New Water-Retentive Pavement Cools Road Surface

A new pavement system developed by Nihon Kogyo Co. lowers road surface temperatures, one cause of the urban heat island effect, by using the cooling power of the vaporization of stored water. Installation of the pavement began in March 2006 at an intersection in Kawasaki City, Kanagawa Prefecture, and it is expected to be functioning this summer.

The system, called the Barrier-Free Road Cooling System, is capable of continuously absorbing groundwater or stored rainwater using water-retaining materials. As the water stored in the pavement evaporates slowly into the air, it absorbs the surrounding heat and the lowers road surface temperature. This particular project is planned to use groundwater as its water source.

The technology was adopted by the Environmental Paving Tokyo Project jointly launched by the Tokyo Metropolitan Government and the Kanto Regional Development Bureau of the Ministry of Land, Infrastructure and Transport. In feasibility tests the pavement lowered the road surface temperature from 63.3 degrees Celsius to 37.87 degrees Celsius, and it earned an excellent rating as a water-retentive pavement technology.

To use resources effectively, the company plans to use water-retentive blocks consisting of 20 percent copper slag, a by-product of the copper refining process. By this demonstration of the pavement's benefits in Kawasaki City, the company hopes to expand its practical applications in the future.


- Water-retentive Pavement and the Heat Island Effect in Tokyo (Related JFS article)
http://www.japanfs.org/db/1167-e

Posted: 2006/05/10 11:22:39 AM
Japanese version