Investigating the mechanical properties, durability, microstructure, and embodied CO ₂ emissions of silica fume‐infused sustainable concrete

Abstract Silica fumes are investigated as a strengthening agent for grade 30 concrete in this study. Silica fume was added in weight proportions of 4, 8, and 12 wt.%. The slump test, ultrasonic pulse velocity, total water absorption, compressive strength, and embodied CO ₂ emissions of the newly developed concrete mix were determined. The results of this study indicate that silica fumes positively affect concrete's mechanical characteristics, durability, and microstructure, as well as its embodied CO ₂ emissions. In addition, silica fume concentrations have been shown to enhance concrete's compressive strength. The major compressive strength increment was 37% with a mixture containing 8 wt.% silica fume. This was compared with a silica fume‐free mixture under the same conditions. Additionally, the SEM images of a newly developed concrete mix revealed positive interaction, resulting in a significant reduction in cracks and pores compared to a silica fume‐free sample. Moreover, the results showed a significant decrease in absorption and an increase in ultrasonic pulse velocity as a result of an increase in the proportion of silica fumes. Compared to the mixture without silica, there was a maximum improvement of 6% with an addition of 8 wt.% silica. The optimum reduction in embodied carbon emissions was 37% at 12 wt.% silica addition. On the other hand, silica fume addition negatively affects workability, where workability decreases inversely with this additive.