USE OF FOAMED ASPHALT IN RECYCLING OF AN ASPHALT PAVEMENT

The recycling of pavement materials is a cost-effective and energy-efficient method of reconstruction. Laboratory studies have demonstrated that foamed asphalt can be used with success as a binder in cold recycling. During the summer of 1981, the Indiana Department of Highways constructed an experimental 9.0-mile (14-km) section in which foamed asphalt was used as a binder in cold recycling. The main purpose was to monitor and evaluate the construction procedures and the performance of such reconstruction. The initial concept was to use in-place cold recycling. due mainly to the inability of the milling machine to reduce the pavement to a full depth of 5 in. (125 mm), the construction procedure was changed. During actual construction the initial pavement was removed in two 2.5-in. (65-mm) layers and the material stockpiled at a nearby central plant. Some additional aggregate was precoated with 4 percent foamed asphalt and mixed with an additional 1.5 percent of foamed asphalt in a ratio of 1 to 3 to form the finnl base-course mixture. All mixing was done by a twin-shaft pugmill. The final mixture was placed in two layers with a total thickness of approximately 5.5 in. This new base course was overlaid by 1.25 in. (38 mm) of hot asphalt mixture. Tests were conducted before, during, and after construction to evaluate the properties of the mixture and the performance of the recycled layer. The use of foamed asphalt caused no serious problems during construction. Convntional equipment could be used with only small modifications. The recycled pavement could be opened to traffic soon after compaction without any problems. It was therefore also possible to keep the road open to traffic throughout the construction. Foamed asphalt appears to behave as well as a binder in cold recycling. The initial performance of the recycled layer is satisfactory. (Author)

Media Info

  • Media Type: Print
  • Features: Figures; Maps; References; Tables;
  • Pagination: pp 96-103
  • Monograph Title: Asphalt materials, mixtures, construction, moisture effects and sulfur
  • Serial:

Subject/Index Terms

Filing Info

  • Accession Number: 00390797
  • Record Type: Publication
  • ISBN: 0309035546
  • Files: TRIS, TRB
  • Created Date: Dec 30 1984 12:00AM