Effects of ground granulated blast furnance slags (GGBS) and lime/activated magnesium oxide on engineering properties of Kaolin

Abstract

Recently, land reclamation has become a vital activity due to the rapid industrialization and urbanization. For Singapore, a geographically small nation with booming population, land reclamation is essential to fulfill the demand of land usage. Singapore used to import sea sand, the raw materials for reclamation, from Southeast Asian region. However, lately some neighboring nations such as Indonesia and Malaysia refused to export the sand and this impair the land reclamation project. Hence, Singapore has to find alternative ways for land reclamation not only to meet the demand but also to pursue the upcoming development projects.

This project aims to propose an alternate solution of using clay soil with low strength for land reclamation. It will focus on the effect of ground granulated blast furnace slags and its activator magnesium oxide on improving engineering properties of kaolin (model soil for clay). A range of tests were performed to identify the strength, stability and suitability of the treated soil mixture. The tests conducted include unconfined compressive strength, soaking test, field emission scanning electron microscopy and energy dispersive X-ray spectroscopy. The result shows that MgO-GGBS binder is capable to improve the strength of kaolin yet the amount of binder content and the MgO:GGBS ratio need to be chosen carefully for land reclamation project due to the stability issue.