Changes in geotechnical properties of urban soils during carbonation

Ehsan M. Jorat, Ben W. Kolosz, Saran P. Sohi, Elisa Lopez-Capel, David A. C. Manning

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Abstract

Urban soils that contain materials derived from demolition undergo carbonation as a consequence of a reaction between Ca derived from cement and concrete, and carbonate ultimately derived from the atmosphere. Estimated rates of CaCO3 accumulation are equivalent to the removal of 150T CO2 ha-1 yr-1. Although this process has benefits for carbon capture, the formation of CaCO3 within the soil potentially affects the geotechnical properties. Trial pits at a number of locations have consistently yielded CaCO3 contents of 20 wt% from 0-1m depth. Carbonate has formed in intergranular space within the soil, possibly with improvements in strength but also with changes in permeability that may affect through drainage. This paper investigates the limits to CaCO3 formation imposed by soil porosity for a number of artificial soils: 'well sorted sand or gravel', 'sand and grave, mixed', 'silt' and 'clay'. Calculated values for CaCO3 for the various soil types are used to determine limits to CaCO3 formation within the first 1 m of sediments at the Science Central Site in Newcastle upon Tyne, UK, using information derived from five trial pits within made ground.
Original languageEnglish
Title of host publicationFrom fundamentals to applications in geotechnics
Subtitle of host publicationproceedings of the 15th Pan-American Conference on Soil Mechanics and Geotechnical Engineering, 15-18 November 2015, Buenos Aires, Argentina
EditorsDiego Manzanal, Alejo O. Sfriso
Place of PublicationAmsterdam
PublisherIOS Press
Pages912-918
Number of pages7
ISBN (Electronic)9781614996033
ISBN (Print)9781614996026
DOIs
Publication statusPublished - 11 Dec 2015
Externally publishedYes

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Jorat, E. M., Kolosz, B. W., Sohi, S. P., Lopez-Capel, E., & Manning, D. A. C. (2015). Changes in geotechnical properties of urban soils during carbonation. In D. Manzanal, & A. O. Sfriso (Eds.), From fundamentals to applications in geotechnics: proceedings of the 15th Pan-American Conference on Soil Mechanics and Geotechnical Engineering, 15-18 November 2015, Buenos Aires, Argentina (pp. 912-918). IOS Press. https://doi.org/10.3233/978-1-61499-603-3-912