Concrete is the material of basic significance in building construction. It also plays essential role in agriculture and food industry. The aim of this study was to compare selected properties of a concrete mix and mature concrete, depending on the percentage of silica dust (microsilica). The greatest potential for reuse of waste has the building materials industry. There was designed a concrete with the composition as for the C20/25 concrete without any silica dust as well as three concrete types containing respectively 5, 10, 15% silica dust. The concrete mixes were subjected to the slump test and air content test, the matured concrete h compressive and bending strength test, the test of penetration depth of water under pressure, water absorption test and frost resistance test. The investigations showed the usefulness of silica dust as a material for the production of concrete.

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