Experimental Investigation of Sustainable Concrete With Precipitated Calcium Carbonate Binders and Upcycled Concrete Aggregates

This study explores the feasibility of using Precipitated Calcium Carbonate (PCC) as a partial cement replacement and Upcycled Concrete Aggregates (UCA) as a substitute for virgin aggregates while maintaining viable mechanical properties. The benchmark mix was designed using the absolute volume method, with PCC replacing 20%, 30%, 60%, and 70% of Portland cement by weight, and UCA (both fine and coarse) introduced as replacements for virgin aggregate. The results indicate that PCC and UCA can be effectively utilized in concrete production without significant compromise in compressive strength, particularly at lower replacement levels. A 20% PCC substitution demonstrated a compressive strength of 23 MPa. However, higher replacement ratios resulted in a reduction in the compressive strength of the concrete by 48.44%, 75.43%, and 81.25% for PCC substitution of 30%, 60%, and 70%, respectively, compared to the benchmark specimen with 100% UCA and 0% PCC. These findings highlight the potential application of PCC and UCA in sustainable construction by reducing reliance on virgin materials, reducing carbon footprint, and minimizing construction waste. Further research on the optimization of the mixture and treatment methods for PCC can enhance the structural performance of the concrete.