锂渣对水泥浆体强度和收缩性能的试验研究

Experimental Research of Lithium Slag on Strength and Shrinkage Performance of Cement Paste

研究了不同掺量锂渣的水泥浆体强度、自收缩和干燥收缩,并采用压汞法和扫描电镜分析了水泥浆体的微观结构。结果表明:锂渣的掺入明显降低了水泥浆体的早期抗压强度、自收缩和干燥收缩,但后期抗压强度下降幅度降低,当锂渣掺量不超过15%时,锂渣可以提高水泥浆体的后期抗压强度。掺15%锂渣的水泥浆体120 d的孔隙率小于纯水泥浆体,且锂渣颗粒表面有大量水化产物生成。同时,锂渣的掺入明显降低水泥浆体10～50 nm的孔隙率,从而降低了水泥浆体的自收缩和干燥收缩。

The compressive strength,autogenous shrinkage and drying shrinkage of cement paste with various replacement levels of lithium slag were measured and the microstructures of cement paste were analyzed by mercury intrusion porosimetry(MIP)and scanning electron microscopy(SEM).The results show that the early compressive strength,autogenous shrinkage and drying shrinkage of cement paste decrease with the increasing of contents of lithium slag,but lithium slag tends to increase the later compressive strength of cement paste.When the content of lithium slag is lower than 15%,the later compressive strength of cement containing lithium slag is higher than that of Portland cement.When the content of lithium slag is 15%,the 120 d porosity of cement paste is lower than that of Portland cement,large quantities of hydration products are generated on the surface of lithium slag.In addition,10~50 nm pores of cement paste decrease,the autogenous shrinkage and drying shrinkage of cement paste reduce.