Student-Designed Cool Sidewalk Could Reduce 'Urban Heat Island' Effect

Traditional concrete sidewalks "absorb heat, occasionally buckling because of the pressure from heated expansion; and can even reflect heat, causing 'heat islands' in urban areas." Hope Muñoz and Rachel Whitt report on an innovation that could replace concrete with cooler, more environmentally friendly materials. Research students at the University of New Mexico have "designed a sidewalk built using recycled and less energy- and carbon-intensive materials," which is also much thinner than the average four-inch sidewalk.

After looking at historic sidewalk construction, researcher Patience Raby said "[i]t seems there was not good explanation for the use of standard concrete mixes in sidewalks or even for the fact that they’re usually four inches deep." According to a Federal Highway Administration report, "Atmospheric heat islands can affect communities by increasing summertime peak energy demand, electrical grid reliability, air conditioning costs, air pollution and GHG emissions, heat-related illness and death, and water quality." The new design reduces heat and the amount of materials needed for its construction. "The researchers fabricated three slabs to compare their thermal output, emissivity, and energy balance."

"In the future, the team would like to design 3D printed concrete slabs and those which are thin fiber reinforced with voids. These slabs would later be tested for heat storage potential."