AT WORLD OF Concrete in January, it was hard to walk through the exhibit hall, attend a presentation, or listen to a speaker without hearing "sustainability." Although companies have been calling their products and services green for years, the technologies are now more proven. And green practices will be crucial to industry growth.
Following are examples of environmentally friendly solutions promoted at this year's event.
CarbonCure Technologies, based in Halifax, Nova Scotia, invents, licenses, and markets technologies that consume waste CO2 while producing high-quality concrete products to ASTM and CSA (Canadian Standards Association) standards.
CarbonCure makes lowcarbon concrete block on a large scale that are stronger, greener, and cheaper to produce. The system captures CO2 gas in the block during the molding process and sequesters it as solid limestone. The process uses 10 percent less cement and produces 20 percent less waste than traditional methods, while reducing greenhouse gas emissions by 20 percent and energy use by 38 percent.
The equipment is compatible with most block plants, integrates easily into existing production processes, and pays for itself within a year, the company claims. CarbonCure is also developing precast panels and pipe.
Several North American block producers are commissioning the system: Basalite Concrete Products in California, Shaw Group in Nova Scotia, and Atlas Block in Ontario. The first CarbonCure block structures will be unveiled this spring. Visit www.carboncure.com.
Heavy-duty hybrid technology
BAE Systems' heavy-duty HybriDrive parallel propulsion system is designed for "big-bore" and diesel engines in Class 6, 7, and 8 vehicles. The system blends combustion engine technology with electric torque and power to improve fuel economy and performance while reducing noise and emissions. In field tests with dump, refuse, and semitrucks, HybriDrive improved fuel economy by 30 percent compared to diesel.
Its backbone is a single electric machine integrated between the engine and transmission. With large motor/ generator and energy storage capacity, the system is well-equipped to capture recuperative braking energy.
Through long-term supplier agreements, the system will use Caterpillar transmissions and Remy International electric motor components. BAE plans to launch HybriDrive in early 2013. See www.hybridrive.com.
Less cement, more limestone
In Canada, Lafarge North America has introduced Contempra, a portlandlimestone cement (PLC) that uses up to 15 percent limestone, compared to the 5 percent in typical portland cement. Manufacturing PLC produces up to 10 percent less CO2 than regular portland cement, and it produces concrete with equal strength and durability.
Contempra is made by grinding portland cement clinker with 6 to 15 percent limestone. The finely ground materials create a particle packing effect that increases concrete strength.
The PLC's performance also depends on using high-quality limestone, which is tested for calcium carbonate, clay, and total organic carbon content. Contempra is subject to the same standards (CSA A3001-08) as regular portland cement.
Lafarge expects to introduce Contempra in the U.S. in two to three years. Visit http://www.lafargenorthamerica.net for more and for field trial data.
2012 International Green Construction Code Released
As reported in our November/December 2011 sustainability column, "Deciphering the Code" (November/December 2011), the 2012 International Green Construction Code (IgCC) was released in March. It is intended as a model for state and local governments looking to codify green building practices.
The IgCC incorporates Standard 189.1 (ANSI/ASHRAE/IES/USGBC 2011) Standard for the Design of High Performance Green Buildings - which provides a "total building sustainability package" for designing, building, and operating green buildings - as an optional path to compliance. The code offers a baseline that can be tailored to the design of new construction and renovation projects, whether or not they use other programs such as LEED.
The 2012 IgCC is a first step toward bringing healthier, lower impact, more efficient, and responsible building practices into the mainstream. It was authored by the International Code Council (ICC) in partnership with the American Institute of Architects (AIA), ASTM international (ASTM), ASHRAE, the Illuminating Engineering Society (IES), and U.S. Green Building Council (USGBC).
Green Building Megatrends for 2012 (Builder, 2012)
U.S. Green Building Council Director, Jerry Yudelson predicts the year's top 10 green growth areas.