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NEWS (Previous News Items)

  • Upcoming Symposium, June 3-6, 2020: International Symposium on Pavement, Roadway, and Bridge Life Cycle Assessment 2020. The International Symposium on Pavement, Roadway, and Bridge Life Cycle Assessment 2020, will be held in Sacramento on June 3-6, 2020. The Symposium will cover areas such as recent advances in quantifying environmental impacts using LCA for pavement, roadways, and bridges; current status and future developments, standardization and implementation of pavement, roadway, and bridge LCA. Registration is Now OPEN.
    Posted 12/13/2019.
  • Presentation: Alameda County Green Procurement Roundtable-December 10, 2019. John Harvey made a presentation to the Alameda County Green Procurement Roundtable in Hayward on 10 December, 2019 to an audience of city and county pavement engineers, sustainability officers, and procurement officers. The presentation covered methods to quantify environmental impacts, and recommendations for how local government can reduce the impacts of their pavement operations and decisions.
    Posted 12/13/2019.
  • New Research Report Published: Development of Improved Guidelines and Designs for Thin BCOA: Summary, Conclusions, and Recommendations. This report summarizes the investigations undertaken by the UCPRC between 2014 and 2017 to develop recommendations and guidance on the use of thin bonded concrete overlay of asphalt (BCOA) as a rehabilitation alternative for California based on the adoption of, and improvements to, the technology developed in other US states. The report summarizes, among other things, the Heavy Vehicle Simulator testing of eleven thin BCOA sections. The main conclusion from this research project is that a well-designed, well-built 6×6 thin bonded concrete overlay placed on top of an asphalt base that is in fair-to-good condition can potentially provide 20 years of good serviceability on most of California’s non-interstate roadways.
    Posted 8/19/2019.
  • Presentation Given: John Harvey made a keynote presentation in the Sustainability and Circular Economy session of the European Asphalt Technology Association (EATA) 8th Conference at the University of Granada, Spain on 3 June, 2019.
    Posted 6/4/2019.
  • Call for Abstracts: The International Symposium on Pavement, Roadway, and Bridge Life Cycle Assessment 2020, to be held in Sacramento, California on June 3-6, 2020 is now accepting abstracts. Abstracts should be submitted by June 15, 2019. To submit abstracts, you need to set up an account with EasyChair. Go to and click “create an account”. The LCA2020 Instructions for Authors document details the process of creating an EasyChair account and submitting an abstract. You only need to specify the first author at submission time (you can specify all authors if you would like) andyou can add additional authors (or remove and/or update authors) later by logging into EasyChair andupdating your submission.
    Posted 3/12/2019.
  • New Research Report Published: Laboratory Evaluation of the Mechanical Properties of Asphalt Concrete Reinforced with Aramid Synthetic Fibers. “The research project presented in this report evaluates the effects that the addition of aramid fibers has on the mechanical properties of a dense-graded mix frequently used in California, a Superpave mix with 19 mm (3/4 in.) nominal maximum aggregate size, 15 percent reclaimed asphalt pavement (RAP) content, and PG 64-10 binder. A fiber-reinforced asphalt concrete (FRAC) was prepared by adding aramid fibers at a rate of 0.013 percent of total mix weight. The mechanical properties of the two mixes, original and FRAC, were determined in the laboratory. Based on laboratory testing, adding the fibers improved fatigue resistance...”
    Posted 4/29/2019.
  • New Research Report Published: Pavement Recycling: Shrinkage Crack Mitigation in Cement-Treated Pavement Layers - Phase 1 Laboratory Testing. “The California Department of Transportation (Caltrans) has been using full-depth reclamation (FDR) as a rehabilitation strategy since 2001. Most projects to date have used a combination of foamed asphalt and portland cement as the stabilizing agent. Recently though, the fluctuating and at times high cost of asphalt binder coupled with the relatively complex mix-design procedure for mixes that include foamed asphalt has generated interest in the use of portland cement alone as an alternative stabilizing agent. However, shrinkage cracking associated with the hydration and curing...”
    Posted 12/10/2018.
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Winter 2019 UCPRC Activities

Candidate for fully permeable shoulder retrofit validation site

Caltrans Thin Bonded Concrete Overlay of Asphalt (BCOA) Pilot Project. First Caltrans thin bonded concrete overlay of asphalt (BCOA) has been recently built in SR113 at Woodland, District 3. Thin BCOA, formerly known as thin whitetopping, is a pavement rehabilitation technique that consists of placement of a 4 to 6 in. thick concrete overlay on an existing flexible or composite pavement.

Caltrans thin BCOA pilot includes two stretches of SR113: PM 11.8-12.8 and PM 14.7-17.6. The latter was paved on October-November, 2018, while the former was paved on April-May, 2019. The design section of the project includes 6 in. thick concrete overlay on the milled asphalt base, 6 ft transverse joint spacing, and widened slabs. The overlay was built with a rapid strength concrete that was designed to provide 450 psi flexural strength (requirement for opening to traffic) in 24 hours. The pilot project includes also the use of new rubberized asphalt mix as a base.

The early field performance of the thin BCOA pilot is being monitored as part of Caltrans 3.39 Partnered Pavement Research Center project. The monitoring is focused on slab cracking, longitudinal unevenness, and transverse joint faulting and load transfer efficiently. To help the monitoring process, the pavement has been instrumented with a total of 110 sensors, which will be measuring concrete and asphalt strain, concrete and asphalt temperature, and concrete internal relative humidity.

It is expected that the monitoring of the construction and the early field performance of this pilot project will help to identify best and improved practices and standards applicable to California’s climate, materials, and construction work zone practices.