by Shane Henson — November 9, 2011—High Concrete Group, a producer of sustainable precast structures and components, has introduced a new high solar reflectance concrete mix design that was created to significantly improve the heat reflectance of precast concrete surfaces, causing them to stay cooler. Solar reflectance testing from partner BASF Construction Chemicals confirmed the mix design has a solar reflectance index (SRI) of 82, nearly doubling the SRI of the company’s conventional gray concrete mixes.
Building owners and managers overseeing projects that incorporate sustainable design will appreciate that the high solar reflectance precast concrete helps buildings reflect rather than absorb solar radiation. The solar reflectance of a building’s exterior surfaces impacts its contribution to the urban heat island effect, a phenomenon in which built areas are dramatically warmer than surrounding rural areas, resulting in poorer air quality and increased utility costs. High solar reflectance precast can also be used to reverse the urban heat island effect.
According to the company, it developed the high solar reflectance concrete mix design with BASF using 75% white cement and 25% ground granulated blast furnace slag, a recycled material, for the cementitious content. Local limestone aggregates provided a neutral-colored base. The SRI of 82 was achieved on a form-finished white concrete block sample.
