Study on properties and micro-properties of cement-sodium silicate double-liquid grouting material

In order to explore the internal relationship between the microstructure and macroscopic properties of cement-sodium silicate double-liquid grouting materials, Portland cement was used as the base cementing material and sodium silicate as the admixture. The effects of low sodium silicate content (mass fraction of 0%, 1%, 2% and 3%) on physical density, fluidity, water bleeding, setting time, stone rate and compressive strength of cement-sodium silicate double-liguid were investigated. The results show that with the increase of the amount of water glass, the flow and density of the cement slurry continues to decrease, the condensation time is significantly shortened, the bleeding water rate decreases, the stability of the slurry is increased, the stones are increased; the compressive strength increased first and then decreased, especially when the content of sodium silicate was 1%, the compressive strength of the stone body reached the best (12.48 MPa) at 28 days, which was 10.4% higher than that of the cement slurry without sodium silicate. XRD, FTIR and SEM confirm that the content of sodium silicate will affect the size and quantity of pores inside the cement matrix, and the appropriate content of sodium silicate can effectively promote hydration reaction, improve the density of stone body, and then improve the slurry performance and mechanical strength of grouting materials.