Paper 1: The broad gap between research on asphaltic concrete specimens prepared in laboratory bench-type equipment and test roads or public highways has been narrowed by providing full-scale paving equipment in a research facility. This facility permits asphaltic concrete pavement construction under conditions of control which cannot be reached in field operations. Paper 2: Laboratory and field data have been collected from 12 regular contract hot-mix asphaltic concrete paving projects in various areas of Texas for the purpose of comparing laboratory and field densities. Paper 3 proposes a mechanism by which mixes can be unstable at high temperatures during rolling and still be quite stable by normal design criteria.

Paper 1: The results of comprehensive laboratory tests on asphalt paving mixtures with chrysotile asbestos are described. Paper 2: Data are presented on 1. progressive hardening and embrittlement of the asphalt cement with aging, 2. loss of adhesion of the asphalt cement to the aggregate with the resultant lower compressive strengths due to water displacement of the asphalt binder at the asphalt-aggregate interface, 3. progressive loss of water resistance of the asphalt cement as the asphalt hardens, and 4. progressive loss of the ability of the asphalt binder to readhere to the aggregate after displacement by water. Paper 3: The viscoelastic behavior of bitumens varies with film thickness. therefore, for correlation of laboratory testing with field performance in bituminous pavements, it is important to match the geometry of testing to geometry of end use.