Fly ash concrete has advantages over regular concrete, including reduced water permeability and increased strength. Poorly produced fly ash has disadvantages, but properly manufactured fly ash produces a quality product. Fly ash fills small spaces within the mix for a cohesive substance that resists water infiltration and has a high strength. The slow curing time can be a drawback or an advantage. Proper production is important to avoid water permeability and slow curing times.
Fly ash concrete offers many advantages over regular concrete, including reduced water permeability and increased strength. However, when produced improperly, poor quality fly ash has disadvantages, such as increased permeability of the concrete and slow curing times. Properly manufactured fly ash, plus specific ratio calculations, normally produce a quality concrete product that overcomes any drawbacks.
The actual fly ash is a residue derived from the combustion of coal; this precipitate can be mixed with other cement ingredients to make concrete. When fly ash is mixed with cement constituents, such as sand and aggregate, it fills small spaces within the mix for an extremely cohesive substance. The resulting fly ash cement resists water infiltration, which can damage the final cured concrete product; water trapped within a concrete mix can expand and contract with changes in temperature until the concrete cracks.
The higher density of the fly ash cement mix contributes to its high strength. Because the fly ash fills tiny cracks within the cement mix, the residue actually adheres to more constituents than an equivalent substitute, such as Portland cement. As a result, the final strength of concrete after curing is substantially better than other types of cement mixes.
How the fly ash is made is very important to the properties of the cement mix; fly ash that is not burned enough will have larger particles. These larger pieces do not fit into the small constituent cracks in the concrete and actually form new voids or spaces. The resulting fly ash concrete is prone to water permeability as the internal spaces are large enough to accommodate many liquid molecules.
Slow curing times can also be a drawback for fly ash concrete. The dense concrete structure does not allow much air to infiltrate the space between the molecules; consequently, the setting time is lengthened. For example, construction projects that require a quick repair of a concrete wall may not want to use fly ash concrete since it won’t harden fast enough for traffic to flow nearby safely.
Conversely, some concrete workers see the slow setting time as an advantage, rather than a disadvantage. Fast cure times tend to produce stress fractures through the concrete, both along the surface and localized internally. These cracks significantly reduce the strength of the concrete object. The slow curing times allow the fly ash concrete to set consistently in place, even with fluctuating temperatures.
Protect your devices with Threat Protection by NordVPN
