Study On The Shrinkage Property And Shrinkage Control Of Solidified Dredged Material

Much dredged material occurred in the projects of hydraulic engineering, environment engineering and civil engineering. The solidification method is a resultful method of disposing the dredged material. The mechanics property of solidified dredged material has been fully studied, but the shrinkage property of solidified dredged material is not so clear. The high water content of solidified dredged material leads to high shrinkage which cause serious damage to the project. We should see the importance of the shrinkage property of solidified dredged material. In the paper, the shrinkage property and shrinkage control was studied.The main contents are as follows:(1) By indoor experiments of dredged material shrinkage in different levels of solidified dredged material. And it shows the shrinkage laws of solidified dredged material .To the solidified dredged material of different initial water content , cement addible quantity and curing time , its volume decrease with the smaller water content , then go to a stabilization value The solidified dredged material with lower initial water content, higher cement addible quantity and longer curing time has smaller shrinkage.(2) By analysing the experimental result of unconfined compressive strength, porosity and liquid and plastic limits, we can know the influence factor of shrinkage is the result of the variety of solidified effect: the effect of frame supported and pore filling induced the resistant function in dredged material shrinkage process by frame and packing filling; the soil property improvement made the shrinkage property of soil grain decrease, so did the shrinkage property of solidified dredged material.(3) Adding sand has remarkable function to decrease the shrinkage property of solidified dredged material. It was achieved by reducing the pore ratio, and it can improve the structure strength but can't affect the soil property of solidified dredged material. Adding gypsum can control the shrinkage of solidified dredged material, and the adding quantity exist an optimized value. The gypsum can't change the pore ratio, it can improve the structure strength but is disadvantage to the soil property.