Adding fly ash to your concrete mix offers you a practical, cost-effective way to increase its strength, plasticity and durability. You'll use less cement, but actually produce a superior product.
Benefits to plastic concrete:
- Improved workability – The small, spherical shape of fly ash particles provides a “ball bearing” effect that creates a concrete paste with superior plasticity.
- Decreased water demand – Replacing cement with fly ash reduces the water demand for a given slump and, in certain situations, can even reduce drying shrinkage.
- Increased pumpability – The spherical shape of fly ash reduces internal friction, producing a mix that is easier to pump.
- Reduced segregation – Fly ash adds body to plastic-state concrete, increasing its cohesiveness.
- Less bleedwater – Fly ash's lower water content reduces bleeding.
Benefits to hardened concrete
- Increased strength – In concrete, fly ash will continue to react with available lime and alkali, causing it to gain strength beyond 28 days.
- Reduced drying shrinkage – Fly ash concrete requires less water, hence less volume lost in drying.
- Decreased permeability – Fly ash particles pack tightly. In addition, the chemical reaction between fly ash and lime forms bonds that block bleed channels and fill pore spaces.
- Resistance to sulfate attack – Fly ash combines with free lime, making it unavailable to react with sulfates that can cause expansion problems.
- Improved durability - Less free lime, greater strength and less permeability produce concrete that withstands more punishment over the long term.
- Reduced heat of hydration – Large concrete masses typically generate high internal temperatures and experience thermal cracking as a result. By replacing a portion of portland cement with fly ash, your concrete will generate less heat and thus be less prone to fractures.
- Mitigated alkali silica reaction 'ASR' – Fly ash reacts with available alkalis in the hardened cement matrix, making them less likely to react with the aggregate.
For more information on how fly ash can improve your concrete products, contact us today.