Fly Ash-Based Geopolymer Cement
Fly ash-based geopolymer cement is an innovative type of cement which has gained popularity in recent years due to its advantages such as low embodied energy and CO2 footprint, and its ability to withstand extreme temperatures without undergoing significant degradation. The geopolymer cement is manufactured using fly ash, an industrial byproduct of coal combustion, which is combined with an alkali activator, a small quantity of quicklime and water to form a paste. After curing, this mixture forms a strong material which can be used as a binding agent in construction applications and as a substitute for Portland cement.
The fly ash used for the production of geopolymer cement comes from industrial facilities, such as coal-fired power plants, which produce large amounts of residue during their operations. The fly ash is collected from the bottom of the boiler and transported to the production facility, where it is then milled to a fine powder and sieved for particles of a specific size. The milled material is then conditioned with an alkali activator, such as sodium silicate or potassium silicate. The alkali activator helps to create a reaction between the silica within the fly ash and the alkali present, which leads to the formation of a strong and durable material. The resulting material is then mixed with a small amount of quicklime and water to form a paste.
The paste is then subjected to a curing process, typically lasting around five to seven days, which allows the material to reach its final form. During this process, the material undergoes a reaction in which various minerals react with the silicate to form a semi-liquid compound with a consistency similar to that of jelly. This product is then dried and ground to a fine powder to make geopolymer cement.
The properties of geopolymer cement have attracted considerable attention since its introduction. It has been found to possess superior mechanical and thermal properties compared to traditional cement products. This means that it offers increased resistance to high temperatures and can be used in applications where traditional cement would break down. It is also low in embodied energy and CO2 footprint when compared to other cement products, which means it can be used as an environmentally friendly alternative.
Overall, the advantages of geopolymer cement mean that it is an attractive substitute for traditional Portland cement. Its widespread use is likely to increase in the coming years, given its notable performance and potential for use in a range of applications in the construction industry.
