Abstract
Development of low-cost and environmentally-friendly techniques to treat construction wastes containing toxic substances is one of the crucial issues in construction projects. A mechano-chemical treatment technology for construction waste containing non-scattering asbestos, such as cement-asbestos slate boards, has been developed recently. This treatment process discharges high water content sludge, which is composed of fine-grained waste slate, as a residue, since slate boards are crushed and ground into fine particles under a wet condition to enhance the reactivity between a treatment agent and asbestos. Recycling this high water content residual sludge is a challenging issue to improve the environmental suitability of this treatment technology. In this study, applicability of two cement treatment techniques (i.e. granulation and liquefied stabilization) was investigated for recycling this sludge in geotechnical applications. Granulated sludge was accepted for geotechnical utilization in regards to its mechanical properties. For liquefied stabilization, workability, bleeding, unconfined compression strength and consolidation characteristics were evaluated for the sludge treated with various water-cement (W/C) ratios. Testing results indicated that these characteristics of the liquefied stabilized sludge were consistent with those of typical high water content cement-stabilized soil, and W/C is a fundamental parameter for the compressive strength.
