Manager of engineering and technical director, Construction, Materials, and Services, Koppers Co., Inc., Pittsburgh, PA
Pages: 23 Published: Jan 1987
The central tenet of this paper is that a proper level of bearing capacity is essential to good asphalt pavement performance. Methods for designing pavements with increased bearing capacity and methods for measuring this property are recommended. Since the bearing capacity of asphalt pavements is seldom determined, the fact is often overlooked that many pavement failures that are attributed to stripping, inferior asphalt quality, and inferior stone quality are actually structural failures due to inadequate bearing capacity. Increased truck tire pressures menace many pavements which were designed to traditional standards but which have bearing capacities too low to cope with the higher stresses. The only practical way to save these pavements from premature failure is to lower the stresses or tire pressures on them during hot weather.
The complexity of the rheology of asphalt and asphalt pavements and the poor precision of test methods used to measure these properties require that the conditions of test be carefully matched to road conditions in order that the results be meaningful.
The use of aggregate graded to a high volume concentration and with a top size two-thirds the thickness of the pavement dramatically increases bearing capacity.
Low-viscosity asphalt and air voids of less than 3% greatly increase the durability of asphalt pavements.
asphalt pavements, mechanical properties, rheology, viscosity, yield strength, bearing capacity, structural failure, durability, tire pressures, large aggregate, low-temperature fracture
Paper ID: STP18521S