Abstract
This paper investigates the effectiveness of slag and lime-mixing and mechanical dehydration method (called “SLMD” in this paper) as one of new recycling technique for dredged soils. Steel slag has been used in geotechnical field to improve soil property because it induces chemical reaction to solidify between soil particles. In the SLMD procedure, soft clay mixed with slag and slaked lime and dehydrated with a high pressure to increase the strength. In order to evaluate the effective of mixing slag and lime instead of cement, the strength property of clay produced by the SLMD (called “SLMD clay”) was investigated and the factors that make up the SLMD clay was investigated by principal component analysis. Soft clays dredged at the Hakata port was used to prepare slag and lime-mixed specimen. The main conclusions obtained from this study are as follows: 1) The highest strength for the specimen is 23MPa, when the SLMD clay includes slag content 45%, lime content 10% and 10MPa of dehydration pressure. 2) The unconfined compressive strength tends to increase sharply with decreasing water-slag and lime ratio, which decreases with the increasing slag content. 3) A new design of the SLMD clay was proposed by focusing on physical properties of Hakata clay, contents of slag and lime, dehydration pressure.
