Accelerated wear tests have been carried out on a wide range of concrete and mortar mixes in order to establish the influence of materials, the mix design and type of texture on the skid resistance values as measured by the portable tester and texture depths of concrete road surfaces. The most important constituent in the mix was the fine aggregate. The use of high-silica content natural sands always yielded higher skid resistance values than did relatively soft sands or crushed fine materials. The incorporation of the very hard and polish-resistant calcined bauxite fines in the mix yielded the highest skid resistance values. The polishing characteristics of the coarse aggregate had only a very slight effect on the skid resistance value of concrete, an increase in polished-stone value from 35 to 72 producing an increase in skid resistance value of less than five units. Normally not more than 12 percent of the surface of concrete consists of exposed coarse aggregate. /Author/
Samenvatting