关键词: 低温;硫酸盐侵蚀;水泥砂浆;腐蚀机理

Abstract: The effects of cement types and mineral admixtures on the performance of cement-based materials against sulfate attack at 5 ℃were studied .Ordinary portland cement , medium sulfur-resistant cement and slag with silica fume cement mortar samples were prepared .Mortar samples were stored in 3%Na2 SO4 sulfate solution at ( 5 ±1 ) ℃, and their strength developments were measured .Sulfate resistance of mortar samples was evaluated by considering the mortar strength and corrosion resistance . The corrosion mechanism was analyzed by SEM , EDS and XRD.The results show that the strength of the mortar samples at 5℃is lower than that of the normal temperature environment , the mortar resistance to sulfate attack is 15%slag+3%silica fume>medium sulfur-resistant cement >15%slag+1%silica fume>ordinary portland cement .Addition of mineral admixture improves the sulfate resistance of cement mortar, and the better the sulfate resistance , the more the addition of silica fume;Corrosion products at low temperatures are not only gypsum , but also the thaumasite .

Key words: low temperature;sulfate attack;cement mortar;corrosion mechanism