The Usability of Fly Ash for the Construction of Embankment Dams

Power supplying industry in the Czech Republic is still dependent on thermal power plants. Due to the on-going and completed renovation of the existing power plant units, it is expected that they will be serviceable for the following 30 years. It is therefore necessary to look for suitable use of the by-products of these plants. Using the energy by-products during construction of dikes is currently limited to creation of little protective dikes on unloading yards of fly ash stabilizers. Here we can take advantage of the binding abilities of the energy by-product to stabilize the unloading yards and protect the environment. This method is technologically less effective for constructions of anti-flood dikes. Therefore we use the soils from the vicinity of the building area. A suitable method of using fly ash in water building industry lies in repairs of existing earth dams by using fly-ash and clay grouting that increase homogeneity, stability and impermeability of the dam. This paper deals with laboratory verification of suitability of different types of fly-ash in the mixture with special sealing clay. It also deals with designing optimal recipes for "on-site" testing. Results of the tests clearly recommend classical fly ash as the most suitable raw material. On the other hand, the bedding ash marked is not suitable for this technology.