Research On Application Performance Of Sulphoaluminate Cement-based Grouting Materials

Relying on the National Key research and development project(2017YFC0603004)"Key Materials and Technologies for Surrounding Rock Modification of Kilometers in Deep Wells",using micro-nano sulfoaluminate cement-based grouting material as raw material,this paper focuses on the effects of water-cement ratio and double material mass ratios of grouting on the basic properties of grouting materials,the effect of stress(the joint effect of grouting pressure and in-situ stress)on the strength of grouting stones,and the applications of sulphoaluminate cement-based grouting material.The research in this paper can provide theoretical basis and guidance for the performance optimization and engineering application of sulphoaluminate cement-based grouting materials.The main research results gained in this paper are as follows:1.The bleeding rate of the yellow and white slurry is small,the density is not much different,and the viscosity is close,which ensures the mass ratio of the two-liquid grouting pump is close to 1: 1.The fluidity of a single liquid does not change with time.The setting time of the mixed slurry can adjust within 10 min to 22 min,and the strength of the stone body is high in the early stage,and there is no shrinkage in the later stage.With the increase of the ratio of yellow material,the fluidity of the mixed liquid first increases and then decreases,and the fluidity can meet the engineering needs.Too much or too little yellow material will affect the performance of the grouting material,and the optimal mass ratio range is 1.0: 1.0 ? 1.0: 0.6.2.Stress pre-curing for 2 h has the same effect on strength performance as pre-curing for 4 h.When the stress is 5 MPa,the strength performance has been improved,and continued to increase the stress strength does not increase much.There is a relationship between stress-density and compressive strength,which can be used to evaluate the quality of grouting reinforcement in coal mines.Stress promotes to form early hydration products without changing species and final yield.The greater the stress,and the denser the microstructure of the stone body.Under normal pressure,the test blocks have a lot of harmful holes and multiple harmful holes.After the stress is applied,there are few harmful holes and harmful holes,and the greater the stress,the more harmless holes.The mechanism of stress action was revealed.3.The field application determined the grouting parameters and explained the difference between the grouting amount and the theoretical grouting amount.After grouting and strengthening of broken surrounding rocks,deformation reduced,and the anchoring force of the anchor rod doubled.The material slurry can be injected into coal rock cracks with a size of 10 ?m,that can effectively fill fractures,forming a compact stone body,closely bonding to coal rocks.