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Maplewood, MN, United States

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

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. Source

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

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. Source

Kevern J.T.,University of Missouri - Kansas City | Izevbekhai B.,Office of Materials and Road Research | Cutler H.E.,Iowa State University | Wiegand P.,Iowa State University
Transportation Research Record

Portland cement pervious concrete (PCPC) has shown great potential to reduce roadway noise, improve splash and spray, and improve friction as a surface wearing course. A study is under way at Iowa State University and the National Concrete Pavement Technology Center to develop mix designs and procedures for PCPC overlays for highway applications. A report is produced on the construction and performance of a PCPC overlay constructed at the Minnesota Road Research Project low-volume roadway test facility to determine the effectiveness of pervious concrete as an overlay. Issues related to construction of the overlay are described, as are results of field tests to characterize the condition of the pavement 7 months following construction, to determine flow characteristics of the overlay, and to characterize the tire-pavement noise of the overlay. Results of these studies show that effective PCPC overlays can be designed for wearing course applications. Source

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

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. Source

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

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 Source

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