波特兰-白云石微粉水泥砂浆的抗碳硫硅钙石型硫酸盐侵蚀性能  

Resistance of Portland-Dolomite Micro-Powder Cement Mortar to Thaumasite Sulfate Attack

作　　者：徐江涛[1] 刘飞 杨同 卢都友[1] XU Jiangtao;LIU Fei;YANG Tong;LU Duyou(College of Materials Science and Engineering,Nanjing Tech University,Nanjing 211816,China)

机构地区：[1]南京工业大学材料科学与工程学院,南京211816

出　　处：《硅酸盐通报》2024年第12期4322-4329,4349,共9页Bulletin of the Chinese Ceramic Society

基　　金：国家自然科学基金(52102025)。

摘　　要：为评估波特兰-白云石微粉水泥砂浆的抗碳硫硅钙石型硫酸盐侵蚀(TSA)性能,研究了白云石微粉掺量为0%~30%(质量分数)时,水泥砂浆在5℃、5%(质量分数)Na_(2)SO_(4)溶液中的外观、膨胀和质量变化,并采用XRD、FTIR、TGA-DTG、SEM及热力学模拟分析了侵蚀产物。结果表明,白云石微粉的引入显著降低了水泥砂浆的抗TSA性能。随着白云石微粉掺量增加,砂浆的外观破坏等级、膨胀程度和质量均明显增大,且掺量越高,劣化效应越显著。相较于参比样,含白云石微粉水泥砂浆体系侵蚀早期生成更多钙矾石和石膏,侵蚀后期生成大量碳硫硅钙石。白云石微粉参与水泥水化反应生成水滑石、碳铝酸盐和方解石。在低温硫酸盐侵蚀中,水滑石的稳定存在抑制了钙矾石的生成,而碳铝酸盐和方解石则显著促进了碳硫硅钙石的形成。白云石微粉反应生成水滑石产生的积极效应远不及其生成碳铝酸盐、方解石所引发的消极效应,最终导致了水泥砂浆的TSA破坏。In order to evaluate the resistance of Portland-dolomite micro-powder cement mortar to thaumasite sulfate attack(TSA),the appearance,expansion and mass change of cement mortar in 5%(mass fraction)Na_(2)SO_(4)solution at 5℃were studied when the content of dolomite micro-powder was 0%~30%(mass fraction).The erosion products were analyzed by XRD,FTIR,TGA-DTG,SEM and thermodynamic simulation.The results show that the introduction of dolomite micro-powder significantly reduces the TSA resistance of cement mortar.With the increase of dolomite micropowder content,the appearance damage grade,expansion degree and mass of mortar increase significantly.The higher the content is,the more significant the deterioration effect is.Compared with the reference sample,the cement mortar system containing dolomite micro-powder system produces more ettringite and gypsum in the early stage of erosion,and a large amount of thaumasite is generated in the later stage of erosion.Dolomite micro-powder participates in the hydration reaction of cement to form hydrotalcite,carboaluminate and calcite.In low temperature sulfate attack,the stable existence of hydrotalcite inhibits the formation of ettringite,while carboaluminate and calcite significantly promote the formation of thaumasite.The positive effect of the reaction of dolomite micro-powder to hydrotalcite is far less than the negative effect caused by the formation of carboaluminate and calcite,which eventually leads to TSA damage of cement mortar.

关 键 词：白云石微粉 碳硫硅钙石 硫酸盐侵蚀 膨胀率 质量变化 

分 类 号：TQ172.4[化学工程—水泥工业]