Study On Characteristics Of Soda Residue Grouting Material Used For Goal Filling

Soda residue and fly ash were used as the main raw materials to develope a grouting material,aiming at goaf filling.The basic physical and chemical properties and reaction mechanism were studied.The main research work is as follow:1.Using particle size test to determine the suitable particle size of soda residue,and orthogonal experiment was conducted to research the effect of the mass ratio of fly ash to soda residue,the ratio of liquid to solid and the concentration of sodium silicate solution on setting time,fluidity,compressive strength,syneresis rate,solidification ratio,and pH value of the leaching solution.And the optimal ratio for each performance is obtained.2.SEM image of the of soda residue grouting material can be seen with fibrous,elongated particles and some gel-like substance around fly ash glasses;XRD shows that the amorphous material diffusion peak shift after reaction,a proof of new amorphous material generation.The diffuse peak center angle and crystal plane spacing proved amorphous material is C-S-H gel,and with the curing time,the diffraction intensity of SiO₂ crystal is reduced and CaCO₃ crystal is increased.From the EDS diagram and FTIR diagram,combined with the Si/Al ratio and related theory,it can be determined that the geological polymer is generated,and within the range of less than 3,the greater the ratio of silicon to aluminum,the greater the strength of the stone body.3.Compare to cement-fly ash grouting material,soda residue grouting material water resistance,acid resistance is superior to the traditional material,not only will not corrode the steel material components,but also to a certain extent to play a protective role.4.Through the compound stimulation test and optimization of composite activator test,the influence of partial replacement of sodium silicate with gypsum on the performance of soda residue grouting material was analyzed,and the two groups of optimal ratio were determined:the quality of soda residue,fly ash,sodium silicate,gypsum and water ratio were 1:1:1.04:0.26:1.65,1:1:0.84:0.45:2.16.They can meet the requirements of highway goaf filling.5.Because of the use of compound activator,not only the amorphous substances such as C-S-H gel,but also AFt?ettringite?and AFm?mono sulfur type calcium sulphoaluminate?have been formed.