... Both load and nonload-associated cracking of asphalt pavements are prevalent in Canada and the northern United States. It is essential to identify the rheological properties of the asphalt binder responsible for this type of distress. An asphalt durability research project began...

... Polymer modification dramatically changes the rheological properties and therefore the performance of asphalt cement. This study discusses conventional and new methods of specification testing for the polymeric elastic and tensile properties. Five asphalts were tested before and after polymer...

... Before 1974, stripping in hot mix asphalt concrete was considered to be a relatively minor problem in Oregon. During the three-year period from 1974 to 1977, several problems were noted during and after construction of asphalt pavements. One of the major problems associated with asphalt...

... The effectiveness of various immersion-mechanical tests in measuring the water susceptibility of cold-recycled asphalt mixtures was investigated. The immersion-mechanical tests involved subjecting compacted recycled asphalt mixtures to a 24-h water immersion process followed by mechanical tests...

... Durability characteristics of certain foamed asphalt mixtures were established during this laboratory investigation. Durability was characterized by a water sensitivity test and cyclic freezing and thawing. The various foamed asphalt mixtures were evaluated for durability after the mixtures had...

... This paper summarizes the findings of a six-year study of moisture damage of asphalt mixtures, which was conducted at The University of Texas at Austin. The objectives of the study were to define the nature and severity of moisture damage in asphalt pavement mixtures, develop techniques...

... After 2000 years or more of using asphalts for engineering purposes that involve their rheological properties, we are finally beginning to understand their behavior. It is our opinion that the mystery of deformation of bitumen or its composites or both under stress has to be no different from...

... Plasticized sulfur (Sulphlex) binders have been developed by the Southwest Research Institute (SWRI) in Texas as a total replacement for asphalt. The Pennsylvania Department of Transportation constructed an experimental pavement in October 1980 using Sulphlex 233-A binder. This study consists...

... Recent trends in the formulating of hot applied rubberized asphalts have led to increased cohesive strengths in these materials. As a result, it was noted that these products would fail adhesively in the conventional toughness-tenacity test, making it impossible to assess their true elastomeric...

... In 1929, three types of failure occurred in large areas of asphalt surfacing in Singapore. Research undertaken in 1930 to 1931 at the University of London, appeared to indicate the causes. The problem was not only that of preparing revised specifications but that of finding economical means...

... Practical recommendations are made for recycling asphalt pavements by ( a ) use of selected reclaiming agents to restore durability and consistency to the aged asphalt, and ( b ) application of a rational mix design. Satisfactory reclaiming agents are characterized as ( a ) being fully...

... Properties of modifiers for recycling of asphalt concrete should be such that the recycled asphalt will have properties essentially the same as neat asphalt with the least addition of modifier possible. Recommended specification requirements for a modifier include a flash point of 200°C...

... Addition of rejuvenating oils to aged, dry asphaltic pavement materials to restore them to their original condition is a practice currently being used on many construction projects. Typically, the effect of rejuvenation is measured using standard mix design procedures such as stability...

... Recycling asphaltic concrete pavements was investigated as a means of utilizing the asphalt and graded aggregates they contain and solving waste disposal problems. Discarded asphaltic concrete pavement materials from three sources in the Las Vegas, Nev. area were studied; each contained...

... The viscosity of asphalt was found to be dependent upon its thermal history. Asphalt thermally dissociated at 250°C had a lower viscosity than asphalt that had been allowed to associate at 130°C. Viscosities were obtained by forcing a sphere or cylinder (wire) through the asphalt. Temperature...

... Pavement transverse cracking is a recurring problem in Canada and the northern United States. Field trials and laboratory investigations have confirmed that the major influence on this cracking is the mix stiffness, and consequently asphalt stiffness, at low temperatures. It has been...

... Some low-temperature durability tests on two asphaltic concretes and similar concretes with sulfur-modified asphalt as the binder are described. The results of the tests indicate that sulfur-modified asphaltic concretes may be more durable and are potentially more economic than their unmodified...

... The data on changing asphalt properties, especially the low-temperature ductility measured at 39.2 and 60°F (4 and 15.6°C), have been analyzed and related to the performance of ten experimental pavements in Pennsylvania. It has been observed that aging of the pavement results in progressively...

... This study was undertaken to assess the value of high-density rock as a mineral stabilizer for the asphalt coatings used in the manufacture of prepared roofings. The hope was that more mineral stabilizers could be used in the roofings than was the usual practice, thus saving on the high-energy...

... Stress-strain properties of Type 15 asphalt-saturated, organic, and asbestos felts are compared at room temperature and 50 percent relative humidity. The rate of water sorption by asphalt-saturated organic felt immersed for 520 h in distilled water at room temperature and the effect of moisture...