Application of Recycled Materials in Highway Projects

The impetus and pressure for pavement and geotechnical engineers to incorporate sustainability in engineering projects has led to a rise in the reuse of materials such as recycled concrete aggregate (RCA), reclaimed asphalt pavement (RAP) and recycled glass (RG) as fill and in pavement sub-layers. Consequently, an understanding of their behavior and characteristics are necessary prior to use in practice. Tests to characterize the materials, to assess their compactability and to address the vulnerability of RCA to tufa formation and aluminum corrosion were performed. It was found that RCA from a mechanical viewpoint has superior strength and stiffness. However, when exposed to water, it has a tendency to hydrate. Initially, the hydration leads to a gain in strength and stiffness. Subsequently, the material is prone to shrinkage cracking. Nevertheless, the RCA stiffness and strength are still quite appreciable compared to the pre-cracked value. RCA made with Hawaiian basaltic aggregate was found to not produce tufa in significant quantities as compared to dolomitic-based RCA when subjected to an accelerated leaching experiment. However, corrosion of aluminum in the presence of RCA was found to cause significant swell pressures and as such, RCA should not be used in close proximity with any aluminum infrastructure or should not be contaminated with aluminum. RAP on the other hand is more inert. However, the mechanical properties are less desirable than those of virgin aggregate and RCA. While the resilient modulus of RAP is quite appreciable, it suffered significant permanent deformation or rutting and its use should be contained by limiting its percent content. The RG obtained in this study was crushed to a very fine gradation. The large quantities of fines make working with RG hazardous as it can cause skin irritation. Finally, changes to the State of Hawaii Standard Specifications are proposed to incorporate the use of these three recycled materials as a fill or as an unbound layer in pavements. Two new sections (for RAP and RCA) are also proposed as additions to the current standard specifications.

• Corporate Authors:

  University of Hawaii, Manoa

  Department of Civil and Environmental Engineering
  2540 Dole Street, Holmes Hall 383
  Honolulu, HI  United States  96822

  Hawaii Department of Transportation

  Highways Division, 869 Punchbowl Street
  Honolulu, HI  United States  96813

  Federal Highway Administration

  1200 New Jersey Avenue, SE
  Washington, DC  United States  20590
• Authors:
  • Ooi, Phillip S K
  • Archilla, A R
  • Song, Yingjie
  • Sagario, M L Q
• Publication Date: 2010-12-17

Language

• English

Media Info

• Media Type: Print
• Edition: Final Report
• Features: Appendices; Figures; References; Tables;
• Pagination: 390p

Subject/Index Terms

• TRT Terms: Aluminum; Concrete aggregates; Corrosion; Deformation; Glass; Modulus of resilience; Pavements; Reclaimed asphalt pavements; Recycled materials
• Uncontrolled Terms: Tufa
• Subject Areas: Construction; Highways; Materials; I30: Materials;

Filing Info

• Accession Number: 01343218
• Record Type: Publication
• Report/Paper Numbers: HWY-L-2005-04
• Files: TRIS, USDOT, STATEDOT
• Created Date: Jun 28 2011 2:00PM