UTILIZATION OF MARBLE DUST TO IMPROVE THE GEOMECHANICAL PROPERTIES OF A FINE GRAINED SOIL.

Abstract

The current study aims to explore the potential of marble dust (MD) to improve the geotechnical features of Karewa soil. For this purpose, a comprehensive exper- imental programme was carried out, in which different percentages of marble dust (10%, 20%, 30%, 40% and 50%) by dry weight of soil were added to assess its impact on its geomechanical properties. The strength gain was evaluated by conducting direct shear tests (DST) and unconfined compressive strength tests (UCS) after curing of samples for 7, 14 and 28 days. The test results depicted an increase in the strength characteristics of marble dust treated samples, reduced strain at failure and changed the behaviour to a relatively brittle one. Test results revealed that the strength of Karewa soil improved upto 40% addition of marble dust to soil beyond which a drop in the strength was noticed. Further the strength improved with the curing time, irrespective of the marble dust concentration in the soil. The gain in strength is attributed to the formation of cementitious products due to hydration and other pozollanic reactions between calcium oxide (CaO) of the marble dust and the oxides of Karewa soil. Utilization of marble dust in the construction sector serves two benefits; first, it will eliminate of the environmental degradation due to its wide spread disposal and second, it will prove an economical means of soil improvement.