Development Of Anti-dispersion Grouting Material And Research On Dynamic Water Erosion Characteristics

The quality of underwater grouting for rock and soil reinforcement is affected by many factors such as complex geological conditions,materials and equipment,process parameters,etc.It is more difficult to achieve ideal results in strata with strong effects of moving water on the dilution and erosion of grout.Commonly used ordinary cement and cement-chemical slurries have low slurry retention rate and poor quality of stone rate under hydrodynamic environmental conditions,which makes it difficult to guarantee the reinforcement effect;while chemical slurries are expensive and have a certain risk of environmental pollution,so the development of granular underwater anti-dispersion.The grouting material is the prerequisite to ensure the effect of dynamic water grouting.In the dynamic water grouting project in the field of ecological restoration,traditional cement materials are difficult to degrade,chemical materials are environmentally unfriendly,and traditional materials are difficult to set under dynamic water conditions.The development of non-cement-based anti-dispersion grouting materials is an urgent problem to be solved.Based on the full analysis of the effect of dynamic water on the slurry,sulfoaluminate cement is used as the matrix material,based on cement chemistry,and admixtures are selected to control the hydration and hardening reaction of the slurry,to develop cement-based anti-dispersion grouting materials;use glutinous rice Amylopectin in the slurry regulates the formation of calcite,selects non-cement-based anti-dispersion materials as matrix materials,uses admixtures to coordinate the hydration reaction of the slurry,and develops non-cement-based anti-dispersion materials.The main work and research results of the thesis are as follows:?1?Research and development of cement-based anti-dispersion materialsBased on the analysis of the action of moving water on the slurry,the material composition and function requirements of the anti-dispersion material are proposed.The univariate analysis method is used to select the type and amount of the admixture with the fluidity,setting time,and stone body strength as indicators;Orthogonal test method to develop cement-based anti-dispersion materials.The cement-based anti-dispersion material uses sulfoaluminate cement as the matrix material,and the polycarboxylic acid water-reducing agent is used to regulate the fluidity of the slurry;the sodium gluconate retarder is used to adjust the setting time of the slurry;Use hydroxyethyl methyl cellulose ether as an anti-dispersant to improve the dispersion resistance of the slurry;use silica fume as a mineral additive to improve the physical and mechanical properties of the slurry.The cement-based anti-dispersion material has the following properties:the anti-dispersion grouting material does not release water,and the stone rate of the hardened slurry is high;the early strength of the hardened slurry of the anti-dispersion material increases quickly and the later strength is high;the hardened slurry has sulfate resistance,The low alkalinity in the slurry material is the material basis for resistance to sulfate attack,and the high density is an important reason for reducing the crystallization and expansion damage caused by the sulfate intrusion into the hardened slurry.Develop anti-dispersion material dynamic water anti-dispersion simulation test device,evaluate the optimal formula dynamic water anti-dispersion performance,and obtain the material's ultimate scouring speed;establish the relationship between the material dynamic water anti-dispersion performance and the dynamic water flow rate,slurry flow pattern,as the dynamic water grouting resistance The choice of dispersed materials provides the basis.Cement-based anti-dispersion materials have the characteristics of high heat release and rapid hydration rate.The hardened paste material is mainly composed of calcium vanadium?AFt?and hydrated calcium silicate?C-S-H?,and the content of calcium hydroxide?Ca?OH?₂?is low;in the early stage of hydration,the anti-dispersion material hydration is caused by the phase boundary?I?Reaction control,from crystal nucleation and crystal growth?NG?reaction to diffusion?D?reaction control,hydration reaction is mainly controlled by diffusion?D?reaction;based on cement chemistry,admixture chemistry,use Hydration heat method,environmental scanning test method?ESEM?,X-ray diffraction test method?XRD?,continuous observation of hydration product morphology and material composition changes,put forward anti-dispersion material hydration mechanism model.?2?Research and development of non-cement based anti-dispersion materialsUsing the control effect of amylopectin in glutinous rice pulp on the formation of calcite,the composition and function requirements of non-cement-based anti-dispersion materials were studied to solve the problem of difficult solidification of the slurry under dynamic water conditions.The non-cement-based anti-dispersion material uses glutinous rice mortar as the matrix material to improve the early strength of the slurry through gypsum and reduce the lack of low calculus rate of the matrix material;the self-developed external admixture is used to adjust the slurry fluidity,setting time and other technical indicators;Use hydroxyethyl methyl cellulose ether to improve the dispersion resistance of the slurry;use stone powder and calcium carbonate sand to improve the physical and mechanical properties of the hardened slurry.Based on the uniform test method,research and development of non-cement based anti-dispersion grouting material.The non-cement-based anti-dispersion material has the following properties:the hardened slurry has a high stone formation rate and a small volume expansion;the anti-dispersion material has good initial fluidity and strong fluidity retention ability;the hardened slurry is resistant to water corrosion and sulfate salt invasion,which is beneficial to the engineering structure The long-term stability of the hardened slurry;the strength of the hardened slurry grows fast in the early stage and high in the later stage.The hardened paste is composed of calcium carbonate?Ca CO₃?and gypsum?Ca SO₄·2H₂O?;the carbonization reaction of glutinous rice slurry forms calcium carbonate?Ca CO₃?,which has a strong filling and cementing effect on the hardened paste;based on the cementing material chemistry and admixture Chemistry,using environmental scanning test technology?ESEM?as a research method to obtain the hydration mechanism of non-cement based anti-dispersion materials.?3?Research on anti-dispersion material erosion characteristics under moving waterUsing the developed anti-dispersion material dynamic water erosion simulation test device to simulate the anti-dispersion material's anti-erosion performance under dynamic water conditions;combined with on-site in-situ grouting simulation test,the anti-dispersion material's anti-erosion performance and performance are verified from different scales Diffusion performance.The cement-based anti-dispersion material is used to simulate the grouting of the moving water overhead formation.The moving water flow rate is in the range of0.6?1.0m/s,and the slurry retention rate reaches more than 80%.Reducing the moving water flow rate and increasing the slurry static shear force and plastic viscosity can improve The anti-erosion ability of the slurry;non-cement-based materials are used for grouting in the simulated moving water overhead formation,the moving water velocity is in the range of 0.6?1.0m/s,the retention rate of the slurry reaches more than 82%,improves the consistency of the slurry and reduces the dynamic Water flow rate can improve dynamic water erosion performance.On-site in-situ grouting simulation tests verified that cement-based?non-cement-based?anti-dispersion materials have good erosion resistance in simulated pore formations,and proposed suitable conditions for slurries with different ratios.Cement-based anti-dispersion material Proportion 1 slurry is suitable for grouting reinforcement and water plugging projects with dynamic water velocity less than 1m/s;Proportion 2 slurry is suitable for water plugging projects with dynamic water velocity less than 0.8m/s;Proportion 3 slurry is suitable Anti-seepage project with moving water velocity less than 0.6m/s.The non-cement-based anti-dispersion material N01 ratio slurry has high stone strength,suitable setting time,and the material is suitable for reinforcement and water plugging projects with a moving water velocity of less than 1m/s;the N08 ratio slurry has good fluidity,high stone strength,and slurry It is suitable for water blocking projects with moving water velocity less than 0.8m/s;N15 mixed slurry has good fluidity,and the slurry is suitable for anti-seepage projects with moving water velocity less than 0.8m/s.The anti-erosion mechanism of the anti-dispersion material is as follows:large static shear force and high consistency in the plastic stage of the slurry are the material basis of anti-erosion.The hydroxyethyl methyl cellulose ether?HEMC?has a long chain structure and has""Bridge effect"and"adsorption"improve the erosion resistance of the slurry through the adhesion between the slurry and the stone surface.The slurry solidification and solidification has a"mutation effect",the early strength increases quickly,and the rapid hydration reaction forms the stone body The slurry's anti-erosion ability is enhanced.?4?Application research of anti-dispersion materialsTaking the reinforcement of drainage channels in Zhangzha Town of Jiuzhaigou and the repair of the spark damage seascape in Jiuzhaigou scenic area as examples,the field application test of cement-based?non-cement-based?anti-dispersion materials was carried out.The field application test of anti-dispersion material shows that the new material developed can achieve direct pouring and reinforcement under dynamic water conditions without the use of cofferdams and drainage measures.It has achieved good application results and verified that the new material has good engineering applicability.