水泥基材料抗TSA侵蚀性能影响因素研究

FACTORS AFFECTING THAUMASITE FORM OF SULFATE ATTACK ON CEMENT-BASED MATERIAL

研究了不同配合比掺石灰石粉水泥砂浆在不同硫酸盐溶液中浸泡1年期间的外观、强度和矿物成分变化。结果表明,水灰比越低,砂浆抗TSA侵蚀性能越好;不同品种水泥的抗TSA侵蚀能力由高到低依次为:硫铝酸盐水泥>抗硫酸盐水泥>普硅水泥;掺硅灰和矿渣细粉均能明显改善混凝土抗TSA侵蚀性能,且矿渣粉掺量越大效果越明显。镁盐对碳硫硅酸钙晶体(thaumasite)的生成和TSA侵蚀破坏具有一定促进作用;水泥基材料TSA侵蚀破坏也可能发生于15℃以上环境中,环境温度对水泥基材料整体抗硫酸盐侵蚀性能的影响规律与材料组分有关。

The limestone filler cement mortars with different mixing proportions were immersed into different sulfate solutions for one year, and their visual appearances, strength and mineral composition were measured at intervals. The results show that the resistance of mortar to thanmasite form of sulfate attack （TSA） increases with the reduction of water-cement ratio. The relative resistance to TSA of the cements is outlined below, from best to worst： sulphoaluminate cement, sulfate resisting Portland cement, ordinary Portland cement. The resistance to TSA of mortar is remarkably improved by the addition of silica fume or ground granulated blasffurnaee slag （ggbs）, and the better the resistance to TSA, the more the addition of ggbs is. Magnesium salts reinforce the thanmasite formation and the thaumasite form of sulfate attack in the cement mortars. It reveals that TSA may also occur to structures at temperatures of higher than 15℃ .The influence of temperature on the whole resistance to sulfate attack of mortar is related to the material composition.