Radial deformation and failure of stabilised soft clay under uniaxial compression

Abstract

This study examined the performances of four newly developed binders in stabilising soft Finnish clay by considering both the mechanical behaviour and environmental effect (i.e., carbon footprint). Thirty-six compacted clay-binder mixtures were investigated via uniaxial compression tests, during which photogrammetric scans were performed at axial strains of 0, 1, 3, and 7.5%. The testing protocol enabled the characterisation of full-field radial deformations and fracture developments. Experimental results demonstrated that varying the amounts and types of industrial by-products used in the production of binders has substantial potential to reduce carbon footprints. In terms of radial deformations, their distributions were highly non-uniform at different heights and loading stages. Radial displacements increased continuously at axial strains smaller than 3% (corresponding to peak strength point), whereas such a continuity disappeared afterwards, and global failures appeared. Based on three-dimensional (3D) reconstructions, the observed failures were categorised into three modes: inclined shearing (IS), axial splitting (AS) and hybrid shearing-splitting (HSS). For the studied specimens, shearing was the most common mechanism leading to failure.

Keywords

• Stabilised soft clay
• Photogrammetry
• Compressive cracks
• Failure mode
• CO2 emissions per strength
• Sustainable binder mixture