Extending Full Depth Reclamation Service Lives

Details

• Creators:
  Amarh, Eugene A. ; Tong, Bilin ; Katicha, Samer W. ; Flintsch, Gerardo W. ; Diefenderfer, Brian K.
• Corporate Creators:
  Virginia Transportation Research Council (VTRC) ; Virginia Tech Transportation Institute
• Corporate Contributors:
  Virginia. Department of Transportation ; United States. Department of Transportation. Federal Highway Administration
• Subject/TRT Terms:
  Aggregate Mixtures Asphalt Pavements Full-depth Reclamation Pavement Distress Pavement Performance Portland Cement Reflection Cracking Service Life Testing
• Publication/ Report Number:
  VTRC 26-R21
• Resource Type:
  Tech Report
• Geographical Coverage:
  United States ; Virginia
• Edition:
  Final Report
• Corporate Publisher:
  Virginia Transportation Research Council (VTRC)
• Abstract:
  The Virginia Department of Transportation (VDOT) has successfully used in-place recycling strategies on approximately 40 pavement rehabilitation projects in the state during the past decade. One such technique, full-depth reclamation (FDR), is usually selected as an alternative to conventional reconstruction to rehabilitate failing pavements where distresses are within the pavement system foundation. To perform FDR, equipment pulverizes, stabilizes, and compacts the bound layers and a predetermined portion of the unbound layers of the existing pavement to form a new stabilized base. Despite its advantages, cement-stabilized FDR may be prone to shrinkage cracking, which remains a critical concern for long-term pavement longevity. Such cracking is primarily induced by hydration and curing processes that generate tensile stresses exceeding the tensile strength of the material. These cracks may then propagate through the asphalt surface, following the underlying pattern in the base layer, and are commonly referred to as “reflection” cracks. To mitigate shrinkage-related issues, microcracking may be employed to reduce the severity of shrinkage-induced cracking in cement-treated layers by introducing a network of fine cracks to relieve initial stresses within the first 24 to 72 hours after construction. Several transportation agencies have implemented microcracking on FDR. However, the results show that the technique has not always been effective in preventing cracking. Consequently, further research has been recommended to improve the understanding of the microcracking mechanism, its long-term performance, and its interaction with these influencing factors (Louw et al., 2016). In this study, cement-stabilized FDR test cells were constructed at Virginia’s Accelerated Pavement Testing Facility to assess the differences in performance between microcracked and non-microcracked FDR test cells having two different cement contents. A relatively thin hot mix asphalt surfacing was placed over the FDR layer. The selection of a thin layer allows the experiment to focus on responses in the FDR layer. The test cells were instrumented and subjected to loading using a Heavy Vehicle Simulator throughout various weather conditions. The test was conducted during an approximate 2-year period.
• Format:
  PDF
• Funding:
  122696
• Collection(s):
  US Transportation Collection
• Main Document Checksum:
  urn:sha-512:b7480cc7246c7515d8daedcfb78b1e5bba07b72196b31c299b246a2a4417afd6f4040290e4970c6cc895c1ceb75c093722d7446ca47a78fae3b3986f427942f6
• Download URL:
  https://rosap.ntl.bts.gov/view/dot/87586/dot_87586_DS1.pdf
• File Type:
  [PDF - 4.43 MB ]