Carbonation curing behavior and performance improvement of recycled coral waste concrete

Carbonation curing can improve material properties and reduce the concrete industry's carbon emissions. This study used powder prepared from waste coral to replace ordinary Portland cement (0, 10, and 20 %). After initial curing for 24 h, the mortar was cured by sealing and carbonation. The dilution effect of coral powder substantially reduces the mechanical properties under sealing curing. Under carbonation curing, the coral powder helps develop carbonation and CO2 diffusion, reducing strength loss and increasing resistivity. XRD and Fourier transform infrared spectroscopy analysis results showed that carbonation transforms hydration products and clinker phases into different types of CaCO3, such as calcite and aragonite. The novelty of this study is that it proposes a method that organically combines carbonation curing and marine waste reuse. Provide a sustainable solution to the problem of material shortage in marine engineering construction. Moreover, the carbon footprint can be considerably reduced by replacing cement materials, improving carbonation curing efficiency, and promoting CO2 uptake.