Geopolymer binders such as ground granulated blast furnace slag (GGBS) and fly ash (FA) have been promisingly surfaced as probable alternatives to ordinary portland cement (OPC) in concrete preparation over the last few decades. The production of geopolymer concrete (GPC) generates approximately 30 - 50 % less carbon-dioxide (CO2) gas emissions than OPC concrete. GPC not only reduces 2 emissions, but it also uses industrial solid wastes. To achieve optimum mechanical strength, three parameters which play crucial roles have been considered: Molarity of sodium hydroxide (NH) concentration, solution to binder ratio (S/B) and sodium silicate-sodium hydroxide (NS/ NH) proportion. So, in present paper, the mechanical and microstructural characteristics of GPC cured at ambient curing condition using several mixes prepared with varying NaOH concentrations (10 M - 16 M), solution to binder ratios (total alkali activator/total binder content) (0.45 - 0.55) and sodium silicate (NS) to (NH) ratios (1.5 - 2.5) has been investigated. In addition to this, for a conceptualization of environmental impact of GPC, life-cycle assessment (LCA) has been performed.