磷铝酸盐水泥浆体抗碳化性能的研究

Behaviors of Carbonation Resistance of Phosphoaluminate Cement Pastes

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.

Carbonation degree was analyzed by means of quantitative X-ray diffraction（QXRD） and the elec-tronic probe. The mechanisms of carbonation resistance of phosphoaluminate cement（PALC） pastes were discussed by analyzing the concentration of dissolved Ca^2＋ , ion conductivity, pH of the extracted solution and pore structure of the pastes. The comparisons of the above investigations were conducted with the cor-responding 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 carbona-tion 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.