矿物掺合料对水泥胶砂抗硫酸盐侵蚀性能的影响

Influence of Mineral Admixture on Resistance to Sulfate Attack of Cement Mortar

为获得在云南保瑞(保山—瑞丽)铁路硫酸盐侵蚀环境下,当地火山灰、粉煤灰、硅灰对普通硅酸盐水泥胶砂试件的抗硫酸盐侵蚀能力的影响规律及快速评价方法,进行了浸泡抗蚀性能试验和差热分析(Differential Thermal Analysis,DTA)。结果表明:以当地火山灰替代30%的水泥并外掺3%硅灰的试件具有优异的抗硫酸盐侵蚀性能;DTA方法可作为分析火山灰质矿物掺合料火山灰效应的有效手段;加入单一矿物掺合料时,硫酸钠溶液浸泡试件的Ca(OH)_2吸热峰面积与抗蚀系数呈线性关系,利用该关系,可辅助快速评定工程结构中水泥基材料的抗硫酸盐侵蚀性能。

In order to obtain the influence of the local pozzolana,fly ash and silica fume on resistance to sulfate attack of cement mortar under the sulfate corrosion environment in Yunnan Baoshan-Ruili railway,cement mortar specimens were made to carry out the immersion corrosion resistance test and differential thermal analysis(DTA).Then,the rapid evaluation method of resistance to sulfate attack was investigated.The results show that the specimens with30%pozzolana and3%silica fume have excellent resistance to sulfate attack;DTA is an effective method to analysis pozzolanic effect of pozzolanic mineral admixture;For specimens with single admixture in sodium sulfate solution,there is a linear relationship between corrosion resistance coefficient and the area of the endothermic peak of Ca(OH)2,which can be used as an assisted rapid method to assess the resistance to sulfate attack of cement-based materials in practical engineering structure.