A Study on Characteristics of Subgrade Soil by Use of Foundry Sand and Iron Turnings

It is due to continuous increase in industrial by-products and wastes, solid waste management in present scenario has become a global environmental concern. Due to costly disposal of waste materials and shortage of landfills, it is the need of the hour to reuse the waste materials in various construction activities in a eco-friendly way. Foundry sand is one of such industrial by-product causing hazardous effect on environment and human being. The natural properties of foundry sand can be used to utilize it in sub-grade of a pavement to avoid any possible threat to environment and giving a way for safe and economical disposal of the same. Other industrial waste is iron turnings which can also be reused. This study is about the improvement of compaction and sub-grade characteristics of sandy clayey soil by blending it with foundry sand and iron turnings in specified proportions. The various strength parameters i. e. compaction characteristics and California Bearing Ratio (CBR) of different mix proportions of soil, foundry sand along with iron turnings were studied. It was observed that the Maximum Dry Density (MDD) and California Bearing Ratio (CBR) values increases up to certain proportion of addition of foundry sand in sandy clayey soil and thereafter on further addition of foundry sand it starts decreasing. The same trend was also observed with the introduction of iron turnings in selected soil-foundry sand mixture. As a result a suitable composition with optimum percentage of clayey soil, foundry sand and iron turnings was found, which can be effectively used in the construction of sub-grade of roads and embankments giving a way for good and economical construction.