Abstract

The depletion of the resources of coarse aggregates with good strength parameters (including basalt and granite aggregates, and good-quality gravels) creates a necessity to conduct searches for alternative solutions. Such a solution can be a wider use of limestone or dolomite aggregates, due to the rich deposits of this raw material occurring in the Kraków-Częstochowa Jurassic Upland and in the Kielce region. The dolomite aggregate used for preparing concretes investigated within this study, and from which concretes of the best strength properties were obtained, originated from Górnicze Zakłady Dolomitowe S.A. (Dolomite Mining Works, Inc.) in Siewierz. The aggregate is successfully used for the construction and maintenance of roadways, streets and other traffic routes. In the light of the present challenges in the construction of motorways in Poland, the wider use of this aggregate might have a great economic importance, also because of its relatively lower price, owing to the situation of its deposits in the central location relative to the planned motorways. The paper presents the results of the fracture toughness and compressive strength parameters of plain concrete carried out after 7, 14, 28 and 90 days of concrete curing. The tests covered ordinary concrete (B40) and high-performance concrete (HPC) made from gravel, dolomite and basalt coarse aggregates. A significant increase in the values of investigated parameters was found in the period between the 28th and the 90th day of curing and was particularly important in the case of B40 concretes.