Micro-level analysis of marine clay stabilised with polyurethane

Abstract

Soil stabilisation is one type of ground improvement technique regarded as effective in minimising foundation problems associated with marine clay (MC). In this paper, in-depth micro-level analysis was conducted on MC stabilised with 8% Polyurethane (PU). The effectiveness of PU as a stabiliser was evaluated using unconfined compressive strength (UCS) tests and one-dimensional consolidation tests. Mineralogy of MC was studied using X-ray diffraction analysis (XRD). Furthermore, field emission scanning electron microscopy (FESEM) and energy dispersive spectroscopy (EDX) were used to discern the roots of improvement in the strength of MC. The result of XRD analysis identified the presence of Quartz, Montmorillonite, Calcite and Clinochlore. FESEM results discovered that MC showed crumpled, curled and flaked soil particles that have a fuzzy arrangement and cusp-like crystals in a joined fashion. The contact among the particles is surface-to-surface and surface-to-edge. The PU foam was composed of intramolecular closed cells that are non-homogeneous, non-identical, and of inconsistent average diameters of about 2.3 µm. Finally, EDX results revealed that O, C, Si, Al, Fe and N are the elements that contributed more than 96% of the composition of MC and PU. © 2020, Korean Society of Civil Engineers.