Fast gelation, slight expansion and high strength type grouting material

Abstract

The invention belongs to karst stratum reinforcement and water blocking technique in tunnel and underground construction. The quick gelling, micro expansion and high strength type injecting grout material is prepared from P.O42.5 cement, and calcium lignosulphonate, soda and calcium sulphoaluminate expanding agent (specially for grout injection) of which the weight percentages account for the weight of the cement are 0.4 percent, 0.4 percent and 8 percent respectively, and the water cement ratio of the grout is as follows: W/C is equal to 1.2 to 1. The injecting grout material prepared by the invention has characteristics of quick gelling, micro expansion and high strength, a plurality of experiments and site tests in tunnel underground construction show that the injecting grout material has relatively ideal gelling time and water blocking reinforcement and seepage preventing effects.

Description

technical field [0001] The invention belongs to the water blocking and reinforcement technology of karst formations in tunnels and underground engineering, and mainly proposes a fast-gelling, micro-expansion, high-strength grouting material. Background technique [0002] In the construction of mountain tunnels, karst formations are often encountered, and the construction of such formations is difficult, especially in high-pressure, water-rich karst areas, where catastrophic accidents of water gushing and mud inrush are prone to occur. In order to ensure construction safety and minimize the impact on the surrounding environment, especially the groundwater, at home and abroad, the grouting method is often used to block water and drain the ground in accordance with the principle of "combining blockage and drainage, adapting measures to local conditions, comprehensive treatment, and leaving no future troubles". reinforcement. The grouting method is to inject the prepared grout ...

AI Technical Summary

Problems solved by technology

In karst areas, especially high-pressure and water-rich karst areas, ordinary grouting materials such as ordinary cement single-fluid grout are easily taken away by water flow after entering the formation due to their long gel time, and the retention rate is low, making it difficult to achieve the purpose of water blocking and reinforcement; Special cements such as sulfoaluminate are expensive, and the cost is too high for grouting in karst areas with a large amount of grouting; under the action of water, the sodium ions in the cement-water glass slurry gel often precipitate, and the solidification The colloid is easily disintegrated, and has a strong alkali dissolution, which causes alkaline pollution of the environment, and the alkaline environment causes the amorphous silicon dioxide (SiO2) in the gel to 2 ) continue to precipitate, further reducing the strength of the gel

Chemical slurries are generally expensive, in which polyurethane reacts immediately when it meets water, and its volume expands rapidly, but its strength is too low to achieve the effect of blocking high-pressure water; when using epoxy resin, diluent and other additives need to be added, and the operation is relatively difficult. It is troublesome, and the viscosity of the slurry is too high, and the curing time is long, so it is difficult to meet the requirements of large-scale use