Development of Serpentine Carbon Sequestration Foamed Concrete with Self-Carbonation Mechanism

Serpentine tailings could be used as a low-carbon binder to replace Portland cement. This paper developed a novel technique of foamed concrete using serpentine tailings, reactive magnesium oxide (RMC), and carbon dioxide (CO2) foams, so called serpentine carbon sequestration foamed concrete (S-FC). The technology enhances the carbonation efficiency and mechanical performance of MgO-based materials by combining a foaming agent with CO2 curing. Six sample groups were prepared to investigate the impact of serpentine proportions on the mechanical behavior and microstructure of S-FC. Hydration of serpentine and RMC was evaluated by isothermal calorimetry. Compressive strength results were used to assess the mechanical performance of SC-FLS samples. Quantification of hydrate and carbonate phases was conducted via XRD and TGA to examine the potential of SC-FLS in carbon sequestration. An optimal design was determined for serpentine content by the combination of the above tests. Results highlight the capacity of SC-FLS to sequester CO2 actively.