The paper presents results of investigations of properties (consistency, density, compressive strength, flexural strength, tensile strength) of ordinary concretes and concretes containing steel fibers and fly ashes. To make the samples, the Portland cement CEM I 32.5R; 42.5R; 52.5R was used. Each type of cement, was used to prepare concrete with steel fibers in the quantity of 0.7% of cement mass as well as with steel fibers in the quantity of 0.7% and fly ash in the quantity of 5% of cement mass. After the tests, it was concluded that the admixture of steel fibers and fly ash improves the features connected with flexural and tensile strength but the compressive strength decreases.

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