Project Journal

Pouring (over) Concrete 2 – Fly Ash Doesn’t Fly at the GIH
by Robert Fortunato on April 9th, 2011 3 Comments

We got a number of responses to our post re concrete.  One of the most popular suggestions we got to reduce the harmful impacts of cement is to add fly ash to the mix.  This solution also gets you LEED and Build It Green points.

Fly ash is the leftover material from the burning of coal.  Unfortunately, there are serious health and environmental concerns with this material.  Burning coal concentrates heavy metals and radioactive material from the ground in the fly ash.  See below:;housing

A friend who recently wanted to use fly ash to replace Portland cement in his project tried to get a declaration from the supplier of fly ash that it does not contain hazardous waste materials.  The supplier refused to provide one and simply referred them to the EPA.   Given many people are using fly ash in their floors and kitchen counter tops…, there should be an easy way to know it is safe.

Also, by using fly ash we are making it easier/ cheaper for coal burning industries to get rid of their toxic waste in our cement.  Coal fired electric plants would otherwise have to pay to dump their fly ash.  This is making clean renewable energy relatively less price competitive!

Before adding fly ash as a Portland cement replacement the GIH would like to see:

1. Ways to ensure the safety of everyone involved in the handling, use and disposal of the fly ash waste material and the products made from it.

2. Research on the potential economic impacts on renewable energy production of making coal burning waste easier and cheaper to dispose of.

Without that research we run the risks that are associated with the law of unintended consequences.  Will we need Geiger counters and testing kits before we jackhammer in the future as fly ash becomes the new asbestos??  Are we actually slowing the adoption of renewable energy by paying for someone else’s toxic waste to be used in our green homes??

Until we know for sure, we will take a pass on Fly Ash.

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3 Responses to “Pouring (over) Concrete 2 – Fly Ash Doesn’t Fly at the GIH”

  1. David Frank says:

    Perhaps you should talk to me re Fly Ash.
    Here in Australia we are able to take 99% fly ash from Black Coal and turn it into rocks and sand with a MPa of up to 100. Totally inert and non leaching.
    If the power stations can turn the CO2 into a room temp liquid, well we can use that in making the end resultant.
    I have more info if you want.



    • Robert says:

      Thanks Dave, We would like to learn more about that. How do you guarantee that the heavy metals and uranium are kept out of that waste stream? What does MPa of 100 mean? Please explain the CO2 liquid comment. We want to be open to all sides of the dialogue.

  2. Jet graphics says:

    The pascal (symbol: Pa) is the SI derived unit of pressure, internal pressure, stress, Young’s modulus and tensile strength.
    MPa = mega pascal (one million pascals)
    MPa(m2) to psi(in2), multiply by 910.06.
    100 MPa x 910.06 = 91,006 psi, or 45.5 tons per square inch load bearing capacity.

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