STUDY ON C80 HIGH PERFORMANCE CONCRETE WITH SILICA FUME AND FLY ASH BEING ADMIXTURES

It was studied that the effect of the addition of silica fume and flyash on concrete strength and fluidity and the rule of 28d strength of concrete with silica fume and fly ash as well as the relation of the increment of later stage strength of concrete.Using grade P.O.42.5 ordinary portland cement,medium sand,5～25mm broken stone,silica fume,flyash,proper quantity of NF-2-6 retarding high effect water-reducing agent,water cementitious materials ratio 0.28,5% of silica fume and 5%～15% of fly ash or 10%～15% of silica fume and 5%～20% of fly ash,C80 high performance concrete can be prepared;and water cementitious materials ratio 0.31,15% of silica fume,5%～10% of fly ash were adopted,C80 high performance concrete can be prepared also.The reference formula for concrete commercial mix can also be educed.