Investigation of the Durability of Concrete Made with Volcanic Ash and Metakaolin as Partial Cement Replacements

Abstract

Finding material that can either completely or partially replace cement is the current focus in concrete research, as the cement industry uses an energy-intensive method. There have been recent attempts to identify cement substitutes. The production of high-strength and high-performing concrete depends heavily on supplementary cementing materials (SCMs). This study assesses the durability characteristics of concrete made using metakaolin (MTK) and volcanic ash (VA) under various curing conditions of H2O, H2SO4, and MgSO4, and assessed at 7, 14, 28, and 56 days. A 1:2:4 mixture with a 0.5 water-to-cement ratio was employed. 10%, 15%, 20%, 25%, and 30% VA/MTK were used in place of cement. The chemical composition, setting time, workability, density, compressive strength, water absorption, and abrasion test are the factors that are examined. SiO2, Al2O3, and Fe2O3 contents sum up to 76.82% for VA and 98.07% for MTK, which shows that both are good pozzolans. At 28 days, the average compressive strength was 28.2N/mm2 and 28.5N/mm2 for water-cured specimens, 25.2N/mm2 and 26.2N/mm2 for MgSO4-cured specimens, and 26.6N/mm2 and 27.1N/mm2 for H2SO4-cured specimens, respectively, for 0% and 10%, VA/MTK. This demonstrates a 3.82% and 1.85% improvement in strength at 28 days for samples with 10% VA/MTK substitutions that were cured in MgSO4 and H2SO4 resisted the medium better than the control. At 56 days, concrete made with 10% VA/MTK shows better abrasion resistance and less absorption properties than concrete made with different cement replacement levels. To sum up, VA and MTK are pozzolana that meet ASTM C618-05 criteria, and can be used for structural purposes and high-quality concrete in both normal and chemically conditions. This research suggests substituting up to 10% of cement in concrete with VA/MTK.