The chemical constituents present in water may actively participate in the chemical reactions and thus affect the setting, hardening and strength development of concrete. This paper presents the results of an experimental investigation carried out to study the effect of chemical compounds in water on strength of high-performance-concrete with metakaolin in which Ordinary Portland cement is partially replaced by 20% of metakaolin by weight and aggressive chemical environment is simulated by subjecting the concrete to different concentrations of Hydrochloric acid (HCl) in deionised water during mixing and curing. In addition to that, health issues related to the safe handling of such water must be considered. The results indicate that the compressive strength and split tensile strength decrease with the increase in concentration of HCl when compared with concrete without HCl in mixing and curing water.