The paper reflects the current topic, processing of energy coal combustion products (CCP). This issue has been the subject of research intentions not only in the Czech Republic for many years. This paper focuses on the use of CCPs from fluidized bed combustion for road construction, especially for treatment of pavement subgrade. Because of increasing emission limits, energy industry invests lot of money to modernize current technologies. One of the options is combustion in special boilers on fluidized bed. Specifications of this technology are combustion at lower temperatures. The process of desulphurisation of flue gases with sorbent, most frequently limestone leads to residual lime remaining in the fly ash in the form of softly burnt lime which is capable of further hydration. At the same time there is the possibility of burning multiple types of fuels at the same time, which could be a potential danger influencing the quality and homogeneity of CCPs.
The paper deals with the usage of untreated fluidized fly ashes, and it also focuses on possible processing of these ashes by high-speed milling technology and their potential use as a replacement for current hydraulic binders. High-speed milling process initiates the ability of the processed material to further hydrate. We try to use this property in the pavement industry, where activated fluidized fly ash has the potential to substitute the current hydraulic binders.
The laboratory comparison was performed on the mixtures of soil with and without CCPs from different sources and on a selected soil treated by standard hydraulic binders and binders based on CCPs. The main parameter was CBR test. The paper also deals with the issue of swelling, which is a very common problem of fluidized fly ash application. In terms of laboratory assessment, linear swelling was measured during saturation before the CBR test.

CBR, fluidised fly ash, fluidised coal combustion, soil treatments