American Concrete Institute
American Coal Ash Association
American Concrete Paving Association
American Concrete Pumping Association
American Society of Concrete Contractors
National Stone Sand and Gravel Association
National Ready Mixed Concrete Association
Portland Cement Association
Post Tensioning Institute
Tilt-up Concrete Association
Expanded Shale, Clay, and Slate Institute
Boral Material Technologies
BASF Corporation
Colorado Ready Mixed Concrete Association
Con-expo Con-agg 2008
Aggregate Research