STUDY OF FROST RESISTANCE OF CONCRETE MIXED WITH FLY ASH AND SILICA FUME

A method of adding silica fume and fly ash to the concrete was presented based on investigating concrete freeze-thaw mechanism and its influential factors． The frost resistance testing of both ordinary concrete and the concrete mixed with silica fume and fly ash was conducted． The results showed that both the compressive strength and elastic modulus of the concrete mixed with silica fume and fly ash were lower than those of ordinary one due to part of cement replaced by silicon powder and fly ash based on the equivalent substitution method，in that case，the content of cement was reduced and the water-cement ratio was increased． However，the use of water reducing agent reduced the ratio of water to cementitious material，which leaded to a better frost resistance of double mixing concrete than that of ordinary concrete．