If you’re not in the concrete industry, you may have never heard of fly ash before. For the layperson, fly ash is a byproduct of coal burning that is often used as an additive when mixing concrete. The pros and cons of using fly ash in concrete for renovations are many and there are varying opinions on its use. In this post, we’ll go over the advantages and disadvantages of using fly ash in concrete for renovations.
Should You Use Fly Ash In Concrete For Renovations?
High-quality fly ash can create many improvements in the concrete that’s used in commercial and residential renovations. When fly ash has been adequately burned, the resulting particles are relatively small compared to fly ash that hasn’t undergone sufficient combustion. Smaller fly ash particles can help reduce water permeability of concrete and thus make it stronger. As long as the fly ash has been properly produced, it should only make the concrete better.
What Are The Consequences Of Using Poor Quality Fly Ash In Concrete?
The larger particle size of poorly produced fly ash can create concrete that is more permeable to water and more susceptible to temperature fluctuations. This can result in a concrete that’s weaker than that made with high-quality fly ash or no fly ash at all. Concrete made using poor-quality fly ash can also be more sensitive to chemical reactions.
Is Concrete Made With Fly Ash Environmentally Sound?
Before stricter environmental laws, fly ash produced by coal-burning power plants was allowed to disperse into the atmosphere. This caused significant air quality problems that were eventually rectified by the introduction of fly ash capture equipment. However, the disposal of fly ash became a subsequent environmental problem. Using fly ash in concrete helps prevent this contaminant from being placed in landfills and leaching into water supplies.
What Are The Pros Of Using Fly Ash In Concrete?
As mentioned above, fly ash can help make concrete stronger, less permeable to water and resistant to chemical reactions. Concrete made with fly ash is considered more workable when wet, shrinks less than non-fly ash concrete and requires less water.
What Are the Cons Of Using Fly Ash In Concrete?
Some builders find the slow setting rate of fly ash concrete to be problematic. However, in certain situations, concrete with a slow setting rate can be desirable. Concrete made with fly ash also has a slower strength gain rate which can cause problems in situations where a quick-setting, high-strength finished product is necessary.