A Thai team treated recycled concrete aggregate with high-calcium fly ash, ground calcium carbide residue and CO2 curing before using it as the full coarse-aggregate fraction in high-strength concrete. Treatment reduced water absorption and improved strength, shrinkage, creep and chloride-migration behavior relative to untreated recycled aggregate.
Key findings
- The HFA-GCR-CO2 treatment performed best. Its 28- and 90-day compressive strength approached the natural-aggregate control; total shrinkage was 25.9% lower and specific creep 22.4% lower than untreated-RCA concrete, with lower chloride migration.
Why this matters globally
The work addresses natural-aggregate depletion, demolition waste and alkaline industrial residues while exploring CO2 mineralization within construction materials.
Thai researcher contribution
Researchers from three Thai universities developed and tested the material across multiple performance dimensions, with Tawich Klathae serving as corresponding author.
Limitations to consider
The study does not yet cover industrial scale-up, field exposure, service life, cost, energy use or full life-cycle carbon balance. CO2 curing and residue quality may vary by location.