Study On The Ratio Test And Property Of Low PH Grouting Materials Based On Silicate Cement

Excavation of the deep geological repository will damage the surrounding rock to form fissures,leading to groundwater infiltration,which in turn will erode the bentonite and destroy the stability of the engineering barrier system.Therefore,it is of great significance to study the grouting material suitable for sealing the cracks in the surrounding rock of the reservoir.This thesis obtains the optimal formula through laboratory tests on silicate cement-based low-pH grouting material according to different performance indicators and analazes the best formula slurry diffusion characteristics in a single crack.Finally,combined with macroscopic and microscopic test methods,the performance of the optimally formulated mixture structure under groundwater erosion is discussed.The specific research results are as follows:(1)Test of low pH grouting material ratio based on silicate cement is carried out.Silica fume can significantly reduce the pH value of the grouting material,and the water reducer and water-cement ratio can improve the fluidity of the grouting material.The optimal formulation of silicate cement based low pH grouting material is as follows: silicate cement has a silica fume content of 60:40,the content of the water reducer is 0.8%,and the content of the watercement ratio is 1.2.(2)Experiments and numerical simulation analysis on the slurry diffusion characteristics of the silicate cement based low pH grouting material are performed.The particle size analysis shows that the effective slurry diffusion crack opening of slurry material is 140.15μm.The slurry diffusion range gradually increases with grouting time,crack opening,and grouting pressure.The slurry pressure at the same position and time also gradually increases,and it is maximum at the grouting port and decreases with the increase in longitudinal diffusion distance.(3)Test on the properties of low-pH grouting material consolidation based on silicate cement under groundwater erosion in Beishan is investigated.With the increase of erosion time,the mass and density of consolidation first increases and then decreases.The volume first increases,then decreases,then continues to increase.The internal pore structure of consolidation changes in a complex way.First,the products generated by hydration fill the internal pores,and the internal pores are reduced due to the aggravation of erosion.The compressive strength of consolidation first increases and then decreases.The gas permeability of consolidation first decreases and then increases.There are 63 figures,10 tables and 130 references in the thesis.