Možnosti použití popílků z vybraných zdrojů pro úpravu zemin a přípravu alternativních pojiv pro úpravu zeminy

Abstract

At present, land filling and recycling of materials is the current topic. Much of hydraulic road binders contain a share of fly ash. However, soil treatment was not carried out exclusively by fly ash in the Czech Republic. Production volume allows it. For this reason, greater efficiency in the use of fly ash needs to be evaluated and implemented. Properties of fly ashes from different sources and types are compared in this doctoral thesis - calcareous fluidized fly ash, siliceous fly ash, fly ash after denitrification or lagoon fly ash after reclamation. Tested fly ashes are or were produced by different technologies, therefore their diversity of properties is assumed. Physical properties and bearing capacity of fly ash and tested fine-grained soils are important in determining the procedure of the research. The advantage of calcareous fly ash from fluidized bed combustion is its hydraulic activity, which favourably affects properties of treated soils. However, the main disadvantage is volume changes that may occur by the presence of free CaO in the fly ash structure. On the other hand, siliceous fly ashes are often used as a substitute for the fine soil component or as a pozzolanic material. The subject of the research was the practical application of secondary materials in road constructions. Results show that the tested materials have a high potential to the treatment of fine-grained soils by fly ash binders. Each fly ash had a positive effect on the properties of tested soil after the treatment.