Solar Reflectance of Concretes for LEED Sustainable Sites Credit: Heat Island Effect

This 94-page report presents the results of solar reflectance testing on 135 concrete specimens from 45 concrete mixes, representing a broad range of concrete mix designs. The purpose of this testing is to determine which combinations of concrete constituents will meet the solar reflectance index requirements in the Leadership in Energy and Environmental Design for New Construction (LEED-NC) Sustainable Sites credit for reducing the heat island effect. Samples for each component (cement, fine and coarse aggregates, and supplementary cementitious materials) were selected to test the broadest range of color (light to dark) of readily available materials for concrete construction. While all materials were tested, second round testing focused on concrete mixes with the darkest (lowest reflectance) combinations of materials, that is, those more likely to fail the LEED criteria requirements. The following conclusions are based on the solar reflectance measurements of 45 sets of concrete specimens representing exterior concrete flat-work: All concretes in this study have average solar reflectances of at least 0.30 (corresponding to an SRI of at least 29), and therefore meet the requirements of LEED-NC SS 7.1. These concretes also meet the requirements for steep-sloped roofs in LEED-NC SS 7.2. The lowest solar reflectances are from concretes composed of dark gray fly ash. The solar reflectance of the cement has more effect on the solar reflectance of the concrete than any other constituent material. The solar reflectance of the supplementary cementitious material (in this study, fly ash or slag cement) has the second greatest effect.

• Availability:
  • Find a library where document is available. Order URL: http://www.cement.org/bookstore/profile.asp?itemid=SN2982
• Supplemental Notes:
  • Abstract reprinted with permission from the Portland Cement Association
• Corporate Authors:

  Portland Cement Association

  5420 Old Orchard Road
  Skokie, IL  United States  60077
• Authors:
  • Marceau, M
  • VanGeem, M
• Publication Date: 2007

Language

• English

Media Info

• Media Type: Print
• Pagination: 94p

Subject/Index Terms

• TRT Terms: Admixtures; Cement; Coarse aggregates; Color; Concrete; Fine aggregates; Solar energy; Sustainable development
• Identifier Terms: Leadership in Energy and Environmental Design Green Building Rating System
• Uncontrolled Terms: Heat island effect; Reflectance
• Subject Areas: Highways; Materials; I32: Concrete;

Filing Info

• Accession Number: 01079995
• Record Type: Publication
• Files: TRIS
• Created Date: Oct 25 2007 10:26AM