Assessing the influence of cement replacement materials on concrete performance through image processing

The use of Cement Replacement Materials (CRM) such as silica fume and fly ash in concrete has been extensively studied, yet their impact on aggregate distribution and air voids remains an area of ongoing investigation. This study advances the understanding of CRM’s role in concrete by employing novel image processing techniques. Cylindrical concrete specimens with mix design ratios of 1:2:4 and 1:3:6, and varying water-cement ratios (0.4, 0.5, 0.6) and CRM ratios (0%, 15%, and 25%), were imaged at different cylinder heights after cutting. Pixel-labeled images were used to quantify aggregate and air void properties, including area, size, and distance. The proposed image processing methods were validated against manual measurements, showing percentage errors of less than 1.90% in the measurement of aggregate and air void properties. Dual-section image analysis provided insights into CRM’s impact on aggregate segregation. By integrating measurements of aggregate area, size, roundness, and inter-aggregate distances, indicators of concrete homogeneity were introduced. Specimens with 25% CRM exhibited a more uniform distribution of aggregates compared to those with 0% and 15% CRM, as evidenced by lower values of homogeneity indicators such as Cv and excess kurtosis. The 0% and 15% CRM specimens showed a higher and moderate tendency for segregation, respectively, resulting in less homogeneous concrete. The results also indicate that increased CRM content significantly reduces air void proportion and size. The role of CRM in optimizing concrete mix design is established, offering improved structural performance and durability in construction applications. • Image dataset with diverse mix designs, CRM and W/C ratios is curated. • Pixel-labeled images for aggregate and air void segmentation are utilized. • Innovative image processing methods quantify air voids, aggregates, and distribution. • Aggregate area, size, roundness, and distances used to assess homogeneity.