<p>This study investigates the effect of nano-TiO₂ in strength development of concrete subjected to acid and alkaline curings. Nano-TiO₂ is substituted into concrete in the range of 0% to 2% by mass of cement. The strength performance of concrete with and without nano-TiO₂ is examined against acid and alkali curings for the periods of 3, 7, and 28 days. In this study, 3% concentrations of sulfuric and hydrochloric acids were used for acid curing. For alkali curing, solutions of 3% sodium chloride and sodium hydroxide were used. To understand the influence of acid and alkaline curing’s on concrete at micro level, Field Emission Scanning Electron Microscope (FESEM) images were obtained. Heat maps were also developed to identify the correlation among curing mediums adopted. Performance analysis was done with Response Surface Methodology for assessing strength at any other unexperimented combination of variables nano-TiO₂ and curing period. Results of this study showed that substitution of nano-TiO₂ can improve resistance against acid curing, alkaline curing and strength of concrete over conventional concrete. Moreover, at the 1% substitution of nano-TiO₂ by mass of cement in both acid and alkaline curing mediums shows significant improvement of strength performance.</p>