Optimal mix design of low-CO2 blended concrete with limestone powder

Abstract

Limestone powder has increasingly been employed in the production of sustainable concrete. This research shows an optimal design framework for the design of low-CO2 blended concrete with limestone, considering strength, workability, and carbonation durability in the context of global warming. First, the purpose of the optimal design, i.e., to reduce CO2 emissions, is explained. The restrictions of the optimal design include design strength, design workability, carbonation service life in the context of global warming, component ratio, component range, and absolute volume. The compressive strength and carbonation depth are evaluated using a hydration-based integrated model. Second, concrete mixtures, with different strength levels, are determined based on a genetic algorithm. The results of a low-CO2 concrete mixture for carbonation durability in the context of global warming are provided. The suggested method can find a threshold strength, which could allow for the isolation of the control factor of the mixture design, for example, a carbonation durability control or strength control. In addition, the threshold strength of the mixture design increases with global warming.