Sustainable cementitious blends for strength enhancement of dredged mud in Queensland, Australia

Abstract

Cement is commonly used as a stabilisation material in soft soil stabilisation. However, the use of cement can cause environmental issues, as the production of cement results in high emission of carbon dioxide (CO2). Hence, it is essential to develop other suitable stabilisation materials to reduce the amount of cement used in the stabilisation of soft soil. Fly ash and DuraCrete (blended cement) were investigated in this study to be used as partial replacements for traditional cement-only mixes. The behaviour of specimens stabilised using cement, fly ash and DuraCrete under both unconfined compressive and consolidated isotropic undrained conditions was investigated in this study. The experimental results proved that both fly ash and DuraCrete can be used as partial replacements for cement. Fly ash can provide the highest reduction in terms of percentage of cement. Meanwhile, DuraCrete is more cost effective, as a relatively smaller quantity of DuraCrete can replace a correspondingly larger amount of cement for a similar strength gain. The contribution of this research can provide engineers with alternative, more sustainable design mixes for soft soil stabilisation that can readily satisfy design strength requirements while emitting relatively less carbon dioxide.