Abstract
	The contribution presents results that follow from research of blast furnace slag products utilisation in production of concretes for road construction applications. In the first part it briefly characterizes the materials utilised in production of concrete. The strength of concrete is defined together with tests used for its characterisation. Especially the concrete utilised in road engineering is characterised, its different kinds and required strength properties. Pilot plant trials with production of concrete are described, in which only gravel, produced from blast furnace slag, grain sizes 0 – 4; 4 – 8; 8 – 16 mm, was used. Specifics of use of blast furnace slag gravel and the other materials of concrete mixture were defined. Large scale research, related to portions of blast furnace slag gravel fractions, quantity and kind of utilised cement and quantity of water added to the mixture, was performed. On the basis of results three concrete mixtures were specified that produced concretes with the best values of strength properties. Suitability of use of concretes, produced with utilisation of blast furnace slag gravel, for road engineering is discussed. Only the concrete produced from mixture no.2, meets the demands of road communications of the 1st and 2nd class. The concretes made form the next two mixtures do not meet the strength values defined by the standard and their utilisation is mostly for construction of local or in – factory communications. Suitability of use of concretes, produced with utilisation of blast furnace slag gravel for other, less demanding construction applications, is mentioned.