October 13, 2008

B.C. Ready-Mixed Concrete Association

Concrete helps lead the way to green, sustainable construction, Willmer says

Brian Martin

correspondent

Trip, fall and land on it and you will likely wind up black and blue.

Build with it, however, and you may very well wind up remarkably green.

Concrete, an ancient building material, is helping to lead the way to sustainable or green construction.

Bruce Willmer is quite familiar with concrete’s green revolution.

Willmer is vice-president of the B.C. Ready-Mixed Concrete Association.

He is also vice-president of Lafarge Canada Inc.’s ready-mix concrete operations in Vancouver.

Concrete and its major component, cement, he pointed out, have come a long way in the past few years.

For one thing, fly ash is now replacing as much as 50 per cent of cement in the manufacturing of concrete.

This is important because making cement is an energy intensive process.

Fly ash, on the other hand, is a waste product, which until recently was sent to landfills by the tonne.

British Columbia doesn’t create fly ash because there aren’t any coal fired electrical plants to produce it.

Fly ash is a coal combustion by-product.

However, Alberta and Washington produce it, as do a number of U.S. states and Canadian provinces.

Until fairly recently, fly ash was disposed of in landfills, but it is now a commodity, Willmer pointed out.

LEED has become a fundamental fact of life in the design and construction industry.

It is a points-based system that measures a building’s environmental sustainability.

Virtually all government buildings and many private sector buildings now call for LEED design and construction.

Using “green” concrete mixtures that incorporate up to 50 per cent fly ash can earn builders and developers valuable points as they pursue those LEED standards.

When going after LEED points, where a product is produced is important.

The idea is to not pollute the atmosphere by hauling building materials over long distances.

Concrete is normally manufactured locally and aggregate, one of its major components, is also normally local.

Even fly ash, however, can gain points.

While it is not exactly local in the Vancouver area, it is regional as it comes from either Alberta or Washington State.

A regional classification is also good for LEED points.

Wallboard made from synthetic gypsum (an ash related by-product also produced from coal-fired plants) is also an extremely green product.

Although not as common in the B.C. market, its use is growing. It’s already in much of the rest of Canada and the United States.

In the U.S., it represents about 70 per cent of the wall board market.

Again, it depends on re-using that otherwise useless ash.

A slurry of ash is combined with oxygen to produce synthetic gypsum that is then used to manufacture wallboard.

The backing on both sides is produced from recycled paper.

It’s hard to get much greener than that.

All the major wallboard manufacturers now produce it.

“Most builders in the U.S. are now demanding that products have recycled content. Obviously, synthetic gypsum meets the bill rather well,” said Willmer.

In addition to the obvious green advantages that have been developed by the cement and concrete industries, as well as wallboard industry, the fact also remains that concrete by its very nature tends to create green buildings.

Willmer pointed out that when combined with properly designed mechanical systems, the thermal mass of concrete buildings can be used for both cooling and heating.

Not all is rosy, of course.

The ready-mix industry along with all industries has been hit hard by the rapid rise in the cost of gasoline and diesel fuel.

There is also considerable concern about the impact of the provincial government’s carbon tax.

The B.C. Ready-Mixed Concrete Association has expressed concern regarding the tax.

Carolyn Campbell, the association’s executive director, pointed out the result could be potentially no reduction in green house gases, but rather could be a relocation of them to areas with less stringent legislation.

Print | Email | Comment