Carbon capture and storage potential of biochar-enriched cementitious systems

Geetika Mishra, Panagiotis A. Danoglidis, Surendra P. Shah, Maria S. Konsta-Gdoutos*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

9 Scopus citations

Abstract

A promising solution to nullify the net embodied greenhouse gas emissions of civil infrastructure is the use of carbon-negative materials for concrete manufacturing. Carbon-neutral coal ash and agriculture/forestry by-products, such as biochar, exhibit a high carbon dioxide (CO2) uptake potential. The aim of the study is to explore the viability of using biochar as a carbon sink and to develop carbon-neutral concrete with improved performance. Experimental findings suggest that the optimal amount of biochar (1%) slightly improves hydration and mechanical properties, but the combination with mineral additives significantly enhances the performance. Thermogravimetric analysis (TGA) revealed that compared to OPC, the addition of 1% biochar contributes to a 42% increase in CO2 uptake, while the combination of biochar with 10% class C fly ash further increases CO2 capture capacity of the mix by 92%. Under accelerated carbonation conditions, the biochar-enriched mortars exhibit a 20% higher modulus of elasticity indicating an effectively increased stiffness over the reference carbonated OPC. The carbonated biochar mortars also exhibit up to 64% increased toughness indices indicating the material's great resistance to crack coalescence and propagation at the strain softening stage. Scanning Electron Microscopy and Energy Dispersive X-ray Spectroscopy (SEM-EDS) results validated our prediction that the porous morphology of biochar promoted enhanced CO2 absorption and in-situ mineralization of calcium carbonate, resulting in a denser and stronger cement matrix.

Original languageEnglish (US)
Article number105078
JournalCement and Concrete Composites
Volume140
DOIs
StatePublished - Jul 2023

Keywords

  • Biochar
  • CO sequestration
  • Crack propagation
  • Fly ash
  • Mineralization

ASJC Scopus subject areas

  • Building and Construction
  • General Materials Science

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