Abstract
Fiber-reinforced mixture of dredged soil and steel-making slag (FRMDS) was tested to study its applicability as the sealing geo-material for waste disposal sites in coastal area. In this study, FRMDS was made of Nagoya-port dredged soil with a water content of 160 %, steel-making slag with a diameter of smaller than 9.5 mm and polyester fiber with a shape of 14.8 μm in diameter and 20 ± 5 mm in length. Unconfined compression test was carried out to evaluate the fiber-reinforcing effect on FRMDS, where the stress and strain relationship exhibited strain hardening behavior. Such behavior results from the crack suppression by fiber admixture. Triaxial compression-permeability test was also performed to evaluate the sealing potential of FRMDS. As a result, the permeability of FRMDS was increased with an increase in axial strain, and its increasing trend depended on the effective confining stress before shearing process. Asample of FRMDS, which was composed of 30 vol% steel-making slag and 0.5 vol% polyester fiber, initially possesses a permeability of 2.2×10-9 m/s. This sample was able to maintain a permeability of less than 1.0×10-8 m/s, even when an axial strain of 17 % was applied under an effective stress of 50 kN/m2.
