Sources: Lafarge North America, Chicago; CP staff
Lafarge North America has attained LEED for Commercial Interiors Gold certification at its recently occupied Chicago headquarters, the rating partly reflecting specification of internally procured product: reception area backdrop of Elburn, Ill.-quarried limestone, plus tile and countertops of Ductal ultra-high performance concrete.
Read MoreSources: Cement Association of Canada (CAC), Ottawa; CP staff
Two years after its launch across Canada, an industry-branded portland cement with up to 15 percent ground limestone content—promoted for reducing carbon dioxide emissions by 10 percent against conventionally milled powder—has gained significant traction among concrete producers and their customers.
Read MoreSources: National Institute of Science and Technology (NIST), Gaithersburg, Md.; CP staff
Adding limestone powder to fly ash-rich mixtures can improve finished concrete performance when measured against more conventional formulations, note NIST and Federal Highway Administration researchers in an August report, “Ternary blends for controlling cost and carbon content.”
Read MoreSources: National Ready Mixed Concrete Association; CP staff
In a move that will provide the opportunity for the cement and concrete industries to reduce products’ carbon footprint, a proposal was approved to permit up to 15 percent ground limestone in blended cements under ASTM C595 (Blended Hydraulic Cements), with the resulting product characterized as limestone blended cements. Similar revisions are being made to the equivalent AASHTO standard by the AASHTO Subcommittee on Materials. Under C595, there was previously no specifically stated limit on ground limestone content.
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