC (α=0.092) and SALC(α=0.118) pastes.