The Study On Deterioration Of Clay Cement Stones Under Erosion Conditions

Clay-cement grouting materials are inorganic materials with good stability,impact resistance,environmentally friendly and can save a lot of cement.As the ideal impermeable grouting material,clay-cement has been widely applied to various fields of seepage grouting.It's verified that its seepage effect can meet the requirements of the engineering construction,however,the anti-erosion performance of stone determines its use results and durability during long-term effects of soft water and other erosion solution.The location of underground construction is hidden and always belong a permanent project with long service life.As a result,study on the erosion resistance of grouting has great significance.This paper analyzes the deterioration mechanism of clay-cement grouting material and combined erosion test with macro(CaO cumulative dissolution rate,mass loss rate,intensity)and micro(porosity,SEM)index to study the erosion resistance law of the grouting stones.The main contents and conclusions are as follows:(1)Study on the deterioration law of clay-cement grouting materials under the soft water erosion conditions.Through tests on the anti-corrosion of clay-cement which consolidation under normal pressure conditions with different water-cement ratio,clay content and the dosage of accelerator with CaO cumulative dissolution rate as the evaluate index.The result shows that the clay content is the greatest factor which detennine the anti-corrosion performance of clay-cement grouting material.The clay content should not exceed 50%,accelerator dosage should not exceed 1%to get good anti-corrosion in soft water properties of clay-content;Through tests on anti-corrosion properties of the sample which made by homemade pressure filtration device,it shows that pressure filtration effects can significantly impact the consolidation and anti-corrosion properties of clay-cement grout,at the same tine,the improve magnitude of clay-cement is greater than the magnitude of water slurry material under pressure filtration conditions.(2)Study on the deteriorate law of clay-cement slurry under sulfate attack condition.Samples with clay content of 0%,30%,50%were immersed in water and sodium sulfate solution respectively,the test ages are 30d,60d,90d,120d,150d which using the strength and quality loss as the evaluation index.It shows that deteriorate law and anti-corrosion properties of the clay-cement specimens affect by erosion medium and time,clay content of 30%has optimum sulfate resistance.(3)Microscopic properties of clay slurry stones based on SEM and absorption kinetics.Measuring uniformity coefficient and the average size of pore in stones to evaluate the anti-corrosion properties of the clay-cement,the result shows that material ratio,curing period,curing conditions are have an impact on the pore characteristics of the clay-cement stone.The conclusions of observations and tests on pore characteristics is basically consistent.