Alkali Stabilized Fly Ash: A New Generation Geo-Material

Abstract

In this project, an effort was made to assess the index, chemical and engineering properties of fly ash and alkali stabilized fly ash to evaluate alkali stabilized fly ash as new generation geo-material in civil engineering construction. First the physical, chemical and engineering properties of the fly ash samples were studied by conducting grain size distribution, hydrometer analysis, heavy compaction test, UCS test, falling head Permeability test and pH test of original fly ash samples. Then fly ash was mixed with 2%, 4%, 8 %,12% , 16% and 20% of alkalis (i.e. NaOH, KOH and Ca(OH)2) as a percentage of total weight of the mixture and with the resultant mixture modified proctor test was performed, corresponding to particular maximum dry density (MDD) and optimum moisture content (OMC) obtained from heavy compaction test the unconfined compressive strength (UCS) samples and permeability samples were prepared. The UCS samples were cured for 0, 3, 7, 28 and 70 days at a constant temperature of 270C, whereas permeability samples are cured for 0, 3, 7 and 28 days before testingto evaluate the effectiveness of alkali stabilized fly ash as an alternate geo-material.Further more XRD, SEM and EDX study were conducted for selected samples.The UCS samples were sealed with wax to avoid the loss of moisture and the permeability samples were made fully saturated before testing.