Enhancing Concrete Sustainability: A Study on the Strength and Durability of Low-Carbon Concrete Matrices with Alternative SCMs

In recent years, there has been a growing interest in improving the sustainability of the concrete industry mainly through the incorporation of supplementary cementitious materials (SCMs) into concrete mixtures. This approach reduces the dependency on Portland cement and allows the recycling of waste generated by numerous industries. In order to achieve this symbiotic relationship, an analysis was carried out on the corresponding mortar matrices of low-carbon concrete. In this study, alternative SCMs, such as rice husk ash, glass waste powder, forest biomass ash, and rock wool residues were tested by partially replacing cement at both 25% and 50% replacement rates. The mixtures were then compared with a reference mixture in which the same proportion of cement was replaced by fly ash, a well-established and extensively researched traditional SCM that is becoming inaccessible in several developed countries due to environmental restrictions. This paper presents and discusses the results of the mechanical properties (compressive and flexural strength) and durability performance (capillary water absorption, surface electrical resistivity, and carbonation resistance). The results show that the replacement of cement with rice husk ash is more advantageous than with fly ash for all the considered properties.