Mechanical-volumetric behaviour of soils stabilised with low carbon binders

Expansive soils are clay-rich materials characterised by high compressibility, low shear strength, and significant volumetric changes in response to moisture fluctuations. These properties make them particularly problematic for engineering applications, as they can lead to substantial structural damage over time. Such soils are widespread globally, and in Australia alone, expansive soils affect approximately 20% of the land surface. This extensive presence poses serious challenges to the safe and cost-effective development of infrastructure, including residential, commercial, and transportation projects.

Traditional soil stabilisation methods, such as the use of cement and lime, have been widely adopted to improve the performance of expansive soils. While effective in enhancing strength and reducing swell-shrink behaviour, these approaches contribute significantly to carbon emissions due to the energy-intensive nature of cement and lime production. With increasing concerns about climate change and environmental sustainability, there is a pressing need for alternative solutions that are both effective and environmentally responsible.

This research aims to address that need by developing innovative, low-carbon stabilisation techniques for expansive soils. The focus is on the incorporation of fibres and additives derived from recycled or waste materials, particularly biochar. Biochar, a carbon-rich product resulting from the pyrolysis of biomass, has shown promise in improving the mechanical behaviour of soils while also contributing to long-term carbon sequestration.

The study will assess the effects of various organic and synthetic fibres, in combination with biochar, on the volumetric behaviour and mechanical strength of expansive soils. A rigorous research programme involving laboratory testing and analytical modelling will be undertaken to evaluate the performance and sustainability of the proposed stabilisers.

The ideal candidate for this research should have a strong interest in sustainable environmental geotechnics, a passion for hands-on experimental work, and well-developed analytical and mathematical skills. Fluent written and oral communication skills and past research experience will be highly valued.