Work

Towards Net-Zero Ground Improvement: Sustainable Sulfate Soil Stabilisation Using Lime, Ground Granulated Blast Furnace Slag and Metakaolin

Year: 2026

Type: article

Abstract: This article presents laboratory experiments examining the potential benefits of the synergistic effects of ground granulated blast furnace slag (GGBS) and metakaolin (MK) on lime (L) stabilisation of synthetic sulfate-bearing soil. The different soil–binder mixtures considered in this study were prepared by partially replacing lime with GGBS, metakaolin, or a combination of both, at substitution levels ranging from 25% to 75% by mass. The engineering performance of the mixtures was characterised through physico-mechanical analyses (unconfined compressive strength and linear expansion) and microstructural analyses (X-ray diffraction and scanning electron microscopy). Among the binary binders examined in this study, the GGBS-rich binder demonstrated the highest strength, while the metakaolin-rich binder exhibited the lowest swelling behaviour. This difference in performance was balanced by the ternary L–GGBS–MK blend, particularly at a blending ratio of 5L–12.5GGBS–2.5MK. This optimal blend produced a near-zero linear expansion of 0.04%, with only a negligible reduction in strength compared with the binary blend 5L–15GGBS. By replacing a substantial proportion of lime with industrial by-products, the proposed stabilisation strategy reduces reliance on high-carbon conventional binders, supporting the development of green, low-carbon, and resource-efficient construction materials. The findings demonstrate the potential of circular material utilisation to mitigate sulfate-induced heaving while enhancing the durability and sustainability of ground improvement practices. This innovative approach addresses geo-environmental challenges associated with lime stabilisation and aligns with the broader transition towards net-zero construction, promoting the beneficial reuse of industrial by-products, reducing embodied carbon, conserving natural resources, and advancing environmentally responsible geotechnical engineering solutions for sustainable infrastructure development.

Source: Buildings

DOI: 10.3390/buildings16173525

Authors: Mansour Ebailila, Khaled Ehwailat, Jonathan Oti, Mohd Ismail, John Kinuthia

Institutions: Bani-Waleed University, University of South Wales, Universiti Sains Malaysia

Language: English

Topic: Geotechnical Engineering and Soil Stabilization

Subfield: Civil and Structural Engineering

Field: Engineering

Domain: Physical Sciences

SDGs: Responsible consumption and production, Climate action, Sustainable cities and communities, Industry, innovation and infrastructure

Open Access status: gold

Estimated APC paid: $3,137