01018925

Component

http://onlinepubs.trb.org...nepubs/circulars/ec078.pdf

The performance of recycled asphalt pavement (RAP), the effects of milling, and overlay thickness are important factors for pavement engineers to consider when making decisions on rehabilitation and maintenance activities. Specific Pavement Studies- (SPS-) 5 sections were built 10 years ago to address this issue. Performance data under well-documented SPS sections have provided valuable insight that could not have been achieved otherwise. SPS-3, SPS-5, and three hot-in-place (HIP) recycled sections were studied. One of the HIP recycled sections was adjacent to an SPS-3 and an SPS-5 section, thus they all possessed the same underlying subsurface layers. It was found that after more than 10 years of service, the RAP sections perform as well as the virgin asphalt concrete (AC) sections. This indicates that the RAP can be effective when used properly. Also, little difference was found in terms of performance on milled and non-milled sections. However, to date, there is less distress on the 125-mm sections than on the 50-mm sections. It is important to note that all SPS-5 sections are able to resist reflective cracking when a mixture of 30% RAP and a softer binder is used, the result is a high penetration number (30 to 45), with a flexible mixture able to resist cracking. In contrast, cracks came through the HIP recycled sections in just a few weeks for US-175 and US-84. Low penetration numbers in the range of 20 to 21 were found. A 75% mixture of RAP was found to be too high, because aged binder tends to become brittle, and consequently does a poor job resisting cracking. The HIP recycled process was used satisfactorily on US-281 where no cracking potential existed. Thus, it was concluded that high percentage RAP mixture should not be used on any location where cracking potential is present. Also, a lower viscosity AC should be added to the RAP to increase the flexibility. The results in the SPS-3 sections indicated that chip seal is the most cost-effective, preventive maintenance (PM) treatment. Although rehabilitation strategy on SPS-5 sections costs more than PM treatments on SPS-3 sections, SPS-5 sections performed better than the SPS-3 sections. The most important factor influencing pavement performance on SPS-3, SPS-5, and HIP recycled sections is the type of surface treatment.

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01018923

English

pp 70-84

2005-10

Transportation Research Circular

First National Conference on Pavement Preservation

Web

Figures (1) ; Maps (1) ; Photos (6) ; References; Tables (2)

Asphalt concrete; Asphalt pavements; Chip seals; Cost effectiveness; Hot in-place recycling; Lessons learned; Milling; Overlays (Pavements); Pavement distress; Pavement maintenance; Pavement performance; Preventive maintenance; Recycled materials; Reflection cracking; Rehabilitation; Test sections; Thickness; Viscosity

Long-Term Pavement Performance Program; Specific Pavement Studies (LTPP)

Texas

Design; Highways; Maintenance and Preservation; Pavements; I22: Design of Pavements, Railways and Guideways; I23: Properties of Road Surfaces; I61: Equipment and Maintenance Methods

TRIS, TRB

Feb 4 2006 3:33PM

• Analysis of New Zealand Chip Seal Design and Construction Practices
• Changing Our Way of Thinking: Have We Succeeded?
• Chip Sealing over Fabric in Borrego Springs, California
• Condition-Based Determination of Preservation Needs of a Road Network
• Constructability of Longitudinal Construction Joints in Hot-Mix Asphalt Pavements with Sealers to Retard Future Deterioration
• Development of the Caltrans Maintenance Technical Advisory Guide
• Gravel Roads Asset Management
• Improving Safety as Part of a Pavement Preservation Program
• Integration of Preventive Maintenance in the Pavement Preservation Program: Ontario Experience
• Pavement Preservation Training in Texas
• Performance Evaluation of Novachip Surface Treatment in Louisiana
• Preventive Surface Treatments Versus Traditional Corrective Maintenance Measures
• Quality Control and Quality Assurance on Chip Seal Projects
• Seal Coat Options: Taking Out the Mystery
• Sustaining Toll-Road Operation Through Performance-Based Management
• The Role of Pavement Preservation in Privatized Maintenance
• Warranty Administration in the Michigan Department of Transportation's Capital Preventive Maintenance Program