ELLMIX aggregate is an artificial aggregate made of furnace slag, based on a mixture of ash and slag, obtained in the process of burning hard coal and co-burned material. Due to the production process and the combination of ingredients, the following types of ELLMIX aggregate are distinguished: – single-component K: consisting of 100% of the basic ELLMIX aggregate, – multi-component W: it is a mixture that may consist of components with specified proportions