Browsing by Subject "Concrete pavements"

Now showing 1 - 11 of 11
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    Adaptation of the 2002 Guide for the Design of Minnesota Low-Volume Portland Cement Concrete Pavements
    (Minnesota Department of Transportation, Research Services Section, 2007-06) Yut, Iliya; Husein, Shariq; Turgeon, Carly; Khazanovich, Lev
    A new Mechanistic-Empirical Pavement Design Guide (MEPDG), also known as the 2002 Design Guide, was recently proposed in the United States. The development of such a procedure was conducted by the National Cooperative Highway Research Program (NCHRP) under sponsorship by the AASHTO. The Design Guide is a significant innovation in the way pavement design is performed. A comprehensive evaluation of the MEPDG performance predictions was conducted. It was found that the faulting model produced acceptable predictions, while the cracking model had to be adjusted. The cracking model was re-calibrated using the design and performance data for 65 pavement sections located in Minnesota, Iowa, Wisconsin, and Illinois. A prototype of the catalog of recommended design features for Minnesota low volume PCC pavements was developed using the MEPDG version 0.910. The catalog offers a variety of feasible design alternatives (PCC and base thickness, joint spacing and PCC slab width, edge support type, and dowel diameter) for a given combination of site conditions (traffic, location, and subgrade type). It is recognized, however, that version 0.910 is not the final version of the MEPDG. Therefore, the catalog should be updated after the MEPDG software is finalized.
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    Concrete Strength Required to Open to Traffic
    (Center for Transportation Studies, University of Minnesota, 2016-01) Freeseman, Katelyn; Hoegh, Kyle; Khazanovich, Lev
    The current empirical methods for determining traffic-opening criteria can be overly conservative causing unnecessary construction delays and user costs. The research described here recommends innovative mechanistic based procedures for monitoring concrete early age development and evaluating the effect of early traffic opening on long-term damage accumulation. The procedure utilizes recent developments in nondestructive testing to optimize traffic opening timing without jeopardizing pavement longevity. These tasks were achieved via extensive field and laboratory experiments allowing for the analysis of variables such as curing condition and loading type with respect to the effect of early loading of concrete. The results of these efforts culminated in the development of a program that analyzes the effect of design and opening time decisions on pavement damage. The deliverable can be utilized by transportation agencies to make more informed decisions.
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    A coupled lattice and nite element model for fracture in composite concrete pavements
    (2012-11) Tompkins, Derek Michael
    Recent research in the United States has focused on the design, construction, and performance of composite concrete pavements - i.e., two heterogeneous concrete layers placed soon after the other using "wet-on-wet" techniques. While these pavements offer many benefits, they also introduce some uncertainties, including the possibility of thermally, hygrally, or mechanically induced fracture and separation at interface of the concrete layers. Despite over 40 years of experience in Europe that has yet to observe debonding in composite concrete pavements, debonding remains a commonly held concern among pavement engineers in the United States. To complement field evidence from Europe in addressing debonding concerns, this dissertation describes the development of a computational tool specifically designed for the simulation of a composite pavement under thermal, hygral, and mechanical loads. This simulation would be difficult using an exclusively continuum approach such as finite element methods in view of the heterogeneity of the pavement materials and the associated lack of smoothness in the crack propagation path. Given that the problem involves both heterogeneous media and the interface between the pavement layers, in this thesis the simulations are instead conducted using three-dimensional lattice modeling with emphasis on the potential for mixed-mode fracture at the interface. This discrete approach is coupled with a finite element model for plate behavior away from the potential cracking zone. The intricacies of that coupling are discussed and illustrated through numerical tests and examples.
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    Design and Construction Guidelines for Thermally Insulated Concrete Pavements
    (Minnesota Department of Transportation, 2013-01) Khazanovich, Lev; Balbo, Jose T.; Johanneck, Luke; Lederle, Rita; Marasteanu, Mihai; Saxena, Priyam; Tompkins, Derek; Vancura, Mary; Watson, Mark; Harvey, John; Santero, Nicholas J.; Signore, James
    The report describes the construction and design of composite pavements as a viable design strategy to use an asphalt concrete (AC) wearing course as the insulating material and a Portland cement concrete (PCC) structural layer as the load-carrying material. These pavements are intended for areas with heavy trucks and problem soils to increase the service life and minimize maintenance. The project focused specifically on thermally insulated concrete pavements (TICPs) (that is, composite thin AC overlays of new or structurally sound existing PCC pavements) and developed design and construction guidelines for TICPs. Specific research objectives include determining behavior of the layers of the TICP system, understanding life-cycle costs and the feasibility of TICPs, and incorporating the results into design and construction guidelines. Both construction and design guidelines are considered in light of the construction and performance of TICP test sections at the Minnesota Road Research project (MnROAD).
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    Establishing Fresh Properties of Fiber Reinforced Concrete for Performance Engineered Mixture (PEM)
    (Minnesota Department of Transportation, 2022-06) Barman, Manik; Kamara, Alieu; Janson, Austin
    The addition of macro or structural fibers into concrete enhances its post-cracking performance. The objective of this study was to conduct a laboratory investigation to determine the influence of structural fibers on the fresh concrete test parameters (Super air meter (SAM) number, V-Kelly index, and Box test rating) recommended for the performance engineered mixture (PEM) procedure. As many as fifty-seven different concrete mixes were designed and prepared, varying fiber types and dosages, aggregate types, and air contents of the concrete. Various fresh and hardened concrete tests were conducted on each of the mixes, and the results were used to determine the influence of the structural fibers on the fresh and hardened concrete properties. The study recommended the allowable range of the SAM number and provided necessary guidance on the box test rating and V-Kelly index for the fiber-reinforced concrete mixtures to be designed as per the PEM procedure.
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    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.
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    Evaluation, Development, and Implementation of 3D GPR for Assessment of Minnesota Infrastructure
    (Center for Transportation Studies, University of Minnesota, 2016-12) Hoegh, Kyle; Thompkins, Derek; Khazanovich, Lev
    This research project evaluated the 3D Radar ground penetrating radar (3D GPR) equipment to determine applications and develop software for immediate use. A major focus was the use of 3D GPR to determine asphalt compaction uniformity. Other pavement assessment applications were explored. The research resulted in the development of new software that provides on-site mapping shortly after the last roller pass is completed on new construction. This provides the potential to select validation locations and give feedback to the contractor detailing the as-constructed performance during the paving process. The outputs of the software were also designed to allow for comparison with other technology and as-constructed information. (A user’s guide for the software is included in the project final report.) Overall, the use of 3D GPR with the developed software, combined with as-constructed data such as Intelligent Compaction pass counts, vibration amplitude, and other measures, can lead to better asphalt compaction and longer lasting roads.
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    New Approach Helps Maximize Saw-Cutting Times
    (Transportation Engineering and Road Research Alliance (TERRA), 2015-07) Transportation Engineering and Road Research Alliance (TERRA)
    This 2-page fact sheet provides information about a new approach that would increase accuracy in determining the optimal time to saw freshly placed concrete.
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    Performance Benefits of Fiber-Reinforced Thin Concrete Pavement and Overlays
    (Minnesota Department of Transportation, 2021-07) Barman, Manik; Roy, Souvik; Tiwari, Amarjeet; Burnham, Tom
    This study investigates the performance benefits of synthetic structural fibers in mitigating distresses in thin concrete pavements and overlays. In this study, two ultra-thin (3 and 4 inches thick) and four thin (5 and 6 inches thick) concrete pavements placed on a gravel base along with two thin unbonded concrete overlay cells (5 inches thick) placed on an existing concrete pavement were constructed at the Minnesota Road Research (MnROAD) facility in 2017. This report discusses the objectives and methodology of the research, including the construction of the test cells, instrumentation, traffic load application, and data collection and analysis procedures. The structural responses and distresses observed over three years, such as fatigue cracking and faulting, as well as the joint performance measured in each cell, were discussed and compared in this report.
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    Portland Cement Concrete Pavement Thickness Variation Versus Observed Pavement Distress
    (Minnesota Department of Transportation, 2016-09) Khazanovich, Lev; Hoegh, Kyle; Barnes, Randal; Conway, Ryan; Salles, Lucio
    Benefits from a potential significant correlation between distresses and slab thickness can be broadly applied in all stages of highway development from design and construction to maintenance decisions. In order to comprehensive explore this possibility, thickness data and existing distresses were related for three highway projects in Minnesota. Thickness was obtained through non-destructive ultrasonic testing, while distresses were recorded for the same location with a distress image software. Significant thickness variation was observed in both longitudinal and transverse directions. The combined results of thickness, shear wave velocity and distresses analysis revealed that an increase in shear wave velocity was coincident with a less damaged pavement area within a section. An in-depth statistical analysis confirmed this observation showing that shear surface velocity variation was better correlated with overall pavement performance than thickness variation. Differences in cracking behavior within a section were traced back to changes in construction and design practices, showing the potential of using shear velocity analysis for pavement maintenance. A survey and analysis procedure for shear wave velocity testing of concrete pavements is proposed.
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    Toward the development of pavement-specific structural synthetic fibers
    (Minnesota Department of Transportation, 2024-06) Barman, Manik; Sabu, Rohith; Sharma, Pranav; Janson, Austin
    Thin fiber reinforced concrete (FRC) pavements and overlays can be economical for low- and moderate-traffic volume roads. Due to insufficient concrete cover thickness, thin concrete pavements or overlays cannot accommodate dowel bars that are typically used in conventional thick concrete pavements. The critical distress for such applications is the transverse joint faulting because of the lack of joint load transfer between the concrete slabs. The currently available synthetic structural fibers can contribute to joint performance to a certain extent. However, as pavements experience significant slab contraction and expansion and carry both wheel and environmental loads, there is a need to design and develop fibers that will provide high joint performance and help mitigate transverse joint faulting when used at an affordable dosage. The overall goal of this study is to develop pavement-specific fibers that will yield the needed joint performance benefits to achieve the intended design life. The study is being conducted in two phases. This report is written for Phase 1 of the study. The study started with a literature review, followed by a finite element analysis, falling weight deflectometer (FWD) data analysis, and laboratory testing of fiber reinforced concrete and individual fibers embedded in concrete. The finite element results and FWD data were amalgamated to quantify the possible joint load transfer of the base layer and foundation, aggregate interlocking, and the needed contribution from the structural fibers. A procedure was established to account for the contribution of the fibers. A new parameter, namely, modulus of fiber support, was introduced to evaluate the stiffness of the fibers that participate in joint load transfer. Notably, a laboratory approach is identified to determine the modulus of fiber support, which can help determine the optimum fiber dosages as well as design and test the pavement-specific fibers in the future phase of the study.