Study On Properties And Diffusion Water Plugging Mechanism Of Clay-based Modified Waterborne Polyurethane Composites

Based on the mine grouting material WPU/MMT composite material as the research object,comprehensive using the theoretical analysis,numerical simulation and laboratory experimental research methods,such as for waterborne polyurethane and the comprehensive performance of montmorillonite composite material,molecular combination between principle and the diffusion law of rock mass,the injection slurry seal mechanism and so on has carried on the comprehensive research,the clay modified waterborne polyurethane composite material is obtained comprehensive performance and its diffusion block mechanism.The main research results are as follows:(1)The composite has the best comprehensive properties when the content of montmorillonite is 3%.The basic performance experiments showed that the gel time and the growth rate of water inclusion increased first and then decreased,and both reached the maximum value when the content of montmorillonite was 3%.Molecular dynamics simulation showed that montmorillonite can improve the interaction of the polyurethane system,and make the distance between the atoms or molecules of the system become closer.Meanwhile,polyurethane plays a certain supporting role in the montmorillonite layer,and increases the distance between the montmorillonite layers.When the mass fraction of montmorillonite is 3%,the water-based polyurethane and montmorillonite are intercalated completely,and the montmorillonite is uniformly dispersed in the system.It is believed that the composite material with the content of montmorillonite is 3%,and the best performance is achieved.(2)The physical and mechanical compressive tests of fractured rock mass show that the composite consolidated body has strong elastoplastic properties and can play a good role of buffering and pressure relief in fractured rock mass.When the content of montmorillonite is 3%,the consolidation effect is the best,the compressive strength can reach 80% of the complete rock,the grouting sealing effect is good,and it has a strong shear resistance in the inclined crack,which can bond the fractured rock together.(3)The diffusion law of grouting material in fractured rock mass is revealed.(1)Under the same conditions,with the increase of time,the slurry diffusion range increases and finally tends to be stable.(2)Under different grouting pressure conditions,with the increase of grouting pressure,the diffusion range of grout shows an increasing trend.(3)When the grouting pressure is constant,the diffusion range of the grout is mainly affected by the gelation time T1 and viscosity under different ratio conditions.With the increase of the content of montmorillonite,the gelation time and viscosity of the grout increased,the amount of grouting in the rock mass decreased within the specified time,and the diffusion range of the grout decreased.(4)The plugging mechanism of grouting materials in fractured rock mass is clarified.Chemically,when grouting material meets water,it will produce disperse gel reaction,and the CO2 generated by the reaction will increase the size of foaming body and limit the flow of crack water.On the mechanical level,the grouting material can enhance the pressure intensity around the fractured rock mass.When the content of montmorillonite is 3%,the pressure intensity around the fracture is the maximum and the sealing effect is the best.There are 38 figures,16 tables and 81 references in this paper.