New 'green' geopolymer concrete delivers win-win for industry and the planet

01:09 October 2, 2009 PDT

'Green' research at Louisiana Tech has resulted in new geopolymer concrete technology, like this 5,000lb concrete block cast using fly ash

Concrete is the most prevalent building material on the planet, and though the world would be pretty flat without it (not many tall buildings and structures), it does come at a price – around 5-8 percent of all human-generated atmospheric CO2 comes from the concrete industry. A culprit is Portland cement, the binding agent in concrete. It’s the most widely produced man-made material on earth. Production of Portland cement is currently exceeding 2.6 billion tons per year worldwide and growing at 5 percent annually. To halt these alarming pollution figures, innovative research on geopolymer concrete, along with ways of using a waste byproduct from coal-fired powerplants, is being conducted by Dr Erez Allouche, assistant professor of civil engineering at Louisiana Tech University and associate director of the Trenchless Technology Center.

A greener alternative, inorganic polymer concrete (geopolymer) fits into an emerging class of cementitious materials that utilize ‘fly ash’, one of the most abundant industrial by-products on earth, as a substitute for Portland cement.

Geopolymer concrete has a number of benefits. The first is it has the potential to substantially curb CO2 emissions. It can also produce a more durable infrastructure capable of lasting hundreds of years, instead of tens. And by utilizing the fly ash, it can conserve hundreds of thousands of acres currently used for disposal of coal combustion products, and protect our water ways from fly ash ‘contamination’, too.

In comparison to ordinary Portland cement (OPC), geopolymer concrete (GPC) has better resistance to corrosion and fire (up to 2400°F), high compressive and tensile strengths, a rapid strength gain, and lower shrinkage.

Researchers believe the geopolymer concrete's greatest appeal could like in its life cycle greenhouse gas reduction potential; as much as 90 percent when compared with OPC.

This technology, along with other important research being conducted to meet future energy needs, will be highlighted next month at Louisiana Tech Energy Systems Conference at the Technology Transfer Center in Shreveport.

Tags

User Comments (3)

This technology isn't as "new" as some people think. Cement used in the Roman Empire had a similar Aluminium-Silicate base as Geo-polymer cement (which is probably why so many of their structures are still standing after around 2000 years). Also, buildings in the former Soviet Union also used Aluminium-Silicate based cements over those using Calcium Oxide (Portland Cement).

Sort of makes you wonder what hold the makers of Portland Cement have over Governments & the Building Industry, that their obviously INFERIOR product has been a staple of construction-in the West-for the last couple of centuries.

Aussie_Renewable

- October 4, 2009 @ 06:10 pm PDT

What research has been done into the possible leaching of heavy metals out of a fly ash based aluminum-silicate concrete? If mercury, arsenic, beryllium leach out of the concrete into the soils and water supplies, can it really be called "green"? At least CO2 is eventually taken up by plant life as a nutrient.

Facebook User

- October 6, 2009 @ 09:10 am PDT

The strength and using up of a major waste product are great benefits, but the CO2 concerns are rubbish, of course. The warming effect of CO2 has long been maxed out, and cannot be increased. Plants and agriculture would get up to 4X the productivity if levels were raised to 1-2,000 ppm (as they are in commercial greenhouses). So the more CO2 emissions, the better!

Brian Hall

- October 6, 2009 @ 09:10 pm PDT