Typical ranges for geotechnical properties of fly ash and bottom ash. Fly ash is a fine grained material consisting mostly of spherical, glassy particles. Table 1 lists ranges for some ofthe important geotechnical properties of fly ash and bottom ash. Fly ash properties, types, mechanism and uses the constructor. Fly ash is the finely divided mineral residue resulting from the combustion of coal in electric generating plants. Fly ash consists of inorganic, incombustible matter present in the coal that has. Fly ash consists of inorganic, incombustible matter present in the coal that has been fused during combustion into a glassy, amorphous structure. Optimizing the use of fly ash in concrete portland cement. Fly ash consists of siltsized particles which are generally spherical, typically ranging in size between 10 and 100 micron figure 12. Using a fly ash pozzolan consumes calcium hydroxide ch. Some ashes also containing irregular or angular particles.
Heavy use areas other uses approaches to using fly ash. A pozzolan is a siliceousaluminous material that, when mixed with lime and water, forms a cementitious compound. It is nowadays used in cement, concrete and other cement based applications in india. Moreover fly ash properties depend upon the origin of the fuel and parameters used during the combustion process. Characteristics, management and environmental issues. Fly ash booklet for pdf federal highway administration.
The properties of fly ash can greatly affect the properties for both fresh concrete and hardened concrete. Pdf contribution of fly ash to the properties of mortar. Contribution of fly ash to the properties of mortar and concrete. Use of fly ash for treatment of acid mine drainage. Pozzolans that are commonly used in concrete include fly ash, silica fume and a variety of natural pozzolans such as calcined clay and shale, and. This paper presents an overview of the work carried out on the chemical properties and use of fly ash as. Those cements were made near the small italian town of pozzuoli which later gave its name to the term pozzolan. Fly ash, the fine particulate waste material produced by pulverized coalbased thermal power station, is an environmental pollutant, it has a potential to be a resource material. Many countries have their own national standards and specifications regulating the use of fly ash in concrete. Type f fly ash is produced from the combustion of bituminous or an anthracite coal contains cao below 10 percent and possesses pozzolanic properties. It is produced when the combustion temperature is below 900o c.
Therefore it is crucial to details the characteristics and properties of fly ash, prior to use fly ash particles in any application. In the united states, astm c 6181, standard specification for coal fly ash and. Fly ash properties and uses monolithic dome institute. The chemical composition of fly ash depends upon the type of coal used and the methods used for combustion of coal. Fly ash closely resembles volcanic ashes used in production of the earliest known hydraulic cements about 2,300 years ago. Pdf fly ash is residue from the combustion of coal which widely available in worldwide and lead to waste management proposal. Pdf study on physical and chemical properties of fly ash from. These small glass spheres improve the fluidity and workability of fresh concrete. Approaches to using fly ash fly ash used alone to file hole or area avoid fly ash is fine power and difficult to handle fly ash flows like water requires containment 100% fly ash is expensive approach fly mix with soil may be appropriate fly ash is fine power and difficult to handle requires correct type of clean clay soil. Fineness is one of the important properties contributing to the pozzolanic reactivity of fly ash. The properties of fly ash and bottom ash make them useful for a variety of construction applica tions. Strength gain happens slower with a pozzolanic class f vs.
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