Office of Materials and Road Research

Maplewood, MN, United States

Office of Materials and Road Research

Maplewood, MN, United States
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Freeseman K.,Room 179 | Hoegh K.,Room 110C | Izevbekhai B.I.,Office of Materials and Road Research | Khazanovich L.,University of Minnesota
Transportation Research Record | Year: 2016

The current methods for determining criteria for opening a roadway to traffic are often overly conservative, causing unnecessary construction delays and user costs. This problem can be explained, in part, by the purely empirical nature of the current methods. These criteria require wait periods after concrete placement or certain levels of compressive or flexural strength, or both, after concrete placement, and specific site conditions are not accounted for. Further, the effect of early traffic-related loads on long-term pavement behavior has not been quantified. In this study, the effect of early opening on pavement damage was reexamined through a laboratory study and analytical modeling. The result was a mechanistic-based procedure for evaluating the effect of early opening to traffic on the accumulation long-term damage; this procedure also accounts for critical factors such as climate, traffic level, and pavement design characteristics. The basis of this method is a modification of the fatigue damage analysis in the Mechanistic-Empirical Pavement Design Guide; this modification enables an analysis of traffic loading on the first 28 days of pavement life. The procedure also enables an update to predictions on the basis of as-built nondestructive testing measurements of the pavement. The output of the analysis is a quantitative damage prediction that allows the road owner to do a cost-benefit analysis of the timing for opening the road on the basis of the specific site and traffic characteristics. The results presented here show how innovated opening criteria based on load restrictions can allow for early opening while mitigating any adverse effect on the long-term pavement performance. © 2016, National Research Council. All rights reserved.

Johanneck L.,Office of Materials and Road Research | Dai S.,Office of Materials and Road Research
Transportation Research Record | Year: 2013

This paper details the construction and analysis of three stabilized full-depth reclamation (SFDR) sections (Cells 2, 3, and 4) constructed at the Minnesota Road Research Facility on I-94 in 2008. Three test sections with different ratios of pulverized asphalt concrete to granular base were constructed, and the performance of full-depth reclaimed pavements stabilized with engineered emulsion was studied. Emulsion content and base structure varied between test sections. Each test section was designed for 3.5 million equivalent single-axle loads for a period of 5 years. As of June 30, 2012, the sections had been subjected to approximately 2.2 million such loads. Responses were measured with strain gauges embedded at the bottom of the hot-mix asphalt and SFDR layers in each test section. The strain gauges indicated that the bottom of both the hot-mix asphalt and the SFDR layers was subject to horizontal tensile strain from falling weight deflectometer testing and heavy vehicle loading. Pavement performance for rutting, cracking, and international roughness index was measured periodically. The results indicated that all three cells were performing well. The only crack in the three cells was in Cell 3; the roughness index values were well within the acceptable range and rutting, although progressing, was still acceptable. The paper concludes with modeled responses and performance predictions from DARWinME and BISAR. Model predictions indicate that an SFDR layer will provide greater structural benefits and increased performance than will similar structures with unstabilized full-depth reclaimed or granular base layers.

Xiao Y.,University of Illinois at Urbana - Champaign | Tutumluer E.,University of Illinois at Urbana - Champaign | Qian Y.,University of Illinois at Urbana - Champaign | Siekmeier J.,Office of Materials and Road Research
Transportation Research Record | Year: 2012

Aggregate gradation effects on strength and modulus characteristics of aggregate base-granular subbase materials used in Minnesota are described. The importance of specifying proper aggregate grading or particle size distribution has long been recognized for achieving satisfactory performance in pavement applications. In the construction of densegraded unbound aggregate base-subbase layers, well-graded gradation bands were often established years ago on the basis of the experience of the state transportation agency and may not have a direct link to mechanical performance. To improve specifications for superior performance targeted in the mechanistic-empirical pavement analysis and design framework, there is a need to understand how differences in aggregate gradations may affect unbound aggregate base-subbase behavior for site-specific design conditions. Aggregates with different gradations and material properties were compiled in a statewide database established from a variety of sources in Minnesota. Analyses showed nonunique modulus and strength relationships for most aggregate base and especially subbase materials. Laboratory resilient modulus and shear strength results were analyzed for critical gradation parameters by common gradation characterization methods. The most significant correlations were between a gravel-to-sand ratio (proposed based on ASTM D2487-11) and aggregate shear strength properties. Aggregate compaction (AASHTO T99) and resilient modulus characteristics could also be linked to the gravel-to-sand ratio and verified with other databases in the literature. The gravel-to-sand ratio can be used to optimize aggregate gradations for improved base-subbase performances primarily influenced by shear strength.

Xiao Y.,University of Illinois at Urbana - Champaign | Tutumluer E.,University of Illinois at Urbana - Champaign | Siekmeier J.,Office of Materials and Road Research
Transportation Research Record | Year: 2011

Since high-quality aggregate materials are becoming increasingly scarce and expensive, optimizing the use of locally available materials for aggregate bases and granular subbases on the basis of cost and mechanistic properties linked to pavement performance has become an economically viable alternative. This study investigated the effect of quality of unbound aggregate material on conventional flexible pavement performance in Minnesota through a mechanistic-empirical pavement design approach. A comprehensive matrix of conventional flexible pavement layer thicknesses and mechanistic design moduli was carefully designed to conduct mechanistic analyses for the Minnesota Department of Transportation flexible pavement design program (MnPAVE) with the MnPAVE program for pavement sections in two climatic regions in Minnesota. The type and the quality classes of unbound aggregate materials, identified as high, medium, and low, were characterized with stress-dependent resilient modulus (M R) models from a statewide laboratory-tested aggregate M R database. Despite conventional wisdom to the contrary, in some cases the granular subbase material had much higher moduli than the aggregate base. The typical high, medium, and low modulus values for the aggregate base and granular subbase layers, determined from the modulus distributions predicted by the nonlinear finite element program GT-PAVE, were subsequently input during MnPAVE analyses to calculate fatigue and rutting life expectancies for the comprehensive matrix of pavement structures studied. From the results, use of locally available and somewhat marginal materials may be quite cost-effective for low-volume roads, provided that the 20-year design traffic level does not exceed 1.5 million equivalent single-axle loads. A high-quality, stiff subbase was also found to exhibit a bridging effect that better protected the subgrade and offset the detrimental effects of low base stiffness on rutting performance.

Vennapusa P.K.R.,Iowa State University | White D.J.,Iowa State University | Siekmeier J.,Office of Materials and Road Research | Embacher R.A.,Office of Materials and Road Research
International Journal of Pavement Engineering | Year: 2012

This paper presents experimental test results comparing in situ point test measurements using falling weight deflectometer (FWD), light weight deflectometer (LWD), dynamic cone penetrometer and static piezocone, and near continuous roller-integrated continuous compaction control measurements on a granular pavement foundation embankment. Piezoelectric earth pressure cells buried in the pavement foundation layers were used to compare vertical and horizontal stresses during vibratory roller compaction, and LWD and FWD impulse loading. The resulting total stress paths are compared with standard laboratory resilient modulus stress paths. Insights into differences in measurement influence depths and comparison of vertical stress profiles for the different measurements are discussed and relationships between the various measurements in terms of elastic modulus are presented. Some practical considerations for interpreting the relationships and implementation are discussed. © 2012 Copyright Taylor and Francis Group, LLC.

Han B.,University of North Texas | Han B.,Dalian University of Technology | Zhang K.,University of North Texas | Zhang K.,Dalian Jiaotong University | And 3 more authors.
Smart Materials and Structures | Year: 2013

In this paper, a self-sensing carbon nanotube (CNT) concrete pavement system for traffic detection is proposed and tested in a roadway. Pre-cast and cast-in-place self-sensing CNT concrete sensors were simultaneously integrated into a controlled pavement test section at the Minnesota Road Research Facility (MnROAD), USA. Road tests of the system were conducted by using an MnROAD five-axle semi-trailer tractor truck and a van, respectively, both in the winter and summer. Test results show that the proposed self-sensing pavement system can accurately detect the passing of different vehicles under different vehicular speeds and test environments. These findings indicate that the developed self-sensing CNT concrete pavement system can achieve real-time vehicle flow detection with a high detection rate and a low false-alarm rate. © 2013 IOP Publishing Ltd.

Hoegh K.,University of Minnesota | Khazanovich L.,University of Minnesota | Jense M.,Office of Materials and Road Research
Transportation Research Record | Year: 2010

The AASHTO interim Mechanistic-Empirical Pavement Design Guide (MEPDG) was recently introduced in the United States. Many state agencies have conducted validation and local calibration of the MEPDG performance prediction models. In this study, time history rutting performance data for pavement sections at the Minnesota Department of Transportation full-scale pavement research facility [Minnesota Road Research Project (MnROAD)] have been used for an evaluation and local calibration of the MEPDG rutting model. A detailed comparison of the predicted total rutting, asphalt layer rutting, and measured rutting is presented. The reason that a conventional MEPDG model calibration was not feasible is discussed. Also, a modification of the rutting model is recommended. It was found that the locally calibrated model greatly improved the MEPDG rutting prediction for various pavement designs in MnROAD conditions.

Dasenbrock D.D.,Office of Materials and Road Research | Abdoun T.,Rensselaer Polytechnic Institute | Bennett V.,Rensselaer Polytechnic Institute
Geotechnical Special Publication | Year: 2011

As the impacts of failing geotechnical infrastructure become more apparent, Structural Health Monitoring (SHM) is now more commonly being applied to geotechnical assets: levees, earth dams, landslides, and foundation soils. In particular, real-time monitoring programs are now becoming considered essential for monitoring the performance, or identifying impending failure, of high-risk geosystems. This paper presents several case studies of real-time monitoring of embankments and slopes on Minnesota Department of Transportation (Mn/DOT) projects using MEMS-based in-place inclinometer, ShapeAccelArray (SAA), systems. Background on the SAA inclinometer-accelerometer array system is presented as well as observed project and performance benefits with respect to other displacement monitoring systems. Benefits of real-time monitoring and the larger concept of performance monitoring and SHM of geotechnical assets by remote sensing are discussed. © 2011 ASCE.

Lukanen E.,Office of Materials and Road Research
Transportation Research Record | Year: 2011

The Minnesota Department of Transportation (DOT) adopted the use of performance-graded (PG) asphalt binders in 1997. In 1999 the Minnesota DOT required PG XX-34 binders for all new (not overlay) bituminous construction with the objective of reducing the amount of transverse cracking. Pavement management data were used to track the development of transverse cracking on PG XX-34 projects. The transverse cracking rate of the PG XX-34 projects was then compared with the cracking rates for similar projects from the pre-PG era. The comparison found that after 7 years of service, transverse cracks on the PG projects were developing at approximately 1/10th the rate experienced before performance grading was implemented.

Lalague A.,Sintef | Lebens M.A.,Office of Materials and Road Research | Hoff I.,Norwegian University of Science and Technology | Grov E.,Sintef
Rock Mechanics and Rock Engineering | Year: 2016

Experiments were conducted using Ground-Penetrating Radar (GPR). The performance of six GPR systems was assessed in terms of: (1) remotely mapping cavities behind concrete linings, (2) detecting rockfall from the tunnel roof onto an inner lining comprising, for example, precast concrete segments. Studies conducted in Norway and the United States demonstrate that the GPR technique is a simple and reliable method that can assist stability inspection in existing Norwegian tunnels. The ground-coupled GPR systems represent a step forward in the remote detection of rockfall on tunnel concrete linings, and are particularly suited to self-standing inner linings. The analysis of the data is relatively straightforward and reasonably accurate. © 2016 Springer-Verlag Wien

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