Ordinary Portland Cement has a negative impact on the environment due to the consumption of available natural resources and high energy during production. The use of industrial by-products as a supplementary cementitious material in geopolymer concrete could reduce the CO2 emissions, loss of energy, land fillings, and natural resources can be protected. The paper presents effect of increase in sodium hydroxide concentration from 0.5 to 10 M in the alkaline solution on the strength properties of ternary blended geopolymer concrete specimens cured at ambient temperature. It was found that the compressive strength increases significantly with an increase in the NaOH concentration due to the decrease in the kinetic ratios. The compressive strength of geopolymer concrete with manufactured sand (M-Sand) was varied in the range of 39.3–65.3 MPa at 28 days. The increase in cost of ternary blended geopolymer concrete mixes is less with an increase in the NaOH concentration. © 2021, The Editor(s) (if applicable) and The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd.