Improve The Anti-environmental Water Erosion Of The Anchorage Body Grouting With Cement Based Mortar

To enhance the stability of geotechnical engineering and solve the complex and difficult geotechnical engineering problems, bolt and anchor cable are used in the slope engineering from Shaoguan to Huadu of Wuhan-Guangzhou Passenger Dedicated Railway. As far as anchorage structure is concerned, durability as well as high strength is important for engineering quality and service life. Improving the properties of grouting material is the most fundamental and effective way to enhance the stability of anchorage structure. According to the feature of anchorage structure, working performance, shrinkage deformation, resistance to sulfate attack and resistance to chloride ion penetration of cement mortar have something to do with the durability of grouting material.In our study, mineral admixtures such as fly ash, slag, silica fume were added into cement mortar, with water-soluble resin as thickening agent, to finish the degree of expansion test, Self-desiccation shrinkage test, long term immersion and alternation of wetting and drying, RCM--diffusion coefficient test, corrosion potential test. Flowability, flexibility strength and volume change in 2000ppm sulfate solution, 7d Self-desiccation shrinkage, 24h chloride ion penetration depth and diffusion coefficient, corrosion potential of reinforced steel in mortar were measured to study the influence of the category, addition content of mineral admixture and water-soluble resin on the durability.The experimental results show that, addition of mineral admixtures improved the durability significantly, because mineral admixtures formed grading system with cement particles, and decreased the porosity of mortar, optimized pore structure, and diluted C3A concentration. Fly ash has better effect than slag on improving flowability, Self-desiccation shrinkage, resistance to sulfate attack, resistance to chloride ion penetration, while slag has better effect than fly ash on water retention and corrosion resistance of steel bar. Silica fume is disadvantageous to flowability and shrinkage deformation of mortar, due to the huge surface area. Total addition content should be from 30% to 40%, and effect of co-addition of fly ash and slag is the best.Addition of water-soluble resin as thickening agent introduced a few micro bubble and improved flowability and homogeneity of mortar apparently, optimized internal pore structure, slowed cement hydration rate. Within a certain range of addition content, resistance to sulfate attack, Self-desiccation shrinkage, and resistance to chloride ion penetration had been improved. The effect of steel corrosion potential was not obvious within a propriety addition content of water-soluble resin, and it's taking from with the increase of addition content. When the addition content is 0．5wt%, the effect of durability improvement was obvious. High addition content had no distinct effect even bad effect.Concluding from above, addition of 0．5wt% water-solution resin and 30-40wt% mineral admixture (co-addition of fly ash and slag) can improve the durability of grouting materials effectively, and enhance the security and service life of anchorage structure. Develop the grouting mortar of anchorage engineering can be used in the slope engineering from Shaoguan to Huadu of Wuhan-Guangzhou Passenger Dedicated Railway.