Preparation Of Functionally Graded Grouting Materials

Grouting material, whose performances were very important to the groutingresults as the basis of grouting technology. Cement-based grouting material andchemical grouting material which were usually used to repair fractured rock mass, butthere were some shortcomings stoping them being used and spread, for instance, largegrouting aperture, uncontrolled setting and hardening time, expensive price, poordurability and etc. And in some cases, coupled with complicated groutingenvironments and objects, the grouting results were not desirable or even failing,which badly stopped and limited the application of grouting technology. On this pointof view, researches that cement-based functionally graded grouting material (CFGGM)that was prepared by double molding on the basis of the establishment of thetheoretical system of functionally graded grouting material and the studies ofproperties of inner layer grouting material, outer layer grouting material and gradedgrouting material were done. The main works and results of researches may besummarized as follows:（1）When the ratio of silica fume/SAC varies within a certain range, there arefewer impacts on the initial fluidity and30min fluidity, but prominent impacts on thestone rate and flexural strength of the hardening outer layer grouting material. BothPAM and fly ash have a retarding effect on the slurry, and PAM can reduce thefluidity performance of the outer layer slurry, especially its30min fluidity. However,fly ash can dramatically affect the viscosity and thixotropy of the inner layer slurryexcept for its fluidity performance.（2）the outer layer grouting material has a better fluidity, anti-washout property,higher early mechanical strength and etc, and when the ratio of silica fume, SAC andPAM was5.00%，20.0%and0.10%, respectively, its properties are the best; the innerlayer grouting material was in good properties with the results of higher mechanicalstrength and better micro-expansion property, and its micro-expansion rate is0.0376%for28d when the content ratio of fly ash is15.0%, which is the best one ofits mix components.（3）combined mix component of W3with that of N3as outer layer and inner layer grouting material,respectively,and its compressive strength can reach the value of about10.0MPa for3d and35.9MPa for28d.Meanwhile,a kind of white colloid is produced on the surface of hydrated FGGM because of hydrolysis and crosslinking of PAM.which results in improving its anti-washout property to some extent.(4)the diffusion model and motion trail of FGGM in static water are obtained on the base of establishment of generalized Bingham fluid constitutive equation:(?) And with the help of time-dependent viscosity equations of the inner and outer layer slurry,the constitutive equation of FGGM is acquired as follow:(?)(?)(5)the dynamic water diffusion model on a finite boundary is obtained,which presents the relationship among grouting pressure,diffusion radius of the slurry and underground water fluidity in dynamic water:(?)(?)...