高温与碳化对铝酸盐水泥水化产物氯离子结合稳定性的影响

Effect of High Temperature and Carbonization on Chloride Binding Stability in Calcium Aluminate Cement

通过对比4种铝酸盐水泥(CAC)常见水化产物CAH_(10)、C_(2)AH_(8)、C_(3)AH_(6)、NO_(3)-AFm与氯离子充分结合所得Fs样品在高温和碳化前后的氯离子结合量、浸泡液pH值、物相组成及微观形貌等,研究了温度和碳化作用对CAC水化产物与氯离子结合稳定性的影响.结果表明:高温仅影响CAC水化产物物理吸附氯离子的稳定性,对化学结合稳定性基本无影响;碳化作用导致Friedel's盐溶解,生成以方解石为主的CaCO_(3),使浆体中的自由氯离子浓度增加;相比之下,CAH_(10)、C_(2)AH_(8)与氯离子结合后的Fs样品抗碳化能力较好.

The effect of temperature and carbonization on the chloride binding stability of calcium aluminate cement(CAC)was investigated by comparing the amount of binding chloride,pH value of soaking solution,composition and morphology of Fs samples,which were obtained by four common chloride-bound hydration products(CAH_(10),C_(2)AH_(8),C_(3)AH_(6) and NO_(3)-AFm)of CAC,before and after high temperature and carbonization.The results show that high temperature has great impact on the physical binding chloride instead of chemical binding one.Carbonization causes Friedel's salt to dissolve,forming calcium carbonate products dominated by calcite,thus increasing the content of free chloride in the pore solution.Chloride-bound Fs(CAH_(10))and Fs(C_(2)AH_(8))exhibit relatively better resistance to carbonization.