Effectiveness of a hydrothermally produced alternative cementitious material on the physical and mechanical performance of concrete

Abstract

With the aim to reduce the carbon dioxide (CO2) emission during the cement manufacturing, the production of an alternative cementitious material (ACM) would be a promising approach. In this investigation, the ACM was produced by the hydrothermal method utilizing calcium carbonate, silica fume, and hydrated alumina. The performance of the ACM was evaluated fabricating and characterizing the concrete composites. Finally, a plausible model has been proposed to explain the overall performances of the ACM. Based on the particle size, chemical composition, X-ray diffraction, and microstructure analysis, it is demonstrated that the ACM contains some geopolymer compounds with an average particle diameter 1.4 gm. As the hydrothermal synthesis of ACM requires much lower temperature than that of the traditional clinker production step, therefore, the method is expected to be a less energy intensive, which would emit a less extent of CO2 as compared to that of the existing process. Analyzing the physical and mechanical properties, it is revealed that the ACM based concrete behaves similarly to that of the conventional concrete and yields-33 MPa compressive strength and 4.1 MPa splitting tensile strength. Utilization of the hydrothermally produced ACM as a primary binder for the fabrication of a concrete composite can be considered to be a sustainable development.