Study On The Effect Of Lithium Salt On The Properties Of Cement-bentonite-sodium Silicate Solution Slurry

With the development of the Beijing subway in the direction of deep burial,the phenomenon of crossing water-rich pebble formations in tunnel sections is becoming more and more frequent.The formation has loose structure,poor self-stability,large water inrush,difficult grouting reinforcement,and common cement-sodium silicate slurry gel time is slow and the early strength is low.In the water-rich pebble formation,it is easy to passively flush out water,and it is difficult to achieve a good grouting reinforcement effect.Therefore,it is of great significance to improve traditional grouting materials.In this paper,through laboratory experiments,the cement-bentonite-sodium silicate slurry studied by the previous people is improved,and the grouting water-stopping material used in water-rich pebble formation is explored.The specific research content is as follows:(1)Through laboratory experiments,the water release rate,viscosity,gel time,and compressive strength of the lithium salt,lithium sulfate,lithium chloride and other lithium salt additives to ordinary Portland cement-lithium bentonite-sodium silicate slurry were analyzed.The influence law of other performance parameters is obtained,and the optimal lithium salt dosage is obtained.(2)The influence of lithium silicate on the properties of ordinary Portland cement-lithium bentonite-sodium silicate slurry was analyzed through laboratory experiments,and it was analyzed that lithium water glass is not suitable for such grouting materials.(3)The effects of iron aluminate cement on the properties of the cement-lithium bentonite-sodium water glass slurry modified by lithium carbonate were analyzed through experimental studies,and the advantages and disadvantages of the formulation were analyzed.(4)By comparing the properties of the slurries of various formulations,the optimal ratio of improved cement-water glass-bentonite slurry is obtained.