Synergistic effects of calcium carbonate (CaCO3) as binder and granite waste as aggregate type on hydraulic composite material performances: mechanical strength and environmental impacts

Protecting the environment by recycling waste is one of the major challenges of our time. Inert waste, mainly generated by industry, represents a significant proportion of the total, which is harmful to the environment through its accumulation in nature. The main objective of this study is to examine the influence of using calcium carbonate (CaCO3) (seashell powder (SSP)) as cementitious materials combined with granite waste (GW) as fine aggregates on the rheological, mechanical properties and environmental impacts of new self-compacting sand concrete (SCSC). For this study, GW was used as fine aggregate sand to replace the natural sand at rates of 0%, 10%, 20%, and 30% by volume, and the SSP has been used to substitute the cement at rates of 0%, 5%, and 10% by weight. The results of this study demonstrate that the introduction of seashell powder as cementitious materials positively influenced the rheological characteristics, notably reducing the need for superplasticizer dosage. Nonetheless, in terms of mechanical outcomes, the use of GW led to improved mechanical strengths. This study offers encouraging results into optimizing SCSC mixtures with SSP and GW in environmental impacts.