Dedicated to providing knowledge, the Pavement Research Center uses innovative research and sound engineering
principles to improve pavement structures, materials, and technologies.

Summer 2008 UCPRC News

Concerned with sustainability, cost-efficiency, and extending the life of pavements, this summer Caltrans and the UCPRC will continue investigating materials and strategies for “greening” pavement rehabilitation projects. Two projects underway are evaluating pavement rehabilitation strategies using full-depth recycling (FDR), which allows construction crews to rebuild cracked roadways with existing materials. This strategy reduces project costs and the environmental footprint by eliminating the removal of the old pavement as well as excavation and transport of virgin materials. Roads can also be reopened to traffic each day, thereby minimizing impacts to the road user.

One focus area of this research examines the use of foamed asphalt as a stabilizer in the FDR process. This entails mixing hot asphalt binder with water and air to produce asphalt bubbles that are injected directly onto material pulverized from the existing road by a customized pavement recycling machine. The material is then shaped and compacted similar to conventional aggregate bases. Thin asphalt concrete is then placed as a wearing course. Analyses of data gathered in the laboratory and the field (from pilot projects on State Routes 20, 33 and 89) culminate this summer when UCPRC and Caltrans researchers present results and recommendations for mix and structural designs, and construction procedures for using foamed asphalt with FDR.

A related line of research looks into the efficacy of FDR without the addition of stabilizers. Data gathered from field sites and in the laboratory showed that the recycled material could successfully replace the typical aggregate base used by Caltrans and that less of the pulverized material is needed to obtain the same stiffness. From this research comes a revised “gravel factor” for designing pavements, and a life-cycle cost analysis that Caltrans can use when selecting among pavement rehabilitation strategies.

Important Note for Caltrans Users: Prior to scheduling pavement preservation (preventive maintenance or CAPM) or roadway rehabilitation work on flexible pavement highway sections, the District Materials Engineer and/or the Project Manager should review this spreadsheet to ensure that the proposed project does not include sections active in the “Quieter Pavement Research” (QPR) testing program. If the proposed project is within a QPR test section, please contact Linus Motumah of the Caltrans Office of Pavement Design before scheduling the work.

To view maps that show where the sections are located, click the following link: http://maps.google.com/maps?q=http://ucprc.ucdavis.edu/qpsectionsmap.kmz (or cut-and-paste it into a new browser window for a slightly larger view).

For more information, contact Erwin Kohler of the UCPRC or Linus Motumah.

New Reports, Presentations, Posters, and Other Downloads

A number of new reports and technical memoranda are now available on the Publications page, including presentations and posters prepared by UCPRC researchers for the 2007 Annual TRB Meeting. Some of the latest items are:

M. Bejarano, D. Jones, B. Morton, and C. Scheffy. Reflective Cracking Study: Initial Construction, Phase 1 HVS Testing, and Overlay Construction. October 2005. Report prepared for Caltrans Division of Research and Innovation by the University of California Pavement Research Center, Davis and Berkeley. UCPRC-RR-2005-03. (3.0 MB)

D. Jones, B Tsai and J. Harvey. June 2006. Reflective Cracking Study: First-Level Report on HVS Testing on Section 590RF — 90 mm MB4-G Overlay. Report prepared for Caltrans Division of Research and Innovation by the University of California Pavement Research Center, Davis and Berkeley. UCPRC-RR-2006-04. (1.6 MB)

D. Jones, R Wu, J Lea and J. Harvey. August 2006. Reflective Cracking Study: First-Level Report on HVS Testing on Section 589RF — 45 mm MB4-G Overlay. Report prepared for Caltrans Division of Research and Innovation by the University of California Pavement Research Center, Davis and Berkeley. UCPRC-RR-2006-05. (1.6 MB)

R. Wu, D. Jones and J. Harvey. January 2007. Reflective Cracking Study: First-level Report on HVS Testing on Section 587RF — 45 mm RAC-G Overlay. Report prepared for Caltrans Division of Research and Innovation by the University of California Pavement Research Center, Davis and Berkeley. UCPRC-RR-2006-06. (1.8 MB)

D. Jones, R. Wu and J. Harvey. August 2006. Reflective Cracking Study: First-level Report on HVS Testing on Section 588RF — 90 mm AR4000-D Overlay. Report prepared for Caltrans Division of Research and Innovation by the University of California Pavement Research Center, Davis and Berkeley. UCPRC-RR-2006-07. (2.0 MB)

B. Tsai, D. Jones, J. Harvey, and C. Monismith. October 2006. Reflective Cracking Study: First-Level Report on Laboratory Fatigue Testing. Report prepared for Caltrans Division of Research and Innovation by the University of California Pavement Research Center, Davis and Berkeley. UCPRC-RR-2006-08. (1.3 MB)

I. Guada, J. Signore, B. Tsai, D. Jones, J. Harvey, and C. Monismith. September 2007. Reflective Cracking Study: First-Level Report on Laboratory Shear Testing. Report prepared for Caltrans Division of Research and Innovation by the University of California Pavement Research Center, Davis and Berkeley. UCPRC-RR-2006-11. (7.4 MB)

D. Jones, R Wu and J. Harvey. December 2006. Reflective Cracking Study: First-Level Report on HVS Testing on Section 586RF — 45 mm MB15-G Overlay. Report prepared for Caltrans Division of Research and Innovation by the University of California Pavement Research Center, Davis and Berkeley. UCPRC-RR-2006-12. (1.8 MB)

D. Jones, R Wu and J. Harvey. July 2007. Reflective Cracking Study: First-Level Report on HVS Testing on Section 591RF — 45 mm MAC15TR-G Overlay. Report prepared for Caltrans Division of Research and Innovation by the University of California Pavement Research Center, Davis and Berkeley. UCPRC-RR-2007-04. (1.9 MB)

D. Jones, B. Steven, and J. Harvey. July 2007. Reflective Cracking Study: HVS Test Section Forensic Investigation. Report prepared for Caltrans Division of Research and Innovation by the University of California Pavement Research Center, Davis and Berkeley. UCPRC-RR-2007-05. (13.6 MB)

B. Steven, D. Jones and J. Harvey. April 2007. Reflective Cracking Study: First-Level Report on the HVS Rutting Experiment. Report prepared for Caltrans Division of Research and Innovation by the University of California Pavement Research Center, Davis and Berkeley. UCPRC-RR-2007-06 (4.3 MB)

Q. Lu, D. Jones, and J. Harvey. November 2007. Reflective Cracking Study: Backcalculation of HVS Test Section Deflection Measurements. Report prepared for Caltrans Division of Research and Innovation by the University of California Pavement Research Center, Davis and Berkeley. UCPRC-RR-2007-08. (2.9 MB)

D. Jones, B.Tsai, P. Ullidtz, R. Wu, J. Harvey, and C. Monismith. July 2007. Reflective Cracking Study: Second-Level Analysis Report. Report prepared for Caltrans Division of Research and Innovation by the University of California Pavement Research Center, Davis and Berkeley. UCPRC-RR-2007-09. (12.1 MB)

D. Jones, J. Harvey, and C. Monismith. December 2007. Reflective Cracking Study: Summary Report. Report prepared for Caltrans Division of Research and Innovation by the University of California Pavement Research Center, Davis and Berkeley. UCPRC-SR-2007-01. (2.7 MB)

Evaluation of Modified Binder Gap-Graded Mixes for Half-Thickness Reflective Cracking Overlays. Four-page summary prepared by the University of California Pavement Research Center. UCPRC-SR-2007-03. (3.3 MB)

Some Earlier Reports and Technical Memoranda

P. Ullidtz, J. Harvey, B.-W. Tsai, and C. L. Monismith. November 2006. Calibration of CalME Models Using WesTrack Performance Data. Report prepared for Caltrans Division of Research and Innovation by the University of California Pavement Research Center, Davis and Berkeley. UCPRC-RR-2006-14. (3 MB)

J. T. Harvey, C. L. Monismith, W. A. Nokes, and N. F. Coetzee. August 2006. Caltrans Partnered Pavement Research Program (PPRC) Summary Report, Four Year Period: 2000–2004. Report prepared for Caltrans Division of Research and Innovation by the University of California Pavement Research Center, Davis and Berkeley. UCPRC-SR-2006-02. (654 KB)

A large number of new technical memoranda are also available on the Publications page. Topics include economic analyses of several real-life rehabilitation projects and evaluation of an open-graded asphalt concrete patching material.

Technology Transfer

CA4PRS Software

Cost-effective highway rehabilitation tools and the need for efficient planning are critical for today’s highway agencies and contractors, especially with so many of the nation’s aging roadways far outliving their 20-year design lives. CA4PRS (Construction Analysis for Pavement Rehabilitation Strategies) software aids engineers and contractors in selecting economical highway rehabilitation strategies that minimize disruptions to drivers and to the surrounding community. This powerful software program, which provides highway rehabilitation professionals with the ability to identify optimal rehabilitation strategies, was designated as a “priority technology” by the American Association of State Highway and Transportation Officials (AASHTO) Technology Implementation Group in 2006.

Proven successful on a number of urban Interstate highway rehabilitation projects, CA4PRS software helps agencies and contractors plan their highway rehabilitation strategies by taking into account long-life pavement performance, construction productivity, traffic delay, and total cost. Click here for more information about CA4PRS software.

Pavement Design Courses

In addition to the release of Pavement Research Center reports, the PRC staff are often involved in teaching pavement design courses. These courses provide an opportunity for participants to learn more about the new research being conducted at the PRC and often include short tours of the facilities. More information can be found at the Institute of Transportation Studies Technology Tranfer Website at: http://www.techtransfer.berkeley.edu/.

Web Site News

New reports and tech memos are always being added to the publications page. In addition, the publications page is where you can find the most up-to-date revisions of reports.

The Pavement Research Center encourages suggestions as to how this Web site can be made more useful. Please contact the

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