Research On Delaying Expansion Of Flexible Anti-seepage Materials With Bentonite

The watertight screen which is made of mixing pile with spraying bentonite into the soil can not only effectively reduce the permeability of the soil to achieve the purpose of seepage,but also can avoid leakage because the flexibility of bentonite mixing pile is good for the deformation of foundation pit retaining structure.At the same time bentonite sprayed to the soil,the groundwater which will not produce pollution and make the soil solidification,is conducive to the environmental protection of underground works.The bentonite is swelling quickly with water,and the slurry suspension time is very short.The pore of the soil can be filled by the mixing material made of the combination of bentonite and soil,which can form the impermeable areas to achieve the purpose of water seepage.In addition,the expansion force not only enhances the anti-seepage capacity of underground anti-seepage project,but also enhances the strength of impervious soil.Therefore,controlling bentonite water swelling time becomes the key technology of bentonite agitating pile construction.It is very important to find a reagent to slow the expansion of bentonite to seepage control project.In order to solve the problem of grouting and anti-seepage of bentonite,this paper focuses on the experimental study of bentonite-modified reagent,and explores the effect of slow expansion agent of bentonite-glucose solution on bentonite.Through a series of macroscopical experiments to explore the bentonite slow expansion effect of the optimal concentration of glucose and anti-seepage effect of the optimal mixture ratio of bentonite composite materials.And the microstructures of the composites were investigated by microscope scanning electron microscopy(SEM).The results show that the proposed method is more reasonable,convenient and economical for the practical engineering application.The main works of this paper includes:1.The effects of different dosage of bentonite,concentration of different retarder-glucose solution and different standing time on the mechanical properties of bentonite composites were analyzed.2.Comparison of microstructure on different bentonite content,different concentration of retarder-glucose solution and different standing time.3.Summarizing the results of macroscopic indoor experiment and microscopic scanning electron microscopy,the optimum mixing ratio of bentonite composite material is put forward.