This study was structured towards addressing that portion of the Intermodal Surface Transportation Efficiency Act (ISTEA) which directs the individual states to conduct studies on the recyclability of crumb rubber modified hot mix asphalt (CRMHMA), and the technical performance of CRMHMA pavement by monitoring the construction and evaluating the performance of highway test sections in which CRMHMA is removed by cold milling and recycled into new HMA through an HMA plant. This project is to be constructed in two phases; the CRMHMA will be built in the first phase and approximately one year later it will be recycled. This report deals with the first phase in which the objective was to further document the construction, engineering characteristics, and performance of CRMHMA. Three test sections were constructed with CRM percentages of 8, 10, and 12% by weight of the asphalt cement binder. A fourth section designated as the control section was built without any CRM and used for comparison purposes. Each section was approximately 0.8 km in length and involved a 38 mm binder course and a 38 mm surface for binder course. These sections were constructed in the westbound lanes of US 72 in Alcorn County. This project involved the paving of two new lanes that carried the westbound traffic of this route. The new lanes were paved and then placed under two-way traffic while old bridges were being replaced on the old lanes. The CRMHMA was successfully produced in a normal production facility with only the addition of a blending unit for the rubber and asphalt cement. Temperatures of the loose mix in the trucks ranged from 182 to 193 deg C. Placement of the CRMHMA on the roadway appeared to be in a normal fashion as it would be for regular HMA, except for increased smoke. Performance testing of the new CRMHMA pavement indicated excellent condition of the pavement except for some high deflection readings in the control section and 12% CRMHMA section.


  • English

Media Info

  • Features: Appendices; Figures; Photos; References; Tables;
  • Pagination: 85 p.

Subject/Index Terms

Filing Info

  • Accession Number: 00727348
  • Record Type: Publication
  • Report/Paper Numbers: FHWA/MS-DOT-RD-96-115, Interim Report
  • Created Date: Oct 24 1996 12:00AM