Experimental Study on the Influence of PVA Content on the Performance of Grouting Material in Deep Stope

Based on laboratory experiments, the paper researches the effect of polyvinyl alcohol (PVA) content on the performance of fly ash-based cement grouting materials. The test results show that the addition of PVA has limited effect on the initial and final setting time and brings a certain but minor delay on the appearance of the hydration peak period. It enhances cement hydration during the hydration slow down period. The impermeability of PVA to the grouting material is obviously improved, and it increases with the growing amount of PVA content. PVA improves the flexural strength and compressive strength of the sample block to varying degrees, and the improvement on flexural strength is more obvious than that on the compressive strength. It has a significant effect on the mechanical properties of the grouting material and can effectively improve the rock mass’s hydraulic coupling characteristics. It also has great application value and practical significance for the prevention and control of water hazards in deep coal stopes.