Cement is the most abundantly used ingredient in the production of concrete due to which its production and use has increased manifold. To reduce the carbon footprint left by the cement production, fly ash is used as cement replacement in concrete. Past research studies suggest that the fly ash replacement can be upto 40% beyond which there will be drastic reduction of strength. In the present study, high strength concrete mix of 70 grade is developed with high volume fly ash of 70% as cement replacement. Silica fume of 10% and hydraulic lime of 30% are used as additives in the development of M70 grade high-strength high-volume fly ash concrete. In the present paper, three types of fly ashes are considered for the study of which one which is ultrafine is chosen based on the pozzolanic index and strength activity index. Excess lime needed for various percentage of fly ashes is evaluated based on the empirical equationsgiven by the Dunstan Jr andZayed
Evaluation of activated high volume fly ash systems using Na 2 SO 4 , lime and quicklime in mortars with high loss on ignition fly ashes