Correlations to assess compaction characteristics of local silty clay soil-fly ash mixes

For assessment of compaction characteristics of local silty clay soil-fly ash mixed samples, correlations have been established in this paper. Local silty-clay soil (collected from Agartala, Tripura, India), fly ash (collected from Kolaghat Thermal Power Plant, West Bengal, India) and soilfly ash mixes (with percentages of fly ash in the mix 10, 15, 20, 25 and 30% on dry weight basis), in total nineteen numbers of samples are considered. Geotechnical parameters like, specific gravity (G), maximum dry density (MDD), optimum moisture content (OMC) and initial void ratio (ei) on soil, fly ash and soil-fly ash mixes are found out based on the laboratory tests conducted. Correlations based on the regression analysis in the form of linear, logarithmic and power curves, linear, exponential, logarithmic and polynomial curves, and linear, logarithmic, polynomial and power curves are established to assess MDD as function of OMC, as function of G, and as function of ei respectively; correlations also established in the form of linear, exponential, logarithmic, polynomial and power curves to assess OMC as function of G. Correlations are validated by data of earlier researchers and verified by present data which were not used for development of these correlations. These empirical relationships would be helpful for preliminary estimation of MDD and OMC of samples. The value of the coefficient of determination (R2) is near about 1.00 for all the equations established. Errors in the 89.90% of predicted values, verified with the data of earlier studies and present data are less than 10% which show the efficiency of the relationships. © 2012 ejge.