The use of ash waste saves expenses on main materials without compromising the quality of the product, while solving the problem of disposal of ash materials. The aim of this work is classification of ashes and evaluation its use in construction.

Classification of ash-and-slad wastes based on type of burned coal, way of incineration, flame temperature, way of ash disposal is made. The chemical composition and behavior of shale ash, its main deposits, its advantages as a mineral concrete admixture are analysed. Fly ashes are divided into siliceous ashes and basic ashes.

Various application areas of ash-and-slad wastes in construction are considered, the examples of its use are given.