Study on the Recycling of Dewatered Sludge from a Quarry As a Barrier Material

Abstract

The maximum particle size of dewatered sludge from the quarry is 2 mm, with the water content of 24 - 25 %, the liquid limit of 38% and the plastic limit of 17%. It is usually disposed into the landfill. There is a possibility, however, in authors' mind, to recycle the dewatered sludge as a barrier material, because the soil with fine particles indicates a lower permeability providing appropriate compacted than the one with the coarse particles. In this study, firstly, compaction tests, CBR tests, cone penetration tests and permeability tests were conducted for the row dewatered sludge and the dewatered sludge mixed with crushed stone. As a result, it is found that the dewatered sludge mixed with crushed stones having a size between 5 and 13 mm at a ratio of 20 % in dry mass has the sufficient traffic ability and efficient coefficient of permeability as a barrier material. Then cutting geonets were added into the dewatered sludge mixed with crushed stones in order to prevent a shrinkage crack from progressing. Consequently the mixing ratio of 0.8 % of the cutting geonets is the best for preventing the drying shrinkage crack effectively.