The Use of Coal Fly Ash for Soil Stabilization PDF Download

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Languages : en
Pages : 78

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Book Description
The objective of this work was to examine the potential use of Wyoming subbituminous coal fly ash materials for cementation of soil materials. Specimens made from Laramie River (LR) fly ash had higher unconfined compression strength and more brittleness than the Specimens made with Dave Johnston (DJ) fly ash. However, soil/DJ fly ash mixtures that were cured for 28 days had relatively good strengths without the brittleness that the LR specimens developed. These characteristics of the DJ fly ash may be important attributes for road stabilization applications. The detailed mineralogical evaluation provides some insight into which minerals may enhance development of strength in these materials. In general, selective dissolution of the soil/fly ash mixtures shows that many of the potentially toxic elements (e.g., B, Cr, Fe, Mn, Ni, Pb) are associated with the sulfide phase (HNO3 extractable) and with the residual material. In this study, the dynamics of elemental release from the element pools did not result in toxic conditions. The formation of colloidal material capable of mobilizing potentially toxic elements was not found in the soil/fly ash mixtures. Apparently, the high pH of the materials enhanced immobilization of the high molecular weight material.