NECESSARY (Net zEro CEments for Soil Stabilisation via wAste RecoverY)

This is an exciting opportunity to work on an industrial PhD research project at Ulster University with the UK’s leading specialist in ‘deep soil mixing’ (DSM) ground improvement, Deep Soil Mixing Ltd.

The UK is upgrading and expanding its highway and railway infrastructure. Significant sections of these infrastructure networks cross large areas of soft ground (e.g. river floodplains). To permit construction in such troublesome areas, ‘heavy engineering’ solutions such as reinforced-concrete piling are commonly used. However, this approach is unfavourable due to: 1) the high costs of Portland cement and steel in concrete and 2) Portland cement manufacture generates 8-10% of global CO₂ emissions.

An increasingly popular alternative ground improvement technique that: 1) produces zero waste; 2) achieves engineering strengths comparable with concrete and 3) makes time savings is DSM. DSM involves injecting cementitious binders into the ground, which produces a ‘soil-concrete’ to form foundations and remediate contaminated land. 

To date, DSM has used Portland cement binders. However, continuing this approach is unsustainable if the civil engineering industry is to achieve net zero carbon emissions by 2050 and limit global warming to 1.5^oC. It is therefore NECESSARY to expedite the development/commercialisation of Portland cement-free binders.

The ‘NECESSARY’ project will develop a new generation of Portland cement-free Net zEro carbon CEments for deep mixing Soil Stabilisation via wAste RecoverY. Focus will be paid towards valorising some of the UK’s largest and ‘untapped’ waste reserves (e.g. quarry dusts, excavated soils/rocks, plastics), representing >220m tonnes/year. This sustainable approach will facilitate growth within the UK’s circular economy.

Working with Deep Soil Mixing Ltd will have the added benefits of using findings from the NECESSARY project in developing new low-carbon ‘state-of-the-art’ practice in DSM ground improvement technology. Furthermore, this will provide pathways to impact in the ground engineering industry that will benefit engineering infrastructure stakeholders.