Performance Characteristics of Pavement Sub-base Containing Steel Slag

Abstract

A sub-base is normally a granular layer in a pavement and comprises of aggregates with a specified grading. Good quality aggregates mostly derived from natural stone resources are now a days getting scarce and are becoming too costly in several locations because of longer lead involved. In this regard, engineers and researchers are constantly working on replacing aggregates which constitute bulk of a pavement layer, with alternate and waste materials. This paper deals with utilisation of abundantly and locally available steel slag, an industrial waste of a local integrated steel plant in pavement sub-base, thus not only offsetting the problems such as cost of construction, solid waste disposal problems and environmental concerns, but also helping preservation of natural stone resources for other essential uses. The experimental programme includes grading of available steel slag and normal aggre gates, blending of slag with aggregates to achieve the desired gradation, and compaction test to determine the optimum moisture content. The study also includes other important performance characteristics such as expansion potential and CBR besides verifying the hazardous effects of using slag in pavement sub-base. It is observed that the use of aged steel slag results in much better performance characteristics, besides satisfying the environmental requirements, thus providing a solution of building a sustainable pavement in sites not far from steel plants.