Work

Transforming recycled construction waste fines into carbon sink material via accelerated mechanochemical carbonation: A novel approach to CO2 sequestration

Year: 2025

Type: article

Abstract: The increasing demand for sustainability in construction has driven research into alternative CO 2 sequestration and mineral utilization strategies. The present study investigates the innovative solvent-free mechanochemical carbonation (MCC) of various recycled construction waste fines, including construction and demolition waste (CDW), concrete waste (CW), and excavation waste (EW), to enhance carbonation efficiency and CO 2 sequestration. The effect of MCC time on direct mineral carbonation was systematically assessed, and its performance was evaluated based on the calcium carbonate (CC) content. MCC activation reduced crystallite size and promoted depolymerization of the silica chain structure of CDW, CW, and EW, enhancing its carbonation reactivity. Fourier-transform infrared spectroscopy (FTIR) analysis detected significant shifts in peaks corresponding to carbonate and silicate groups, confirming the chemical transformations associated with carbonation. The thermogravimetric analysis (TGA) results indicated the formation of calcite, with maximum CO 2 uptake occurring within one hour of MCC. Prolonged MCC (2h and 4 h) resulted in the formation of metastable and amorphous calcium carbonates. Results indicated that MCC effectively enhances the carbonation of EW, demonstrating the highest carbonation degree of 87.96% after one hour of milling. The carbonation degree of CDW and CW reached 40.11% and 21.47%, respectively, within the same duration. The CO 2 uptake was 12.55 wt% for 1 h MCC-treated EW, highlighting the potential of the MCC to achieve rapid and efficient carbonation. The performance surpassed the results of conventional wet carbonation, which typically requires around 3 hours to achieve a similar outcome.

Source: Journal of Building Engineering

DOI: 10.1016/j.jobe.2025.114630

Authors: Marwa Saadeh, Naeem Albeitjali, Muni Raj Maurya, Mohammad R. Irshidat

Institution: Qatar University

Language: English

Topic: CO2 Sequestration and Geologic Interactions

Subfield: Environmental Engineering

Field: Environmental Science

Domain: Physical Sciences

SDGs: Responsible consumption and production, Climate action, Sustainable cities and communities

Open Access status: hybrid

Estimated APC paid: $3,940