USE OF WASTE GLASS IN IMPROVING SUBGRADE SOIL PROPERTIES

Mwajuma Ibrahim Lingwanda

Abstract: Pavement design standard in Tanzania require all subgrades to have a minimum California Bearing Ratio (CBR) value of 15% along with a Plasticity Index (PI) of not more than 25%. If these conditions are not fulfilled, improvement is mandatory. There are many cases where the natural subgrade fails the criteria. On the other hand, waste materials such as glass may be available locally or at a nearby distance. In many areas of the country, resources may not be available for recycling the glass. This study proposes improvement of a clay soil subgrade using crushed glass whereby a 10% by weight of the natural soil has resulted to an increase in CBR by 300% and a decrease in PI by 46% thus achieving the required quality as stipulated in the relevant standard. Environmental studies are recommended to forecast the possible effect of using crushed glass in subgrade improvement and propose appropriate counter measures

Keywords: Subgrade improvement, waste glass, Tanzania pavement design standard, soil stabilization using waste materials

DOI: https://doi.org/10.15623/ijret.2018.0704005