Effect of voids in kaolin stabilised by ground granulated blast furnaces slag mixtures

Abstract

Kaolin is known as problematic soil which has a low strength that needs to improve before construction. Chemical stabilization with cement is used widely to stabilize different clay types; however, using it comes with disadvantages associated with carbon dioxide emission and sustainability issues. As an alternative to cement, Ground Granulated Furnaces Blast Slag (GGBS) has been applied to stabilise kaolin. The increment in the strength is due to the formation of new products that fill the soil voids. The formation of those new products is verified using Field Emission Scanning Electron Microscopy (FESEM). However, the changes in pore space cannot be quantified using FESEM. Thus, this study uses Image J to calculate voids area detected by (FESEM) for different kaolin-GGBS mixtures with different content of GGBS cured for different curing period. The book-like structure for the raw kaolin have changed slightly when mixed with GGBS. This is due to the formation of hydrate gels as a result of the pozzolanic reaction. The results from image J indicates that the void decreases as the content of GGBS increases as well as the curing period.