Our foundation is finally finished and all our footings, walls and flatwork are in. We installed our vapor barrier, our French Drains and our Sump Pump. (We still have to install our Radon system, not that we have Radon but we are in a high risk area here in the Northeast so that makes it a LEED-H prerequisite).
I’ve been working on my LEED-H binder which has all my photos, my meetings minutes and my invoices which document everything so this is where we will put the paperwork to verify the work is completed, so I get to mark off a half-point on our LEED-H application because we used a 30% Flyash mixture in our concrete which also saved us 4% over our traditional Portland cement bid.
The production of Portland cement worldwide accounts for 6-8% of carbon dioxide (CO2, a primary greenhouse gas) into the atmosphere. Flyash is one of three types of coal combustion byproducts (CCBP’s) that can be mixed to with Portland cement to make concrete.
There are 3 key environmental advantages of the 30% Flyash cement mixture:(1) diverting the Flyash byproduct material from the waste stream; (2) reducing the energy costs associated with producing Portland cement; (3) reducing CO2 pollution. But there are some additional performance advantages of a 30% Flyash mixture over Portland cement that we achieved as well. (1) Flyash alters the plastic properties of concrete to improve workability (this to me means better handprints); (2) Flyash increases strength and sulphate resistance (stronger foundation) and (3) Flyash reduces permeability and corrosion of reinforcing steel (here’s to longevity).
One small negative in my opinion, a 30% Flyash mixture reaches its maximum strength more slowly than concrete made with only Portland cement, so with the cold weather we’ve been facing this December, we’ve had to hope for some warmer days (which we got) but had to pour early in the day so it had to time to harden before the temperature dropped with the afternoon sun. And we had to wait an extra 48 hours to backfill and before we start building on the front porch footings which were the last to be finished.
By the way, I found these statistics online. For every ton of Flyash used:
- Enough energy is saved to provide electricity to an average American home for 24 days.
- The landfill space conserved equals 455 days of solid waste produced by the average American.
- The reduction in CO2 emissions equals 2 months of emissions from an automobile.
Just like with a lot of little changes we’re making building our house, what we’re doing is just one piece of the puzzle. If everyone changed the way they built, we could make a world of difference.
KDL | follow me on Twitter: newscaster