锂渣复合水泥基材料抗硫酸盐侵蚀的性能

Performance of Lithium Slag Composite Cement-based Material on Sulfate Attack

混凝土易受硫酸盐侵蚀破坏。为了提高混凝土的抗硫酸盐侵蚀性能,采用锂渣制备混凝土,对试件进行硫酸盐侵蚀试验。结果表明,在硫酸盐侵蚀下,锂渣掺量在40%以内时,锂渣复合水泥基材料的抗侵蚀系数均在1.0以上,但若掺量增加到60%,其侵蚀系数逐渐降低,甚至低于0.85。这主要是锂渣替代水泥掺入后,不仅减少了水泥中C_3S、C_2S和C_3A的含量,还能参与二次反应,进而减少了水泥水化产物Ca(OH)_2和CAH的数量,同时部分非活性的锂渣能填充于孔隙中,提高了水泥基材料的密实度,即减少了硫酸盐溶液的侵蚀通道。因此,锂渣能改善混凝土抗硫酸盐侵蚀的能力。

Concrete is susceptible to sulfate attack damage. In order to improve the sulfate resistance of concrete, lithium slag is used to prepare concrete for sulfate attack tests. The results show that, under sulfate attack, the erosion coefficient of lithium slag composite cement-based material is above 1.0 when lithium slag content is within 40%, and the erosion coefficient will gradually reduced or even less than 0.85 if the content up to 60%. The substitution of cement with lithium slag can not only reduce the content of C3S, C2S and C3A in cement but also can participate in secondary reactions, that can reduce the content of reaction product Ca（OH） 2 and CAH. And at the same time, some non-reactive lithium slag can be filled in cement pores which will reduce concrete open porosity, i. e., reduce sulfate erosion channel. The lithium slag can improve the capacity of sulfate resistance of concrete.