Evaluation of mechanical properties and environmental impact of using limestone powder in high-performance concrete

Abstract

In this study, various dosages of limestone (LS) powder (10, 15 and 20%) of varying fineness were used as a replacement for cement to investigate its influence on the selected properties of high-performance concrete (HPC). The efficiency factor and carbon dioxide (CO2) equivalent emissions were evaluated for life cycle assessment of HPC mixtures containing LS powder. The workability, compressive, split tensile and flexural strength, semi-adiabatic temperature rise and autogenous shrinkage of HPC were investigated. The results indicated that workability and density were enhanced by replacing cement with fine and intermediate LS powder in comparison with coarse LS powder. The compressive, split tensile and flexural strengths were all reduced by increasing the replacement level of fine, intermediate and coarse LS powder at all curing ages. Furthermore, higher temperature peaks and high autogenous shrinkage were observed in fine LS mixtures due to the nucleation effect and the accelerating hydration reaction of fine LS particles. The highest efficiency factor and highest reduction in carbon dioxide equivalent emissions was observed in the mixtures containing 20% coarse LS powder followed by the intermediate LS powder. This research work may help in understanding the role of varying finenesses of LS powder as a viable material in high-performance-based composites.