PREVIOUS NEWS ITEMS

  • Throughout the summer, the UCPRC has continued sampling pavement materials from asphalt plants around California to gather data for the Standard Materials Library in development for Caltrans and for use in the pavement design software CalME. This sampling work and the research that will build on it have been enabled by industry partners, whose facilities include equipment like the new asphalt sampler and splitter in use at plants in Orland and San Diego. This device minimizes the impact of sampling asphalt materials during production. Posted 7/19/2016.
  • Pavement structural response, macrotexture, and roughness all affect vehicle fuel consumption, but how great the effect of structural response is has not been fully examined yet. A new UCPRC report provides insights based on calculations made with data from measurements on 17 asphalt-surfaced California pavements, including flexible, composite and semi-rigid structures. Three types of models were use to simulate annual excess fuel consumption due to structural response (EFCS) for a factorial of vehicles, traffics flows, speed distributions, and climate regions, and these results were compared with increased fuel consumption caused by roughness and macrotexture. Initial recommendations from the study include adding models for concrete pavements, considering multiple layers in the asphalt, and checking the effects of full dynamic pavement modeling. The next step in the project is field calibration of the models. Posted 6/1/2016.
  • The UCPRC made podium and poster presentations at the 2016 Transportation Research Board (TRB) Annual Meeting held in Washington, DC on January 10-14, 2016. The presentations covered work sponsored primarily by the California Department of Transportation (Caltrans) as well as CalRecycle and the FHWA. Posted 2/8/2016.
  • The work being done by the UCPRC for Caltrans and others was presented at the Australian Asphalt Pavement Association Annual Conference from September 14-16, 2015. Presentations were made on CalME mechanistic-empricial design, development of mechanistic-empirical design methods, heavy duty asphalt pavement design, and a keynote address on driving innovation in pavements. Posted 10/19/2015.
  • A summary of the research findings and design procedure developed during the recently completed permeable interlocking concrete pavement study (see Summer 2015 UCPRC Activities below) was presented at the 11th International Conference on Concrete Block Pavement in Dresden, Germany in September. The design tables developed with the design procedure have been incorporated into the Interlocking Concrete Pavement Institute and ASTM guidelines for designing and constructing permeable interlocking concrete pavements. Posted 10/13/2015.
  • The Caltrans/UCPRC Heavy Vehicle Simulators have completed all testing of different full-depth pavement reclamation strategies on one of the instrumented test tracks at the UC Davis research facility. The strategies included pulverization with no stabilizer (FDR-NS), pulverization with cement (FDR-PC), pulverization with foamed asphalt/cement (FDR-FA), and pulverization with engineered emulsion (FDR-EE). Testing was done under both dry and soaked conditions, with a total of 8.5 million wheel load repetitions applied with the HVSs, equating to about 145 million equivalent single axle loads (ESALs) . A comprehensive forensic investigation has also been completed on each test section. Posted 10/13/2015.
  • The UCPRC has recently worked with colleagues in China and South Africa to expand knowledge of pavement life cycle assessment and support development of national programs for considering development and implementation of pavement LCA. A two day workshop (August 7-8) organized by Jia Yu of the Jiangsu Transportation Institute Group Company, Ltd. and Tan Yiqiu of the Harbin Institute of Technology, who also hosted the event, drew participants from across a wide range of stakeholders in China. Keynote presentations given by UCPRC are available here. In South Africa, the UCPRC participated in the 3rd ISAP International Symposium on Asphalt Pavements and the Environment which focused on improving the sustainability of pavements and was part of the 11th Conference on Asphalt Pavements in Southern Africa. The keynote presentation given by UCPRC on pavement LCA is available here. A workshop was held with industry, government and academic participants to discuss pavement LCA for application in southern Africa, and a resolution has been prepared from the workshop for review by government and industry in South Africa. Posted 8/25/2015.
  • A presentation by UCPRC researchers at the 52nd Petersen Asphalt Research Conference (July 13 to 15, 2015, in Laramie, Wyoming) described the progress of, and some recent findings from, three current studies: 1) Modification of the rolling thin-film oven (RTFO) test to simulate the realistic short-term aging of asphalt rubber binders (view presentation); 2) An evaluation of changes in the performance-related properties of conventional asphalt binder after it is blended with different amounts of age-hardened rubberized binder (view presentation); and 3) Development of a solvent-free approach for evaluating the properties of blended binders in mixes that have large reclaimed asphalt pavement (RAP) and reclaimed asphalt shingle (RAS) content (view presentation). Posted 8/7/2015.
  • The Caltrans/UCPRC Heavy Vehicle Simulators are currently testing different full-depth pavement reclamation strategies on one of the instrumented test tracks at the UC Davis research facility. The strategies include pulverization with no stabilizer (FDR-NS), pulverization with cement (FDR-PC), pulverization with foamed asphalt/cement (FDR-FA), and pulverization with engineered emulsion (FDR-EE). All testing under dry and soaked conditions has been completed. The final test to evaluate the effect of high surface temperatures on rutting in foamed asphalt treated bases is currently in progress. Forensic testing on completed test sections is in progress. HVS testing on this project is scheduled to end at the end of August 2015 and forensic investigations will be completed in September 2015. Posted 8/7/2015.
  • The UCPRC will be sampling and testing throughout California on state highways and on a few construction projects. The objective is to build up the material library for use with Caltrans' mechanistic empirical design method (CalME). We are evaluating the in-situ stiffness of various materials, including cement treated base, lean concrete base, cold in place recycled material, and full depth recycled materials with or without stabilizing agents. Several rounds of testing will be conducted to capture the effects of seasonal variation, curing/aging, and trafficking on layer stiffness. Please remember to drive slow for the cone zone, and move away a lane if possible. We appreciate it. Posted 6/15/2015.
  • In April, the Caltrans/UCPRC-operated Inertial Profiler Certification Center completed its second 2015 session of operator and profiler exams. These sessions are conducted as part of an effort to support Caltrans' implementation of IRI-based smoothness specifications in the state. Coordinating its efforts with Caltrans at the Sacramento certification site, the UCPRC certified 22 operators and 11 profiler vehicles, the largest number of each certified in any session to date. More information about this program and its services are available here, including details on the next scheduled certification date in June 2015. Posted 6/15/2015.
  • The Caltrans/UCPRC Heavy Vehicle Simulators are currently testing different full-depth pavement reclamation strategies on one of the instrumented test tracks at the UC Davis research facility. The strategies include pulverization with no stabilizer (FDR-NS), pulverization with cement (FDR-PC), pulverization with foamed asphalt/cement (FDR-FA), and pulverization with engineered emulsion (FDR-EE). Testing is currently taking place under soaked conditions on the FDR-NS test section with 120mm asphalt surfacing and under high pavement temperatures in dry condition on the FDR-FA test section. HVS testing on this project is scheduled to end at the end of June 2015. Posted 5/18/2015.
  • A presentation was made at the California Asphalt Pavement Association (CalAPA) conference in Ontario on April 16th by John Harvey. The presentation included a look at the 2000 pavement research vision document and a review of progress towards its 15 year goals, a look at ahead at some expected major future research challenges, an overview of the current Caltrans/UCPRC Pavement Research Roadmap projects related to asphalt pavement, and a summary of the Asphalt Concrete Long Life (AC Long Life) long-life rehabilitation strategy that Caltrans District 8 is contemplating using on an upcoming segment of damaged freeway. Posted 4/21/2015.
  • The Caltrans/UCPRC Heavy Vehicle Simulators are currently testing different full-depth pavement reclamation strategies on one of the instrumented test tracks at the UC Davis research facility. The strategies include pulverization with no stabilizer (FDR-NS), pulverization with cement (FDR-PC), pulverization with foamed asphalt/cement (FDR-FA), and pulverization with engineered emulsion (FDR-EE). Testing is currently taking place under soaked conditions on the FDR-FA and FDR-PC test sections. Current load repetition count on the FDR-FA is 700,000 at an 80kN half axle load (36,000lb single axle load) and 300,000 on the FDR-PC at a 40kN (18,000lb) load. Posted 3/16/2015.
  • The LCA 2014 web page with documentation of the Pavement LCA 2014 Symposium has been created and is now LIVE! It includes the program, presentations, papers, results of the breakout sessions, and information about attendees and committees. Follow up meetings on Pavement LCA are being planned for Harbin, China (contact Hui Li for information) and Sun City, South Africa (just before CAPSA, organized by ISAP APE) in August, 2015. Posted 2/6/2015.
  • The UCPRC made podium and poster presentations at the 2015 Transportation Research Board (TRB) Annual Meeting held in Washington, DC on January 11-15, 2015. The presentations covered work sponsored primarily by the California Department of Transportation (Caltrans) as well as the California Air Resources Board (CARB). Posted 1/29/2015.
  • In January 2015, the UCPRC published the fourth and final report based on the Freight-Truck-Pavement interaction pilot study. This logistics augmentation aspect of the study was conducted to examine the ways that public and private sector decision makers approach issues related to road-freight transport in California and to show how direct consultation between the two sectors might align their interests more closely. This project included desktop studies, qualitative analysis, and case studies. Among its other findings, the study concluded that road infrastructure and regulation have a marked impact on the state’s critical supply chain operations and strategies, and that the state may benefit when Caltrans and the private sector engage in the planning and construction of road infrastructure as well in the drafting and implementation of policy. Posted 1/26/2015.
  • Just published on the UCPRC website are the results from the final tasks (Tasks 9 to 11) of a three-phase pilot study (Tasks 1 to 6 and Tasks 7 and 8) undertaken for Caltrans demonstrating the potential economic and other effects of changes in vehicle-pavement interaction caused by varying surface roughness, which can increase from road maintenance delays and pavement management decisions. Undertaken in collaboration with the University of Pretoria and the Council for Scientific and Industrial Research (CSIR) in South Africa, the study used state-of-the-art tools to simulate and measure the peak loads and vertical acceleration of trucks and their freight on a selected range of pavement surface profiles on the state highway system. The study’s aim is to enable Caltrans to better manage the risks of decisions regarding freight and the management and preservation of the pavement network by quantifying the results in economic terms and other effects. Posted 12/16/2014.
  • In September 2014, the UCPRC published the report “Improved Methodology for Mix Design of Open-Graded Friction Courses”. This study presents an improved methodology for the mix designs of open-graded friction courses (OGFC). The methodology has been enhanced by the development of an Excel macro in order to suggest revisions to California Test 368, Standard Method for Determining Optimum Binder Content (OBC) for Open-Graded Asphalt Concrete. In addition to the development of the Excel macro, one of the primary objectives of this study was to evaluate the effect that fines content has on mix performance, which cannot be identified by the “break point sieve” concept or by volumetric properties. Posted 9/30/2014.
  • The Inertial Profiler Certification Program is up and running. Six certifications have been performed since July 2013. The program, which is intended to ensure that qualified operators and profilers perform pavement QA testing, has certified 25 operators and 18 inertial profilers to date. Follow the links to see the lists of Certified Operators and Profilers. Posted 7/22/2014.
  • The variability of On-board Sound Intensity (OBSI) testing results due to different equipment operators is an important consideration in the study of tire/pavement noise on both flexible and rigid pavements. Results of an OBSI "rodeo" conducted by the UCPRC--in partnership with Illingworth and Rodkin (Petaluma, CA)--showed that the difference among test vehicles with different operators was, at most, about 1 decibel, a finding consistent with other OBSI comparisons. Posted 9/30/2014.
  • In June 2014, the UCPRC published the report “Evaluation of Grind and Groove (Next Generation Concrete Surface) Pilot Projects in California”. This report documents a field study undertaken for Caltrans to evaluate pilot projects where this new texturing technique was applied to existing concrete pavements to see whether it would produce quieter and smoother pavement surfaces. The study’s results, based on data collected on seven pilot projects in the Central Valley and San Diego, cover tire/pavement noise, smoothness, skid resistance, and cost, and offer preliminary recommendations regarding where it is most appropriate to use this texture. Posted 7/7/2014.
  • In May 2014, the UCPRC published the report “Surface Treatment Macrotexture and Bicycle Ride Quality”, documenting the results of a study carried out for Caltrans. The report contains research results and preliminary recommendations regarding surface treatment gradations, texture, bicycle vibration, and bicyclists' perceptions of ride quality that are based on data collected on more than 40 northern and central California pavement sections and from over 100 survey participants. Posted 6/16/2014.
  • A study to assess the performance of permeable interlocking concrete pavers in pavement applications continues at the UCPRC facility at UC Davis on behalf of the Interlocking Concrete Pavement Institute Foundation for Education and Research. The first phase of testing under dry conditions was completed in early April. Water was then added and the second phase of HVS testing started to assess performance with a wet subgrade and water in the reservoir layer. Wet testing was completed at the end of May. Some additional response data under varying moisture conditions is now being collected. Posted 6/9/2014.
  • A study to assess the performance of permeable interlocking concrete pavers in pavement applications continues at the UCPRC facility at UC Davis on behalf of the Interlocking Concrete Pavement Institute Foundation for Education and Research. The first phase of testing under dry conditions was completed in early April. The test track was then flooded and the second phase of HVS testing started to assess performance under soaked conditions. Posted 4/28/2014.
  • A new study to assess the performance of permeable interlocking concrete pavers in pavement applications has recently been initiated at the UCPRC facility at UC Davis on behalf of the Interlocking Concrete Pavement Institute Foundation for Education and Research. Construction of a two-lane, 30m long test track using this technology was completed in late January 2014. HVS testing is scheduled to start on the track in early February. Posted 2/6/2014.
  • The two Caltrans/UCPRC Heavy Vehicle Simulators have completed testing of four different full-depth pavement reclamation strategies on one of the instrumented test tracks at the UC Davis pavement research facility. These strategies include pulverization with no stabilizer (FDR-NS), with cement (FDR-PC), with foamed asphalt/cement (FDR-FA), and with engineered emulsion (FDR-EE). Data analysis and preparation of the project report continues. A second round of HVS testing to assess the sections in a soaked state is currently being discussed with Caltrans. Posted 1/6/2014.
  • The two Caltrans/UCPRC Heavy Vehicle Simulators are at present testing four different full-depth pavement reclamation strategies on one of the instrumented test tracks at the UC Davis research facility. These strategies include pulverization with no stabilizer (FDR-NS), with cement (FDR-PC), with foamed asphalt/cement (FDR-FA), and with engineered emulsion (FDR-EE). Testing has been completed on the FDR-NS and FDR-FA sections and continues on the FDR-PC section (currently 1,350,000 load repetitions, testing at 100kN, equivalent to a single axle load of 45,000 lbs.) and FDR-EE section (currently 60,000 load repetitions with a test load of 40kN (equivalent to a single axle load of 18,000 lbs). Posted 10/27/2013.
  • UCPRC is participating in an FHWA round robin study evaluating the interlaboratory variability of results of AASHTO T336-11 testing of the coefficient of thermal expansion of concrete. The UCPRC finished the necessary testing and returned the results to FHWA in early September 2013. Posted 10/21/2013.
  • The UCPRC has published a technical memo for Caltrans that contains initial results and preliminary recommendations regarding surface treatment gradations, macrotexture, bicycle vibration, and bicyclists' perceptions of ride quality. The final report will be completed in several months and will include results from additional pavement test sections. Posted 10/21/2013. Add a review.
  • The two Caltrans/UCPRC Heavy Vehicle Simulators are at present testing four different full-depth pavement reclamation strategies on one of the instrumented test tracks at the UC Davis research facility. These strategies include pulverization with no stabilizer (FDR-NS), with cement (FDR-PC), with foamed asphalt/cement (FDR-FA), and with engineered emulsion (FDR-EE). Testing has been completed on the FDR-NS and FDR-FA sections and continues on the FDR-PC section (currently 900,000 load repetitions, testing at 100kN, equivalent to a single axle load of 45,000 lbs). Testing has just started on the FDR-EE test section with a test load of 40kN (equivalent to a single axle load of 18,000 lbs). Posted 10/2/2013.
  • The roll out to the districts of Caltrans' new pavement management system, called PaveM, has begun. Training for District 7 (Los Angeles) was completed in August and the next training session in District 10 (Stockton) will be held in early October 2013. Posted 9/12/2013.
  • The Caltrans/UCPRC-operated Inertial Profiler Certification Program completed its first two operator and profiler certification sessions in July and August 2013. UCPRC's work to help establish both the certification site and the program supports Caltrans' implementation of an IRI-based smoothness specification. Information about the program and its services is available here. Posted 9/12/2013.
  • The two Caltrans/UCPRC Heavy Vehicle Simulators are at present testing four different full-depth pavement reclamation strategies on one of the instrumented test tracks at the UC Davis research facility. These strategies include pulverization with no stabilizer (FDR-NS), with cement (FDR-PC), with foamed asphalt/cement (FDR-FA), and with engineered emulsion (FDR-EE). Testing is now taking place on the FDR-PC and FDR-NS test sections, with load repetition counts to date of 600,000 and 750,000, respectively. Both machines are currently trafficking at 100 kN loads, equivalent to a single axle load of 45,000 lbs. Posted 9/12/2013.
  • APT2012, the 4th International Conference on Accelerated Pavement Testing, will be held in Davis, California, in September 2012. Information and registration are available here.
  • Lifecycle Analysis Framework Kick-off Workshop held at UCPRC, May 2010. More information is available here.