Study On Proportioning Optimization And Performance Of Alkali Activated Cementitious Grouting Material

In the aspects of mining reinforcement,floor grouting reinforcement to prevent water inrush,road subgrade reinforcement,treatment of the bottom void of the base layer and loose treatment of the base,the grouting material required is very large,while the traditional cement consumption accounts for about 15%of the world total energy consumption.Under the pressure of huge energy consumption,it is urgent to use alternative alkali based grouting materials to meet the needs of people in various engineering fields.In this paper,the alkali activated cement-based grouting material is prepared from solid waste resources.According to the two engineering types of mine and road,the ratio optimization and performance test of grouting materials are studied.The best mix ratio scheme is selected.The microstructure is analyzed by XRD,SEM and EDS the results are as follows.（1）Raw material pretreatment:coal gangue and red mud were grinded for 120 min and 15min respectively,and their specific surface areas were 399 m²·kg^-1、587m²·kg^-1 respectively;the best treatment method for coal gangue powder was calcined at 750℃for 30 min,and the activity index reached 99%after 28 days.（2）Research on proportioning optimization and performance of alkali activated cement-based mine grouting material:the water evolution rate gradually decreases with the increase of slag powder/fly ash ratio,and gradually increases with the increase of water material ratio;the addition of red mud is effective to reduce the water evolution rate;with the increase of slag powder/fly ash ratio,the pressure resistance gradually increases and tends to be stable;at a lower water material ratio,the mechanical properties of the material are better;the optimum 28days compressive strength range is 17.03MPa～22.07MPa,and the three groups of the matching schemes with better stability are:（1）The content of Silicate minerals is 20%and the content of desulfurized gypsum is 10%（the proportion of activator is the mass percentage of slag powder and fly ash,the same below）,slag powder:fly ash=5:5,water ratio=4:6.（2）The content of carbonate is 4%and the content of hydroxide is 3%,slag powder:fly ash=5:5,water ratio=4:6.（3）The content of chloride salt is 4%and that Silicate minerals is 15%,slag powder:fly ash=5:5,water ratio=4:6.（3）The ratio optimization of road grouting materials:with the increase of slag/fly ash ratio,the compressive strength gradually increases and is in a higher state;the optimum ratio of the scheme with viscosity of 19s and 28days compressive strength of 37.64MPa,the content of carbonate is 4%and the content of hydroxide is 3%,slag powder:coal ash=5:5,naphthalene superplasticizer is 3.5%,cellulose ether is 0.2%,plastic expansion is selected The content of swelling agent was 0.05%.（4）Microstructure:by means of XRD,SEM and EDS,the strength of the gel is produced after hydration reaction of alkali activated cement grouting material,and the hydrated product mainly corresponds to ettringite.