Resources

Definitions:

Blended cement: A cement that contains ASTM C 150 Portland cement blended with supplementary cementitious materials. Blended cement as a technical term often refers to cement products blended by cement companies. In the C3 program, the term is used to describe cement blended by any type of company.

Monitoring and verification: A monitoring and verification plan provides technical rigor to ensure that the CO2 offsets are achieved according to an established protocol. Monitoring and verification is the main difference between Climate Trust programs such as C3 and much of the other carbon dioxide offset and trading activity in the U.S. Monitoring and verification is essential for establishing ownership and retirement for something that has not been owned in the past (CO2).

Portland cement: Portland cements are hydraulic cements composed primarily of hydraulic calcium silicates. ASTM C150, Standard Specification for Portland Cement, defines portland cement as “hydraulic cement (cement that not only hardens by reacting with water but also forms a water-resistant product) produced by pulverizing clinkers consisting essentially of hydraulic calcium silicates, usually containing one or more of the forms of calcium sulfate as an inter ground addition.”

Pozzolans: A siliceous or siliceous and aluminous material which in itself possesses little or no cementitious value that can provide cementitious characteristics when mixed with ASTM C150 Portland cement. Examples of pozzolans include flyash, silica fume and rice hull ash. Ground granulated blast furnace slag is often thought of as a pozzolan, but it is actually a cement.

Supplementary cementitious materials: Mineral admixtures consisting of powdered or pulverized materials which are added to concrete before or during mixing to improve or change some of the plastic or hardened properties of Portland cement concrete. Materials are generally natural or by-products of other manufacturing processes, such as flyash, ground granulated blast furnace slag, silica fume and rice hull ash.

Websites:

Climate Trust: www.climatetrust.org
EcoSmart: www.ecosmart.ca
Ecological Building Network: www.ecobuildnetwork.org
7group: www.sevengroup.com
Seattle City Light: www.seattle.gov/light/conserve/globalwarming
Slag Cement Association: www.slagcement.org