The reduction of CO2 emission has recently become a global concern. The use of Portland cement has been responsible for the main global warming effects in the construction industry, Geo-polymer have emerged as a new generation of alternatives.Construction has been most important human activity since early ages. The main aim is to study strength characteristics and flexural behavior of Geo-polymer concrete with Construction Demolision Waste. In this study, Geo-polymer concrete is produced with fly ash, GGBS, and sodium hydroxide and sodium silicate is used as a binder. The mix design is carried out for 12M concentration of sodium hydroxide. Alkaline activator solution ratio of 2.5 and alkaline liquid to fly ash ratio 0.4 is selected for this investigation. The specimen of size 100x100x100mm cubes 100x200mm cylinders and 1200x150x100mm beam were casted and the specimens of Geo-polymer concrete are cured at ambient temperature for 3days, 7 days and 28 days. The cured specimens were then tested for compressive strength, split tensile strength and flexural strength respectively