Utilisation of steel slag as an aggregate in concrete

This paper aims to investigate the possibility of utilizing steel slags produced in Croatian plants as a concrete aggregate. Aggregate properties were determined on coarse slag fractions (4-8, 8-16 mm) according to the relevant European Standards. Considering the obtained results, slags were specified in accordance with the classes as given in the main European standard for aggregates, whereupon these classes were compared to the Croatian regulation requirements. The obtained results proved that coarse slag fractions can be suitable for concrete application. Therefore, concrete mixtures were prepared with coarse slag fractions whose hardened state properties (compressive and flexural strength, static modulus of elasticity, volume changes and corrosion susceptibility) were then compared with the properties of reference concrete made of commonly used natural aggregate materials, namely dolomite. According to the obtained test results it can be concluded that the observed slags can be a good substitute for natural aggregate materials.