Citation

Morgan AD. Highw. Res. Board bull. 1951; 37: 38-56.

Copyright

(Copyright © 1951, National Research Council (U.S.A.), Highway Research Board)

DOI

unavailable

PMID

unavailable

Abstract

A study to correlate riding qualities on recently constructed bitumionus pavements with mixed design policies and construction practices was conducted on the following two types of bituminous mixtures on plain-mix pavement projects: Sand-asphalt and asphaltic concrete. The skid resistance measurements and road roughness measurements resulted in the following conclusions: (1) stabilities on sand-asphalts, using two-in. Diameter specimens, range from a minimum of 150 lb. To the maximum of 1800 lb. By the hubbard field method, (2) stabilities on asphaltic concrete ranged from 500 lb. To 4500 lb. Stability on 6-in. Diameter specimens by the modified hubbard field method, (3) road roughness measurements for sand-asphalt pavements ranged from a maximum of 176 to a minimum of 54 in. Per mi., (4) road roughness measurements for asphaltic concrete pavements ranged from a maximum of 117 to a minimum of 57 in. Per mi., (5) skid resistance tests on wet sand-asphalt pavements at 40 mph ranged from a skid distance of 69 ft. To a skid distance of 126 ft., (6) skid resistance tests on wet asphaltic concrete pavements at 40 mph ranged form a skid distance of 81 ft. To a skid distance of 111 ft., (7) considering only newly laid pavement, the lowest roughness index was obtained with low stability sand-asphalt mixes, and (8) where the preponderence of sand particles occur between the no. 40 and no. 200 mesh sieves, the frictional resistance of the surface is comparatively low.