Sustainable soil stabilisation with ground granulated blast-furnace slag activated by olivine and sodium hydroxide

Fasihnikoutalab, M. H., Pourakbar, S., Ball, R. J., Unluer, C. and Cristelo, N. (2019) Sustainable soil stabilisation with ground granulated blast-furnace slag activated by olivine and sodium hydroxide. Acta Geotechnica, (doi: 10.1007/s11440-019-00884-w)

Abstract

Ground granulated blast-furnace slag (GGBS), activated with olivine (Mg2SiO4) and sodium hydroxide (NaOH), was used to stabilise a clayey soil. Mechanical and microstructural properties of the stabilised soil were assessed through uniaxial compression strength (UCS) tests, X-ray diffraction, scanning electron microscopy and energy-dispersive X-ray spectroscopy (EDS), after curing periods of 7, 18 and 90 days. The UCS of the GGBS-treated soil (without activation with NaOH), even at the highest slag dosage (G20S), after 90 days, showed only a slight increase (142 kPa) relatively to the original soil. When olivine was added to the GGBS-treated mixture (O20G20S), the UCS increased to 444 kPa, after 90 days. However, when NaOH was used as an activator, the UCS of the olivine–GGBS-treated soil (NO20G20S) increased to more than 6000 kPa, after 90 days. This significant strength increase was attributed to the higher reaction degree provided by the NaOH, which enabled a more effective exploitation (dissolution) of the Ca and Mg present in the slag and olivine, respectively, forming a mixture of C–S–H and M–S–H gels.

• Item Type: Articles
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Unluer, Dr Cise
• Authors: Fasihnikoutalab, M. H., Pourakbar, S., Ball, R. J., Unluer, C., and Cristelo, N.
• College/School: College of Science and Engineering > School of Engineering > Infrastructure and Environment
• Journal Name: Acta Geotechnica
• Publisher: Springer
• ISSN: 1861-1125
• ISSN (Online): 1861-1133
• Published Online: 30 November 2019