Role of metakaolin and steel fiber on the relation of strength properties and abrasion resistance of concrete

This study evaluates how metakaolin and different steel fiber geometries influence the strength and abrasion resistance of concrete. Metakaolin was incorporated at replacement levels ranging from 0% to 30%, and the results showed that a 20% substitution provided the most effective enhancement, raising 28-day compressive strength from 35.6 MPa to 44.3 MPa and lowering the surface abrasion loss from 6.65 to 6.35 cm3/50 cm2 . After identifying this optimum level, steel fibers – hooked, flat, and crimped – were added at volume fractions between 0.25% and 1.0%. Among the fiber types, hooked fibers demonstrated the greatest improvement, increasing flexural strength from 5.8 MPa to 6.8 MPa and further reducing abrasion depth. All mechanical and abrasion tests were performed on 28-day specimens in accordance with relevant IS standards. Regression analysis indicated that abrasion resistance correlated more strongly with flexural strength than with compressive strength, with the highest correlation (R2 ≈0.97) observed for mixes containing hooked fibers. Based on the overall performance, a combination of 20% metakaolin and 0.75% hooked steel fibers is recommended for concrete exposed to substantial abrasive wear, such as industrial flooring and pavement applications.