Stabilisation of waste soils using novel binders

Abstract

In Singapore, underground spaces are created by removing large amounts of unwanted residual soils from construction sites. Land-scarce Singapore has adopted the use of these soils in land reclamation to simultaneously solve the challenges of proper disposal of residual soils and the need for imported fill materials in land reclamation. However, with some treatment methods, these stabilised waste soils could be used in other high value applications like unfired bricks. In the recent years, granulated ground blast furnace slag (GGBS) has gained increasing popularity in replacing Ordinary Portland cement (OPC) for soil stabilisation due to its lower energy consumption and carbon emissions. Hence, this project aims to investigate the effectiveness of carbide slag (CS)- activated GGBS, as a novel binder, in stabilising residual soil and its potential in brick making. A range of experiments were conducted to compare the engineering properties of CS-GGBS and PC stabilised soil, which includes unconfined compressive strength (UCS), water absorption and scanning electron microscopy (SEM) tests. Overall, the test results showed that CS-GGBS has the potential to substitute PC as a more economical and environmentally friendly binder in soil stabilisation.