Development of CO2 Mineralised concrete for carbon sequestration: Thermogravimetric analysis and life cycle assessment

Portland cement production accounts for approximately 8% of global anthropogenic CO₂ emissions, necessitating carbon mitigation strategies for the concrete industry. While carbonation curing has demonstrated carbon sequestration potential, existing research focuses predominantly on conventional concrete (w/ c > 0.5) or ultra-high-performance concrete (w/ c < 0.2), leaving high-performance concrete (0.3 < w / c < 0.5) unexplored. This study examined dry ice incorporation at 0%, 5%, 10%, and 15% by cement weight in concrete with w/ c = 0.35, employing X-ray diffraction, thermogravimetric analysis, compressive strength testing, pH measurements, and life cycle assessment. Results demonstrated systematic calcium carbonate formation with CaCO 3 content increasing from 6.38% to 10.23% while Ca(OH)₂ decreased from 9.60% to 7.78%, yielding net CO₂ sequestration of 17.4 kg/m³. Compressive strength at 28 days improved 22.6% (40.2 MPa) relative to control (32.8 MPa), while pore solution pH remained above 11.0, ensuring corrosion protection. Strength-normalized emission intensity decreased 21.5%, substantially exceeding absolute emission reductions of 3.8%. The optimal 10% dry ice dosage achieved 21.3% strength enhancement and 20.3% environmental efficiency improvement without specialized equipment, demonstrating feasibility for industrial carbon utilization in structural concrete applications.