Author: Woodrow J. HalsteadPublisher:
ISBN:
Category : Pavements
Languages : en
Pages : 13
Book Description
Final Report
Author: Woodrow J. HalsteadPublisher:
ISBN:
Category : Pavements
Languages : en
Pages : 13
Book Description
Properties of Asphalt Cements Used in Virginia and Their Effects on Pavement Performance
Author: Woodrow J. HalsteadPublisher:
ISBN:
Category : Pavements
Languages : en
Pages : 10
Book Description
Results of usual tests for specification compliance and special tests to show viscosity-temperature susceptibility and ductility penetration relationships for asphalts supplied for use by the Virginia Department of Highways and Transportation in 1983 are reported. The results to date have not revealed any asphalts with unusual properties. Differences in viscosity-temperature susceptibilities of products from different suppliers were relatively small. The results also indicate that satisfactory performance of properly designed and placed mixtures would be expected with all of these products, but a firm conclusion to this affect cannot be drawn until the ability of the asphalts to adhere to aggregates is determined. Such tests are planned. The addition of a requirement to asphalt cement specifications that the ash not exceed 0.40 percent is recommended. Such a requirement would provide protection against products from unusual refining processes that contain appreciable amounts of organic sodium salts.
Chemical Properties of Asphalts and Their Effects on Pavement Performance
Author: Raymond E. RobertsonPublisher:
ISBN:
Category : Asphalt
Languages : en
Pages : 52
Book Description
The purpose of this Circular is to familiarize the asphalt user with the source of asphalt, the variable chemistry of asphalt, why variable performance should be expected when asphalt is used in roadways and what is currently missing from the specification process. Several areas are identified where refinements in the specification process would improve the ability to classify asphalts by their expected performance. This Circular summarizes more than 2,500 pages written during the past 20 years on the effects of fundamental chemistry on the rheological properties of asphalt. This Circular should be especially useful to civil engineering students who intend to work in some highway construction-related business.
Additional Asphalt to Increase the Durability of Virginia's Superpave Surface Mixes
Author: G. W. MaupinPublisher:
ISBN:
Category : Pavements, Asphalt
Languages : en
Pages : 24
Book Description
Although Superpave has been successful in preventing rutting, many believe that the design asphalt content needs fine-tuning to produce durable mixes. This investigation used various laboratory tests to test samples of field surface mixes (12.5 mm and 9.5 mm) to predict changes in mix properties as extra asphalt was added. Permeability, 50-blow Marshall volumetrics, rutting, and fatigue tests were used. An analysis tool using gyratory compaction was also used to predict what the level of pavement voids would have been had higher asphalt contents been used. For most of the mixes, properties improved as the asphalt content was increased. The asphalt content could have been increased as much as 0.5 percent in most of the mixes with no harmful effects. It is reasonable to expect that the beneficial effects would increase the life of a surface mix by approximately 5 percent. The Virginia Department of Transportation (VDOT) uses approximately 2 million tons of asphalt in surface overlays per year at a cost of approximately $35 per ton. The cost of adding 0.5 percent more asphalt would be approximately $1 per ton. With an estimated increased service life of 5 percent, VDOT would save approximately $1 .5 million per year. The researcher recommended that the effects of increasing the design asphalt content of Superpave mixes be explored and tested in the field.
Federally Coordinated Program of Highway Research, Development and Technology
Author: Highway Research and Development Studies Using Federal-aid Research and Planning Funds
Author: Federally Coordinated Program of Highway Research, Development, and Technology. Annual Progress Report. Fiscal Year 1985
Author: Highway Research and Development Studies Using Federal-aid Research and Planning Funds; Fiscal Year 1968 Or Calendar Year 1967 in Progress as of July 1, 1967
Author: Publisher:
ISBN:
Category : Transportation, Automotive
Languages : en
Pages : 176
Book Description
Highway Research and Development Studies Using Federal-aid Research and Planning Funds, Fiscal Year 1967 Or Calendar Year 1966, in Progress as of July 1, 1966
Author: United States. Bureau of Public RoadsPublisher:
ISBN:
Category :
Languages : en
Pages : 172
Book Description
Author: