Mineralogical and mechanical analysis of cement-stabilised sands

Abstract

Wet deep-soil mixing methods are well-established procedures involving the mixing of a self-hardening slurry with in situ soil in order to improve its original hydraulic and mechanical properties. This paper presents the results of a comprehensive experimental investigation conducted on cement-stabilised sandy soil samples collected from six panels produced by the cutter soil mixing method. The wet-grab material used in the tests was taken at a depth of 2·0 m below ground level and cured in a controlled laboratory environment. A comparison of the outcomes obtained from qualitative and semi-quantitative mineralogical analyses (scanning electron microscopy (SEM) with energy dispersive X-ray spectroscopy (EDS) and X-ray powder diffraction) along with the interpretation of mechanical tests performed on the wet-grab samples provided a better understanding of the reaction mechanisms that occurred on site during hydration of the binder. Qualitative mineralogical analyses supported by an innovative semi-quantitative approach based on SEM–EDS investigations confirmed the presence and the influence of specific binder components (e.g. slag) involved in the hydration process.