| Recently, the common grouting materials against water at home and abroad are cement slurry and chemical pulp. Chemical pulp is high cost and toxic, it will pollute groundwater, so hasn't been used widely. On the contrary, cement slurry has some advantages such as low cost and high strength of stone body, but it also has some disadvantages such as long gel time which hard to be controlled, low stone rate, weak resistance to water erosion, etc. Therefore, it be limited in grouting engineering under hydrodynamic conditions.Combined with the slurry-performance requirement of grouting under dynamic water, this paper designed a kind of bentonite hardening slurry ("hardening slurry" for short in below) which consist of bentonite, cement, sodium silicate and early strength water-reduced agent with different ratios. By single-factor experiment, orthogonal test and durability test, the main performance and durability of hardening slurry has been studied, and the optimum formula of hardening slurry was obtained.With the scanning electron microscopy (SEM), it was found that plenty of hydration gel and ettringite generated in three days after the hydration reaction of hardening slurry; and seven days later, the framework structure of hardening slurry formed and the early strength increased rapidly; then the micropore of stone body was filled densely in twenty-eight days.By grouting simulation test, it revealed that hardening slurry is better than cement slurry in water plugging effects under hydrodynamic conditions. Meanwhile, diffusion rule and water-plugging reinforcement mechanism of hardening slurry were studied.Hardening slurry had been a successful application in grouting engineering in Shengjing NO.1mine, Changqing mine and Qingfeng mine.The reliability of grouting quality were verified by some methods including shaft drainage, water-pressure test, core boring, water inflow and water level comparison. Therefore, hardening slurry has promotion and application value. |
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