Friction and Surface Texture Characterization of 14 Pavement Test Sections in Greenville, North Carolina

Abstract

Three locked-wheel skid trailers, International Cybernetics Corporation (ICC) Model MOR 5041 and K. J. Law Models M 1270 and M 1290, were tested at three speeds on 14 test sections located in Greenville, North Carolina. The test sections included a heavy-duty surface course, polymer-modified heavy-duty surface course, rubber-modified heavy-duty surface course, heavy-duty surface course with carbon black, stone mastic with fibers, polymer-modified stone mastic, and large-stone surface course. Multivariate regression analysis of friction number versus speed for the three test vehicles was performed. Despite having been load cell calibrated 1 day before testing, the ICC MOR 5041 results were statistically different from those of the other skid trailers on all but one test section. The two K. J. Law skid trailers were statistically different from each other, either on intercept or slope, on more than half of the test sections. Each individual skid trailer provided repeatable results with a standard deviation of about 2 when testing was done at 64 km/h, with a higher standard deviation for testing at lower speed. The frictional resistance of the test sections was compared by ranking frictional number at 64 km/h and rate of decline of friction number with speed. The best frictional performance was provided by the heavy-duty surface course and the large-stone surface course, and stone mastic with fibers and stone mastic with polymer were ranked poorest. None of the test sections had an average friction number less than 40, even when tested at 80 km/h.