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:

E. Kohler, L. du Plessis, and H. Theyse. January 2007. Construction and Preliminary HVS Tests of Pre-Cast Concrete Pavement Slabs. Report prepared for Caltrans Division of Research and Innovation and Caltrans District 8 by the University of California Pavement Research Center, Davis and Berkeley. UCPRC-RR-2006-10. (15 MB)

E. Kohler, H. Theyse, and L. du Plessis. January 2007. Interim Assessment of Expected Structural Life of Pre-Cast Concrete Pavement Slabs with HVS Testing. Technical memorandum prepared for the Caltrans Division of Research and Innovation and Caltrans District 8 by the University of California Pavement Research Center, Davis and Berkeley. UCPRC-TM-2007-04. (6.6 MB)

D. Jones, J. Harvey, and E. Kohler. December 2005. Summary Report on the Evaluation of Rigid Pavement Long-life Strategies. Summary report prepared for the California Department of Transportation Division of Research and Innovation by the University of California Pavement Research Center, Davis and Berkeley. UCPRC-SR-2006-01. (1.3 MB)

Construction Analysis for Rehabilitation Strategies (CA4PRS): Design, construction, and traffic engineers now have a decision-making software tool to help select the best construction schedules and minimize traffic delay and agency costs for high-volume highway rehabilitation and reconstruction projects. Brochure. January 2008. (updated). (1.3 MB)

Kohler, E., Santero, N., and Harvey, J. December 2005. Pilot Project for Fixed Segmentation of the Pavement Network. Final report prepared for California Department of Transportation Division of Research and Innovation, Office of Roadway Research. Davis and Berkeley, UC Pavement Research Center. UCPRC-RR-2005-11. (2.0MB)

J.M. Signore, R. Wu, L. Santucci, and J.T. Harvey. September 2007. Summary and Recommendations toward Implementing Innovations Based on Selected Presentations at the Asphalt Rubber Pavement Conference (AR2006), October 2006. Technical memorandum prepared for the California Department of Transportation (Caltrans), Division of Maintenance, Office of Pavement Preservation by the University of California Pavement Research Center, UC Davis and Berkeley. UCPRC-SR-2007-02. (194 KB)

Work Plan for Third Year Field Evaluation of Tire/Pavement Noise, IRI, Macrotexture and Surface Condition of Flexible Pavements. Work Plan prepared for the California Department of Transportation (Caltrans) Division of Research and Innovation by the University of California Pavement Research Center, Davis and Berkeley. UCPRC-WP-2007-02. (57 KB)

M. Troxler, J. T. Harvey, and C. L. Monismith. Asphalt Compaction Mold: Four-Inch Thick Ingot Mold -- Basic Mold Assembly and Operating Instructions. Technical memorandum prepared for the California Department of Transportation (Caltrans) Division of Research and Innovation by the University of California Pavement Research Center, Davis and Berkeley. UCPRC-TM-2007-05. (3.3 MB)

V. Kannekanti and J. T. Harvey. June 2006. Sensitivity Analysis of 2002 Design Guide Rigid Pavement Distress Prediction Models. Report prepared for the California Department of Transportation (Caltrans) Division of Research and Innovation by the University of California Pavement Research Center, Davis and Berkeley. UCPRC-DG-2006-01. (748 KB)

P. Ullidtz, J. T. Harvey, B.-W. Tsai, and C. L. Monismith. April 2006. Calibration of Incremental-Recursive Flexible Damage Models in CalME Using HVS Experiments. Report prepared for the California Department of Transportation (Caltrans) Division of Research and Innovation by the University of California Pavement Research Center, Davis and Berkeley. UCPRC-RR-2005-06. (5.3 MB)

J. T. Harvey. May 2007. Pavement Research in California: Challenges and Results. A presentation made to the Road Pavement Forum (RPF) in Cape Town, South Africa. (3.7 MB)

D. Jones. January 2007. Pavement Preservation Studies Technical Advisory Guide. Guideline prepared for the California Department of Transportation, Division of Research and Innovation, Office of Roadway Research, by the University of California Pavement Research Center, UC Davis and Berkeley. UCPRC-GL-2005-01. (12 MB)

D. Jones. January 2007. Pavement Preservation Studies Technical Advisory Guide: Summary. Guideline summary prepared for the California Department of Transportation, Division of Research and Innovation, Office of Roadway Research, by the University of California Pavement Research Center, UC Davis and Berkeley. UCPRC-GL-2005-02. (9 MB)

Some Earlier Reports and Technical Memoranda

Kohler, E., Ali, A., Harvey, J.August 2005. Goal 4 Long Life Pavement Rehabilitation Strategies-Rigid: Flexural Fatigue Life of Hydraulic Cement Concrete Beams. Draft report prepared for: California Department of Transportation Division of Research and Innovation Office of Roadway Research.Davis and Berkeley, California. UC Pavement Research Center. UCPRC-RR-2005/04 (934KB)

du Plessis, L., F. Jooste, S. Keckwick, W. Steyn. HVS Testing of the Palmdale Test Site, North Tangent Sections: Evaluation of Long Life Pavement Rehabilitation Strategies-Rigid. Draft report prepared for the California Department of Transportation. CSIR Transportek, Pretoria, Republic of South Africa. Pavement Research Center, Institute of Transportation Studies, University of California Berkeley, University of California Davis. August 2005.UCPRC-RR-2005/02 (8.9MB)

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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