Ultra fine Fly ash is a super pozzolanic material. ( it is ultra fine Ash) A pozzolan is a siliceousor aluminous material that when mixed with lime and water forms acementitious compound.Ultra-Fine Fly Ash (UFFA) used as up to 50% partial replacement for cement in concrete. UFFA is a new generation fine coal fly ash, which is double-classified to obtain the finer particles from the classified bulk. The influence of UFFA on fresh properties (flow, setting time and air content), porosity of mid to high strength, medium workability concrete mixes (designed for equal 28-day strength) are reported and compared with concrete mixes made with OPC, Micro-Silica