Browsing by Subject "Patching"

Now showing 1 - 6 of 6
  • Thumbnail Image
    Item
    Best Practices Handbook on Asphalt Pavement Maintenance
    (Minnesota Technology Transfer/LTAP Program, Center for Transportation Studies, 2000-02) Johnson, Ann M.
    The purpose of this handbook is to provide background information about the importance of pavement preservation and preventive maintenance, as well as present maintenance techniques for a variety of distresses and conditions. The major focus of this handbook is on preventive maintenance activities, which are performed while the roadway is still in good condition with only minimal distress, before the pavement falls into a condition where structural overlays, major milling or reclaiming, or replacement is necessary. The most common flexible pavement distresses are cracking, roughness, weathering, raveling, rutting and bleeding. If the distresses identified in a pavement are related to structural deficiencies, the pavement section is most likely not a candidate for preventive maintenance treatment, and should be scheduled for rehabilitation or reconstruction. Maintenance treatments covered in this handbook include: Crack repair w/sealing, including clean and seal, saw and seal, and rout and seal; crack filling, full depth crack repair, fog seal, seal coat, double chip seal, slurry seal, microsurfacing, thin hot mix overlays, and potholes and pavement patching. Tables are outlined giving the most common flexible pavement distresses, along with the best practices for rehabilitation for each. Also given are recommended applications for crack sealers and fillers, surface treatments, and pothole patching. Specifications, technical memoranda and special provisions are included for all treatment methods recommended in the handbook.
  • Thumbnail Image
    Item
    Comprehensive Field Evaluation of Asphalt Patching Methods and Development of Simple Decision Trees and a Best Practices Manual
    (Minnesota Department of Transportation, 2017-06) Barman, Manik; Dailey, Jay; Dave, Eshan V.; Kostick, Robert D.
    The long-term performance of pothole patches largely depends on the selection of the patching method. A number of pothole patching methods are in practice in Minnesota and other nearby states. However, pavement maintenance crews often encounter problems in selecting the most appropriate patching method because proper guidelines are not available. The objective of this project was to investigate the effectiveness of different pavement patching methods and to develop simple decision trees and a best practices manual. The performance of 20 different pothole patches, which were patched with four different types of patching methods and located at five different construction sites, were monitored for approximately two years. Based on the observed performance of the pothole patches considered in this study, two forms of decision trees and a best practices manual have been developed for selecting the most appropriate patching method for a given pothole condition. The developed decision trees can be used to select the patching method based on the location of the pothole (e.g., along longitudinal joints, localized potholes, etc.), construction season, condition of the pothole, and pothole area and depth. The best practices manual provides guidelines on the selection of patching method, pothole preparation, placement of patching materials, and compaction.
  • Thumbnail Image
    Item
    Evaluate and Develop Innovative Pavement Repair and Patching: Taconite-Based Repair Options
    (Center for Transportation Studies, University of Minnesota, 2016-01) Zanko, Lawrence M.; Hopstock, David M.; DeRocher, Will
    In support of a broader MnDOT effort to evaluate current practices, materials, and policies for pavement patching and repair for both asphalt and concrete pavements, the University of Minnesota Duluth Natural Resources Research Institute (NRRI) conducted additional evaluation, refinement, field testing, and performance monitoring of two taconite-related approaches to pavement repair that rely on mixes/techniques that contain (or are enhanced by) taconite mining byproducts and co-products. The first taconite-related approach to pavement repair uses a rigid pavement/pothole repair compound formulation developed and patented by NRRI that is fast-setting, taconite-based, and contains no petroleum or Portland cement. Depending on the formulation, the repair compound can be water-activated or activated by a chemical solution. A water-activated formulation referred to as Rapid Patch was the focus of the investigation. The second taconite- related approach to pavement repair employs a high-power (50kW), vehicle-based (truck-mounted) microwave system for in-place pothole/pavement repair/recycling in which magnetite and/or magnetite-containing aggregate (taconite rock) can enhance microwave absorption and therefore the system’s performance. The two repair alternatives evaluated during this project merit further development and consideration, as the field performance of both suggests they have long-term potential for more widespread use. Based on feedback from maintenance personnel who used and/or observed both repair alternatives during the project, both alternatives would benefit from operational modifications that would reduce the deployment time required to complete a repair and increase the number of repairs that can be accomplished during a single shift. Doing so would likely lead to greater acceptance and more widespread use.
  • Thumbnail Image
    Item
    Evaluation of Concrete and Mortars for Partial Depth Repairs
    (Center for Transportation Studies University of Minnesota, 2014-11) Dave, Eshan V.; Dailey, Jay; Musselman, Eric
    Partial-depth patching mixes must rapidly gain strength to allow the roadway to be reopened to traffic quickly. A patch should also bond well to the substrate to prevent the patch from separating from the existing material and be durable enough to withstand harsh winters. The objective of the research described in this report is to develop improved guidelines for evaluation of pre-bagged commercial patching mixtures and to recommend effective construction practices. To achieve these objectives, 13 different cementitious materials were selected and tested to determine key properties including strength gain, shrinkage, bond strength, and durability. The impact of the proposed research will be a better performing patch material as well as performance criteria that can be used to compare the materials tested in this program to new materials that will certainly be developed in the future. This research was conducted in four main phases, literature review and development of a testing plan and three phases of laboratory testing campaigns. The most commonly available acceptance specification for partial-depth patching materials is the ASTM C928. This specification was followed and the outcomes of each of the recommended tests were evaluated in context of the performance of the patching materials. Several additional tests were developed and conducted to evaluate the bonding properties of patching materials; correlations between lab measured properties were also evaluated. Through aforementioned testing and analysis, a laboratory testing based acceptance procedure was developed for partial-depth patching materials to be used by MnDOT.
  • Thumbnail Image
    Item
    Pothole Prevention and Innovative Repair
    (Minnesota Department of Transportation, 2018-04) Ghosh, Debaroti; Turos, Mugur; Hartman, Marcella; Milavitz, Rose; Le, Jia-Liang; Marasteanu, Mihai
    Pothole repairs continue to be a major maintenance problem for many highway agencies. There is a critical need for finding long-lasting, cost-effective materials and construction technologies for repairing potholes. This research effort investigates critical components associated with pothole formation and pothole repair and proposes solutions to reduce the occurrence of potholes and increase the durability of pothole repairs. The components include investigating and documenting pavement preservation activities, experimental work on traditional repair materials as well as innovative materials and technologies for pothole repairs, stress analysis of pothole repairs to identify whether certain geometric configurations are more beneficial than others, evaluating cost analyses to determine the effectiveness of various repair methods. A number of conclusions and recommendations were made. Potholes are mainly caused by the delayed response to timely fixing common pavement distresses. The state of Minnesota has a number of preservation strategies that are available and have been successfully used. Recommendations are made to improve these strategies using documents made available as part of new Every Day Counts, EDC-4, initiative. Currently, there are no required specifications for patching materials. Mechanical testing can be used to select patching materials based on the estimated durability of the pothole repair, such as short-, medium-, and long-term. A number of new materials and technologies are available for more durable solutions for winter pothole repairs, however, they require additional heat source and are more expensive.
  • Thumbnail Image
    Item
    Synthesis Offers Current Practices for Pothole Patching
    (Transportation Engineering and Road Research Alliance (TERRA), 2014-10) Transportation Engineering and Road Research Alliance (TERRA)
    This 2-page fact sheet provides information about a recent National Cooperative Highway Research Program (NCHRP) Synthesis 463 titled Pavement Patching Practices, including current efforts and key findings about materials and methods.