The aim of the project will be to assess the usability of fluid ash, bed ash and mixture of both materials in earthworks and to propose suitable technological procedures and applications where the properties of fluid ash can be used with advantage. The output will be the pilot plant — construction of the test part of the hopper using fluid combustion products and two proven technologies — modification of the soil products of fluid combustion without additional additives and design of the method of storage (retention) of fluid combustion products.