Effect of Slag on Strength and Hydraulic Properties of Lime Stabilized Pond Ash

Abstract

Massive urbanization in the recent times has led a high increase in the power demands and eventually an increase in the production of pond ash generated as a waste material from thermal power plants. To decrease the environmental pollution and hazardous effects, it is imperative to utilize pond ash. But pond ash as such does not have enough strength to be used in civil engineering. So, it is advisable to improve the engineering properties of the pond ash by stabilizing it by adding other materials. In the present study effect of lime and ground granulated blast furnace slag (GGBS) on strength and hydraulic conductivity properties of pond ash are determined. Lime as stabilizing agent in different proportions (0, 3, 6, 9, 15 %) and slag as admixture are added in different proportions (0, 5, 10 and 15%) and the compaction characteristics of the resulted mixture were determined by standard proctor test, strength by Unconfined Compressive Strength test (UCS) and hydraulic conductivity by permeability test. The UCS samples were cured for 0, 3, 7, 14 and 28 days and the strength was determined. The permeability samples are cured for 0, 7, 14 and 28 days. The results showed an increment of maximum dry density and decrease in optimum moisture content with an increasing lime content, slag and curing period. The effect of lime and slag content on the strength and hydraulic properties of the pond ash samples at various curing periods are studied. The results are examined and the optimum percentages of slag required for attaining maximum strength at 3% and 15% lime at different curing periods are reported as the desired proportion for stabilization.