Tuesday, December 17, 2013

Fly Ash For Driveways: When A Recycled Waste Product Takes An Extraordinary Route


Did you ever try to visit a home where you can see how waste products are transformed into valuable and elegant pieces of objects? The papers and cardboards we usually throw in trash cans can turn into vases, bowls, sculptures and a lot more as paper mache. Simply, this is recycling and also through such process, a waste product from burning pulverized coal in electric power generating plants known as fly ash has found an extraordinary and purposive route towards our concrete driveways as an admixture, improving the qualities of an ordinary concrete driveway.

There is a high demand for fly ash as a partial cement replacement, which means you don't use it to totally replace cement as a raw material for concrete driveway rather you just mix it with cement, because a driveway is a kind of flooring that gets much load and traffic. Fly ash improves the durability of concrete driveways by making them less permeable. But before we further discuss the advantages of recycling this type of admixture, let us first find out how it is produced.

Fly ash is mostly produced in coal fired electrical generating facilities. As these facilities burn coal, a process called combustion; the mineral impurities in coal such as quartz, clay and shale combine with gases and go out from gas chambers as solidified spherical glassy particles. Fly ash as a by-product of burning coal is a powdery cementitous material. If fly ash is not recycled, it is disposed in landfills. Due to environmental concerns on carbon emissions produced by manufacturing cement, some concrete projects add higher ratio of fly ash in cement mix.

The combination of fly ash and Portland cement in aid of moisture and temperature consideration (40 degrees Fahrenheit), Fly ash reacts to the by-product of Portland cement and water which is calcium hydroxide to form calcium silicates. This decreases the settling time of concrete, making your concrete driveway gain strength. Fly ash decreases the water cement ratio
which is beneficial in improving the durability of concrete since less water is needed to bind its components.

In addition, the presence of fly ash results to a variety of colors from buff to brow. It improves the application of coating and sealer as premature curing is avoided. For example if you apply acrylic cement coating to a prematurely cured concrete driveway, the surface would just peel off. Because the addition of fly ash produces slower curing time, bleed water has more time to come out into the driveway surface.
    
From a waste product in power plants to an advantageous admixture in construction projects, fly ash has taken an extraordinary route in giving homeowners a chance to enjoy the quality of their concrete driveways!

1 comment:

  1. en he finishes that up next week, one more loose end will be tied up, and soon we'll be able to concentrate on getting settled into our old/new life in our new/old house.
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