Although flyash offers environmental advantages, it also improves the performance and quality of concrete. Flyash affects the plastic properties of concrete by improving workability, reducing water demand, reducing segregation and bleeding, and lowering heat of hydration. Flyash increases strength, reduces permeability, reduces corrosion of reinforcing steel, increases sulphate resistance, and reduces alkali-aggregate reaction. Flyash reaches its maximum strength more slowly than concrete made with only portland cement. The techniques for working with this type of concrete are standard for the industry and will not impact the budget of a job. Hollow concrete blocks are precast masonry units made out of fly ash concrete mix with 4 hollow cavities and are intended for use in the construction of both load bearing and non-load bearing wall structures advantages Good earth quake resistance properties Easy handling/faster construction Huge saving of labor It offers highest thermal insulation making cool summers and warm winters Reduced air conditioning expenses Fire resistant Excellent acoustic barriers Reduction in plastering due to even walls Option for any finish on the walls