Earth stabilisation via carbonate precipitation by plant-derived urease for building applications

Cuccurullo, A.; Gallipoli, D.; Bruno, A.W.; Augarde, C.; Hughes, P.; La Borderie, C.

Abstract

Raw (unfired) earth represents a sustainable and efficient alternative to traditional construction materials but its dissemination into building practice has been hindered by a relatively high vulnerability to water erosion. Enzyme induced carbonate precipitation (EICP) can improve the durability of earth materials without using traditional chemical binders such as cement and lime. EICP utilises the urease enzyme to catalyse the hydrolysis of urea, which produces carbonate ions that react with the calcium ions dissolved in the pore water, thus resulting in the precipitation of calcium carbonate. The calcium carbonate fills the soil voids and binds particles together, which reduces water permeability and increases material strength. The urease enzyme is a hexameric protein that is found in the tissues of many common plants. This work proposes a low-cost and simple stabilisation technology that makes use of crude urease enzyme extracted from soybeans. This technology is applied to the stabilisation of compacted earth, whose properties are then assessed via unconfined compression, moisture buffering and durability tests. The findings suggest a noticeable improvement of material strength and durability, though further investigation is necessary to increase the competitiveness of EICP stabilisation against standard techniques using cement and lime.

Citation

Cuccurullo, A., Gallipoli, D., Bruno, A., Augarde, C., Hughes, P., & La Borderie, C. (2022). Earth stabilisation via carbonate precipitation by plant-derived urease for building applications. Geomechanics for Energy and the Environment, 30, Article 100230. https://doi.org/10.1016/j.gete.2020.100230

• Journal Article Type: Article
• Acceptance Date: Dec 11, 2020
• Online Publication Date: Dec 14, 2020
• Publication Date: 2022-06
• Deposit Date: Jan 14, 2021
• Publicly Available Date: Nov 4, 2022
• Journal: Geomechanics for Energy and the Environment
• Electronic ISSN: 2352-3808
• Publisher: Elsevier
• Peer Reviewed: Peer Reviewed
• Volume: 30
• Article Number: 100230
• DOI: https://doi.org/10.1016/j.gete.2020.100230
• Public URL: https://durham-repository.worktribe.com/output/1253752