Wear-resistant concrete. Professor John Knapton holding a prototype wear-resistant concrete designed for resurfacing roads damaged by studded tyres in Iceland and other northerly countries. Global warming is causing the usual thick winter ice to melt from the road surfaces in Iceland. The studs that drivers use on their tyres in winter for increased grip are now destroying the road surfaces. The damage is also generating large quantities of asphalt dust, which may be cancer- causing. Knapton and his team are testing the rates of mechanical wear on six different concretes, all made with cement and volcanic ash. Photographed at Newcastle University, England.