STUDY ON PROPERTIES OF CONCRETE WITH ULTRA-FINE PARTICLES PRODUCED FROM FLY ASH

This paper describes the basic properties of concrete containing ultra-fine particles, which are produced from fly ash. The properties of concrete with these particles differ greatly with the specific surface area of the particles. Experiments showed that ultra-fine particles with a specific surface area of 71 sq m/g develop a compressive strength of approx. 118 MPa (w/c-25%), while plain concrete develops approx. 105 MPa. Ultra fine particles with a specific surface area of 35 sq m/g improve the consistency of fresh concrete, especially in low water/cement ratio (w/c=20-25%), enabling concrete to be easily mixed without increasing the dosage of high range air entraining water reducer.