Abstract:This report summarizes a series of eight first-level Heavy Vehicle Simulator testing reports, two laboratory reports
on shear and fatigue testing, a forensic investigation report, a report on the backcalculation of deflection
measurements, and a second-level analysis report, all of which document an investigation undertaken to validate
Caltrans overlay strategies for the rehabilitation of cracked asphalt concrete using modified binder overlays.
The work was conducted by the University of California Pavement Research Center (UCPRC) as part of Partnered
Pavement Research Center Strategic Plan Element 4.10: “Development of Improved Rehabilitation Designs for
Reflective Cracking.” This work was originally requested by the Caltrans/Industry Rubber Asphalt Concrete Task
Group (RACTG) to compare the performance of one set of examples of thin overlays of cracked asphalt pavement
containing different types of binders modified with recycled tire rubber. This work, included as Appendix H of the
Rubber Modified Binder Pilot Projects Review prepared by the RACTG, is part of a more comprehensive work plan
prepared by the Task Group that included evaluation of pilot projects and construction and monitoring of field test
sections (undertaken by Caltrans).
The objective of this UCPRC project was met after completion of the following four tasks:
1. Develop improved mechanistic models of reflective cracking in California,
2. Calibrate and verify these models using laboratory and HVS testing,
3. Evaluate the most effective strategies for reflective cracking, and
4. Provide recommendations for reflective cracking strategies.
This report addresses all the tasks and consists of six main chapters. Chapter 2 lists the objectives and project
organization. Chapter 3 provides an overview of the experiment details. Chapters 4 and 5 summarize HVS and
laboratory testing, respectively. Chapter 6 discusses the second-level analysis. Chapter 7 lists key findings of the
study and provides recommendations for implementation.