Valorization of deep soil mixing residue in cement-based materials

Abstract

This study examined the potential of recycling deep soil mixing residue (DSMR), a cement-soil waste, as a partial Portland cement substitute. The chemical and mineral compositions of DSMR before and after calcination were determined. For the calcined DSMR blended cement pastes, the compressive strength and phase assemblage (characterized using TGA and XRD) were evaluated. Results revealed pozzolanic and hydraulic properties of the calcined DSMR, due to the formation of reactive calcium-rich glassy phases and hydraulic C2S. The calcined DSMR can contribute to the strength development of cement because of the pozzolanic reactions and the formation of additional hydrates. With up to 20% calcined DSMR, negligible side-effect on the strength of the blended cement paste was noticed. The compressive strength development of the blended cement pastes was linearly correlated to the reactive phase content in the calcined DSMR. This work demonstrated the potential of using DSMR to develop greener composite cement.