Effects of composition and exposure on the solar reflectance of Portland Cement Concrete

Journal Article · Sat Jun 01 04:00:00 EDT 2002 · Cement and Concrete Research

DOI:https://doi.org/10.1016/S0008-8846(02)00835-9· OSTI ID:817626

Levinson, Ronnen ^[1]; Akbari, Hashem

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1. LBNL Library

Increasing the solar reflectance (albedo) of a paved surface keeps it cooler in the sun, reducing convection of heat from pavement to air and thereby decreasing the ambient air temperature. Lower air temperatures decrease demand for cooling energy and slow the formation of urban smog. Variations with composition and environmental exposure of the albedos of portland cement concrete pavements were investigated through laboratory fabrication and exposure of 32 mixes of concrete. Concrete albedo generally correlated with cement albedo and sand albedo and, after abrasion, with rock albedo. Cement albedo had a disproportionately strong influence on the reflectance of concrete. Simulated weathering, soiling, and abrasion each reduced average concrete albedo, though some samples became slightly more reflective through weathering or soiling. Concrete albedo grew as the cement hydration reaction progressed, but stabilized within six weeks of casting.

• Research Organization: Ernest Orlando Lawrence Berkeley National Laboratory, Berkeley, CA (US)
• Sponsoring Organization: USDOE Assistant Secretary for Energy Efficiency and Renewable Energy. Building Technologies Program; Environmental Protection Agency (US)
• DOE Contract Number: AC03-76SF00098
• OSTI ID: 817626
• Report Number(s): LBNL--50551
• Journal Information: Cement and Concrete Research, Journal Name: Cement and Concrete Research Journal Issue: 11 Vol. 32; ISSN 0008-8846; ISSN CCNRAI
• Country of Publication: United States
• Language: English

Related Subjects

29 ENERGY PLANNING, POLICY, AND ECONOMY
36 MATERIALS SCIENCE
54 ENVIRONMENTAL SCIENCES
ABRASION
ALBEDO
CASTING
CEMENTS
CONCRETES
CONVECTION
ENVIRONMENTAL EXPOSURE
FABRICATION
HEAT EXCHANGERS
HYDRATION
PAVEMENTS
PORTLAND CEMENT
SAND
SMOG
SOLAR REFLECTANCE CONCRETE AGGREGATE ACCELERATION AGING
SUN
WEATHERING