WorldWideScience

Sample records for base course pavements

  1. Review and environmental impact assessment of green technologies for base courses in bituminous pavements

    International Nuclear Information System (INIS)

    Anthonissen, Joke; Van den bergh, Wim; Braet, Johan

    2016-01-01

    This paper provides a critical review of different approaches applied in the Belgian asphalt sector in order to reduce the environmental impact of bituminous road construction works. The focus is on (1) reusing reclaimed asphalt pavement, (2) reducing the asphalt production temperature, and (3) prolonging the service life of the pavement. Environmental impact assessment of these methods is necessary to be able to compare these approaches and understand better the ability to reduce the environmental impact during the life cycle of the road pavement. Attention should be drawn to the possible shift in environmental impact between various life cycle stages, e.g., raw material production, asphalt production, or waste treatment. Life cycle assessment is necessary to adequately assess the environmental impact of these approaches over the entire service life of the bituminous pavement. The three approaches and their implementation in the road sector in Flanders (region in Belgium) are described and the main findings from life cycle assessment studies on these subjects are discussed. It was found from the review that using reclaimed asphalt pavement in new bituminous mixtures might yield significant environmental gains. The environmental impact of the application of warm mix asphalt technologies, on the other hand, depends on the technique used. - Highlights: • Recycling, lower production temperature and durability of asphalt are investigated. • The use of RAP in new asphalt mixtures yields significant environmental advantages. • It would be beneficial to allow RAP in asphalt mixtures for wearing courses. • The use of particular additives might counteract the environmental gain from WMA. • The service life and the environmental data source influence the LCA results.

  2. Review and environmental impact assessment of green technologies for base courses in bituminous pavements

    Energy Technology Data Exchange (ETDEWEB)

    Anthonissen, Joke, E-mail: joke.anthonissen@uantwerpen.be [Faculty of Applied Engineering, University of Antwerp, Rodestraat 4, 2000 Antwerp (Belgium); Van den bergh, Wim, E-mail: wim.vandenbergh@uantwerpen.be [Faculty of Applied Engineering, University of Antwerp, Rodestraat 4, 2000 Antwerp (Belgium); Braet, Johan, E-mail: johan.braet@uantwerpen.be [Department Engineering Management, Faculty of Applied Economics, University of Antwerp, Prinsstraat 13, 2000 Antwerp (Belgium)

    2016-09-15

    This paper provides a critical review of different approaches applied in the Belgian asphalt sector in order to reduce the environmental impact of bituminous road construction works. The focus is on (1) reusing reclaimed asphalt pavement, (2) reducing the asphalt production temperature, and (3) prolonging the service life of the pavement. Environmental impact assessment of these methods is necessary to be able to compare these approaches and understand better the ability to reduce the environmental impact during the life cycle of the road pavement. Attention should be drawn to the possible shift in environmental impact between various life cycle stages, e.g., raw material production, asphalt production, or waste treatment. Life cycle assessment is necessary to adequately assess the environmental impact of these approaches over the entire service life of the bituminous pavement. The three approaches and their implementation in the road sector in Flanders (region in Belgium) are described and the main findings from life cycle assessment studies on these subjects are discussed. It was found from the review that using reclaimed asphalt pavement in new bituminous mixtures might yield significant environmental gains. The environmental impact of the application of warm mix asphalt technologies, on the other hand, depends on the technique used. - Highlights: • Recycling, lower production temperature and durability of asphalt are investigated. • The use of RAP in new asphalt mixtures yields significant environmental advantages. • It would be beneficial to allow RAP in asphalt mixtures for wearing courses. • The use of particular additives might counteract the environmental gain from WMA. • The service life and the environmental data source influence the LCA results.

  3. Stabilized Base Courses for Advanced Pavement Design Report 1: Literature Review and Field Performance Data

    National Research Council Canada - National Science Library

    Grogan, William

    1999-01-01

    .... Field data collected included structural data in the form of nondestructive testing (NDT) performed with a falling weight deflectometer, visual condition survey using the pavement condition index...

  4. Performance and cost effectiveness of permeable friction course (PFC) pavements.

    Science.gov (United States)

    2013-02-01

    In this project, the research team evaluated the performance of Permeable Friction Courses (PFC) over time and compared it against other types of wearing surface pavement layers. Several pavement sections including Asphalt Rubber (AR) PFCs, Performan...

  5. Short course on: Rehabilitation design of flexible pavements in South Africa

    CSIR Research Space (South Africa)

    De Beer, Morris

    1997-09-01

    Full Text Available This report contains a set of practical course notes on the Rehabilitation Design of flexible pavements in southern Africa based on extensive research by various researchers and / or practitioners in South Africa. The course is intended...

  6. Inverted base pavements: construction and performance

    KAUST Repository

    Papadopoulos, Efthymios

    2017-05-11

    Inverted base pavements involve a well-compacted granular aggregate base built between a thin asphalt concrete layer and a cement-treated base. Inverted base pavements can be constructed using conventional equipment and procedures but require proper quality control. This study reviews the extensive South African experience and case histories in the USA. Accumulating evidence suggests that inverted base pavements are a viable alternative and can outperform conventional pavements at a lower cost. Inverted base pavements rely on the complementary interaction between layers. The cement-treated base provides a stiff foundation for efficient compaction and constrains the deformation of the stress-sensitive granular aggregate base. The thin asphalt surface layer deforms as a membrane and develops low tensile stress. Additional large-scale field tests should be conducted to assess the performance of inverted base pavement designs in a wide range of conditions relevant to the USA.

  7. Evaluation of long-term pavement performance and noise characteristics of open-graded friction courses : project 2.

    Science.gov (United States)

    2012-06-01

    This report describes the second of three experimental installations of open-graded friction course (OGFC) quieter pavements designed to reduce the noise generated at the tire/pavement interface. Experimental sections of OGFC were built using a...

  8. Summary report on the performance of open graded friction course quieter pavements : I-5 Lynnwood, SR-520 Medina, I-405 Bellevue.

    Science.gov (United States)

    2013-09-01

    This document summarizes the acoustic properties and pavement performance of three asphalt quieter pavement projects. Each of the projects included open graded friction course pavement built with sections of crumb rubber and polymer modified asphalt ...

  9. Tire-Pavement Friction Characteristics with Elastic Properties of Asphalt Pavements

    Directory of Open Access Journals (Sweden)

    Miao Yu

    2017-11-01

    Full Text Available The skid-resisting performance of pavement is a critical factor in traffic safety. Recent studies primarily analyze this behavior by examining the macro or micro texture of the pavement. It is inevitable that skid-resistance declines with time because the texture of pavement deteriorates throughout its service life. The primary objective of this paper is to evaluate the use of different asphalt pavements, varying in resilience, to optimize braking performance on pavement. Based on the systematic dynamics of tire-pavement contact, and analysis of the tire-road coupled friction mechanism and the effect of enlarging the tire-pavement contact area, road skid resistance was investigated by altering the elastic modulus of asphalt pavement. First, this research constructed the kinetic contact model to simulate tire-pavement friction. Next, the following aspects of contact behaviors were studied when braking: tread deformation in the tangential pavement interface, actual tire-pavement contact in the course, and the frictional braking force transmitted from the pavement to the tires. It was observed that with improvements in pavement elasticity, the actual tire-pavement contact area increased, which gives us the ability to effectively strengthen the frictional adhesion of the tire to the pavement. It should not be overlooked that the improvement in skid resistance was caused by an increase in pavement elasticity. This research approach provides a theoretical basis and design reference for the anti-skid research of asphalt pavements.

  10. Long-term Performance of Granular Bases Including the Effect of Wet-Dry Cycles on Inverted Base Pavement Performance

    Science.gov (United States)

    2017-06-01

    The main objective of this study was to advance the understanding of alternative pavement designs. In particular, potential techniques such as inverted base pavements (IBP) have increased the importance of granular aggregate bases (GAB) in pavement s...

  11. Inverted base pavements : new field test and design catalogue.

    Science.gov (United States)

    2014-01-01

    The current economic situation has severely affected the US road infrastructure and funding has become : inadequate for either maintenance or future growth. : The inverted base pavement structure is a promising alternative to achieve high quality roa...

  12. Pavement structure mechanics response of flexible on semi-flexible overlay that based on the old cement concrete pavement damage

    Directory of Open Access Journals (Sweden)

    Jiang Ruinan

    2015-01-01

    Full Text Available The old cement pavement damage status directly affect the design of the paving renovation. Based on the state of the old road investigation, combined with the research data at home and abroad, use the control index that average deflection, deflection value and CBR value to determine the reasonable time to overlay. Draw up the typical pavement structure according to the principle of combination of old cement pavement overlay structure design, and calculated that the tensile stress and shear stress in asphalt layer ,semi-flexible layer and the tensile in the old cement pavement adopting BISA3.0 statics finite element analysis model when modulus in the old road was diminishing. Use the computed result to analyses the influence of old road damage condition the influence of pavement structure.

  13. Identification of Pavement Distress Types and Pavement Condition Evaluation Based on Network Level Inspection for Jazan City Road Network

    Directory of Open Access Journals (Sweden)

    M Mubaraki

    2014-06-01

    Full Text Available The first step in establishing a pavement management system (PMS is road network identification. An important feature of a PMS is the ability to determine the current condition of a road network and predict its future condition. Pavement condition evaluation may involve structure, roughness, surface distress, and safety evaluation. In this study, a pavement distress condition rating procedure was used to achieve the objectives of this study. The main objectives of this study were to identify the common types of distress that exist on the Jazan road network (JRN, either on main roads or secondary roads, and to evaluate the pavement condition based on network level inspection. The study was conducted by collecting pavement distress types from 227 sample units on main roads and 500 sample units from secondary roads. Data were examined through analysis of common types of distress identified in both main and secondary roads. Through these data, pavement condition index (PCI for each sample unit was then calculated. Through these calculations, average PCIs for the main and secondary roads were determined. Results indicated that the most common pavement distress types on main roads were patching and utility cut patching, longitudinal and transverse cracking, polished aggregate, weathering and raveling, and alligator cracking. The most common pavement distress types on secondary roads were weathering and raveling, patching and utility cut patching, longitudinal and transverse cracking, potholes, and alligator cracking. The results also indicated that 65% of Jazan's main road network has an average pavement condition rating of very good while only 30% of Jazan's secondary roads network has an average pavement condition.

  14. Effect of drainage in unbound aggregate bases on flexible pavement performance.

    Science.gov (United States)

    2008-05-01

    It has been well demonstrated that a positive subsurface drainage is beneficial in enhancing pavement performance and thus extending pavement service life. Typical permeable base materials include asphalt/cement-treated, open-graded aggregates and un...

  15. Utilize Cementitious High Carbon Fly Ash (CHCFA) to Stabilize Cold In-Place Recycled (CIR) Asphalt Pavement as Base Coarse

    Energy Technology Data Exchange (ETDEWEB)

    Wen, Haifang; Li, Xiaojun; Edil, Tuncer; O' Donnell, Jonathan; Danda, Swapna

    2011-02-05

    The purpose of this study was to evaluate the performance of cementitious high carbon fly ash (CHCFA) stabilized recycled asphalt pavement as a base course material in a real world setting. Three test road cells were built at MnROAD facility in Minnesota. These cells have the same asphalt surface layers, subbases, and subgrades, but three different base courses: conventional crushed aggregates, untreated recycled pavement materials (RPM), and CHCFA stabilized RPM materials. During and after the construction of the three cells, laboratory and field tests were carried out to characterize the material properties. The test results were used in the mechanistic-empirical pavement design guide (MEPDG) to predict the pavement performance. Based on the performance prediction, the life cycle analyses of cost, energy consumption, and greenhouse gasses were performed. The leaching impacts of these three types of base materials were compared. The laboratory and field tests showed that fly ash stabilized RPM had higher modulus than crushed aggregate and RPM did. Based on the MEPDG performance prediction, the service life of the Cell 79 containing fly ash stabilized RPM, is 23.5 years, which is about twice the service life (11 years) of the Cell 77 with RPM base, and about three times the service life (7.5 years) of the Cell 78 with crushed aggregate base. The life cycle analysis indicated that the usage of the fly ash stabilized RPM as the base of the flexible pavement can significantly reduce the life cycle cost, the energy consumption, the greenhouse gases emission. Concentrations of many trace elements, particularly those with relatively low water quality standards, diminish over time as water flows through the pavement profile. For many elements, concentrations below US water drinking water quality standards are attained at the bottom of the pavement profile within 2-4 pore volumes of flow.

  16. Investigation of using steel slag in hot mix asphalt for the surface course of flexible pavements

    Science.gov (United States)

    Nguyen, Hien Q.; Lu, Dai X.; Le, Son D.

    2018-04-01

    The rapid development of heavy industry in Vietnam leads to the establishments of steel industry. Steel slag, a by-product of steelwork industry, under Vietnamese’s law, was considered as a deleterious solid waste which needed to be processed and landfilled. However, this has changed recently, and steel slag is now seen as a normal or non-deleterious solid waste, and has been studied for reuse in the construction industry. In this study, steel slag was used, as a replacement for mineral aggregate, in hot mix asphalt. Two hot mix asphalt mixtures with an equivalent nominal aggregate size of 12.5 (C12.5) and 19 mm (C19) were produced using steel slag. In addition, one conventional hot mix asphalt mixture of C19 was produced using mineral aggregate for comparison purpose. Investigation in laboratory condition and trial sections was carried out on Marshall tests, surface roughness, skid resistance, and modulus of the pavement before and after applying a new surface course of hot mix asphalt. The study showed that all steel slag asphalt mixtures passed the Marshall stability and flow test requirements. The skid resistance of steel slag hot mix asphalt mixtures for the surface course satisfied the Vietnamese specification for asphalt. Moreover, the pavement sections with the surface course of steel slag hot mix asphalt showed a considerable higher modulus than that of the conventional one. Only the roughness of the surface course paved with C19 did not pass the requirement of the specification.

  17. PROTOTYPE WEB-BASED EXPERT SYSTEM FOR FLEXIBLE PAVEMENT MAINTENANCE

    Directory of Open Access Journals (Sweden)

    ABDALRHMAN MILAD

    2017-11-01

    Full Text Available The paper describes the development of a prototype web-based expert knowledge system that can be used to maintain flexible pavement within a tropical region. This prototype system provides the advantages of using existing web-based expert system technology. Currently, deterioration of asphalt pavement layers is one of the biggest problems in Malaysia and requires maintenance to ensure that the roads remain open and able to guarantee the regularity, punctuality, and safety of all transport services. According to this process, the knowledge collection that has acquired and the date concerning to domain expert system of the development web-based system was launched with knowledge representation IF and THEN rules and coded by PHP programming. The web pages that support the user interface are created using a framework consisting of HTML, CSS, and J-Query. The prototype web-based expert system uses the knowledge of a pavement maintenance expert, or a specialist in pavement problem remediation, to emulate a portion of their professional reasoning abilities, which it can then use to assist with the maintenance of existing roads and enhance the efficiency and accuracy of the professional engineers tasked with the assessment of all available remedies. Thus, the system increases the performance level of the engineers in analysing, discerning and customising the information that will assist decision makers throughout the project, so the probability that the right decision and treatment are implemented at the right time is increased.

  18. Evaluating Functional and Structural Condition Based Maintenances of Airfield Pavements

    Directory of Open Access Journals (Sweden)

    Tarefder R.

    2013-01-01

    Full Text Available This study evaluates airfield pavements’ functional- and structural-condition to determine the most economical maintenance method. As a part of the analysis, Pavement Condition Index (PCI for several runways, taxiways, and aprons has been determined by MicroPAVER. Structural evaluation of airport pavements has been performed by Falling Weight Deflectometer (FWD test. Evaluation of Layer Moduli and Overlay Design (ELMOD also determines the required overlay thickness based on the E-values, i.e. FWD data analysis. Damage analysis determines the time of repeated overlay application. In addition, functional parameters have been included to determine the time of functional maintenance. Maintenance and rehabilitation alternatives have been selected to develop different program strategies. Life Cycle Cost Analysis (LCCA has been performed to determine the maintenance cost. Structural condition based maintenance cost is compared to functional condition based maintenance cost. Comparison shows that structural condition based approach yields cheaper maintenance strategies than functional condition based maintenance approach.

  19. Pavement thickness evaluation using ground penetrating radar

    Science.gov (United States)

    Harris, Dwayne Arthur

    Accurate knowledge of pavement thickness is important information to have both at a network and project level. This information aids in pavement management and design. Much of the time this information is missing, out of date, or unknown for highway sections. Current technologies for determining pavement thickness are core drilling, falling weight deflectometer (FWD), and ground penetrating radar (GPR). Core drilling provides very accurate pin point pavement thickness information; however, it is also time consuming, labor intensive, intrusive to traffic, destructive, and limited in coverage. FWD provides nondestructive estimates of both a surface thickness and total pavement structure thickness, including pavement, base and sub-base. On the other hand, FWD is intrusive to traffic and affected by the limitations and assumptions the method used to estimate thickness. GPR provides pavement surface course thickness estimates with excellent data coverage at highway speed. Yet, disadvantages include the pavement thickness estimation being affected by the electrical properties of the pavement, limitations of the system utilized, and heavy post processing of the data. Nevertheless, GPR has been successfully utilized by a number of departments of transportation (DOTs) for pavement thickness evaluation. This research presents the GPR thickness evaluation methods, develops GPRPAVZ the software used to implement the methodologies, and addresses the quality of GPR pavement thickness evaluation.

  20. Performance-Based Evaluation of Joint Sealants for Concrete Pavements

    OpenAIRE

    Khuri, Ramzi Emile

    1998-01-01

    Pavement concrete joints are the weakest locations in concrete pavement systems. They are man-made cracks to accommodate concrete slab expansion and contraction due to temperature fluctuations. Sealant is usually used in pavement joints to prevent roadway debris, deicing chemicals, and moisture from entering the joint. When sealant fails, the pavement deteriorates rapidly; and when joint sealant performs adequately, the pavement preserves its intended performance. In the field, joint seala...

  1. Comparisons of Faulting-Based Pavement Performance Prediction Models

    Directory of Open Access Journals (Sweden)

    Weina Wang

    2017-01-01

    Full Text Available Faulting prediction is the core of concrete pavement maintenance and design. Highway agencies are always faced with the problem of lower accuracy for the prediction which causes costly maintenance. Although many researchers have developed some performance prediction models, the accuracy of prediction has remained a challenge. This paper reviews performance prediction models and JPCP faulting models that have been used in past research. Then three models including multivariate nonlinear regression (MNLR model, artificial neural network (ANN model, and Markov Chain (MC model are tested and compared using a set of actual pavement survey data taken on interstate highway with varying design features, traffic, and climate data. It is found that MNLR model needs further recalibration, while the ANN model needs more data for training the network. MC model seems a good tool for pavement performance prediction when the data is limited, but it is based on visual inspections and not explicitly related to quantitative physical parameters. This paper then suggests that the further direction for developing the performance prediction model is incorporating the advantages and disadvantages of different models to obtain better accuracy.

  2. Stabilizing cinder gravels for heavily trafficked base course ...

    African Journals Online (AJOL)

    The results of the investigation indicated that the optimum amount of cement required to achieve the minimum UCS of 3.0 MPa as specified in ERA and AACRA pavement design standards for heavily trafficked base course without adding fine soils is found to be 7% cement. However, this high cement requirement was ...

  3. Overlay design method based on visual pavement distress.

    Science.gov (United States)

    1978-01-01

    A method for designing the thickness of overlays for bituminous concrete pavements in Virginia is described. In this method the thickness is calculated by rating the amount and severity of observed pavement distress and determining the total accumula...

  4. Decision of National and Provincial Highway Asphalt Pavement Structure Based on Value Engineering

    Directory of Open Access Journals (Sweden)

    Yingwei Ren

    2014-01-01

    Full Text Available It is important that decision of asphalt pavement structure requires overall considerations of the performance and financial investment. To have asphalt pavement structure fulfilling good reliability, the asphalt pavement structure decision was researched based on value engineering theory. According to the national and provincial highway investigation data in Shandong Province during the last decade, the asphalt pavement performance attenuation rules of traffic levels and asphalt layer thicknesses were developed, and then the road performance evaluation method was presented. In addition, the initial investments, the costs of road maintenance, and middle-scale repair in a period were analyzed. For the light traffic and medium traffic example, using the value engineering method, the pavement performance and costs of which thickness varies from 6 cm to 10 cm were calculated and compared. It was concluded that value engineering was an effective method in deciding the asphalt pavement structure.

  5. Rehabilitation design of flexible pavements in South Africa.

    CSIR Research Space (South Africa)

    De Beer

    1997-01-01

    Full Text Available This report contains a set of practical course notes on the Rehabilitation Design of flexible pavements in southern Africa based on extensive research by various researchers and / or practitioners in South Africa. The course is intended...

  6. Rutting Prediction in Asphalt Pavement Based on Viscoelastic Theory

    Directory of Open Access Journals (Sweden)

    Nahi Mohammed Hadi

    2016-01-01

    Full Text Available Rutting is one of the most disturbing failures on the asphalt roads due to the interrupting it is caused to the drivers. Predicting of asphalt pavement rutting is essential tool leads to better asphalt mixture design. This work describes a method of predicting the behaviour of various asphalt pavement mixes and linking these to an accelerated performance testing. The objective of this study is to develop a finite element model based on viscoplastic theory for simulating the laboratory testing of asphalt mixes in Hamburg Wheel Rut Tester (HWRT for rutting. The creep parameters C1, C2 and C3 are developed from the triaxial repeated load creep test at 50°C and at a frequency of 1 Hz and the modulus of elasticity and Poisson’ s ratio determined at the same temperature. Viscoelastic model (creep model is adopted using a FE simulator (ANSYS in order to calculate the rutting for various mixes under a uniform loading pressure of 500 kPa. An eight-node with a three Degrees of Freedom (UX, UY, and UZ Element is used for the simulation. The creep model developed for HWRT tester was verified by comparing the predicted rut depths with the measured one and by comparing the rut depth with ABAQUS result from literature. Reasonable agreement can be obtained between the predicted rut depths and the measured one. Moreover, it is found that creep model parameter C1 and C3 have a strong relationship with rutting. It was clear that the parameter C1 strongly influences rutting than the parameter C3. Finally, it can be concluded that creep model based on finite element method can be used as an effective tool to analyse rutting of asphalt pavements.

  7. Asphalt Concrete Overlay Optimization Based on Pavement Performance Models

    Directory of Open Access Journals (Sweden)

    Jan Mikolaj

    2017-01-01

    Full Text Available The life cycle length of pavement with asphalt concrete material (ACM surfacing is significantly influenced, in addition to transport loading and climatic conditions, by design method and rehabilitation timing. Appropriate overlay thickness calculation and estimation of optimal rehabilitation time are crucial to maximizing life cycle length and, concurrently, reducing road administration costs and road user costs. This article describes a comprehensive method of ACM rehabilitation design. For optimization of life cycle cost analysis (LCCA based design, mathematical analytical solution in combination with experimental verification of physical, mechanical, and fatigue characteristics is utilized. Pavement performance, that is, functions mathematically describing pavement’s degradation characteristics of operational capability, is represented by longitudinal and transverse unevenness; these are used to describe relations between traffic loading and pavement’s bearing capacity on 1 : 1 scale. Optimizing of rehabilitation plan is carried out by making a cost benefit analysis (CBA for several rehabilitation scenarios in which different rehabilitation timing produces different capital cost requirements and social benefits. Rehabilitation scenarios differ in technology, the design of which needs to be mathematically optimized, and timing of rehabilitation execution. This article includes a case study for the sake of illustration of practical results and verification of applicability of used methodology.

  8. An Optimization Model for Design of Asphalt Pavements Based on IHAP Code Number 234

    Directory of Open Access Journals (Sweden)

    Ali Reza Ghanizadeh

    2016-01-01

    Full Text Available Pavement construction is one of the most costly parts of transportation infrastructures. Incommensurate design and construction of pavements, in addition to the loss of the initial investment, would impose indirect costs to the road users and reduce road safety. This paper aims to propose an optimization model to determine the optimal configuration as well as the optimum thickness of different pavement layers based on the Iran Highway Asphalt Paving Code Number 234 (IHAP Code 234. After developing the optimization model, the optimum thickness of pavement layers for secondary rural roads, major rural roads, and freeways was determined based on the recommended prices in “Basic Price List for Road, Runway and Railway” of Iran in 2015 and several charts were developed to determine the optimum thickness of pavement layers including asphalt concrete, granular base, and granular subbase with respect to road classification, design traffic, and resilient modulus of subgrade. Design charts confirm that in the current situation (material prices in 2015, application of asphalt treated layer in pavement structure is not cost effective. Also it was shown that, with increasing the strength of subgrade soil, the subbase layer may be removed from the optimum structure of pavement.

  9. Evaluation of cement and fly ash treated recycled asphalt pavement and aggregates for base construction.

    Science.gov (United States)

    2011-12-01

    Many entities currently use recycled asphalt pavement (RAP) and other aggregates as base material, temporary haul roads, : and, in the case of RAP, hot mix asphalt construction. Several states currently allow the use of RAP combined with cement : for...

  10. Machine-vision-based roadway health monitoring and assessment : development of a shape-based pavement-crack-detection approach.

    Science.gov (United States)

    2016-01-01

    State highway agencies (SHAs) routinely employ semi-automated and automated image-based methods for network-level : pavement-cracking data collection, and there are different types of pavement-cracking data collected by SHAs for reporting and : manag...

  11. Permeable pavement study (Edison)

    Data.gov (United States)

    U.S. Environmental Protection Agency — While permeable pavement is increasingly being used to control stormwater runoff, field-based, side-by-side investigations on the effects different pavement types...

  12. Automatic Pavement Crack Recognition Based on BP Neural Network

    OpenAIRE

    Li, Li; Sun, Lijun; Ning, Guobao; Tan, Shengguang

    2014-01-01

    A feasible pavement crack detection system plays an important role in evaluating the road condition and providing the necessary road maintenance. In this paper, a back propagation neural network (BPNN) is used to recognize pavement cracks from images. To improve the recognition accuracy of the BPNN, a complete framework of image processing is proposed including image preprocessing and crack information extraction. In this framework, the redundant image information is reduced as much as possib...

  13. Urban permeable pavement system design based on “sponge city” concept

    Science.gov (United States)

    Yu, M. M.; Zhu, J. W.; Gao, W. F.; Xu, D. P.; Zhao, M.

    2017-08-01

    Based on the “sponge city” concept, to implement the goal of building a city within the city to solve the sponge waterlogging, rational utilization of water resources, reduce water pollution this paper, combined with the city planning level in China, establishes the design system of city road flooding from the macro, medium and micro level, explore the design method of city water permeable pavement system, and has a practical significance the lower flood risk water ecological problems. On the macro level, we established an urban pavement sponge system under the regional ecological pattern by “spot permeable open space - low impact developing rain water road system - catchment area and catchment wetland”. On a medium level, this paper proposed the permeable suitability of pavement and the planning control indicators when combined with urban functional districts to conduct permeable pavement roads plans and controls. On micro level, the paper studied sponge technology design of permeable pavement from road structure, surface material, and other aspects aimed at the pavement permeability requirements.

  14. GHG emission quantification for pavement construction projects using a process-based approach

    Directory of Open Access Journals (Sweden)

    Charinee Limsawasd

    2017-03-01

    Full Text Available Climate change and greenhouse gas (GHG emissions have attracted much attention for their impacts upon the global environment. Initiating of new legislation and regulations for control of GHG emissions from the industrial sectors has been applied to address this problem. The transportation industries, which include operation of road pavement and pavement construction equipment, are the highest GHG-emitting sectors. This study presents a novel quantification model of GHG emissions of pavement construction using process-based analysis. The model is composed of five modules that evaluate GHG emissions. These are: material production and acquisition, (2 material transport to a project site, (3 heavy equipment use, (4 on-site machinery use, and, (5 on-site electricity use. The model was applied to a hypothetical pavement project to compare the environmental impacts of flexible and rigid pavement types during construction. The resulting model can be used for evaluation of environmental impacts, as well as for designing and planning highway pavement construction.

  15. Automatic Pavement Crack Recognition Based on BP Neural Network

    Directory of Open Access Journals (Sweden)

    Li Li

    2014-02-01

    Full Text Available A feasible pavement crack detection system plays an important role in evaluating the road condition and providing the necessary road maintenance. In this paper, a back propagation neural network (BPNN is used to recognize pavement cracks from images. To improve the recognition accuracy of the BPNN, a complete framework of image processing is proposed including image preprocessing and crack information extraction. In this framework, the redundant image information is reduced as much as possible and two sets of feature parameters are constructed to classify the crack images. Then a BPNN is adopted to distinguish pavement images between linear and alligator cracks to acquire high recognition accuracy. Besides, the linear cracks can be further classified into transversal and longitudinal cracks according to the direction angle. Finally, the proposed method is evaluated on the data of 400 pavement images obtained by the Automatic Road Analyzer (ARAN in Northern China and the results show that the proposed method seems to be a powerful tool for pavement crack recognition. The rates of correct classification for alligator, transversal and longitudinal cracks are 97.5%, 100% and 88.0%, respectively. Compared to some previous studies, the method proposed in this paper is effective for all three kinds of cracks and the results are also acceptable for engineering application.

  16. Identification of Pavement Distress Types and Pavement Condition Evaluation Based on Network Level Inspection for Jazan City Road Network

    OpenAIRE

    M Mubaraki

    2014-01-01

    The first step in establishing a pavement management system (PMS) is road network identification. An important feature of a PMS is the ability to determine the current condition of a road network and predict its future condition. Pavement condition evaluation may involve structure, roughness, surface distress, and safety evaluation. In this study, a pavement distress condition rating procedure was used to achieve the objectives of this study. The main objectives of this study were to identify...

  17. Development of a catalog of resilient modulus values for aggregate base for use with the mechanistic-empirical pavement design guide (MEPDG).

    Science.gov (United States)

    2015-06-01

    Base aggregate is one of the intermediate layers in a pavement system for both flexible and rigid surfaces. Characterization : of base aggregate is necessary for pavement thickness design. Many transportation agencies, including the Virginia Departme...

  18. Coal-tar based pavement sealant toxicity to freshwater macroinvertebrates

    Energy Technology Data Exchange (ETDEWEB)

    Bryer, P.J.; Scoggins, M.; McClintock, N.L. [Lamar University, Beaumont, TX (United States). Dept. of Biology

    2010-05-15

    Non-point-source pollution is a major source of ecological impairment in urban stream systems. Recent work suggests that coal-tar pavement sealants, used extensively to protect parking areas, may be contributing a large portion of the polycyclic aromatic hydrocarbon (PAH) loading seen in urban stream sediments. The hypothesis that dried coal-tar pavement sealant flake could alter the macroinvertebrate communities native to streams in Austin, TX was tested using a controlled outdoor laboratory type approach. The treatment groups were: control, low, medium, and high with total PAH concentrations (TPAH = sum of 16 EPA priority pollutant PAHs) of 0.1, 7.5, 18.4, & 300 mg/kg respectively. The low, medium, and high treatments were created via the addition of dried coal-tar pavement sealant to a sterile soil. At the start of the 24-day exposure, sediment from a minimally impacted local reference site containing a community of live sediment-dwelling benthic macroinvertebrates was added to each replicate. An exposure-dependent response was found for several stream health measures and for several individual taxa. There were community differences in abundance (P = 0.0004) and richness (P < 0.0001) between treatments in addition to specific taxa responses, displaying a clear negative relationship with the amount of coal-tar sealant flake. These results support the hypothesis that coal-tar pavement sealants contain bioavailable PAHs that may harm aquatic environments.

  19. Building Asphalt Pavement with SBS-based Compound Added Using a Dry Process in Greenland

    DEFF Research Database (Denmark)

    Lee, Hosin; Kim, Yongjoo; Geisler, Nivi

    2009-01-01

    PMA where it is formulated to melt and blend with asphalt quickly during a batch mixing process. The main objectives of this study are to (1) build asphalt pavement using asphalt mixtures with SBS-based compound added using a “dry” process at the batch plant and (2) evaluate its performance under......-based compound seemed to affect the asphalt mix to become more flexible under the heavy loads. By adding SBS-based compound to asphalt mixtures using a “dry” process, it is expected that the pavement would become more resistant to rutting than a typical asphalt mixture used in Greenland while enduring its arctic...

  20. Flexibl Pavement Analysis Considering Temperature Profile and Anisotropy Behavior in Hot Mix Asphalt Layer

    Directory of Open Access Journals (Sweden)

    Choi Joonho

    2011-12-01

    Full Text Available A three Dimensional finite element model (FEM incorporating the anisotropic properties and temperature profile of hot mix asphalt (HMA pavement was developed to predict the structural responses of HMA pavement subject to heavy loads typically encountered in the field. In this study, ABAQUS was adopted to model the stress and strain relationships within the pavement structure. The results of the model were verified using data collected from the Korean Highway Corporation Test Road (KHCTR. The results demonstrated that both the base course and surface course layers follow the anisotropic behavior and the incorporation of the temperature profile throughout the pavement has a substantial effect on the pavement response predictions that impact pavement design. The results also showed that the anisotropy level of HMA and base material can be reduced to as low as 80% and 15% as a result of repeated loading, respectively.

  1. Asphalt Pavement Pothole Detection and Segmentation Based on Wavelet Energy Field

    Directory of Open Access Journals (Sweden)

    Penghui Wang

    2017-01-01

    Full Text Available Potholes are one type of pavement surface distresses whose assessment is essential for developing road network maintenance strategies. Existing methods for automatic pothole detection either rely on expensive and high-maintenance equipment or could not segment the pothole accurately. In this paper, an asphalt pavement pothole detection and segmentation method based on energy field is put forward. The proposed method mainly includes two processes. Firstly, the wavelet energy field of the pavement image is constructed to detect the pothole by morphological processing and geometric criterions. Secondly, the detected pothole is segmented by Markov random field model and the pothole edge is extracted accurately. This methodology has been implemented in a MATLAB prototype, trained, and tested on 120 pavement images. The results show that it can effectively distinguish potholes from cracks, patches, greasy dirt, shadows, and manhole covers and accurately segment the pothole. For pothole detection, the method reaches an overall accuracy of 86.7%, with 83.3% precision and 87.5% recall. For pothole segmentation, the overlap degree between the extracted pothole region and the original pothole region is mostly more than 85%, which accounts for 88.6% of the total detected pavement pothole images.

  2. COMPARATIVE EVALUATION OF PAVEMENT CRACK DETECTION USING KERNEL-BASED TECHNIQUES IN ASPHALT ROAD SURFACES

    Directory of Open Access Journals (Sweden)

    A. Miraliakbari

    2016-06-01

    Full Text Available With the increasing demand for the digital survey and acquisition of road pavement conditions, there is also the parallel growing need for the development of automated techniques for the analysis and evaluation of the actual road conditions. This is due in part to the resulting large volumes of road pavement data captured through digital surveys, and also to the requirements for rapid data processing and evaluations. In this study, the Canon 5D Mark II RGB camera with a resolution of 21 megapixels is used for the road pavement condition mapping. Even though many imaging and mapping sensors are available, the development of automated pavement distress detection, recognition and extraction systems for pavement condition is still a challenge. In order to detect and extract pavement cracks, a comparative evaluation of kernel-based segmentation methods comprising line filtering (LF, local binary pattern (LBP and high-pass filtering (HPF is carried out. While the LF and LBP methods are based on the principle of rotation-invariance for pattern matching, the HPF applies the same principle for filtering, but with a rotational invariant matrix. With respect to the processing speeds, HPF is fastest due to the fact that it is based on a single kernel, as compared to LF and LBP which are based on several kernels. Experiments with 20 sample images which contain linear, block and alligator cracks are carried out. On an average a completeness of distress extraction with values of 81.2%, 76.2% and 81.1% have been found for LF, HPF and LBP respectively.

  3. Two-vehicle injury severity models based on integration of pavement management and traffic engineering factors.

    Science.gov (United States)

    Jiang, Ximiao; Huang, Baoshan; Yan, Xuedong; Zaretzki, Russell L; Richards, Stephen

    2013-01-01

    The severity of traffic-related injuries has been studied by many researchers in recent decades. However, the evaluation of many factors is still in dispute and, until this point, few studies have taken into account pavement management factors as points of interest. The objective of this article is to evaluate the combined influences of pavement management factors and traditional traffic engineering factors on the injury severity of 2-vehicle crashes. This study examines 2-vehicle rear-end, sideswipe, and angle collisions that occurred on Tennessee state routes from 2004 to 2008. Both the traditional ordered probit (OP) model and Bayesian ordered probit (BOP) model with weak informative prior were fitted for each collision type. The performances of these models were evaluated based on the parameter estimates and deviances. The results indicated that pavement management factors played identical roles in all 3 collision types. Pavement serviceability produces significant positive effects on the severity of injuries. The pavement distress index (PDI), rutting depth (RD), and rutting depth difference between right and left wheels (RD_df) were not significant in any of these 3 collision types. The effects of traffic engineering factors varied across collision types, except that a few were consistently significant in all 3 collision types, such as annual average daily traffic (AADT), rural-urban location, speed limit, peaking hour, and light condition. The findings of this study indicated that improved pavement quality does not necessarily lessen the severity of injuries when a 2-vehicle crash occurs. The effects of traffic engineering factors are not universal but vary by the type of crash. The study also found that the BOP model with a weak informative prior can be used as an alternative but was not superior to the traditional OP model in terms of overall performance.

  4. Improve the quality and service life of water-based pavement marking paints on pavements with high-iron aggregates.

    Science.gov (United States)

    2015-08-01

    White pavement paint marking on airport runways was being discolored by rust-like staining. Discoloration is a critical safety : problem because white paint indicates runways and yellow paint is used for taxiways and aircraft parking. When the white ...

  5. Evaluation of a performance-based standards approach to heavy vehicle design to reduce pavement wear

    CSIR Research Space (South Africa)

    Nordengen, Paul A

    2013-11-01

    Full Text Available of the Australian PBS system while the infrastructure performance standards are based on South African bridge and pavement design standards. In order to optimise road wear per ton of payload, the South African Mechanistic-Empirical Design Method, which is the basis...

  6. Feasibility of reclaimed asphalt pavement (RAP) use as road base and subbase material.

    Science.gov (United States)

    2015-01-01

    The purpose of this study was to investigate the current state of the practice with regard to the use of reclaimed asphalt : pavement (RAP) material for road base and subbase applications and the potential for such use by the Virginia Department of :...

  7. Flexible pavement rehabilitation using pulverization.

    Science.gov (United States)

    2008-06-01

    Pulverization is a roadway rehabilitation strategy that involves in-place recycling of the entire existing flexible pavement layer and some of the existing granular base layer (Figure 1). Pavement pulverization provides an alternative to conventional...

  8. Characterization of asphalt treated base course material

    Science.gov (United States)

    2010-06-01

    Asphalt-treated bases are often used in new pavements; the materials are available and low-cost, but there is little data on how these materials perform in cold regions. : This study investigated four ATB types (hot asphalt, emulsion, foamed asphalt,...

  9. XML Based Course Websites.

    Science.gov (United States)

    Wollowski, Michael

    XML, the extensible markup language, is a quickly evolving technology that presents a viable alternative to courseware products and promises to ease the burden of Web authors, who edit their course pages directly. XML uses tags to label kinds of contents, rather than format information. The use of XML enables faculty to focus on providing…

  10. OBJECT-BASED AND SUPERVISED DETECTION OF POTHOLES AND CRACKS FROM THE PAVEMENT IMAGES ACQUIRED BY UAV

    Directory of Open Access Journals (Sweden)

    Y. Pan

    2017-09-01

    Full Text Available Roads are the basic element of land transportation system. After construction, the quality of road will decrease because of the aging and deterioration of the road surface. In the end, some distresses will appear on the pavement, such as the most common potholes and cracks. In order to improve the efficiency of pavement inspection, nowadays some new forms of remote sensing data without destructive effect on the pavement are widely used to detect the pavement distresses, such as digital images, LiDAR and Radar. In our study, the digital pavement images acquired by Unmanned Aerial Vehicle (UAV and four popular supervised learning algorithms (KNN, SVM, ANN, RF were used to distinguish between the normal pavement and pavement damages (i.e. cracks and potholes. Each of learning algorithms was given a series of different parameters, and the classification accuracy and computational time as two assessment criteria of the algorithm performance were calculated. Finally, four best models for each kind of learning algorithms were selected based on the standard of highest accuracy and minimum running time.

  11. Object-Based and Supervised Detection of Potholes and Cracks from the Pavement Images Acquired by Uav

    Science.gov (United States)

    Pan, Y.; Zhang, X.; Sun, M.; Zhao, Q.

    2017-09-01

    Roads are the basic element of land transportation system. After construction, the quality of road will decrease because of the aging and deterioration of the road surface. In the end, some distresses will appear on the pavement, such as the most common potholes and cracks. In order to improve the efficiency of pavement inspection, nowadays some new forms of remote sensing data without destructive effect on the pavement are widely used to detect the pavement distresses, such as digital images, LiDAR and Radar. In our study, the digital pavement images acquired by Unmanned Aerial Vehicle (UAV) and four popular supervised learning algorithms (KNN, SVM, ANN, RF) were used to distinguish between the normal pavement and pavement damages (i.e. cracks and potholes). Each of learning algorithms was given a series of different parameters, and the classification accuracy and computational time as two assessment criteria of the algorithm performance were calculated. Finally, four best models for each kind of learning algorithms were selected based on the standard of highest accuracy and minimum running time.

  12. Incorporating Traffic Speed Deflection Data in Pavement Management Decision Making for Flexible Pavements

    OpenAIRE

    Thyagarajan, Senthilmurugan; Sivaneswaran, Nadarajah; Petros, Katherine

    2015-01-01

    Systematic pavement condition evaluation and development of an optimized set of pavement treatment strategies are two key tasks in the pavement management process that assists in making informed decisions on future construction actions. Current State Highway Agency's pavement management systems are primarily based on surface condition data, and surface cracking is mainly used as an indicator of the pavement structural condition. However, with effective pavement preservation activities that in...

  13. Awaso bauxite red mud-cement based composites: Characterisation for pavement applications

    OpenAIRE

    David Dodoo-Arhin; Rania A. Nuamah; Benjamin Agyei-Tuffour; David O. Obada; Abu Yaya

    2017-01-01

    This paper presents the development of Bauxite residue (red mud) based cement composite mortar blocks for applications in pavement construction. The experimental techniques considered include the structural, thermal, morphological and microscopy analysis of the raw bauxite and red mud samples calcined at 800 °C. Composite mortar blocks of different batch formulations were produced and their physicochemical properties were investigated. The results show that the compressive strength of the as-...

  14. Evaluation of the methodologies used to generate random pavement profiles based on the power spectral density: An approach based on the International Roughness Index

    Directory of Open Access Journals (Sweden)

    Boris Jesús Goenaga

    2017-01-01

    Full Text Available The pavement roughness is the main variable that produces the vertical excitation in vehicles. Pavement profiles are the main determinant of (i discomfort perception on users and (ii dynamic loads generated at the tire-pavement interface, hence its evaluation constitutes an essential step on a Pavement Management System. The present document evaluates two specific techniques used to simulate pavement profiles; these are the shaping filter and the sinusoidal approach, both based on the Power Spectral Density. Pavement roughness was evaluated using the International Roughness Index (IRI, which represents the most used index to characterize longitudinal road profiles. Appropriate parameters were defined in the simulation process to obtain pavement profiles with specific ranges of IRI values using both simulation techniques. The results suggest that using a sinusoidal approach one can generate random profiles with IRI values that are representative of different road types, therefore, one could generate a profile for a paved or an unpaved road, representing all the proposed categories defined by ISO 8608 standard. On the other hand, to obtain similar results using the shaping filter approximation a modification in the simulation parameters is necessary. The new proposed values allow one to generate pavement profiles with high levels of roughness, covering a wider range of surface types. Finally, the results of the current investigation could be used to further improve our understanding on the effect of pavement roughness on tire pavement interaction. The evaluated methodologies could be used to generate random profiles with specific levels of roughness to assess its effect on dynamic loads generated at the tire-pavement interface and user’s perception of road condition.

  15. Mechanical Response Analysis of Long-life Asphalt Pavement Structure of Yunluo High-speed on the Semi-rigid Base

    Science.gov (United States)

    Liu, Feng; Wu, Chuanhai; Xu, Xinquan; Li, Hao; Wang, Zhixiang

    2018-01-01

    In order to grasp the rule of the strain change of the semi-rigid asphalt pavement structure under the FWD load and provide a reliable theoretical and practical basis for the design of the pavement structure, based on the test section of Guangdong Yunluo expressway, taking FWD as the loading tool, by using the finite element analysis software ANSYS, the internal variation rules of each pavement structural layer were obtained. Based on the results of the theoretical analysis, the measured strain sensor was set up in the corresponding layer of the pavement structure, and the strain test plan was determined. Based on the analysis of the strain data obtained from several structural layers and field monitoring, the rationality of the type pavement structure and the strain test scheme were verified, so as to provide useful help for the design and the maintenance of the pavement structure.

  16. An empirical model to predict road dust emissions based on pavement and traffic characteristics.

    Science.gov (United States)

    Padoan, Elio; Ajmone-Marsan, Franco; Querol, Xavier; Amato, Fulvio

    2017-11-08

    The relative impact of non-exhaust sources (i.e. road dust, tire wear, road wear and brake wear particles) on urban air quality is increasing. Among them, road dust resuspension has generally the highest impact on PM concentrations but its spatio-temporal variability has been rarely studied and modeled. Some recent studies attempted to observe and describe the time-variability but, as it is driven by traffic and meteorology, uncertainty remains on the seasonality of emissions. The knowledge gap on spatial variability is much wider, as several factors have been pointed out as responsible for road dust build-up: pavement characteristics, traffic intensity and speed, fleet composition, proximity to traffic lights, but also the presence of external sources. However, no parameterization is available as a function of these variables. We investigated mobile road dust smaller than 10 μm (MF10) in two cities with different climatic and traffic conditions (Barcelona and Turin), to explore MF10 seasonal variability and the relationship between MF10 and site characteristics (pavement macrotexture, traffic intensity and proximity to braking zone). Moreover, we provide the first estimates of emission factors in the Po Valley both in summer and winter conditions. Our results showed a good inverse relationship between MF10 and macro-texture, traffic intensity and distance from the nearest braking zone. We also found a clear seasonal effect of road dust emissions, with higher emission in summer, likely due to the lower pavement moisture. These results allowed building a simple empirical mode, predicting maximal dust loadings and, consequently, emission potential, based on the aforementioned data. This model will need to be scaled for meteorological effect, using methods accounting for weather and pavement moisture. This can significantly improve bottom-up emission inventory for spatial allocation of emissions and air quality management, to select those roads with higher emissions

  17. Region Based CNN for Foreign Object Debris Detection on Airfield Pavement

    Directory of Open Access Journals (Sweden)

    Xiaoguang Cao

    2018-03-01

    Full Text Available In this paper, a novel algorithm based on convolutional neural network (CNN is proposed to detect foreign object debris (FOD based on optical imaging sensors. It contains two modules, the improved region proposal network (RPN and spatial transformer network (STN based CNN classifier. In the improved RPN, some extra select rules are designed and deployed to generate high quality candidates with fewer numbers. Moreover, the efficiency of CNN detector is significantly improved by introducing STN layer. Compared to faster R-CNN and single shot multiBox detector (SSD, the proposed algorithm achieves better result for FOD detection on airfield pavement in the experiment.

  18. Nondestructive pavement evaluation using finite element analysis based soft computing models.

    Science.gov (United States)

    2009-09-15

    Evaluating structural condition of existing, in-service pavements constitutes annually a major part of the : maintenance and rehabilitation activities undertaken by State Highway Agencies (SHAs). Accurate : estimation of pavement geometry and layer m...

  19. Simulation of dynamic traffic loading based on accelerated pavement testing (APT)

    CSIR Research Space (South Africa)

    Steyn, WJvdM

    2004-03-01

    Full Text Available The objective of this paper is to introduce the latest Heavy Vehicle Simulator (HVS) technology as part of the South African Accelerated Pavement Testing (APT) efforts, its capabilities and expected impact on road pavement analysis....

  20. Investigation of the Effect of Recycled Asphalt Pavement Material on Permeability and Bearing Capacity in the Base Layer

    Directory of Open Access Journals (Sweden)

    Ayşegül Güneş Seferoğlu

    2018-01-01

    Full Text Available The purpose of this research was to investigate the effects of recycled asphalt pavement (RAP and cement content on the permeability and bearing capacity characteristics of aggregate base courses. Mixtures containing untreated RAP ranging between 0 and 100 percent and 1, 2, and 3% cement-treated RAP were subjected to laboratory tests (bitumen content, sieve analysis, modified proctor, soaked California bearing ratio (CBR, and constant-level permeability tests. The results showed that, as the RAP percentage in the mixture increased, CBR values decreased considerably. Moreover, there is a linear increase in the CBR values with cement treatment. Optimum moisture contents (OMC and maximum dry densities (MDD showed a decreasing trend. Increasing the cement percentages in 100% RAP blend increases the OMC and MDD values. The permeability of RAP showed a decrease as the percentage of RAP and cement increased in blends. The study showed that the CBR value of the 20% RAP blend is also obtained in the 100% RAP/3% cement-treated blend. Thus, it has been understood that cement is a suitable material in order to increase the use of RAP. In addition, the increase in the percentage of RAP and cement made the base course more impermeable.

  1. Coal-tar-based pavement sealcoat and PAHs: implications for the environment, human health, and stormwater management

    Science.gov (United States)

    Mahler, Barbara J.; Van Metre, Peter C.; Crane, Judy L.; Watts, Alison W.; Scoggins, Mateo; Williams, E. Spencer

    2012-01-01

    Coal-tar-based sealcoat products, widely used in the central and eastern U.S. on parking lots, driveways, and even playgrounds, are typically 20-35% coal-tar pitch, a known human carcinogen that contains about 200 polycyclic aromatic hydrocarbon (PAH) compounds. Research continues to identify environmental compartments—including stormwater runoff, lake sediment, soil, house dust, and most recently, air—contaminated by PAHs from coal-tar-based sealcoat and to demonstrate potential risks to biological communities and human health. In many cases, the levels of contamination associated with sealed pavement are striking relative to levels near unsealed pavement: PAH concentrations in air over pavement with freshly applied coal-tar-based sealcoat, for example, were hundreds to thousands of times higher than those in air over unsealed pavement. Even a small amount of sealcoated pavement can be the dominant source of PAHs to sediment in stormwater-retention ponds; proper disposal of such PAH-contaminated sediment can be extremely costly. Several local governments, the District of Columbia, and the State of Washington have banned use of these products, and several national and regional hardware and home-improvement retailers have voluntarily ceased selling them.

  2. Desert Pavement Studies

    National Research Council Canada - National Science Library

    Haff, Peter

    2003-01-01

    Combining plan view information from aerial photography showing details of stream channels on desert pavement surfaces with process-based erosion models, a high-resolution, synthetic topography DEM...

  3. Numerical Study of Tire Hydroplaning Based on Power Spectrum of Asphalt Pavement and Kinetic Friction Coefficient

    Directory of Open Access Journals (Sweden)

    Shengze Zhu

    2017-01-01

    Full Text Available Hydroplaning is a driving phenomenon threating vehicle’s control stability and safety. It happens when tire rolls on wet pavement with high speed that hydrodynamic force uplifts the tire. Accurate numerical simulation to reveal the mechanism of hydroplaning and evaluate the function of relevant factors in this process is significant. In order to describe the friction behaviors of tire-pavement interaction, kinetic friction coefficient curve of tire rubber and asphalt pavement was obtained by combining pavement surface power spectrum and complex modulus of tread rubber through Persson’s friction theory. Finite element model of tire-fluid-pavement was established in ABAQUS, which was composed of a 225-40-R18 radial tire and three types of asphalt pavement covered with water film. Mechanical responses and physical behaviors of tire-pavement interaction were observed and compared with NASA equation to validate the applicability and accuracy of this model. Then contact force at tire-pavement interface and critical hydroplaning speed influenced by tire inflation pressure, water film thickness, and pavement types were investigated. The results show higher tire inflation pressure, thinner water film, and more abundant macrotexture enhancing hydroplaning speed. The results could be applied to predict hydroplaning speed on different asphalt pavement and improve pavement skid resistance design.

  4. Nanotechnology-based system for damage-resistant concrete pavements.

    Science.gov (United States)

    2012-08-01

    The focus of this study was to explore the use of nanotechnology-based nanofilaments, such as carbon nanotubes (CNTs) and nanofibers (CNFs), as reinforcement for improving the mechanical properties of Portland cement paste and creating multifunctiona...

  5. Crushing damage estimation for pavement with lightly cementitious bases

    CSIR Research Space (South Africa)

    De Beer, Morris

    2014-07-01

    Full Text Available the 1990s. Typically, crushing failure starts at the surface of the cementitious base layer, and could extend to 50 mm deep, depending on tyre load/stress conditions. Recently developed crushing damage relationships for 2, 5, 10, 15 and 20 mm level...

  6. Study on Storm-Water Management of Grassed Swales and Permeable Pavement Based on SWMM

    Directory of Open Access Journals (Sweden)

    Jianguang Xie

    2017-10-01

    Full Text Available Grassed swales and permeable pavement that have greater permeable underlying surface relative to hard-pressing surface can cooperate with the city pipe network on participating in urban storm flood regulation. This paper took Nanshan village in Jiangsu Province as an example, the storm-water management model (SWMM was used to conceptualize the study area reasonably, and the low-impact development (LID model and the traditional development model were established in the region. Based on the storm-intensity equation, the simulation scene employed the Chicago hydrograph model to synthesize different rainfall scenes with different rainfall repetition periods, and then contrasted the storm-flood-management effect of the two models under the condition of using LID facilities. The results showed that when the rainfall repetition period ranged from 0.33a to 10a (a refers to the rainfall repetition period, the reduction rate of total runoff in the research area that adopted LID ranged from 100% to 27.5%, while the reduction rate of peak flow ranged from 100% to 15.9%, and when the values of unit area were the same, the combined system (permeable pavement + grassed swales worked more efficiently than the sum of the individuals in the reduction of total runoff and peak flow throughout. This research can provide technical support and theoretical basis for urban LID design.

  7. Permeable pavement study (Edison)

    Science.gov (United States)

    While permeable pavement is increasingly being used to control stormwater runoff, field-based, side-by-side investigations on the effects different pavement types have on nutrient concentrations present in stormwater runoff are limited. In 2009, the U.S. EPA constructed a 0.4-ha parking lot in Edison, New Jersey, that incorporated permeable interlocking concrete pavement (PICP), pervious concrete (PC), and porous asphalt (PA). Each permeable pavement type has four, 54.9-m2, lined sections that direct all infiltrate into 5.7-m3 tanks enabling complete volume collection and sampling. This paper highlights the results from a 12-month period when samples were collected from 13 rainfall/runoff events and analyzed for nitrogen species, orthophosphate, and organic carbon. Differences in infiltrate concentrations among the three permeable pavement types were assessed and compared with concentrations in rainwater samples and impervious asphalt runoff samples, which were collected as controls. Contrary to expectations based on the literature, the PA infiltrate had significantly larger total nitrogen (TN) concentrations than runoff and infiltrate from the other two permeable pavement types, indicating that nitrogen leached from materials in the PA strata. There was no significant difference in TN concentration between runoff and infiltrate from either PICP or PC, but TN in runoff was significantly larger than in the rainwater, suggesting meaningful inter-event dry de

  8. GPR used in combination with other NDT methods for assessing pavements in PPP projects

    Science.gov (United States)

    Loizos, Andreas; Plati, Christina

    2014-05-01

    In the recent decades, Public-Private Partnerships (PPP) has been adopted for highway infrastructure procurement in many countries. PPP projects typically take the form of a section of highway and connecting roadways which are to be construction and managed for a given concession period. Over the course of the highway concession period, the private agency takes over the pavement maintenance and rehabilitation duties. On this purpose, it is critical to find the most cost effective way to maintain the infrastructure in compliance with the agreed upon performance measures and a Pavement Management Systems (PMS) is critical to the success of this process. For the prosperous operation of a PMS it is necessary to have appropriate procedures for pavement monitoring and evaluation, which is important in many areas of pavement engineering. Non Destructive Testing (NDT) has played a major role in pavement condition monitoring, assessments and evaluation accomplishing continuous and quick collection of pavement data. The analysis of this data can lead to indicators related to trigger values (criteria) that define the pavement condition based on which the pavement "health" is perceived helping decide whether there is the need or not to intervene in the pavement. The accomplished perception appoints required management activities for preserving pavements in favor not only of the involved highway/road agencies but also of users' service. Amongst NDT methods Ground Penetrating Radar (GPR) seems to be a very powerful toll, as it provides a range of condition and construction pavement information. It can support effectively the implementation of PMS activities in the framework of pavement monitoring and evaluation. Given that, the present work aims to the development and adaptation of a protocol for the use of GPR in combination with other NDT methods, such as Falling Weight Deflectometer (FWD), for assessing pavements in PPP projects. It is based on the experience of Laboratory of

  9. Awaso bauxite red mud-cement based composites: Characterisation for pavement applications

    Directory of Open Access Journals (Sweden)

    David Dodoo-Arhin

    2017-12-01

    Full Text Available This paper presents the development of Bauxite residue (red mud based cement composite mortar blocks for applications in pavement construction. The experimental techniques considered include the structural, thermal, morphological and microscopy analysis of the raw bauxite and red mud samples calcined at 800 °C. Composite mortar blocks of different batch formulations were produced and their physicochemical properties were investigated. The results show that the compressive strength of the as-prepared composite mortar blocks increased by ∼40% compared to the type M mortar strength of ∼2500 N/mm2. The load bearing applications of the composites are discussed to influence the adoption of the calcined red mud as supplement in the production of low-cost Portland cement based composite mortar blocks for the construction industry.

  10. Licensing web-based nursing programs, courses, and course materials.

    Science.gov (United States)

    Billings, Diane M; Hoke, Mary M; Waldhuetter, Kurt

    2005-01-01

    With the advent of the digital information age, schools of nursing are developing and using web-based programs, courses, and course materials to meet students' needs for access and high-quality learning experiences. In an attempt to maximize scant resources, including faculty, many schools are seeking grant funding, joining consortia, or forming partnerships that require sharing of web-based course materials. Entering such collaborative arrangements usually requires licensing agreements to transfer intellectual capital. This article explains licensing and the related concepts of intellectual property, copyright, and technology transfer. It also identifies the advantages and disadvantages of licensing and describes a licensing process.

  11. Numerical analysis of road pavement thermal deformability, based on Biot viscoelastic model of porous medium

    Directory of Open Access Journals (Sweden)

    Bartlewska-Urban Monika

    2016-03-01

    Full Text Available The following study presents numerical calculations for establishing the impact of temperature changes on the process of distortion of bi-phase medium represented using Biot consolidation equations with Kelvin–Voigt rheological skeleton presented, on the example of thermo-consolidation of a pavement of expressway S17. We analyzed the behavior of the expressway under the action of its own weight, dynamic load caused by traffic and temperature gradient. This paper presents the application of the Biot consolidation model with the Kelvin–Voigt skeleton rheological characteristics and the influence of temperature on the deformation process is taken into account. A three-dimensional model of the medium was created describing the thermal consolidation of a porous medium. The 3D geometrical model of the area under investigation was based on data obtained from the land surveying and soil investigation of a 200 m long section of the expressway and its shoulders.

  12. Long-term pavement performance pavement loading user guide (LTPP PLUG).

    Science.gov (United States)

    2013-10-01

    "This guide addresses the selection and use of axle loading defaults for Mechanistic-Empirical Pavement Design : Guide (MEPDG) applications. The defaults were developed based on weigh-in-motion (WIM) data from the Long- : Term Pavement Performance (L...

  13. Impact of pavement conditions on crash severity.

    Science.gov (United States)

    Li, Yingfeng; Liu, Chunxiao; Ding, Liang

    2013-10-01

    Pavement condition has been known as a key factor related to ride quality, but it is less clear how exactly pavement conditions are related to traffic crashes. The researchers used Geographic Information System (GIS) to link Texas Department of Transportation (TxDOT) Crash Record Information System (CRIS) data and Pavement Management Information System (PMIS) data, which provided an opportunity to examine the impact of pavement conditions on traffic crashes in depth. The study analyzed the correlation between several key pavement condition ratings or scores and crash severity based on a large number of crashes in Texas between 2008 and 2009. The results in general suggested that poor pavement condition scores and ratings were associated with proportionally more severe crashes, but very poor pavement conditions were actually associated with less severe crashes. Very good pavement conditions might induce speeding behaviors and therefore could have caused more severe crashes, especially on non-freeway arterials and during favorable driving conditions. In addition, the results showed that the effects of pavement conditions on crash severity were more evident for passenger vehicles than for commercial vehicles. These results provide insights on how pavement conditions may have contributed to crashes, which may be valuable for safety improvement during pavement design and maintenance. Readers should notice that, although the study found statistically significant effects of pavement variables on crash severity, the effects were rather minor in reality as suggested by frequency analyses. Copyright © 2013 Elsevier Ltd. All rights reserved.

  14. Singularity detection in FOG-based pavement data by wavelet transform

    Science.gov (United States)

    Yang, Dandan; Wang, Lixin; Hu, Wenbin; Zhang, Zhen; Fu, Jinghua; Gan, Weibing

    2017-04-01

    The angular velocity data of Fiber-Optic Gyro (FOG) has been analyzed to locate the singularity by the wavelet transform (WT) method. By using WT analysis method to decompose and reconstruct the signal of pavement data collecting by the FOG, the different types of pavement singularities can be extracted. The experiments are conducted on different road surfaces. The experimental results show that the locations of bumps and expansion joints have been obtained, with a relative precision of 0.5 m and an absolute precision of 2 m over 2.4 km. The characteristic of the pavement roughness can also be identified.

  15. Bioinstrumentation: A Project-Based Engineering Course

    Science.gov (United States)

    Kyle, Aaron M.; Jangraw, David C.; Bouchard, Matthew B.; Downs, Matthew E.

    2016-01-01

    This paper presents the development, implementation, and assessment of a project-based Bioinstrumentation course. All course lectures and hands-on laboratory activities are related to a central project theme: a cardiac pacemaker. The students create a benchtop cardiac pacemaker by applying instrumentation knowledge acquired in the course to each…

  16. Nature based solutions to mitigate soil sealing in urban areas: Results from a 4-year study comparing permeable, porous, and impermeable pavements.

    Science.gov (United States)

    Fini, A; Frangi, P; Mori, J; Donzelli, D; Ferrini, F

    2017-07-01

    Soil sealing is one of the most pervasive forms of soil degradation that follows urbanization and, despite innovative pavements (i.e. pervious) are being installed in urban areas to mitigate it, there is little research on the effects of pervious pavements on soil water and carbon cycle and on the physiology of urban trees. The aim of this 4-year experiment was to assess the effects of three pavements, differing in permeability to water and gases, on some soil physical parameters, and on growth and physiology of newly planted Celtis australis and Fraxinus ornus. Treatments were: 1) impermeable pavement (asphalt on concrete sub-base); 2) permeable pavement (pavers on crushed rock sub-base); 3) porous design (porous pavement on crushed rock sub-base); 4) control (unpaved soil, kept free of weed by chemical control). Soil (temperature, moisture, oxygen content and CO 2 efflux) and plant (above- and below-ground growth, leaf gas exchange, chlorophyll fluorescence, water relations) parameters were measured. All types of pavements altered the water cycle compared to unpaved soil plots, but this disturbance was less intense in porous pavements than in other soil cover types. Porous pavements allowed both higher infiltration and evaporation of water than both pavers and asphalt. Reduction of evaporative cooling from soil paved with permeable and impermeable pavements contributed to significant soil warming: at 20cm depth, soils under concrete pavers and asphalt were 4 and 5°C warmer than soil covered by porous pavements and unpaved soils, respectively. Thus, enhancing evaporation from paved soil by the use of porous pavements may contribute to mitigating urban heat islands. CO 2 greatly accumulated under impermeable and permeable pavements, but not under porous pavements, which showed CO 2 efflux rates similar to control. Soil oxygen slightly decreased only beneath asphalt. Growth of newly planted C. australis and F. ornus was little affected by pavement type. Tree

  17. Nondestructive pavement evaluation using ILLI-PAVE based artificial neural network models.

    Science.gov (United States)

    2008-09-01

    The overall objective in this research project is to develop advanced pavement structural analysis models for more accurate solutions with fast computation schemes. Soft computing and modeling approaches, specifically the Artificial Neural Network (A...

  18. Computer-based guidelines for concrete pavements : HIPERPAV III : user manual

    Science.gov (United States)

    2009-10-01

    This user manual provides guidance on how to use the new High PERformance PAVing (HIPERPAV) III software program for the analysis of early-age Portland cement concrete pavement (PCCP) behavior. HIPERPAV III includes several improvements over prev...

  19. E2CAV, Pavement layer thickness estimation system based on image texture operators

    Directory of Open Access Journals (Sweden)

    Brayan Barrios Arcila

    2017-01-01

    Full Text Available Context: Public roads are an essential part of economic progress in any country; they are fundamental for increasing the efficiency on transportation of goods and are a remarkable source of employment. For its part, Colombia has few statistics on the condition of its roads; according with INVIAS the state of the roads in Colombia can be classified as “Very Good” (21.1%, “Good” (34.7%, and “Regular” or “Bad” (43.46%. Thus, from the point of view of pavement rehabilitation, it is worth securing the quality of those roads classified as “Regular” or “Bad”. Objective: In this paper we propose a system to estimate the thickness of the pavement layer using image segmentation methods. The pavement thickness is currently estimated using radars of terrestrial penetration, extraction of cores or making pips; and it is part of structural parameters in the systems of evaluation of pavement. Method: The proposed system is composed of a vertical movement control unit, which introduces a video scope into a small hole in the pavement, then the images are obtained and unified in a laptop. Finally, this mosaic is processed through texture operators to estimate the thickness of the pavement. Users can select between the Otsu method and Gabor filters to process the image data. Results: The results include laboratory and field tests; these tests show errors of 5.03% and 11.3%, respectively, in the thickness of the pavement. Conclusion: The proposed system is an attractive option for local estimation of pavement thickness, with minimal structural damage and less impact on mobility and number of operators.

  20. Network-based Database Course

    DEFF Research Database (Denmark)

    Nielsen, J.N.; Knudsen, Morten; Nielsen, Jens Frederik Dalsgaard

    A course in database design and implementation has been de- signed, utilizing existing network facilities. The course is an elementary course for students of computer engineering. Its purpose is to give the students a theoretical database knowledge as well as practical experience with design...... and implementation. A tutorial relational database and the students self-designed databases are implemented on the UNIX system of Aalborg University, thus giving the teacher the possibility of live demonstrations in the lecture room, and the students the possibility of interactive learning in their working rooms...

  1. Design and implementation of PAVEMON: A GIS web-based pavement monitoring system based on large amounts of heterogeneous sensors data

    Science.gov (United States)

    Shahini Shamsabadi, Salar

    A web-based PAVEment MONitoring system, PAVEMON, is a GIS oriented platform for accommodating, representing, and leveraging data from a multi-modal mobile sensor system. Stated sensor system consists of acoustic, optical, electromagnetic, and GPS sensors and is capable of producing as much as 1 Terabyte of data per day. Multi-channel raw sensor data (microphone, accelerometer, tire pressure sensor, video) and processed results (road profile, crack density, international roughness index, micro texture depth, etc.) are outputs of this sensor system. By correlating the sensor measurements and positioning data collected in tight time synchronization, PAVEMON attaches a spatial component to all the datasets. These spatially indexed outputs are placed into an Oracle database which integrates seamlessly with PAVEMON's web-based system. The web-based system of PAVEMON consists of two major modules: 1) a GIS module for visualizing and spatial analysis of pavement condition information layers, and 2) a decision-support module for managing maintenance and repair (Mℝ) activities and predicting future budget needs. PAVEMON weaves together sensor data with third-party climate and traffic information from the National Oceanic and Atmospheric Administration (NOAA) and Long Term Pavement Performance (LTPP) databases for an organized data driven approach to conduct pavement management activities. PAVEMON deals with heterogeneous and redundant observations by fusing them for jointly-derived higher-confidence results. A prominent example of the fusion algorithms developed within PAVEMON is a data fusion algorithm used for estimating the overall pavement conditions in terms of ASTM's Pavement Condition Index (PCI). PAVEMON predicts PCI by undertaking a statistical fusion approach and selecting a subset of all the sensor measurements. Other fusion algorithms include noise-removal algorithms to remove false negatives in the sensor data in addition to fusion algorithms developed for

  2. Rapid decision support tool based on novel ecosystem service variables for retrofitting of permeable pavement systems in the presence of trees.

    Science.gov (United States)

    Scholz, Miklas; Uzomah, Vincent C

    2013-08-01

    The retrofitting of sustainable drainage systems (SuDS) such as permeable pavements is currently undertaken ad hoc using expert experience supported by minimal guidance based predominantly on hard engineering variables. There is a lack of practical decision support tools useful for a rapid assessment of the potential of ecosystem services when retrofitting permeable pavements in urban areas that either feature existing trees or should be planted with trees in the near future. Thus the aim of this paper is to develop an innovative rapid decision support tool based on novel ecosystem service variables for retrofitting of permeable pavement systems close to trees. This unique tool proposes the retrofitting of permeable pavements that obtained the highest ecosystem service score for a specific urban site enhanced by the presence of trees. This approach is based on a novel ecosystem service philosophy adapted to permeable pavements rather than on traditional engineering judgement associated with variables based on quick community and environment assessments. For an example case study area such as Greater Manchester, which was dominated by Sycamore and Common Lime, a comparison with the traditional approach of determining community and environment variables indicates that permeable pavements are generally a preferred SuDS option. Permeable pavements combined with urban trees received relatively high scores, because of their great potential impact in terms of water and air quality improvement, and flood control, respectively. The outcomes of this paper are likely to lead to more combined permeable pavement and tree systems in the urban landscape, which are beneficial for humans and the environment. Copyright © 2013 Elsevier B.V. All rights reserved.

  3. Porous concrete basic property criteria as rigid pavement base layer in indonesia

    Directory of Open Access Journals (Sweden)

    Ridwan Aldila Melania Care Frisky

    2018-01-01

    moment of rainfall or after rainfall. In that condition, the present of traffic might also create movement below the foundation layer and reduce its bearing capacity. Nevertheless, the foundation material that contain large fine creates base layer with low permeability and slow water movement. This paper presented the procedure and result of laboratory experimental study to obtain basic property criteria for rigid pavement base layer.The porous concrete mixture was successfully designed and surpassed the minimum requirements required by Directorate General of Highways [11] [12]. It was found that there was very strong correlation between void content and permeability which created fine likelihood to use void content to represent porous concrete permeability behavior. High void content with good connection resulting weaker aggregate interlocking inside the mixture so that permeability rose whereas compressive strength fell. Solid fresh density and more filled by cement paste created a smaller void that would reduce permeability and improve compressive strength. Strong correlation between fresh density towards void content and permeability opened potency to use the fresh density as a reference to set the desired porous concrete void content on the field.

  4. Automated pavement horizontal curve measurement methods based on inertial measurement unit and 3D profiling data

    Directory of Open Access Journals (Sweden)

    Wenting Luo

    2016-04-01

    Full Text Available Pavement horizontal curve is designed to serve as a transition between straight segments, and its presence may cause a series of driving-related safety issues to motorists and drivers. As is recognized that traditional methods for curve geometry investigation are time consuming, labor intensive, and inaccurate, this study attempts to develop a method that can automatically conduct horizontal curve identification and measurement at network level. The digital highway data vehicle (DHDV was utilized for data collection, in which three Euler angles, driving speed, and acceleration of survey vehicle were measured with an inertial measurement unit (IMU. The 3D profiling data used for cross slope calibration was obtained with PaveVision3D Ultra technology at 1 mm resolution. In this study, the curve identification was based on the variation of heading angle, and the curve radius was calculated with kinematic method, geometry method, and lateral acceleration method. In order to verify the accuracy of the three methods, the analysis of variance (ANOVA test was applied by using the control variable of curve radius measured by field test. Based on the measured curve radius, a curve safety analysis model was used to predict the crash rates and safe driving speeds at horizontal curves. Finally, a case study on 4.35 km road segment demonstrated that the proposed method could efficiently conduct network level analysis.

  5. Development of a specification for flexible base construction.

    Science.gov (United States)

    2014-01-01

    The Texas Department of Transportation (TxDOT) currently uses Item 247 Flexible Base to specify a : pavement foundation course. The goal of this project was to evaluate the current method of base course : acceptance and investigate methods to r...

  6. Performance of Asphalt Concrete Wearing Course (AC-WC) Utilizing Reclaimed Asphalt Pavement from Cold Milling Bound with 80/100 Pen Asphalt

    Science.gov (United States)

    Thanya, I. N. A.; Suweda, I. W.; Putra, G. K.

    2018-03-01

    Demands on natural aggregate materials for road pavement can be reduced by utilizing reclaimed asphalt pavement (RAP). This research was aimed at evaluating the performance of AC-WC mixture using RAP materials from cold milling, bound with 80/100 pen asphalt. The RAP aggregate gradation was adjusted by adding the required amount of natural aggregates to meet the specification in Indonesia. The RAP and added aggregates were hotmixed and compacted with Marshall hummer at 2×75 blows. The asphalt content were varied. It was found that the optimum asphalt content was 6.05 % with the following Marshall characteristics: stability 1237.08 kg; flow 3.36 mm; Marshall quotient 324,73kg/mm; void in mix (VIM) 3,360%; void in mineral aggregate (VMA) 15.103; and void filled with bitumen (VFB) 77.759% and residual stability 91.04; all met the Indonesian specification. The cantabro abration loss (CAL) at 30°C was 9,02%. The indirect tensile stiffness modulus (ITSM) at 20 °C was 7961.4 MPa; dynamic creep with 100 kPa pressure at 40°C gave slope 0.0112 microsstrain/pulse which is suitable for heavy load traffic. The fatigue test results was obtained at increased stress level, i.e. at 900, 1100, and 1300 kPa. Based on the equation derived from the fatigue strain and repeated loading relationship, at 100 microstrain (με) the repeated load was 434,661.58 times, and at one million (106) repeated loading, the samples could withstand strain of 92,38 microstrain. The performance of the samples were overall better than AC-WC mixture using virgin aggregates bound with 60/70 pen asphalt.

  7. Finite element simulation of structural performance on flexible pavements with stabilized base/treated subbase materials under accelerated loading.

    Science.gov (United States)

    2011-12-01

    Accelerated pavement testing (APT) has been increasingly used by state highway agencies in recent years for evaluating pavement structures and/or materials. However, running an APT experiment is expensive. It requires costly accelerated loading devic...

  8. Performance evaluation of JRCP with stabilized open-graded drainage course.

    Science.gov (United States)

    2009-08-01

    From 1990 to 1995 the department used recycled concrete pavement as open-graded drainage course (OGDC) base : aggregate for thirteen concrete reconstruction projects. Overall, the JRCP projects with coated/stabilized OGDC have : performed very well i...

  9. Laser-based approach for determining flakiness index of aggregates used in pavements

    CSIR Research Space (South Africa)

    Anochie-Boateng, Joseph

    2011-07-01

    Full Text Available There are concerns about the standard methods/procedures for quantifying shape properties of rock aggregates used in road and airfield pavements. The CSIR has recently acquired a portable three-dimensional (3D) laser scanning device to address some...

  10. Structural evaluation of asphalt pavements with full-depth reclaimed base.

    Science.gov (United States)

    2012-12-01

    Currently, MnDOT pavement design recommends granular equivalency, GE = 1.0 for non-stabilized full-depth : reclamation (FDR) material, which is equivalent to class 5 material. For stabilized full-depth reclamation (SFDR), : there was no guideline for...

  11. Fracture mechanics in pavement design

    CSIR Research Space (South Africa)

    Denneman, E

    2009-07-01

    Full Text Available MODELLING FRACTURE IN PAVEMENT MATERIALS The cohesive crack approach can be incorporated in finite element method (FEM) to simulate fracture in pavement materials. In this paper an embedded discontinuity method (EDM) based on the work by Sancho et al... through elements, in other words, independent of nodal positions and element boundaries. The EDM was used for the numerical simulation of two examples of fracture tests on road materials from the literature. The model is applied to reproduce...

  12. Potential applicability of stress wave velocity method on pavement base materials as a non-destructive testing technique

    Science.gov (United States)

    Mahedi, Masrur

    Aggregates derived from natural sources have been used traditionally as the pavement base materials. But in recent times, the extraction of these natural aggregates has become more labor intensive and costly due to resource depletion and environmental concerns. Thus, the uses of recycled aggregates as the supplementary of natural aggregates are increasing considerably in pavement construction. Use of recycled aggregates such as recycled crushed concrete (RCA) and recycled asphalt pavement (RAP) reduces the rate of natural resource depletion, construction debris and cost. Although recycled aggregates could be used as a viable alternative of conventional base materials, strength characteristics and product variability limit their utility to a great extent. Hence, their applicability is needed to be evaluated extensively based on strength, stiffness and cost factors. But for extensive evaluation, traditionally practiced test methods are proven to be unreasonable in terms of time, cost, reliability and applicability. On the other hand, rapid non-destructive methods have the potential to be less time consuming and inexpensive along with the low variability of test results; therefore improving the reliability of estimated performance of the pavement. In this research work, the experimental program was designed to assess the potential application of stress wave velocity method as a non-destructive test in evaluating recycled base materials. Different combinations of cement treated recycled concrete aggregate (RAP) and recycled crushed concrete (RCA) were used to evaluate the applicability of stress wave velocity method. It was found that, stress wave velocity method is excellent in characterizing the strength and stiffness properties of cement treated base materials. Statistical models, based on P-wave velocity were derived for predicting the modulus of elasticity and compressive strength of different combinations of cement treated RAP, Grade-1 and Grade-2 materials. Two

  13. Simultaneous multi-vehicle detection and tracking framework with pavement constraints based on machine learning and particle filter algorithm

    Science.gov (United States)

    Wang, Ke; Huang, Zhi; Zhong, Zhihua

    2014-11-01

    Due to the large variations of environment with ever-changing background and vehicles with different shapes, colors and appearances, to implement a real-time on-board vehicle recognition system with high adaptability, efficiency and robustness in complicated environments, remains challenging. This paper introduces a simultaneous detection and tracking framework for robust on-board vehicle recognition based on monocular vision technology. The framework utilizes a novel layered machine learning and particle filter to build a multi-vehicle detection and tracking system. In the vehicle detection stage, a layered machine learning method is presented, which combines coarse-search and fine-search to obtain the target using the AdaBoost-based training algorithm. The pavement segmentation method based on characteristic similarity is proposed to estimate the most likely pavement area. Efficiency and accuracy are enhanced by restricting vehicle detection within the downsized area of pavement. In vehicle tracking stage, a multi-objective tracking algorithm based on target state management and particle filter is proposed. The proposed system is evaluated by roadway video captured in a variety of traffics, illumination, and weather conditions. The evaluating results show that, under conditions of proper illumination and clear vehicle appearance, the proposed system achieves 91.2% detection rate and 2.6% false detection rate. Experiments compared to typical algorithms show that, the presented algorithm reduces the false detection rate nearly by half at the cost of decreasing 2.7%-8.6% detection rate. This paper proposes a multi-vehicle detection and tracking system, which is promising for implementation in an on-board vehicle recognition system with high precision, strong robustness and low computational cost.

  14. Rigid pavements distresses - pavement condition index evaluation

    OpenAIRE

    Pereira, Tiago David da Costa Prudente

    2014-01-01

    Pavements require maintenance in order to provide good service levels during their life period. Because of the significant costs of this operation and the importance of a proper planning, a pavement evaluation methodology, named Pavement Condition Index (PCI), was created by the U.S. Army Corps of Engineers. This methodology allows for the evaluation of the pavement condition along the life period, generally yearly, with minimum costs and, in this way, it is possible to plan the maintenance a...

  15. WEB BASED LEARNING OF COMPUTER NETWORK COURSE

    Directory of Open Access Journals (Sweden)

    Hakan KAPTAN

    2004-04-01

    Full Text Available As a result of developing on Internet and computer fields, web based education becomes one of the area that many improving and research studies are done. In this study, web based education materials have been explained for multimedia animation and simulation aided Computer Networks course in Technical Education Faculties. Course content is formed by use of university course books, web based education materials and technology web pages of companies. Course content is formed by texts, pictures and figures to increase motivation of students and facilities of learning some topics are supported by animations. Furthermore to help working principles of routing algorithms and congestion control algorithms simulators are constructed in order to interactive learning

  16. Full-Scale Accelerated Testing of Multi-axial Geogrid Stabilized Flexible Pavements

    Science.gov (United States)

    2017-06-01

    axial geogrid in a flexible pavement base course provides a significant structural benefit. ERDC/GSL TR-17-9 39 References American Society for...Geotechnical and Structures Laboratory U.S. Army Engineer Research and Development Center 3909 Halls Ferry Road Vicksburg, MS 39180-6199 Final...Effective stabilized layer structural coefficient. ...................................................................... 37 ERDC/GSL TR-17-9 vii

  17. An assessment of the feasibility of developing and implementing an automated pavement distress survey system incorporating digital image processing.

    Science.gov (United States)

    1997-01-01

    The rational allocation of pavement maintenance resources requires the periodic assessment of the condition of all pavements. Traditional manual pavement distress surveys, which are based on visual inspection, are labor intensive, slow, and expensive...

  18. Oral exposure to commercially available coal tar‐based pavement sealcoat induces murine genetic damage and mutations

    Science.gov (United States)

    Watson, Margaret; Arlt, Volker M.; White, Paul A.

    2016-01-01

    Coal tar (CT) is a thick black liquid produced as a by‐product of coal carbonization to produce coke or manufactured gas. It is comprised a complex mixture of polycyclic aromatic compounds, including a wide range of polycyclic aromatic hydrocarbons (PAHs), many of which are genotoxic and carcinogenic. CT is used in some pavement sealants (also known as sealcoat), which are applied to pavement in order to seal and beautify the surface. Human exposure is known to occur not only during application, but also as a result of the weathering process, as elevated levels of PAHs have been found in settled house dust in residences adjacent to CT‐sealed surfaces. In this study we examined the genotoxicity of an extract of a commercially available CT‐based sealcoat in the transgenic Muta™Mouse model. Mice were orally exposed to 3 doses of sealcoat extract daily for 28 days. We evaluated genotoxicity by examining: (1) stable DNA adducts and (2) lacZ mutations in bone marrow, liver, lung, small intestine, and glandular stomach, as well as (3) micronucleated red blood cells. Significant increases were seen for each endpoint and in all tissues. The potency of the response differed across tissues, with the highest frequency of adducts occurring in liver and lung, and the highest frequency of mutations occurring in small intestine. The results of this study are the first demonstration of mammalian genotoxicity following exposure to CT‐containing pavement sealcoat. This work provides in vivo evidence to support the contention that there may be adverse health effects in mammals, and potentially in humans, from exposure to coal tar. Environ. Mol. Mutagen. 57:535–545, 2016. © 2016 Her Majesty the Queen in Right of Canada PMID:27473530

  19. Oral exposure to commercially available coal tar-based pavement sealcoat induces murine genetic damage and mutations.

    Science.gov (United States)

    Long, Alexandra S; Watson, Margaret; Arlt, Volker M; White, Paul A

    2016-08-01

    Coal tar (CT) is a thick black liquid produced as a by-product of coal carbonization to produce coke or manufactured gas. It is comprised a complex mixture of polycyclic aromatic compounds, including a wide range of polycyclic aromatic hydrocarbons (PAHs), many of which are genotoxic and carcinogenic. CT is used in some pavement sealants (also known as sealcoat), which are applied to pavement in order to seal and beautify the surface. Human exposure is known to occur not only during application, but also as a result of the weathering process, as elevated levels of PAHs have been found in settled house dust in residences adjacent to CT-sealed surfaces. In this study we examined the genotoxicity of an extract of a commercially available CT-based sealcoat in the transgenic Muta™Mouse model. Mice were orally exposed to 3 doses of sealcoat extract daily for 28 days. We evaluated genotoxicity by examining: (1) stable DNA adducts and (2) lacZ mutations in bone marrow, liver, lung, small intestine, and glandular stomach, as well as (3) micronucleated red blood cells. Significant increases were seen for each endpoint and in all tissues. The potency of the response differed across tissues, with the highest frequency of adducts occurring in liver and lung, and the highest frequency of mutations occurring in small intestine. The results of this study are the first demonstration of mammalian genotoxicity following exposure to CT-containing pavement sealcoat. This work provides in vivo evidence to support the contention that there may be adverse health effects in mammals, and potentially in humans, from exposure to coal tar. Environ. Mol. Mutagen. 57:535-545, 2016. © 2016 Her Majesty the Queen in Right of Canada. © 2016 Reproduced with the permission of the Government of Canada.

  20. Stress Regression Analysis of Asphalt Concrete Deck Pavement Based on Orthogonal Experimental Design and Interlayer Contact

    Science.gov (United States)

    Wang, Xuntao; Feng, Jianhu; Wang, Hu; Hong, Shidi; Zheng, Supei

    2018-03-01

    A three-dimensional finite element box girder bridge and its asphalt concrete deck pavement were established by ANSYS software, and the interlayer bonding condition of asphalt concrete deck pavement was assumed to be contact bonding condition. Orthogonal experimental design is used to arrange the testing plans of material parameters, and an evaluation of the effect of different material parameters in the mechanical response of asphalt concrete surface layer was conducted by multiple linear regression model and using the results from the finite element analysis. Results indicated that stress regression equations can well predict the stress of the asphalt concrete surface layer, and elastic modulus of waterproof layer has a significant influence on stress values of asphalt concrete surface layer.

  1. Multilayer airdrome pavement modeling on the base of numeically-analythical method of potential

    Directory of Open Access Journals (Sweden)

    О.М. Шевченко

    2004-04-01

    Full Text Available  There are problems of the take into account the multilayered foundation distributive properties which are ignored in the elementary case of Winkler foundation at calculation of constructions on the elastic foundation. In article the apparatus realization of numerically-analytical method of potential for a problem about stress and strain state analysis is considered for the multilayered pavement consisting from two isotropic layers with a separating layer between.

  2. Comportamiento de una pista experimental de pavimento flexible con base estabilizada con cal Behavior of an experimental track of flexible pavement with lime stabilized base

    Directory of Open Access Journals (Sweden)

    César Augusto Hidalgo Montoya

    2010-01-01

    Full Text Available En este trabajo se presentan resultados de una investigación realizada para determinar las propiedades de deformabilidad de bases estabilizadas con cal a partir de ensayos de campo no destructivos. Se realizaron ensayos de placa estática y viga Benkelman en un tramo de prueba de pavimento flexible de 70m de longitud. Se usaron diferentes mezclas de suelo-cal y varios espesores de la estructura para evaluar el comportamiento del pavimento. A partir de los resultados de estos ensayos fueron realizados retroanálisis del comportamiento del pavimento. El método de los elementos finitos y el modelo elástico de esfuerzos y deformaciones en sistema de capas múltiples se usaron en los retroanálisis para estimar los módulos de deformabilidad de la base estabilizada con cal. Se concluye que la adición de cal mejora sustancialmente las propiedades de los pavimentos evaluados.This paper presents results of a research carried out to determine the proprieties of deformation of lime stabilized bases using non destructive field tests. Static plate tests and Benkelman beam tests were made on an experimental track of flexible pavement of 70 m length. Several mixtures of soil-lime and several thickness of the stabilized base were used to evaluate the behavior of the pavement. With the results of these tests, back analysis of the behavior of pavement was carried out. The finite elements method and the elastic stress and strain in a multi layers system were used to estimate the deformation modulus of the lime stabilized bases. It is concluded that the lime addition significantly improves the properties of evaluated pavements.

  3. Evaluation of Procedures for Backcalculation of Airfield Pavement Moduli

    Science.gov (United States)

    2015-08-01

    surface and the base pavement is positively in good condition Cb = 0.8 if only reflective cracks or only joint reflective cracks are present on...backcalculation routine with the real pavement scenario.  Testing in proximity of cracks or joints results in measured deflection basins that... pavement (JPCP) 1 Plant mix (emulsified asphalt) material, cold-laid 20 Jointed reinforced concrete pavement (JRCP) 1 Cracked and seated PCC

  4. A fuzzy logic approach for pavement section classification

    OpenAIRE

    Mahmood, M; Rahman, M; Nolle, L; Mathavan, S

    2013-01-01

    Section classification is one of the primary challenges in any successful pavement management system. Sections are normally classified based on their pavement condition index in order to categorise as "good", "moderate" and "poor". Conventionally, this has been done by comparing various pavement distress data against threshold values. However, borderline values between two categories have significant influence on the subsequent pavement maintenance and rehabilitation decision. This study is t...

  5. Effects of Interlocking and Supporting Conditions on Concrete Block Pavements

    Science.gov (United States)

    Mahapatra, Geetimukta; Kalita, Kuldeep

    2018-02-01

    Concrete Block Paving (CBP) is widely used as wearing course in flexible pavements, preferably under light and medium vehicular loadings. Construction of CBP at site is quick and easy in quality control. Usually, flexible pavement design philosophy is followed in CBP construction, though it is structurally different in terms of small block elements with high strength concrete and their interlocking aspects, frequent joints and discontinuity, restrained edge etc. Analytical solution for such group action of concrete blocks under loading in a three dimensional multilayer structure is complex and thus, the need of conducting experimental studies is necessitated for extensive understanding of the load—deformation characteristics and behavior of concrete blocks in pavement. The present paper focuses on the experimental studies for load transfer characteristics of CBP under different interlocking and supporting conditions. It is observed that both interlocking and supporting conditions affect significantly on the load transfer behavior in CBP structures. Coro-lock block exhibits better performance in terms of load carrying capacity and distortion behavior under static loads. Plate load tests are performed over subgrade, granular sub-base (GSB), CBP with and without GSB using different block shapes. For an example case, the comparison of CBP with conventional flexible pavement section is also presented and it is found that CBP provides considerable benefit in terms of construction cost of the road structure.

  6. High calcium fly ash geopolymer stabilized lateritic soil and granulated blast furnace slag blends as a pavement base material.

    Science.gov (United States)

    Phummiphan, Itthikorn; Horpibulsuk, Suksun; Rachan, Runglawan; Arulrajah, Arul; Shen, Shui-Long; Chindaprasirt, Prinya

    2018-01-05

    Granulated Blast Furnace Slag (GBFS) was used as a replacement material in marginal lateritic soil (LS) while class C Fly Ash (FA) was used as a precursor for the geopolymerization process to develop a low-carbon pavement base material at ambient temperature. Unconfined Compression Strength (UCS) tests were performed to investigate the strength development of geopolymer stabilized LS/GBFS blends. Scanning Electron Microscopy and X-ray Diffraction analysis were undertaken to examine the role of the various influencing factors on UCS development. The influencing factors studied included GBFS content, Na 2 SiO 3 :NaOH ratio (NS:NH) and curing time. The 7-day soaked UCS of FA geopolymer stabilized LS/GBFS blends at various NS:NH ratios tested was found to satisfy the specifications of the Thailand national road authorities. The GBFS replacement was found to be insignificant for the improvement of the UCS of FA geopolymer stabilized LS/GBFS blends at low NS:NH ratio of 50:50. Microstructural analysis indicated the coexistence of Calcium Silicate Hydrate (CSH) and Sodium Alumino Silicate Hydrate products in FA geopolymer stabilized LS/GBFS blends. This research enables GBFS, which is traditionally considered as a waste material, to be used as a replacement and partially reactive material in FA geopolymer pavement applications. Copyright © 2017 Elsevier B.V. All rights reserved.

  7. Sampling optimization for high-speed weigh-in-motion measurements using in-pavement strain-based sensors

    International Nuclear Information System (INIS)

    Zhang, Zhiming; Huang, Ying; Bridgelall, Raj; Palek, Leonard; Strommen, Robert

    2015-01-01

    Weigh-in-motion (WIM) measurement has been widely used for weight enforcement, pavement design, freight management, and intelligent transportation systems to monitor traffic in real-time. However, to use such sensors effectively, vehicles must exit the traffic stream and slow down to match their current capabilities. Hence, agencies need devices with higher vehicle passing speed capabilities to enable continuous weight measurements at mainline speeds. The current practices for data acquisition at such high speeds are fragmented. Deployment configurations and settings depend mainly on the experiences of operation engineers. To assure adequate data, most practitioners use very high frequency measurements that result in redundant samples, thereby diminishing the potential for real-time processing. The larger data memory requirements from higher sample rates also increase storage and processing costs. The field lacks a sampling design or standard to guide appropriate data acquisition of high-speed WIM measurements. This study develops the appropriate sample rate requirements as a function of the vehicle speed. Simulations and field experiments validate the methods developed. The results will serve as guidelines for future high-speed WIM measurements using in-pavement strain-based sensors. (paper)

  8. Load Response Analysis of Asphalt Pavement

    Directory of Open Access Journals (Sweden)

    Xiao Zhijun

    2016-01-01

    Full Text Available Based on the filed data of Fuzhou test road, load response regulation of nonlinear pavement structure was analyzed in this paper; Mechanics software was adopted to analyze linear elastic and nonlinear of the pavement structure, analyzed results and road filed data were compared, and determine the correlation between them and the field data.

  9. 0-6621 : developing a mixture-based specification for flexible base.

    Science.gov (United States)

    2012-08-01

    The Texas Department of Transportation : (TxDOT) currently utilizes Item 247, Flexible : Base, to specify a foundation course of flexible : base utilized in a pavement. Base materials are : not allowed to be used by the contractors until : the ...

  10. Empirical prediction of mechanical properties of flexible pavement through GPR

    Science.gov (United States)

    Bianchini Ciampoli, Luca; Benedetto, Andrea

    2017-04-01

    To date, it is well known that the frequency of accidental events recorded on a road, is related to the deterioration rate of its pavement. In this sense, the monitoring of the pavement health over a road network is a crucial task for the administrations, to define a priority scale for maintenance works, and accordingly to lower the risk of accidents. Several studies suggest the possibility to employ Ground-penetrating Radar (GPR) to overcome the limits of traditional bearing tests, which due to their low productivity and high costs, can only give a discrete knowledge about the strength of the pavement. This work presents a GPR-based empirical model for the prediction of the bearing capacity of a road pavement, expressed as Young's Modulus. The model exploits the GPR to extract information on the thickness of the base course and the clay content, by referring to the signal velocity and attenuation, respectively. To test the effectiveness of the model, experimental activities have been accounted for. In particular, multi-frequency GPR tests have been performed along road sections of rural roads, composed of a flexible pavement, for a total of 45 Km. As ground-truth, light falling weight deflectometer (LFWD) and Curviameter have been employed. Both the electromagnetic and the mechanical datasets have been properly processed, in order to reduce misinterpretations and to raise the statistical significance of the procedure. Hence, the calibration of the parameters composing the model was run in a subsection, equal to 8% of the total length, randomly selected within the surveyed track. Finally, as validation, the model has been applied to the whole analysed dataset. As a result, the empirical model showed a good effectiveness in predicting the mechanical response of the pavement, with a normalised root mean squared deviation equal to 0.27. Finally, by averaging the measured and predicted mechanical data every 50 m and sorting the results into strength classes, a

  11. Field cracking performance of airfield rigid pavements

    Directory of Open Access Journals (Sweden)

    Yusuf Mehta

    2017-08-01

    Full Text Available This paper discusses cracking in airport pavements as studied in Construction Cycle 6 of testing carried out at the National Airport Pavement Testing Facility by the Federal Aviation Administration. Pavements of three different flexural strengths as well as two different subgrades, a soft bituminous layer and a more rigid layer known as econocrete, were tested. In addition to this, cracking near two types of isolated transition joints, a reinforced edge joint and a thickened edge joint, was considered. The pavement sections were tested using a moving load simulating that of an aircraft. It has been determined that the degree of cracking was reduced as the flexural strength of the pavement was increased and that fewer cracks formed over the econocrete base than over the bituminous base. In addition, the thickened edge transition joint was more effective in preventing cracking at the edges compared to the reinforced edge joint.

  12. Fatigue and rutting lives in flexible pavement

    Directory of Open Access Journals (Sweden)

    Ahmed Ebrahim Abu El-Maaty Behiry

    2012-12-01

    Full Text Available Flexible pavement is designed based on axle load limits and climatic conditions. The Egyptian code has specified certain load limits that should not be exceeded. The overweight trucks cause severe deterioration to the pavement and thus reduce its life. The study aims at studying the effect of axle load increase, and the variation in pavement modulus, on the overall pavement life. The research uses the BISAR software and the Egyptian environmental and pavement materials conditions to estimate the tensile strains occurring under the asphalt concrete (AC layer and the compressive strains above the subgrade surface. The results revealed that tensile and compressive strain increased with increasing axle loads and decreased with increasing asphalt layer modulus thus the violating trucks should be unloaded when their weights exceed certain limits. Base thickness and subgrade resilient modulus were the key elements which control the equilibrium between fatigue and rutting lives.

  13. Finite element simulation of structural performance on flexible pavements with stabilized base/treated subbase materials under accelerated loading : tech summary.

    Science.gov (United States)

    2011-12-01

    Accelerated pavement testing (APT) has been increasingly used by state highway agencies in recent years for evaluating pavement : design and performance through applying a simulative heavy vehicular load to the pavement section under controlled fi el...

  14. Recommendations and strategies for using reclaimed asphalt pavement in the Flemish Region based on a first life cycle assessment research

    Science.gov (United States)

    Van den bergh, Wim; Kara, Patricia; Anthonissen, Joke; Margaritis, Alexandros; Jacobs, Geert; Couscheir, Karolien

    2017-09-01

    In Flanders, using Reclaimed Asphalt Pavement (RAP) is allowed in asphalt mixes for base layers. Primary economic and secondary laboratory-measured mechanical properties are given as justification for higher amounts in specific mixes. However, one should evaluate the performance of these mixes on long-term by environmental impact of the production until end-of-life. In this paper recommendations and strategies for using RA, based on current research, are discussed in a broader perspective such as using a carbon-footprint tool and warm-mix asphalt production in the Flemish Region. The paper aims to a wide discussion by reporting several outcomes of laboratory research, statistics and practical application in order to set a general strategy for the road engineering sector in the Flemish Region.

  15. Experimental evaluation of high performance base course and road base asphalt concrete with electric arc furnace steel slags.

    Science.gov (United States)

    Pasetto, Marco; Baldo, Nicola

    2010-09-15

    The paper presents the results of a laboratory study aimed at verifying the use of two types of electric arc furnace (EAF) steel slags as substitutes for natural aggregates, in the composition of base course and road base asphalt concrete (BBAC) for flexible pavements. The trial was composed of a preliminary study of the chemical, physical, mechanical and leaching properties of the EAF steel slags, followed by the mix design and performance characterization of the bituminous mixes, through gyratory compaction tests, permanent deformation tests, stiffness modulus tests at various temperatures, fatigue tests and indirect tensile strength tests. All the mixtures with EAF slags presented better mechanical characteristics than those of the corresponding asphalts with natural aggregate and satisfied the requisites for acceptance in the Italian road sector technical standards, thus resulting as suitable for use in road construction. Copyright 2010 Elsevier B.V. All rights reserved.

  16. Strain transfer analysis of optical fiber based sensors embedded in an asphalt pavement structure

    Science.gov (United States)

    Wang, Huaping; Xiang, Ping

    2016-07-01

    Asphalt pavement is vulnerable to random damage, such as cracking and rutting, which can be proactively identified by distributed optical fiber sensing technology. However, due to the material nature of optical fibers, a bare fiber is apt to be damaged during the construction process of pavements. Thus, a protective layer is needed for this application. Unfortunately, part of the strain of the host material is absorbed by the protective layer when transferring the strain to the sensing fiber. To account for the strain transfer error, in this paper a theoretical analysis of the strain transfer of a three-layered general model has been carried out by introducing Goodman’s hypothesis to describe the interfacial shear stress relationship. The model considers the viscoelastic behavior of the host material and protective layer. The effects of one crack in the host material and the sensing length on strain transfer relationship are been discussed. To validate the effectiveness of the strain transfer analysis, a flexible asphalt-mastic packaged distributed optical fiber sensor was designed and tested in a laboratory environment to monitor the distributed strain and appearance of cracks in an asphalt concrete beam at two different temperatures. The experimental results indicated that the developed strain transfer formula can significantly reduce the strain transfer error, and that the asphalt-mastic packaged optical fiber sensor can successfully monitor the distributed strain and identify local cracks.

  17. Strain transfer analysis of optical fiber based sensors embedded in an asphalt pavement structure

    International Nuclear Information System (INIS)

    Wang, Huaping; Xiang, Ping

    2016-01-01

    Asphalt pavement is vulnerable to random damage, such as cracking and rutting, which can be proactively identified by distributed optical fiber sensing technology. However, due to the material nature of optical fibers, a bare fiber is apt to be damaged during the construction process of pavements. Thus, a protective layer is needed for this application. Unfortunately, part of the strain of the host material is absorbed by the protective layer when transferring the strain to the sensing fiber. To account for the strain transfer error, in this paper a theoretical analysis of the strain transfer of a three-layered general model has been carried out by introducing Goodman’s hypothesis to describe the interfacial shear stress relationship. The model considers the viscoelastic behavior of the host material and protective layer. The effects of one crack in the host material and the sensing length on strain transfer relationship are been discussed. To validate the effectiveness of the strain transfer analysis, a flexible asphalt-mastic packaged distributed optical fiber sensor was designed and tested in a laboratory environment to monitor the distributed strain and appearance of cracks in an asphalt concrete beam at two different temperatures. The experimental results indicated that the developed strain transfer formula can significantly reduce the strain transfer error, and that the asphalt-mastic packaged optical fiber sensor can successfully monitor the distributed strain and identify local cracks. (paper)

  18. Saw & seal, airport pavement.

    Science.gov (United States)

    2009-05-01

    Due to extreme cold temperatures, hot bituminous pavements on Maines airports are subject to transverse : or thermal cracking. This can lead to poorly performing pavement structure causing heaving and : settlement problems. Studies have shown that...

  19. Pavement Subgrade Performance Study

    DEFF Research Database (Denmark)

    Zhang, Wei; Ullidtz, Per; Macdonald, Robin

    1998-01-01

    The report describes the second test in the Danish Road Testing Machine (RTM) under the International Pavement Subgrade Performance Study. Pavement response was measured in different layers, and compared to different theroretical values. Performance in terms of plastic strains, rutting...

  20. Quieter pavements guidance document

    Science.gov (United States)

    2013-02-01

    This report provides guidance and better practice recommendations to the National Park : Service for selecting pavement surfaces to minimize tire-pavement noise. The report : contains an overview of common technologies and methods for quieter pavemen...

  1. Concrete pavement joint deterioration.

    Science.gov (United States)

    2015-12-01

    Concrete pavements are an important part of our national infrastructure. In recent years the relatively small number of reported joints deteriorating prematurely in concrete pavements around Indiana has increased. Changes over the past 45 years in IN...

  2. A site assessment of pavement cracking in a drought environment: a case history

    Directory of Open Access Journals (Sweden)

    Nevels James B.

    2016-01-01

    Full Text Available This paper builds upon the findings of a site investigation into the causes of longitudinal cracks that developed soon after the re-construction of Himes and Johnson Streets in the City of Norman, Oklahoma between May to September 2012. The re‒construction of the city street pavement and base course were completed during a protracted drought period, and shortly after completion of the pavement section longitudinal cracks occurred predominantly along the curb line. The case history concluded that the drought conditions resulted in significant subgrade soil shrinkage. The shrinkage caused changes in soil suction with depth resulting in tensile stresses in the asphalt pavement and stabilized subbase that lead to the pavement cracking. A simple practical moisture/suction variation model with depth (Hamberg was used in conjunction with the soil water characteristic curve (SWCC to make predictions of the soil suction changes that are resulting in the pavement cracking. The paper documents the comparison of the Hamberg model used in the case history with the Mitchell and finite element (FEM models. The purpose of the comparison was to see if improved accuracy of the Mitchell model and a finite element model resulted in significant changes in the prediction of soil suction.

  3. Influence of hot asphalt mixture using asbuton on road composite pavement

    Science.gov (United States)

    Gaus, Abdul; Darwis, Muhammad; Imran

    2017-11-01

    Construction and rehabilitation of road infrastructure in Indonesia require about 1.2 million tons of asphalt per year, approximately 100% used of petroleum asphalt. Only a half of asphalt demand can be provided domestically, while about 600 thousand tons have to be imported from abroad. Indonesia has natural asphalt with a quite large deposit but has not been fully utilized. Lack of availability of asphalt and the increasing demand of the domestic market will give effect to an increase in bitumen cost in the domestic market. Somehow, this is not a sufficient condition due to the rising cost of road infrastructure. This study aims to determine the effect of using a layer of asphalt concrete pavement asbuton to rigid pavement (PR-modification). Stressing that occur in rigid pavement, asphalt concrete layer and base course measured by using LVDT and for the subgrade using soil pressure transducer. Using asbuton on asphalt concrete will have more benefit on improving the stability of the marshall. The maximum deflection occurring in the PR-modification at 5.19 mm with a maximum stress of 175.10 kN. Vertical and horizontal tension that occur at the base course at -20 cm row by 0.855 MPa and 0.00282 MPa. Addition of layers of asphalt concrete in rigid pavement using asbuton has increased power by 9.5%.

  4. Resilient Modulus Characterization of Alaskan Granular Base Materials

    Science.gov (United States)

    2010-08-01

    Resilient modulus (MR) of base course material is an important material input for : pavement design. In Alaska, due to distinctiveness of local climate, material source, : fines content and groundwater level, resilient properties of D-1 granular base...

  5. Labour-based construction, testing and monitoring of proof-of-concept ultrathin continuously reinforced concrete pavement technology demonstrators

    CSIR Research Space (South Africa)

    Dlamini, N

    2011-09-01

    Full Text Available For this workshop, members of the Regional research alliance (RRA) and delegates from the construction industry were invited to present ideas and contribute towards the implementation of Ultrathin Concrete road pavements. Dr. Joe Mapiravana made a...

  6. User's guide: estimation of key PCC, base, subbase, and pavement engineering properties from routine tests and physical characteristics

    Science.gov (United States)

    2012-08-01

    Material characterization is a critical component of modern day pavement analysis, design, construction, quality : control/quality assurance, management, and rehabilitation. At each stage during the life of a project, the influence of : several funda...

  7. Problem-based, interdisciplinary field-based courses

    DEFF Research Database (Denmark)

    Hill, Trevor; Birch-Thomsen, Torben; Traynor, Catherine

    2008-01-01

    the context of their learning better and have a greater appreciation of their own personal development. The process calls for long-term commitment to the communities with whom one works closely, the recognition of sometimes having to 'think on one's feet', being prepared to make mistakes and use frustration......Student field courses at Universities are increasingly incorporating problem-based interdisciplinary approaches to enhance learning opportunities. This paper reports upon seven field-based, problem-oriented, interdisciplinary courses held within southern Africa concerning natural resource...... management and sustainable land use. The SLUSE (Sustainable Land Use and Natural Resource Management) project, under which these courses were devised, is introduced and the process of field-course implementation is described. The SLUSE approach is discussed in terms of management issues, levels...

  8. An Innovative Cellular Automata Technique for Mapping Cracking Pattern of Airport Pavement

    Directory of Open Access Journals (Sweden)

    Yin Fucheng

    2017-01-01

    Full Text Available In this study, an innovative cellular automata (CA technique was proposed for mapping cracking pattern of the airport pavement. The CA technique was developed to establish a numerical model describing the effect of boundary condition of pavement on zones (CA cells within the pavement. A state function was used to describe the state values in the cells within the CA lattice. The correction coefficient principle is used as the criterion of zone similarity and the corresponding technique is proposed to find similar zones within and between pavements. Three pavement models, HRS, MRS and LRS, tested in FAA, USA, are set as the base pavements to map the cracking patterns of pavements with different sizes from the base pavements. The mapped cracking patterns of unseen pavements are empirically verified by referring to the relative experimental models.

  9. Quantifying Evaporation in a Permeable Pavement System ...

    Science.gov (United States)

    Studies quantifying evaporation from permeable pavement systems are limited to a few laboratory studies and one field application. This research quantifies evaporation for a larger-scale field application by measuring the water balance from lined permeable pavement sections. The U.S. Environmental Protection Agency (USEPA) constructed a 0.4-ha parking lot in Edison, NJ, that incorporated three different permeable pavement types in the parking lanes – permeable interlocking concrete pavers (PICP), pervious concrete (PC), and porous asphalt (PA). An impermeable liner installed 0.4 m below the driving surface in four 11.6-m by 4.74-m sections per each pavement type captures all infiltrating water and routes it to collection tanks that can contain events up to 38 mm. Each section has a design impervious area to permeable pavement area ratio of 0.66:1. Pressure transducers installed in the underdrain collection tanks measured water level for 24 months. Level was converted to volume using depth-to-volume ratios for individual collection tanks. Using a water balance approach, the measured infiltrate volume was compared to rainfall volume on an event-basis to determine the rainfall retained in the pavement strata and underlying aggregate. Evaporation since the previous event created additional storage in the pavement and aggregate layers. Events were divided into three groups based on antecedent dry period (ADP) and three, four-month categories of potential e

  10. Preparation and performance evaluation of epoxy-based heat reflective coating for the pavement

    Science.gov (United States)

    Hu, B.; Liang, Y. H.; Guo, L. Y.; Jiang, T.

    2017-04-01

    According to the basic characteristics and composition of heat-reflective coating, combining with the functional requirements of road materials, the experiment selects the epoxy resin with good wear resistance and adhesive force as a film forming material, with TiO2, SiO2 and extinction powder as the main functional filler. The experiment gets a good formula with suitable viscosity, low glossiness and good cooling effect, optimizes by orthogonal experiment. The experiment evaluates the indoor and outdoor cooling effect of heat-reflective coating, and analyses the road performance of the coating. The results shows that the better heat-reflective coating formula included 12% of titanium dioxide, 4% of silica and 4% of extinction powder. When the dosage of coating is 0.8kg/m2, the indoor specimen of heat-reflective coating decrease the temperature of 12 ∼ 14°C, and the specimen under solar radiation can reduce the temperature of 7 ∼ 9°C. The pavement of heat-reflective coating has good wear resistance, but the road slip resistance partly declines. Therefore, it needs to add the anti-sliding particles to meet the safe driving requirements.

  11. Thermal stability analysis under embankment with asphalt pavement and cement pavement in permafrost regions.

    Science.gov (United States)

    Junwei, Zhang; Jinping, Li; Xiaojuan, Quan

    2013-01-01

    The permafrost degradation is the fundamental cause generating embankment diseases and pavement diseases in permafrost region while the permafrost degradation is related with temperature. Based on the field monitoring results of ground temperature along G214 Highway in high temperature permafrost regions, both the ground temperatures in superficial layer and the annual average temperatures under the embankment were discussed, respectively, for concrete pavements and asphalt pavements. The maximum depth of temperature field under the embankment for concrete pavements and asphalt pavements was also studied by using the finite element method. The results of numerical analysis indicate that there were remarkable seasonal differences of the ground temperatures in superficial layer between asphalt pavement and concrete pavement. The maximum influencing depth of temperature field under the permafrost embankment for every pavement was under the depth of 8 m. The thawed cores under both embankments have close relation with the maximum thawed depth, the embankment height, and the service time. The effective measurements will be proposed to keep the thermal stabilities of highway embankment by the results.

  12. Thermal Stability Analysis under Embankment with Asphalt Pavement and Cement Pavement in Permafrost Regions

    Directory of Open Access Journals (Sweden)

    Zhang Junwei

    2013-01-01

    Full Text Available The permafrost degradation is the fundamental cause generating embankment diseases and pavement diseases in permafrost region while the permafrost degradation is related with temperature. Based on the field monitoring results of ground temperature along G214 Highway in high temperature permafrost regions, both the ground temperatures in superficial layer and the annual average temperatures under the embankment were discussed, respectively, for concrete pavements and asphalt pavements. The maximum depth of temperature field under the embankment for concrete pavements and asphalt pavements was also studied by using the finite element method. The results of numerical analysis indicate that there were remarkable seasonal differences of the ground temperatures in superficial layer between asphalt pavement and concrete pavement. The maximum influencing depth of temperature field under the permafrost embankment for every pavement was under the depth of 8 m. The thawed cores under both embankments have close relation with the maximum thawed depth, the embankment height, and the service time. The effective measurements will be proposed to keep the thermal stabilities of highway embankment by the results.

  13. The comparisons of computational models of pavement due to the dynamic load act

    Directory of Open Access Journals (Sweden)

    Valašková Veronika

    2017-01-01

    Full Text Available Finite element method (FEM is frequently used to solve current problems of the structural mechanics in engineering practice. The dynamic interaction of the two systems is one of the topics that can be solved using FEM. To simplify the solution of the interaction, it is possible to divide the system in two independent subsystems, vehicle and pavement. Computing software ADINA, based on the principles of the finite element modelling, was adopted to solve the given problem. The results from the first computational model can be used as the inputs for the second model. To analyse stress state of the pavement with different composition, three specific types of pavements were selected – concrete pavement, semi-rigid pavement and flexible pavement. The pavements represent the typical pavement types used for the regular road structures. This article is focused on the analysis of the stress state and the displacements of the pavement induced by the moving load from the traffic.

  14. Studio-based courses in architectural acoustics

    Science.gov (United States)

    Siebein, Gary W.

    2003-04-01

    Examples of 4 nontraditional, elective courses offered to students in the Master of Architecture, Master of Science and Doctor of Philosophy degree programs in architecture are presented. Listening to Buildings involves experiential exercises in architectural acoustics for undergraduate students in a required large lecture course to form links between what people hear in a room and the architectural shapes and materials of the room that affects what is heard. The Applied Acoustics Design Lab takes students through each of the major components of an actual consulting project. Student work includes room acoustic design, sound isolation design, sound system design and HVAC noise control design for an actual building project. An Acoustical History of Theaters and Concert Halls teaches fundamentals of computer-based acoustic modeling and has students compare the physical design and aural simulations of a historic and a contemporary performance space. Graduate design studio in acoustics examines sound and silence as potential form-givers in architecture and as generative ideas for the basis of architectural interventions in complex sites and programs. Interior and exterior soundscapes and phenomenological philosophy form the background research for the studio.

  15. Assessment of highway pavements using GPR

    Science.gov (United States)

    Plati, Christina; Loizos, Andreas

    2015-04-01

    Highway infrastructure is a prerequisite for a functioning economy and social life. Highways, often prone to congestion and disruption, are one of the aspects of a modern transport network that require maximum efficiency if an integrated transport network, and sustainable mobility, is to be achieved. Assessing the condition of highway structures, to plan subsequent maintenance, is essential to allow the long-term functioning of a road network. Optimizing the methods used for such assessment will lead to better information being obtained about the road and underlying ground conditions. The condition of highway structures will be affected by a number of factors, including the properties of the highway pavement, the supporting sub-base and the subgrade (natural ground), and the ability to obtain good information about the entire road structure, from pavement to subgrade, allows appropriate maintenance programs to be planned. The maintenance of highway pavements causes considerable cost and in many cases obstruction to traffic flow. In this situation, methods that provide information on the present condition of pavement structure non-destructively and economically are of great interest. It has been shown that Ground-Penetrating-Radar (GPR), which is a Non Destructive Technique (NDT), can deliver information that is useful for the planning of pavement maintenance activities. More specifically GPR is used by pavement engineers in order to determine physical properties and characteristics of the pavement structure, information that is valuable for the assessment of pavement condition. This work gives an overview on the practical application of GPR using examples from highway asphalt pavements monitoring. The presented individual applications of GPR pavement diagnostics concern structure homogeneity, thickness of pavement layers, dielectric properties of asphalt materials etc. It is worthwhile mentioning that a number of applications are standard procedures, either

  16. Pavement Testing Facility

    Data.gov (United States)

    Federal Laboratory Consortium — Comprehensive Environmental and Structural AnalysesThe ERDC Pavement Testing Facility, located on the ERDC Vicksburg campus, was originally constructed to provide an...

  17. Effectiveness of Web-Based Courses on Technical Learning

    Science.gov (United States)

    Lam, Monica

    2009-01-01

    The author investigated the effectiveness of Web-based courses on technical learning. The regression results show that the delivery format (Web-based or traditional classroom courses) has no significant effect on student performance. However, although gender is a significant predictor in traditional classroom courses, its effect disappears in…

  18. Web-Based Gerontology Courses: How Do They Measure Up?

    Science.gov (United States)

    Hills, William E.; Brallier, Sara A.; Palm, Linda J.; Graham, Jamie M.

    2009-01-01

    This study compared Web-based and lecture-based Gerontology and Psychology of Aging courses in terms of student performance, demographic and academic characteristics of students enrolled in the courses, and extent to which these characteristics differentially predicted outcomes of learning in the two course types. Participants for this study were…

  19. Evaluating the performance of sustainable perpetual pavements using recycled asphalt pavement in China

    Directory of Open Access Journals (Sweden)

    Saud A. Sultan

    2016-10-01

    Full Text Available The vast highways network in China is moving from the phase of construction to the phase of maintenance, and with the introduction of new technique of perpetual pavement in last decade, it is necessary to consider recycling as one of the promising solutions for rehabilitation of old asphalt concrete pavement and ultimately to convert them into perpetual pavements. The aim is to reuse the existing pavement materials for several reasons, mainly to preserve natural resources such as aggregates, and to satisfy economic requirements by reducing the cost of highway construction and rehabilitation. A detailed testing program has been carried out on recycled asphalt pavements materials (RAP to evaluate their mechanical and structural characteristics to be used for the construction and rehabilitation of road pavements. Different types of RAP mixes have been stabilized by Portland cement to find the most suitable one from the point of view of design, construction, economy and environment. The analysis of life cycle costs has been carried out using system analysis and management of pavement program (SAMP5. The analysis of life cycle costs showed that the use of Portland cements with small percentages improves the structural characteristics of recycled asphalt materials to be used as stabilized base pavement layers for new or rehabilitated old road pavements and also for the construction and rehabilitation of perpetual pavements. A large amount of savings in construction and rehabilitation cost has been achieved by the use of stabilized RAP materials in addition to important contributions to the environment and preserving of natural resources.

  20. Crack identification for rigid pavements using unmanned aerial vehicles

    Science.gov (United States)

    Bahaddin Ersoz, Ahmet; Pekcan, Onur; Teke, Turker

    2017-09-01

    Pavement condition assessment is an essential piece of modern pavement management systems as rehabilitation strategies are planned based upon its outcomes. For proper evaluation of existing pavements, they must be continuously and effectively monitored using practical means. Conventionally, truck-based pavement monitoring systems have been in-use in assessing the remaining life of in-service pavements. Although such systems produce accurate results, their use can be expensive and data processing can be time consuming, which make them infeasible considering the demand for quick pavement evaluation. To overcome such problems, Unmanned Aerial Vehicles (UAVs) can be used as an alternative as they are relatively cheaper and easier-to-use. In this study, we propose a UAV based pavement crack identification system for monitoring rigid pavements’ existing conditions. The system consists of recently introduced image processing algorithms used together with conventional machine learning techniques, both of which are used to perform detection of cracks on rigid pavements’ surface and their classification. Through image processing, the distinct features of labelled crack bodies are first obtained from the UAV based images and then used for training of a Support Vector Machine (SVM) model. The performance of the developed SVM model was assessed with a field study performed along a rigid pavement exposed to low traffic and serious temperature changes. Available cracks were classified using the UAV based system and obtained results indicate it ensures a good alternative solution for pavement monitoring applications.

  1. Mechanistic-empirical design concepts for continuously reinforced concrete pavements in Illinois.

    Science.gov (United States)

    2009-04-01

    The Illinois Department of Transportation (IDOT) currently has an existing jointed plain concrete pavement : (JPCP) design based on mechanistic-empirical (M-E) principles. However, their continuously reinforced concrete : pavement (CRCP) design proce...

  2. Experiences from in-situ monitoring of pavement under weather conditions change

    Directory of Open Access Journals (Sweden)

    Likar Barbara

    2016-01-01

    Full Text Available Very strong winters with temperatures under 0°C and hot summers with temperatures more than 30°C are observed in the South East part of Slovenia. Those big differences in temperature during the year and especially temperatures below freezing point have strong influence on asphalt layer and sub base of road pavement. The freeze/thaw cycles lead to formation of ice lenses in base course causing cracks in asphalt layers and degrade the pavement usually in a few years. For this reason one section of the national road in the South East part of Slovenia was rebuilt with cold in-situ pavement retreatment. A test field with inbuilt sensors for measuring water content, temperature and deformation in various depths and locations was constructed during the remediation works to study the mechanism of freeze-thaw degradation of pavements. The main goal of the test field is to determine water content in sub base, freezing depth, temperature distribution and deformations, which lead to cracks in asphalt layer after the remediation work in the road construction.

  3. Study on Flexible Pavement Failures in Soft Soil Tropical Regions

    Science.gov (United States)

    Jayakumar, M.; Chee Soon, Lee

    2015-04-01

    Road network system experienced rapid upgrowth since ages ago and it started developing in Malaysia during the colonization of British due to its significant impacts in transportation field. Flexible pavement, the major road network in Malaysia, has been deteriorating by various types of distresses which cause descending serviceability of the pavement structure. This paper discusses the pavement condition assessment carried out in Sarawak and Sabah, Malaysia to have design solutions for flexible pavement failures. Field tests were conducted to examine the subgrade strength of existing roads in Sarawak at various failure locations, to assess the impact of subgrade strength on pavement failures. Research outcomes from field condition assessment and subgrade testing showed that the critical causes of pavement failures are inadequate design and maintenance of drainage system and shoulder cross fall, along with inadequate pavement thickness provided by may be assuming the conservative value of soil strength at optimum moisture content, whereas the exiting and expected subgrade strengths at equilibrium moisture content are far below. Our further research shows that stabilized existing recycled asphalt and base materials to use as a sub-base along with bitumen stabilized open graded base in the pavement composition may be a viable solution for pavement failures.

  4. Problem-based learning biotechnology courses in chemical engineering.

    Science.gov (United States)

    Glatz, Charles E; Gonzalez, Ramon; Huba, Mary E; Mallapragada, Surya K; Narasimhan, Balaji; Reilly, Peter J; Saunders, Kevin P; Shanks, Jacqueline V

    2006-01-01

    We have developed a series of upper undergraduate/graduate lecture and laboratory courses on biotechnological topics to supplement existing biochemical engineering, bioseparations, and biomedical engineering lecture courses. The laboratory courses are based on problem-based learning techniques, featuring two- and three-person teams, journaling, and performance rubrics for guidance and assessment. Participants initially have found them to be difficult, since they had little experience with problem-based learning. To increase enrollment, we are combining the laboratory courses into 2-credit groupings and allowing students to substitute one of them for the second of our 2-credit chemical engineering unit operations laboratory courses.

  5. Assessing Asphalt and Concrete Pavement Surface Texture in the Field

    Directory of Open Access Journals (Sweden)

    Saad I. Sarsam

    2016-06-01

    Full Text Available The incorporation of safety characteristics into the traditional pavement structural design or in the functional evaluation of pavement condition has not been established yet. The design has focused on the structural capacity of the roadway so that the pavement can withstand specific level of repetitive loading over the design life. On the other hand, the surface texture condition was neither included in the AASHTO design procedure nor in the present serviceability index measurements. The pavement surface course should provide adequate levels of friction and ride quality and maintain low levels of noise and roughness. Many transportation departments perform routine skid resistant testing, the type of equipment used for testing varies depending on the preference of each transportation department. It was felt that modeling of the surface texture condition using different methods of testing may assist in solving such problem. In this work, Macro texture and Micro texture of asphalt and cement concrete pavement surface have been investigated in the field using four different methods (The Sand Patch Method, Outflow Time Method, British Pendulum Tester and Photogrammetry Technique. Two different grain sizes of sand have been utilized in conducting the Sand Patch while the Micro texture was investigated using the British Pendulum tester method at wet pavement surface conditions. The test results of the four methods were correlated to the skid number. It was concluded that such modeling could provide instant data in the field for pavement condition which may help in pavement maintenance management.

  6. New findings regarding the significance of pavement skid resistance for road safety on Swiss freeways.

    Science.gov (United States)

    Lindenmann, H P

    2006-01-01

    The significance of the influence of poor pavement skid resistance values on accident frequency in wet pavement conditions has been the object of many studies over several years. The various investigations have produced very diverse findings. Only seldom, however, has detailed consideration been given to the central question of whether pavement skid resistance is a decisive parameter in the occurrence of local accident "black spots." Until now, the focus has been more on describing a relationship between pavement skid resistance and accident frequency. In the course of the network-wide survey of the states of pavements and of accident occurrence on Switzerland's freeways from 1999 to 2003, it emerged that a relationship with inadequate pavement skid resistance was provable for only a small proportion of accident black spots. These findings were used to frame a guideline for authorities and highway operators about how to treat skid resistance when assessing pavements and accident occurrence on freeways.

  7. Fusing complementary images for pavement cracking measurements

    International Nuclear Information System (INIS)

    Yao, Ming; Zhao, Zuyun; Xu, Bugao; Yao, Xun

    2015-01-01

    Cracking is a major pavement distress that jeopardizes road serviceability and traffic safety. Automated pavement distress survey (APDS) systems have been developed using digital imaging technology to replace human surveys for more timely and accurate inspections. Most APDS systems require special lighting devices to illuminate pavements and prevent shadows of roadside objects that distort cracks in the image. Most artificial lighting devices are laser based, and are either hazardous to unprotected people or require dedicated power supplies on the vehicle. This study was aimed to develop a new imaging system that can scan pavement surface at highway speed and determine the level of severity of pavement cracking without using any artificial lighting. The new system consists of dual line-scan cameras that are installed side by side to scan the same pavement area as the vehicle moves. Cameras are controlled with different exposure settings so that both sunlit and shadowed areas can be visible in two separate images. The paired images contain complementary details useful for reconstructing an image in which the shadows are eliminated. This paper intends to present (1) the design of the dual line-scan camera system, (2) a new calibration method for line-scan cameras to rectify and register paired images, (3) a customized image-fusion algorithm that merges the multi-exposure images into one shadow-free image for crack detection, and (4) the results of the field tests on a selected road over a long period. (paper)

  8. Feasibility of perpetual pavement stage construction in China: A life cycle cost analysis

    Directory of Open Access Journals (Sweden)

    Zhongyin Guo

    2016-12-01

    Full Text Available The main objective of pavement design and management is to build sustainable pavement structure with minimum costs during its whole life. There are many uncertainties in the process of pavement design pertaining many of its variables, such as future traffic estimation, long time behavior of materials, future weights and types of traveling vehicles, availability of funds etc. Therefore, it is important to apply pavement stage construction technique during the process of pavement design and management to minimize the risk associated with these uncertainties. From the beginning of 2000, the research and application of perpetual asphalt pavement (PP technology has been deployed in China. The semi rigid base for asphalt pavement has been normally considered as typical component of high class highways in the design according to the Chinese experience since 1997. The research objective is to apply pavement stage construction for the evaluation of life cycle costs of Chinese perpetual and traditional semi rigid pavements using operational pavement management system in addition to examine its suitability for design and construction of more economical and durable flexible pavements. It has been found that the stage construction of asphalt layers in PP over semi rigid pavement foundation will create more sustainable and trusted pavement structures in spite of 2–5% increase in present total cost.

  9. Competency-Based Education: A Framework for Measuring Quality Courses

    Science.gov (United States)

    Krause, Jackie; Dias, Laura Portolese; Schedler, Chris

    2015-01-01

    The growth of competency-based education in an online environment requires the development and measurement of quality competency-based courses. While quality measures for online courses have been developed and standardized, they do not directly align with emerging best practices and principles in the design of quality competency-based online…

  10. PAH concentrations in lake sediment decline following ban on coal-tar-based pavement sealants in Austin, Texas

    Science.gov (United States)

    Van Metre, Peter C.; Mahler, Barbara J.

    2013-01-01

    Recent studies have concluded that coal-tar-based pavement sealants are a major source of polycyclic aromatic hydrocarbons (PAHs) in urban settings in large parts of the United States. In 2006, Austin, TX, became the first jurisdiction in the U.S. to ban the use of coal-tar sealants. We evaluated the effect of Austin’s ban by analyzing PAHs in sediment cores and bottom-sediment samples collected in 1998, 2000, 2001, 2012, and 2014 from Lady Bird Lake, the principal receiving water body for Austin urban runoff. The sum concentration of the 16 EPA Priority Pollutant PAHs (∑PAH16) in dated core intervals and surficial bottom-sediment samples collected from sites in the lower lake declined about 44% from 1998–2005 to 2006–2014 (means of 7980 and 4500 μg kg–1, respectively), and by 2012–2014, the decline was about 58% (mean of 3320 μg kg–1). Concentrations of ∑PAH16 in bottom sediment from two of three mid-lake sites decreased by about 71 and 35% from 2001 to 2014. Concentrations at a third site increased by about 14% from 2001 to 2014. The decreases since 2006 reverse a 40-year (1959–1998) upward trend. Despite declines in PAH concentrations, PAH profiles and source-receptor modeling results indicate that coal-tar sealants remain the largest PAH source to the lake, implying that PAH concentrations likely will continue to decline as stocks of previously applied sealant gradually become depleted.

  11. A Theory Based Introductory Programming Course

    DEFF Research Database (Denmark)

    Hansen, Michael Reichhardt; Kristensen, Jens Thyge; Rischel, Hans

    1999-01-01

    This paper presents an introductory programming course designed to teach programming as an intellectual activity. The course emphasizes understandable concepts which can be useful in designing programs, while the oddities of today's technology are considered of secondary importance. An important...... goal is to fight the trial-and-error approach to programming which is a result of the students battles with horribly designed and documented systems and languages prior to their studies at university. Instead, the authors strive for giving the students a good experience of programming as a systematic......, intellectual activity where the solution of a programming problem can be described in an understandable way. The approach is illustrated by an example which is a commented solution of a problem posed to the students in the course....

  12. Laboratory Grouping Based on Previous Courses.

    Science.gov (United States)

    Doemling, Donald B.; Bowman, Douglas C.

    1981-01-01

    In a five-year study, second-year human physiology students were grouped for laboratory according to previous physiology and laboratory experience. No significant differences in course or board examination performance were found, though correlations were found between predental grade-point averages and grouping. (MSE)

  13. An Immune Agent for Web-Based AI Course

    Science.gov (United States)

    Gong, Tao; Cai, Zixing

    2006-01-01

    To overcome weakness and faults of a web-based e-learning course such as Artificial Intelligence (AI), an immune agent was proposed, simulating a natural immune mechanism against a virus. The immune agent was built on the multi-dimension education agent model and immune algorithm. The web-based AI course was comprised of many files, such as HTML…

  14. Interactive Assessment and Course Transformation Using Web-Based Tools.

    Science.gov (United States)

    Byers, Celina

    2002-01-01

    Discusses the need for course assessment that includes the instructor's perception, the student's perception, and the student's performance and describes the roles that Web-based tools can play in the active learning process and in interactive assessment based on experiences with a multimedia production course. (LRW)

  15. Improving Student Engagement Using Course-Based Social Networks

    Science.gov (United States)

    Imlawi, Jehad Mohammad

    2013-01-01

    This study proposes an engagement model that supports use of course-based online social networks for engaging student, and hence, improving their educational outcomes. This research demonstrates that instructors who create course-based online social networks to communicate with students can increase the student engagement in these online social…

  16. Work-Based Courses: Bringing College to the Production Line

    Science.gov (United States)

    Kobes, Deborah; Girardi, Amy

    2016-01-01

    Work-based courses are an innovative way to bring college to the production line by using the job as a learning lab. This toolkit provides guidance to community college administrators and faculty who are interested in bringing a work-based course model to their college. It contains video content and teaching tips that introduce the six steps of…

  17. Pervious Pavement System Evaluation

    Science.gov (United States)

    Porous pavement is a low impact development stormwater control. The Urban Watershed Management Branch is evaluating interlocking concrete pavers as a popular implementation. The pavers themselves are impermeable, but the spaces between the pavers are backfilled with washed, grade...

  18. Web-based Courses for All Disciplines: How?

    Directory of Open Access Journals (Sweden)

    Karen S. Y. Lee

    2004-06-01

    Full Text Available World Wide Web functions offer flexible and powerful tools to online course instructorsm across disciplines. WebCT being one of the leading providers of integrated elearning systems, provides features that are conducive to learning and instruction.This article will discuss how to: 1. design and conduct WebCT courses across disciplines, 2. use the constructivist pedagogy of learning and teaching in WebCT courses, and 3. enhance the problem-based and self-regulated features of Web-based learning.The focal points of this article emphasize pedagogical reengineering for designing and conducting online courses that differ in delivery, reception, and learner participation from courses being offered via traditional instructional mode. Qualitative and innovative online instruction demands more complicated work, time, and patience than traditional mode of instructional delivery. Examples from two uniquely different disciplines are elaborated. Suggestions for creating and delivering online courses are also provided.

  19. Precast concrete pavement - systems and performance review

    Science.gov (United States)

    Novak, Josef; Kohoutková, Alena; Křístek, Vladimír; Vodička, Jan

    2017-09-01

    Long-term traffic restrictions belong to the key disadvantages of conventional cast-in-plane concrete pavements which have been used for technical structures such as roads, parking place and airfield pavements. As a consequence, the pressure is put on the development of such systems which have short construction time, low production costs, long-term durability, low maintenance requirements etc.. The paper presents the first step in the development of an entirely new precast concrete pavement (PCP) system applicable to airfield and highway pavements. The main objective of the review of PCP systems is to acquire a better understanding of the current systems and design methods used for transport infrastructure. There is lack of information on using PCP systems for the construction of entirely new pavements. To most extensive experience is dated back to the 20th century when hexagonal slab panels and system PAG were used in the Soviet Union for the military airfields. Since cast-in-situ pavements became more common, the systems based on precast concrete panels have been mainly utilized for the removal of damaged sections of existing structures including roads, highways etc.. Namely, it concerns Fort Miller Super Slab system, Michigan system, Uretek Stitch system and Kwik system. The presented review indicates several issues associated with the listed PCP systems and their applications to the repair and rehabilitation of existing structures. Among others, the type of manufacturing technology, particularly the position of slots for dowel bars, affects the durability and performance of the systems. Gathered information serve for the development of a new system for airfield and highway pavement construction.

  20. Depression storage capacities of different ideal pavements as quantified by a terrestrial laser scanning-based method.

    Science.gov (United States)

    Nehls, T; Menzel, M; Wessolek, G

    2015-01-01

    Rainfall partition on paved urban surfaces is governed to a great extent by depression storage. This is especially the case for small rainfall events, which are often ignored in urban hydrology. If storage, infiltration and evaporation (important for urban heat island mitigation), rather than storm water run-off, are of interest, high-resolution simulations with exact values for depression storage capacities are required. Terrestrial laser scanners deliver fast, high-resolution surveys of pavement surface morphology. The depression storage capacity can be quantified from 3D points by generating digital elevation models and applying cut-and-fill algorithms in a geographic information system. The method was validated using a test model. It was possible to quantify depressions with a depth of at least 1.4 × 10(-3) m and a surface of at least 15 × 10(-6) m(2) with an uncertainty below 30%. Applying this method, the depression storage capacities for 11 ideal, typical pavement designs were found to vary from 0.07 to 1.4 mm. Realistic urban pavements must also be surveyed, as cracks and puddles from their use history can have a major impact on the depression storage capacities and thus on infiltration, evaporation and, finally, the annual run-off.

  1. Base Stabilization Guidance and Additive Selection for Pavement Design and Rehabilitation

    Science.gov (United States)

    2017-12-01

    Significant improvements have been made in base stabilization practice that include design specifications and methodology, experience with the selection of stabilizing additives, and equipment for distribution and uniform blending of additives. For t...

  2. Consideration of pavement roughness effects on vehicle-pavement interaction

    CSIR Research Space (South Africa)

    Steyn, WJvdM

    2001-07-01

    Full Text Available The aim of this paper is to present some of the results of the vehicle-pavement interaction project, mainly in terms of the expected effects of pavement roughness on the moving dynamic effects in pavement analysis and design. Background is provided...

  3. Introducing Process Competences in a PBL-based Engineering Course

    DEFF Research Database (Denmark)

    Soler, José; Andersson, Pernille Hammar

    2013-01-01

    The article describes an experiment in which elements related to generic professional competences, such as group work methodology, project planning, task delegation and communication, have been introduced in an existing course, tailored as a Problem Base Learning (PBL) course in Advanced Telecomm...

  4. Implementation of a Project-Based Telecommunications Engineering Design Course

    Science.gov (United States)

    Aliakbarian, Hadi; Soh, Ping Jack; Farsi, Saeed; Xu, Hantao; Van Lil, Emmanuel H. E. M. J. C.; Nauwelaers, Bart K. J. C.; Vandenbosch, Guy A. E.; Schreurs, Dominique M. M.-P.

    2014-01-01

    This paper describes and discusses the implementation of a project-based graduate design course in telecommunications engineering. This course, which requires a combination of technical and soft skills for its completion, enables guided independent learning (GIL) and application of technical knowledge acquired from classroom learning. Its main…

  5. An Honors Interdisciplinary Community-Based Research Course

    Science.gov (United States)

    Dunbar, David; Terlecki, Melissa; Watterson, Nancy; Ratmansky, Lisa

    2013-01-01

    This article describes how two faculty members at Cabrini College--one from biology and the other from psychology--incorporated interdisciplinary community-based research in an honors course on environmental watershed issues. The course, Environmental Psychology, was team-taught in partnership with a local watershed organization, the Valley Creek…

  6. Problem-Based Learning in Engineering Ethics Courses

    Science.gov (United States)

    Kirkman, Robert

    2016-01-01

    I describe the first stages of a process of design research in which I employ problem-based learning in a course in engineering ethics, which fulfills a requirement for students in engineering degree programs. The aim of the course is to foster development of particular cognitive skills contributing to moral imagination, a capacity to notice,…

  7. Influence of Hydrated Lime on the Properties and Permanent Deformation of the Asphalt Concrete Layers in Pavement

    Directory of Open Access Journals (Sweden)

    Al-Tameemi Ahmed F.

    2015-07-01

    Full Text Available Flexible or asphalt concrete pavement is the paving system most widely adopted all over the world. It has been recognized that there are many different types of the factors affecting the performance and durability of asphalt concrete pavement, including the service conditions, such as: the variation of temperature from mild to extremes and the repeated excessive axle loading as well as the inadequate quality of the raw materials. All of these when combined together are going to accelerate the occurrence of distresses in flexible pavement such as permanent deformation and fatigue cracking. As the result, there has an urgent need to enhance the ability of asphalt concrete mixture to resist distresses happened in pavement. Use of additives is one of the techniques adopted to improve pavement properties. It has been found that hydrated lime might be one of the effective additives because it is widely available and relatively cheap compared to other modifiers like polymers. This paper presents an experimental study of the hydrated-lime modified asphalt concrete mixtures. Five different percentages of the hydrated lime additive were investigated, namely (1, 1.5, 2, 2.5 and 3 percent. The hydrated lime additive was used as partial replacement of limestone filler by total weight of the aggregate. The designed Hot Mix Asphalt (HMA concretes are for the application of three pavement courses, i.e. Surface, Leveling and Base. These mixtures are designed and tested following Marshall procedure and uniaxial repeated loading to evaluate permanent deformation at different temperatures of 20°C, 40°C and 60°C. The experimental results show that the addition of hydrated lime as a partial replacement of ordinary limestone mineral filler results a significant improvement on mechanical properties and the resistant to permanent deformation of the designed asphalt concrete mixtures.

  8. Training development for pavement preservation.

    Science.gov (United States)

    2013-05-01

    This research project strives to help the Iowa Department of Transportation (DOT) fully achieve the full benefits of pavement : preservation through training on proper selection, design, and application of pavement preservation treatments. In some ca...

  9. Development of Enhanced Pavement Deterioration Curves

    OpenAIRE

    Ercisli, Safak

    2015-01-01

    Modeling pavement deterioration and predicting the pavement performance is crucial for optimum pavement network management. Currently only a few models exist that incorporate the structural capacity of the pavements into deterioration modeling. This thesis develops pavement deterioration models that take into account, along with the age of the pavement, the pavement structural condition expressed in terms of the Modified Structural Index (MSI). The research found MSI to be a significant input...

  10. Project-Based Learning Courses: The Relationship Between Faculty-Intended Course Implementation and Students' Perceptions

    Science.gov (United States)

    Simonovich, Jennifer A.; Towers, Emily; Zastavker, Yevgeniya V.

    2012-02-01

    Project-based learning (PjBL) has been shown to improve students' performance and satisfaction with their coursework, particularly in science and engineering courses. Specific aspects of PjBL that contribute to this improvement are student autonomy, course scaffolding, and instructor support. This study investigates two PjBL courses required for engineering majors at a small technical school, Introductory Mechanics Laboratory and Introductory Engineering Design. The three data sources used in this work are classroom observations (one laboratory and four design sessions) and semi-structured in-depth interviews with twelve students and six faculty. Grounded theory approach is used in a two-step fashion by (1) analyzing each data set individually and (2) performing full triangulation of all three data sets. In this talk, we demonstrate the relationship between faculty intentions and student perceptions regarding the three PjBL aspects -- student autonomy, course scaffolding, and instructor support -- within the context of these two courses. We further discuss implications for the course design and professional development of faculty.

  11. Evaluation of the base/subgrade soil under repeated loading : phase I--laboratory testing and numerical modeling of geogrid reinforced bases in flexible pavement.

    Science.gov (United States)

    2009-10-01

    This report documents the results of a study that was conducted to characterize the behavior of geogrid reinforced base : course materials. The research was conducted through an experimental testing and numerical modeling programs. The : experimental...

  12. Deterioration modeling for condition assessment of flexible pavements considering extreme weather events

    Science.gov (United States)

    Hashemi Tari, Yasamin; Shahini Shamsabadi, Salar; Birken, Ralf; Wang, Ming

    2015-04-01

    Accurate pavement management systems are essential for states' Department Of Transportation and roadway agencies to plan for cost-effective maintenance and repair (M and R) strategies. Pavement deterioration model is an imperative component of any pavement management system since the future budget and M and R plans would be developed based on the predicted pavement performance measures. It is crucial for the pavement deterioration models to consider the factors that significantly aggravate the pavement condition. While many studies have highlighted the impact of different environmental, load, and pavement's structure on the life cycle of the pavement, effect of extreme weather events such as Floods and Snow Storms have often been overlooked. In this study, a pavement deterioration model is proposed which would consider the effect of traffic loads, climate conditions, and extreme weather events. Climate, load and performance data has been compiled for over twenty years and for eight states using the Long Term Pavement Performance (LTPP) and National Oceanic and Atmospheric Administration (NOAA) databases. A stepwise regression approach is undertaken to quantify the effect of the extreme weather events, along with other influential factors on pavement performance in terms of International Roughness Index (IRI). Final results rendered more than 90% correlation with the quantified impact values of extreme weather events.

  13. An interactive Web-based radiation protection course in fluoroscopy

    International Nuclear Information System (INIS)

    Aldrich, J.

    2001-01-01

    The teaching of radiation protection to a large group of physicians, who are separated geographically and have complicated schedules, is a formidable problem. Therefore a Web-based solution is attractive, allowing access to the material at any time and place. In this implementation the didactic material is presented in a Web-based format. Subsequently, students attend a practical demonstration in one of the departments' fluoroscopy rooms. Because of local experience with distance education, WebCT was chosen to present the material. WebCT (Web Course Tools) was developed by the University of British Columbia (UBC) to allow educators, with or without technical expertise, to create a sophisticated Web-base. Authors use a standard Web browser to create courses, and students use their browsers to access course material. WebCT provides a wide variety of tools and features that can be added to a course. Among the most useful tools used in this fluoroscopy course are the glossary, multiple-choice questions for each section, and a final test which is scored by the computer. As with all Web-based material the courses can be viewed in the traditional linear fashion or in any random way through the use of linkages. (author)

  14. Incorporating Code-Based Software in an Introductory Statistics Course

    Science.gov (United States)

    Doehler, Kirsten; Taylor, Laura

    2015-01-01

    This article is based on the experiences of two statistics professors who have taught students to write and effectively utilize code-based software in a college-level introductory statistics course. Advantages of using software and code-based software in this context are discussed. Suggestions are made on how to ease students into using code with…

  15. A Comparative Study of Competency-Based Courses Demonstrating a Potential Measure of Course Quality and Student Success

    Science.gov (United States)

    Krause, Jackie; Dias, Laura Portolese; Schedler, Chris

    2015-01-01

    While competency-based education is growing, standardized tools for evaluating the unique characteristics of course design in this domain are still under development. This preliminary research study evaluated the effectiveness of a rubric developed for assessing course design of competency-based courses in an undergraduate Information Technology…

  16. Reflective Pedagogy: Making Meaning in Experiential Based Online Courses

    Directory of Open Access Journals (Sweden)

    Kathy L. Guthrie

    2010-07-01

    Full Text Available The use of reflective pedagogies has long been considered critical to facilitating meaningful learning through experientially based curricula; however, the use of such methods has not been extensively explored as implemented in virtual environments. The study reviewed utilizes a combination of survey research and individual interviews to examine student perceptions of the meaningful learning which occurred as a result of their participation in two Web-based courses that utilized reflective pedagogies. One course focuses on topics related to service-learning and the second on placement-based internships. Both were instructed using online coursework based in reflective pedagogies to compliment on-site placements within local communities.

  17. Lessons learned : pavement marking warranty contract.

    Science.gov (United States)

    2013-12-01

    In 2012, UDOT implemented a performance-based warranty on a portion of an I-15 pavement marking : project. The awarded contract requested a contractor warranty on the implemented markings for a total : duration of six years. This is the first time th...

  18. Mobile geographic information system (GIS) solution for pavement condition surveys.

    Science.gov (United States)

    2012-06-28

    This report discusses the design and implementation of a software-based solution that will improve the data collection processes during the Pavement Condition Surveys (PCS) conducted by the State Materials Office (SMO) of the Florida Department of Tr...

  19. Iowa pavement asset management decision-making framework.

    Science.gov (United States)

    2015-10-01

    Most local agencies in Iowa currently make their pavement treatment decisions based on their limited experience due primarily to : lack of a systematic decision-making framework and a decision-aid tool. The lack of objective condition assessment data...

  20. Airport Pavement Design For The Boeing 777 Airplane

    Science.gov (United States)

    1995-10-22

    The purpose of this advisory circular is to provide thickness design standards : for pavements intended to serve the Boeing 777 airplane. A new method of design : based on layered elastic analysis has been developed to calculate design : thickness fo...

  1. Field and lab evaluation of the use of lime fly ash to replace soil cement as a base course : final report.

    Science.gov (United States)

    1997-09-01

    This study evaluates the performance of lime/fly ash stabilized base as an alternative to soil cement stabilized base for flexible pavement systems on reconstructed highways in Louisiana. Louisiana has historically used soil cement for most flexible ...

  2. Development of Improved Mechanistic Deterioration Models for Flexible Pavements

    DEFF Research Database (Denmark)

    Ullidtz, Per; Ertman, Hans Larsen

    1998-01-01

    The paper describes a pilot study in Denmark with the main objective of developing improved mechanistic deterioration models for flexible pavements based on an accelerated full scale test on an instrumented pavement in the Danish Road Tessting Machine. The study was the first in "International...... Pavement Subgrade Performance Study" sponsored by the Federal Highway Administration (FHWA), USA. The paper describes in detail the data analysis and the resulting models for rutting, roughness, and a model for the plastic strain in the subgrade.The reader will get an understanding of the work needed...

  3. Optimization and standardization of pavement management processes.

    Science.gov (United States)

    2004-08-01

    This report addresses issues related to optimization and standardization of current pavement management processes in Kentucky. Historical pavement management records were analyzed, which indicates that standardization is necessary in future pavement ...

  4. Permeable Pavements at Purdue

    OpenAIRE

    Knapp, Jim

    2013-01-01

    Two case studies will be presented describing sustainable drainage alternatives. The processes used for the 2nd Street project in Seymour will provide a comparison of the design processes for conventional and green infrastructure solutions. Purdue University will discuss a number of permeable pavement installations on campus and provide a map for viewing. Asphalt, concrete, and permeable paver options will be discussed.

  5. Problem-based learning in a health sciences librarianship course.

    Science.gov (United States)

    Dimitroff, A; Ancona, A M; Beman, S B; Dodge, A M; Hutchinson, K L; LaBonte, M J; Mays, T L; Simon, D T

    1998-01-01

    Problem-based learning (PBL) has been adopted by many medical schools in North America. Because problem solving, information seeking, and lifelong learning skills are central to the PBL curriculum, health sciences librarians have been actively involved in the PBL process at these medical schools. The introduction of PBL in a library and information science curriculum may be appropriate to consider at this time. PBL techniques have been incorporated into a health sciences librarianship course at the School of Library and Information Science (LIS) at the University of Wisconsin-Milwaukee to explore the use of this method in an advanced Library and Information Science course. After completion of the course, the use of PBL has been evaluated by the students and the instructor. The modified PBL course design is presented and the perceptions of the students and the instructor are discussed. PMID:9681169

  6. Introducing Risk Management Techniques Within Project Based Software Engineering Courses

    Science.gov (United States)

    Port, Daniel; Boehm, Barry

    2002-03-01

    In 1996, USC switched its core two-semester software engineering course from a hypothetical-project, homework-and-exam course based on the Bloom taxonomy of educational objectives (knowledge, comprehension, application, analysis, synthesis, and evaluation). The revised course is a real-client team-project course based on the CRESST model of learning objectives (content understanding, problem solving, collaboration, communication, and self-regulation). We used the CRESST cognitive demands analysis to determine the necessary student skills required for software risk management and the other major project activities, and have been refining the approach over the last 5 years of experience, including revised versions for one-semester undergraduate and graduate project course at Columbia. This paper summarizes our experiences in evolving the risk management aspects of the project course. These have helped us mature more general techniques such as risk-driven specifications, domain-specific simplifier and complicator lists, and the schedule as an independent variable (SAIV) process model. The largely positive results in terms of review of pass / fail rates, client evaluations, product adoption rates, and hiring manager feedback are summarized as well.

  7. Integration of Task-Based Approaches in a TESOL Course

    Science.gov (United States)

    Chien, Chin-Wen

    2014-01-01

    Under task-based language teaching (TBLT), language learners engage in purposeful, problem-oriented, and outcome-driven tasks that are comparable to real-world activities. This qualitative case study discusses the integration of a task-based approach into a TESOL course in a language teacher education program in Taiwan with regard to 39…

  8. Inferring pavement layer properties from a moving measurement platform

    DEFF Research Database (Denmark)

    Andersen, Sebastian; Levenberg, Eyal; Andersen, M.B.

    2017-01-01

    This work offered a new method for accessing the mechanical properties of pavement layers based on data obtained by a moving measurement platform. The method has the following features: (i) calculations are based on tracking distances to a point on the pavement surface, (ii) measurements...... are not required outside the zone of load influence, and (iii) possibility to access absolute pavement deflections. First, the envisioned platform-design and required readings were presented; next, the interpretation method was outlined and then applied to synthetic (computer-generated) data. Perfect convergence...... was achieved when the correct pavement model and accurate input data were employed. Also, when artificial errors were introduced for assessing sensitivities, only small deviations were generated. Based on these promising outcomes the method will be further studied and developed to support the construction...

  9. Best practices for team-based assistive technology design courses.

    Science.gov (United States)

    Goldberg, Mary R; Pearlman, Jonathan L

    2013-09-01

    Team-based design courses focused on products for people with disabilities have become relatively common, in part because of training grants such as the NSF Research to Aid Persons with Disabilities course grants. An output from these courses is an annual description of courses and projects but has yet to be complied into a "best practices guide," though it could be helpful for instructors. To meet this need, we conducted a study to generate best practices for assistive technology product development courses and how to use these courses to teach students the fundamentals of innovation. A full list of recommendations is comprised in the manuscript and include identifying a client through a reliable clinical partner; allowing for transparency between the instructors, the client, and the team(s); establishing multi-disciplinary teams; using a process-oriented vs. solution-oriented product development model; using a project management software to facilitate and archive communication and outputs; facilitating client interaction through frequent communication; seeking to develop professional role confidence to inspire students' commitment to engineering and (where applicable) rehabilitation field; publishing student designs on repositories; incorporating both formal and informal education opportunities related to design; and encouraging students to submit their designs to local or national entrepreneurship competitions.

  10. Depletion of E. coli in permeable pavement mineral aggregate storage and reuse systems.

    Science.gov (United States)

    Myers, B R; Beecham, S; van Leeuwen, J A; Keegan, A

    2009-01-01

    Permeable pavement reservoirs provide an important opportunity for the harvesting and storage of stormwater for reuse. This research aims to determine whether storage in dolomite, calcite and quartzite mineral aggregates in the base course of a permeable pavement impacts on the survival of the pathogen indicator organism Escherichia coli (E. coli) in storage. The reasons for depletion were also investigated. Twelve model permeable pavement storage reservoirs were filled, in triplicate, with dolomite, calcite and quartzite. Three reservoirs contained no aggregate. After filling with pathogen spiked rainwater, the concentration of E. coli was examined for 22 days in the reservoirs. The reservoirs were then agitated to determine if there was E. coli present which was not in aqueous suspension. The results of the experiments show that there is no significant difference in the depletion of E. coli found in reservoirs without aggregate, and those filled with dolomite or calcite. The rate of depletion was found to be significantly lower in the quartzite filled reservoirs. Agitation of the reservoirs yielded increases in the aqueous concentration of E. coli in all reservoir types, suggesting that the bacteria are adhering to the surface of the mineral aggregate and to the reservoir walls.

  11. Field evaluation of in-situ test technology for Q(C)/Q(A) during construction of pavement layers and embankments

    Science.gov (United States)

    Nazzal, Munir Darwish

    2007-12-01

    This dissertation documents the results of an extensive research study that was conducted to characterize the behavior of geogrid reinforced base course materials. The research was conducted through an experimental testing and numerical modeling programs. The experimental testing program included performing different laboratory tests to evaluate the effect of various factors on the performance geogrid reinforced base course materials. Finite element models were also developed to investigate the benefits of placing geogrids within the base course layer in a flexible pavement structure. The results of the experimental testing demonstrated that the inclusion of the geogrid reinforcement layer(s) improved the compressive strength and stiffness of base course materials under static loading. This improvement was more pronounced at higher strain levels. Furthermore, the results showed that the geogrid significantly reduced the base course material permanent deformation under cyclic loading, but it did not show appreciable effect on their resilient deformation. The results also showed that for stress levels less than the plastic shakedown stress limit, the geogrid had a minimum contribution to the permanent deformation resistance during primary post-compaction stage; however, it significantly increased this resistance during the secondary stage. The results also showed that the change in the moisture content of the base material altered its state of stress; this significantly affected the geogrid improvement. The finite modeling program showed that the geogrid reinforcement reduced the lateral, vertical, and shear strains within the base course and subgrade layers. Furthermore, the geogrid had appreciable reduction in permanent deformation for pavement sections built on top of weak subgrade soils with medium to thin base layer thickness; with the thin base layer thickness showing greater values of improvement. However, negligible to modest reinforcement effect on permanent

  12. A Methods-Based Biotechnology Course for Undergraduates

    Science.gov (United States)

    Chakrabarti, Debopam

    2009-01-01

    This new course in biotechnology for upper division undergraduates provides a comprehensive overview of the process of drug discovery that is relevant to biopharmaceutical industry. The laboratory exercises train students in both cell-free and cell-based assays. Oral presentations by the students delve into recent progress in drug discovery.…

  13. Web-Based Course Management and Web Services

    Science.gov (United States)

    Mandal, Chittaranjan; Sinha, Vijay Luxmi; Reade, Christopher M. P.

    2004-01-01

    The architecture of a web-based course management tool that has been developed at IIT [Indian Institute of Technology], Kharagpur and which manages the submission of assignments is discussed. Both the distributed architecture used for data storage and the client-server architecture supporting the web interface are described. Further developments…

  14. A Research-Based Development Economics Course for Undergraduates

    Science.gov (United States)

    Singh, Prakarsh; Guo, Hongye; Morales, Alvaro

    2015-01-01

    The authors present details of a research-based course in development economics taught at a private liberal arts college. There were three key elements in this class: teaching of applied econometrics, group presentations reviewing published and working papers in development economics, and using concepts taught in class to write an original…

  15. Problem-Based Learning in a General Psychology Course.

    Science.gov (United States)

    Willis, Sandra A.

    2002-01-01

    Describes the adoption of problem-based learning (PBL) techniques in a general psychology course. States that the instructor used a combination of techniques, including think-pair-share, lecture/discussion, and PBL. Notes means and standard deviations for graded components of PBL format versus lecture/discussion format. (Contains 18 references.)…

  16. stabilization of cinder gravel with cment for base course

    African Journals Online (AJOL)

    Girma Berhanu

    design standards for heavily trafficked base course without adding fine soils is found to be 7 % cement. However, this high cement requirement was reduced to 5% cement which is a practical value by mechanically stabilizing cinder gravel with 12 % of fine soils before cement stabilization. Nevertheless, the performance of ...

  17. Formative Evaluation of a Web-Based Course in Meteorology.

    Science.gov (United States)

    Phelps, Julia; Reynolds, Ross

    1999-01-01

    Describes the formative-evaluation process for the EuroMET (European Meteorological Education and Training) project, Web-Based university courses in meteorology that were created to address the education and training needs of professional meteorologists and students throughout Europe. Usability and interactive and multimedia elements are…

  18. Effects of the Asynchronous Web-Based Course: Preservice Teachers' Achievement, Metacognition, and Attitudes towards the Course

    Science.gov (United States)

    Topcu, Abdullah; Ubuz, Behiye

    2008-01-01

    This present study aimed to investigate the effects of the asynchronous web-based "General Teaching Methods" course conducted based on direct or indirect instructional methods on pre-service teachers' achievement, metacognition, and attitudes towards web-based course. Two groups, a total of 63 third grade elementary science and mathematics…

  19. Genre-based Course Book for Hospitality Departmentn in Surakarta

    OpenAIRE

    Suprihatin, Yeni

    2016-01-01

    This research is aimed at designing ESP Course book at SMK Sahid Surakarta that mainly focus: To investigate the quality of existing learning book used in English teaching and learning at SMK especially in hospitality department and to describe the design of Genre-based ESP course book for hospitality department of SMK.This research and development was carried out in SMK Sahid Surakarta in the academic year of 2015/2016. The number of population was three classes (that consisted of the eighth...

  20. An overview of curriculum-based course timetabling

    DEFF Research Database (Denmark)

    Bettinelli, Andrea; Cacchiani, Valentina; Roberti, Roberto

    2015-01-01

    In 2007, the Second International Timetabling Competition (ITC-2007) has been organized and a formal definition of the Curriculum-Based Course Timetabling (CB-CTT) problem has been given, by taking into account several real-world constraints and objectives while keeping the problem general. CB......-CTT consists of finding the best weekly assignment of university course lectures to rooms and time periods. A feasible schedule must satisfy a set of hard constraints and must also take into account a set of soft constraints, whose violation produces penalty terms to be minimized in the objective function...

  1. Rutgers/NJDOT Pavement Resource Program (NJDOT Statewide GPR Project Network GPR Data Collection and Analysis Update of HPMA GPR Database)

    Science.gov (United States)

    2008-05-01

    Center for Advanced Transportation Infrastructure (CAIT) of Rutgers University is mandated to conduct Ground Penetrating Radar (GPR) surveys to update the NJDOT's pavement management system with GPR measured pavement layer thicknesses. Based on the r...

  2. High-performance concrete carpet : A new concept of concrete pavement

    OpenAIRE

    DE LARRARD, François

    2005-01-01

    LCPC (Central Laboratory for Roads and Bridges, a French public research laboratory) has developed for four years a new concept of concrete pavement. It is based upon the following ideas : - High-Performance Concrete shows unique qualities with regard to pavement application, like high tensile strengh, durability, freeze-thaw resistance, abrasion resistance and prevention of steel corrosion ; - but economy does note promote the use of HPC in conventional pavement, since the gain in flexural s...

  3. ANALYSIS OF GROUP MAINTENANCE STRATEGY -ROAD PAVEMENT AND SEWERAGE PIPES-

    Science.gov (United States)

    Tanimoto, Keishi; Sugimoto, Yasuaki; Miyamoto, Shinya; Nada, Hideki; Hosoi, Yoshihiko

    Recently, it is critical to manage deteriorating sewerage and road facilities efficiently and strategically. Since the sewerage pipes are mostly installed under road pavement, the works for the replacement of the sewerage pipes are partially common to the works for the road. This means that the replacement cost can be saved by coordinating the timing of the replacements by sewerage pipe and road pavement. The purpose of the study is to develop the model based on Markov decision process to derive the optimal group maintenance policy so as to minimize lifecycle cost. Then the model is applied to case study area and demonstrated to estimate the lifecycle cost using statistical data such as pipe replacement cost, road pavement rehabilitation cost, and state of deterioration of pipes and road pavement.

  4. Prediction of average annual surface temperature for both flexible and rigid pavements

    Directory of Open Access Journals (Sweden)

    Karthikeyan LOGANATHAN

    2017-12-01

    Full Text Available The surface temperature of pavements is a critical attribute during pavement design. Surface temperature must be measured at locations of interest based on time-consuming field tests. The key idea of this study is to develop a temperature profile model to predict the surface temperature of flexible and rigid pavements based on weather parameters. Determination of surface temperature with traditional techniques and sensors are replaced by a newly developed method. The method includes the development of a regression model to predict the average annual surface temperature based on weather parameters such as ambient air temperature, relative humidity, wind speed, and precipitation. Detailed information about temperature and other parameters are extracted from the Federal Highway Administration's (FHWA Long Term Pavement Performance (LTPP online database. The study was conducted on 61 pavement sections in the state of Alabama for a 10-year period. The developed model would predict the average annual surface temperature based on the known weather parameters. The predicted surface temperature model for asphalt pavements was very reliable and can be utilized while designing a pavement. The study was also conducted on seven rigid pavement sections in Alabama to predict their surface temperature, in which a successful model was developed. The outcome of this study would help the transportation agencies by saving time and effort invested in expensive field tests to measure the surface temperature of pavements.

  5. Research on English course based on career planning

    Directory of Open Access Journals (Sweden)

    Ying Shi

    2017-02-01

    Full Text Available For the current higher vocational English education way, this paper researches English course on the basis of the need of English competence in career planning, and determines four main objectives to be accomplished in English teaching through the research of the need of English in career planning, and establishes the principle of course design. This paper proposes four kinds of teaching mode according to the career development and career demands, and establishes the hierarchical analysis structure on the basis of the teaching objectives as criteria, analyzes the weight of four objectives, and gives out the quantifiable results for matching with the teaching programs. The results show that, the way of theory and practice education is the most effective, and the academic language competence in career planning is the most important demand. The optimization ratio of English course teaching way based on career planning is 0.26: 0.29: 0.22: 0.23.

  6. Evidence-based reflective teaching practice: a preceptorship course example.

    Science.gov (United States)

    Josephsen, Jayne M

    2013-01-01

    This preceptorship course case study employed an evidence-based reflective teaching practice perspective based on a nursing process framework to develop, implement, and evaluate assignment efficacy directly related to course objectives. Journaling and article analysis had been used to assess development of role socialization, critical thinking, and self-reflective practice. These activities were found to be ineffective; new assignments were needed to address essential issues and allow for evaluation of assignment efficacy. Based upon contextual constructivism, four assignments were developed focused on learning goals, nursing skills, assumptions/biases, and role socialization.Assignment efficacy was evaluated via anonymous exploratory surveys. Student reports identified that assignments met learning outcomes. Methods for improvement in instructional practice were identified and revisions made. Participation in evidence-based reflective teaching practice can enhance reflective practice in students through appropriate assignment development, advancing the discipline of nursing education.

  7. Problem-based learning on quantitative analytical chemistry course

    Science.gov (United States)

    Fitri, Noor

    2017-12-01

    This research applies problem-based learning method on chemical quantitative analytical chemistry, so called as "Analytical Chemistry II" course, especially related to essential oil analysis. The learning outcomes of this course include aspects of understanding of lectures, the skills of applying course materials, and the ability to identify, formulate and solve chemical analysis problems. The role of study groups is quite important in improving students' learning ability and in completing independent tasks and group tasks. Thus, students are not only aware of the basic concepts of Analytical Chemistry II, but also able to understand and apply analytical concepts that have been studied to solve given analytical chemistry problems, and have the attitude and ability to work together to solve the problems. Based on the learning outcome, it can be concluded that the problem-based learning method in Analytical Chemistry II course has been proven to improve students' knowledge, skill, ability and attitude. Students are not only skilled at solving problems in analytical chemistry especially in essential oil analysis in accordance with local genius of Chemistry Department, Universitas Islam Indonesia, but also have skilled work with computer program and able to understand material and problem in English.

  8. Stormwater quality of spring-summer-fall effluent from three partial-infiltration permeable pavement systems and conventional asphalt pavement.

    Science.gov (United States)

    Drake, Jennifer; Bradford, Andrea; Van Seters, Tim

    2014-06-15

    This study examined the spring, summer and fall water quality performance of three partial-infiltration permeable pavement (PP) systems and a conventional asphalt pavement in Ontario. The study, conducted between 2010 and 2012, compared the water quality of effluent from two Interlocking Permeable Concrete Pavements (AquaPave(®) and Eco-Optiloc(®)) and a Hydromedia(®) Pervious Concrete pavement with runoff from an Asphalt control pavement. The usage of permeable pavements can mitigate the impact of urbanization on receiving surface water systems through quantity control and stormwater treatment. The PP systems provided excellent stormwater treatment for petroleum hydrocarbons, total suspended solids, metals (copper, iron, manganese and zinc) and nutrients (total-nitrogen and total-phosphorus) by reducing event mean concentrations (EMC) as well as total pollutant loadings. The PPs significantly reduced the concentration and loading of ammonia (NH4(+)+NH3), nitrite (NO2(-)) and organic-nitrogen (Org-N) but increased the concentration and loading of nitrate (NO3(-)). The PP systems had mixed performances for the treatment of phosphate (PO4(3-)). The PP systems increased the concentration of sodium (Na) and chloride (Cl) but EMCs remained well below recommended levels for drinking water quality. Relative to the observed runoff, winter road salt was released more slowly from the PP systems resulting in elevated spring and early-summer Cl and Na concentrations in effluent. PP materials were found to introduce dissolved solids into the infiltrating stormwater. The release of these pollutants was verified by additional laboratory scale testing of the individual pavement and aggregate materials at the University of Guelph. Pollutant concentrations were greatest during the first few months after construction and declined rapidly over the course of the study. Copyright © 2014 Elsevier Ltd. All rights reserved.

  9. Problems and Projects Based Approach For Analog Electronic Circuits' Course

    Directory of Open Access Journals (Sweden)

    Mustapha Rafaf

    2009-04-01

    Full Text Available New educational methods and approaches are recently introduced and implemented at several North American and European universities using Problems and Projects Based Approach (PPBA. The PPBA employs a teaching technique based mostly on competences/skills rather than only on knowledge. This method has been implemented and proven by several pedagogical instructors and authors at several educational institutions. This approach is used at different disciplines such as medicine, biology, engineering and many others. It has the advantage to improve the student's skills and the knowledge retention rate, and reflects the 21st century industrial/company needs and demands. Before implementing this approach to a course, a good resources preparation and planning is needed upfront by the responsible or instructor of the course to achieve the course and students related objectives. This paper presents the preparation, the generated documentation and the implementation of a pilot project utilizing PPBA education for a second year undergraduate electronic course over a complete semester, and for two different class groups (morning and evening groups. The outcome of this project (achieved goals, observed difficulties and lessons learned is presented based on different tools such as students 'in class' communication and feedback, different course evaluation forms and the professor/instructor feedback. Resources, challenges, difficulties and recommendations are also assessed and presented. The impact, the effect and the results (during and at the end of the academic fall session of the PPBA on students and instructor are discussed, validated, managed and communicated to help other instructor in taking appropriate approach decisions with respect to this new educational approach compared to the classical one.

  10. The Road Pavement Condition Index (PCI Evaluation and Maintenance: A Case Study of Yemen

    Directory of Open Access Journals (Sweden)

    Karim Fareed M. A.

    2016-12-01

    Full Text Available The pavement condition index (PCI is a simple, convenient and inexpensive way to monitor the condition of the surface of roads, identify maintenance and rehabilitation (M-and-R needs as well as ensure that road maintenance budgets are spent wisely. In this research, the pavement condition was evaluated in terms of the surface distresses existing at the time of the field evaluation. The PCI procedure was used in this research because it deals with the subject of pavement distress identification most comprehensively and is based on a sound statistical technique of pavement sampling.

  11. Mechanical performance of porous concrete pavement containing nano black rice husk ash

    Science.gov (United States)

    Ibrahim, M. Y. Mohd; Ramadhansyah, P. J.; Rosli, H. Mohd; Ibrahim, M. H. Wan

    2018-01-01

    This paper presents an experimental research on the performance of nano black rice husk ash on the porous concrete pavement properties. The performance of the porous concrete pavement mixtures was investigated based on their compressive strength, flexural strength, and splitting tensile strength. The results indicated that using nano material from black rice husk ash improved the mechanical properties of porous concrete pavement. In addition, the result of compressive, flexural, and splitting tensile strength was increased with increasing in curing age. Finally, porous concrete pavement with 10% replacement levels exhibited an excellent performance with good strength compared to others.

  12. Problem-based, interdisciplinary field-based courses

    DEFF Research Database (Denmark)

    Hill, Trevor; Birch-Thomsen, Torben; Traynor, Catherine

    2008-01-01

    of responsibility, staff and student development and the benefits to rural host communities. The courses are very intense experiences and Students encounter difficulties working across traditional academic disciplines and in cross-cultural groups. Through critical thinking and self-reflection students understand...... the context of their learning better and have a greater appreciation of their own personal development. The process calls for long-term commitment to the communities with whom one works closely, the recognition of sometimes having to 'think on one's feet', being prepared to make mistakes and use frustration...

  13. Evaluation of pavement skid resistance using high speed texture measurement

    Directory of Open Access Journals (Sweden)

    Jay N. Meegoda

    2015-12-01

    Full Text Available Skid resistance is an important parameter for highway designs, construction, management, maintenance and safety. The purpose of this manuscript is to propose the correlation between skid resistance, which is measured as skid resistance trailer, and mean profile depth (MPD or the macro surface texture, which is measured by vehicle mounted laser, so that highway agencies can predict the skid resistance of pavement without the use of expensive and time consuming skid resistance trailer, which also causes disruption of traffic in use. In this research skid numbers and MPD from 5 new asphalt pavements and 4 old asphalt pavements were collected using a locked wheel skid trailer and a vehicle mounted laser. Using the data collected, a correlation between the skid number (SN40R collected by locked wheel skid tester and the texture data or MPD collected by a vehicle mounted laser operating at highway speeds was developed. The proposed correlation for new pavements was positive for MPD values less than 0.75 mm to reach a peak SN40R value, then there was a negative correlation as the MPD increases until the MPD value was equal to 1.1 mm and beyond the MPD value of 1.1 mm to the maximum value of 1.4 mm, SN40R value remained almost constant. There were significant data scatter for the MPD value of 0.8 mm. To explain these results, water film thickness during the friction test was calculated and the critical MPD was defined. The effect of sealed water pool on the SN40R was discussed. The test result showed a similar trend for older asphalt pavements, but with lower SN40R values due to the polishing of pavement micro-texture by traffic. Hence, a reduction factor was proposed for older pavements based on cumulative traffic volume for the above correlation to predict the skid resistance of older pavements.

  14. Noise emission of concrete pavement surfaces produced by diamond grinding

    Directory of Open Access Journals (Sweden)

    Jens Skarabis

    2015-04-01

    Full Text Available In Germany, diamond grinding is frequently used to improve the evenness and skid resistance of concrete pavement surfaces. Since diamond grinding has been observed to affect tyre/pavement noise emission favourably, the relationship among surface texture, concrete composition and noise emission of concrete pavement surfaces has been systematically investigated. The simulation program SPERoN was used in a parameter study to investigate the main factors which affect noise emission. Based on the results of the simulations, textured concrete surfaces were produced by using a laboratory grinding machine. As well as the composition of the concrete, the thickness and spacing of the diamond blades were varied. The ability of the textured surfaces to reduce noise emission was assessed from the texture characteristics and air flow resistance of textured surfaces measured in the laboratory. It was found that concrete composition and, in particular, the spacing of the blades affected the reduction in noise emission considerably. The noise emission behaviour of numerous road sections was also considered in field investigations. The pavement surfaces had been textured by diamond grinding during the last years or decades. The results show that diamond grinding is able to provide good, durable noise-reducing properties. Several new pavement sections were investigated using thicknesses and spacings of the blades similar to those used in the laboratory to optimize noise emission reduction. It is concluded that diamond grinding is a good alternative to exposed aggregate concrete for the production of low-noise pavement surfaces.

  15. Development and Construction of the Multimedia Web-Based Courses Based on ASP

    Science.gov (United States)

    Wang, Yu; Liu, Jianbo

    2011-01-01

    With the quick development of internet and computer technology, more and more information acquirers begin to more depend on the network, and for the transmission route of knowledge, the advantageous state of web-based courses becomes more and more obvious. The support of modern education technology for the web-based courses would gradually replace…

  16. Students' perceptions and satisfaction with a web-based human nutrition course.

    Science.gov (United States)

    Rochester, Charmaine D; Pradel, Francoise

    2008-08-15

    To assess the perceptions and satisfaction of third-year pharmacy students with a Web-based, distance-learning course, Principles of Human Nutrition, and describe the challenges faculty members encountered while implementing the course. The human nutrition course was redesigned from a traditional classroom-based format to a Web-based format. Precourse and postcourse surveys were administered to 2 consecutive classes of 120 students. Students gave positive feedback regarding the Web-based format and especially appreciated the flexibility the course offered. Students recommended that a hybrid Web-based/classroom-based course be developed instead of a Web-based only course. A Web-based format was used to effectively deliver a course in human nutrition to third-year pharmacy students; however, implementation of the course revealed several challenges that will need to be addressed before additional Web-based courses can be added.

  17. Facilitating problem based learning in an online biology laboratory course

    Science.gov (United States)

    Wesolowski, Meredith C.

    Online instruction offers many benefits to underserved populations in higher education, particularly increased access. However, incorporation of preferred pedagogical methods, particularly those involving student collaboration, can be more difficult to facilitate in online courses due to geographic separation. In the area of laboratory science education, there is a strong argument for use of constructivist, collaborative pedagogy to promote many facets of student learning. This EPP describes the process used to develop two problem based learning (PBL) laboratory activities based on recommendations found in the literature, their incorporation into an online biology laboratory science course (BIO101) and their impact on student achievement and critical thinking skills. Data analysis revealed a high level of achievement within the study semester. In addition, use of synchronous group discussions as part of the PBL framework resulted in a broad range of discussions reflective of successful problem solving interactions described in the literature. Together, these suggest a observed benefit from incorporation of PBL in this online course. In addition, specific areas for modification were identified as potential future improvements.

  18. Use of a Course Management System Based on Claroline to Support a Social Constructivist Inspired Course: A Greek Case Study

    Science.gov (United States)

    Papastergiou, Marina

    2007-01-01

    This study aimed to use a course management system (CMS) based on the open source software Claroline within a blended mode course, incorporating social constructivist approaches to learning, and to investigate its strengths and the challenges faced by the students and the instructor. Participants were 72 students and their instructor. Research…

  19. Benders’ Decomposition for Curriculum-Based Course Timetabling

    DEFF Research Database (Denmark)

    Bagger, Niels-Christian F.; Sørensen, Matias; Stidsen, Thomas R.

    2018-01-01

    In this paper we applied Benders’ decomposition to the Curriculum-Based Course Timetabling (CBCT) problem. The objective of the CBCT problem is to assign a set of lectures to time slots and rooms. Our approach was based on segmenting the problem into time scheduling and room allocation problems....... The Benders’ algorithm was then employed to generate cuts that connected the time schedule and room allocation. We generated only feasibility cuts, meaning that most of the solutions we obtained from a mixed integer programming solver were infeasible, therefore, we also provided a heuristic in order to regain...

  20. Weak interlayers in flexible and semi-flexible road pavements: Part 1

    CSIR Research Space (South Africa)

    Netterberg, F

    2012-04-01

    Full Text Available flexible or semi-flexible pavement is far more deleterious thanis commonly appreciated. In Part 2 the effects of these weak layers are further modelled and discussed using various examples based an HVS testing and mechanistic pavement analyses...

  1. Web-Based Questionnaires for Type Theory Course

    Directory of Open Access Journals (Sweden)

    Daniel MIHÁLYI

    2017-12-01

    Full Text Available This paper describes our effort on the usage of modern information and communication technologies as well as innovation process in the field of teaching. % Our goal is to design and develop a web-based system to support management and analysis of course questionnaires for students. The proposed system is broadly divided into two parts. First, we describe the system architecture followed by a preparation of a suitable network environment and a design of a database model used for storage of data about the questionnaires. Second, we present a design of the proposed website, its structure, and finally a proper layout of the questionnaires. An important functionality of our system is also to provide various statistical information obtained from the responses. This enables teachers to exercise introspection and self-reflection in order to improve quality of their teaching of the course. The main goal of our long-term effort is a deployment of the system into use within the course on Type theory, which allows students to grow their knowledge in the principles of type systems and languages of functional programming paradigm.

  2. Peer Instruction in an Algebra-Based General Physics Course

    Science.gov (United States)

    Listerman, Thomas W.

    1999-10-01

    We have restructured our algebra-based general physics course to increase peer instruction. For the last three years each lecture has been followed by a recitation class. In recitation class students break up into small groups to work on "study guides" concerning the previous lecture. The recitation instructor is available to answer questions and to provide encouragement. The study guides ask qualitative and quantitative questions to lead students step-by-step through the material. Two completed study guides and a homework assignment are submitted each week for grading and the solutions are available later on the internet. Student surveys show the majority of students have a good attitude about the course, like to work in groups with their friends, and like the ready availability of the instructor for help. Both students and faculty seem to like the more frequent one-to-one contact of this format. We have also noticed that one student in each group tends to ask most of the questions and then "translates" the instructor's response into words the others understand. Lest you think "the millenium has arrived," student performance on multiple-choice tests has not improved markedly, some students strongly resist cooperation with others, and many students still think this is the hardest course they have ever taken.

  3. Web-Based Virtual Laboratory for Food Analysis Course

    Science.gov (United States)

    Handayani, M. N.; Khoerunnisa, I.; Sugiarti, Y.

    2018-02-01

    Implementation of learning on food analysis course in Program Study of Agro-industrial Technology Education faced problems. These problems include the availability of space and tools in the laboratory that is not comparable with the number of students also lack of interactive learning tools. On the other hand, the information technology literacy of students is quite high as well the internet network is quite easily accessible on campus. This is a challenge as well as opportunities in the development of learning media that can help optimize learning in the laboratory. This study aims to develop web-based virtual laboratory as one of the alternative learning media in food analysis course. This research is R & D (research and development) which refers to Borg & Gall model. The results showed that assessment’s expert of web-based virtual labs developed, in terms of software engineering aspects; visual communication; material relevance; usefulness and language used, is feasible as learning media. The results of the scaled test and wide-scale test show that students strongly agree with the development of web based virtual laboratory. The response of student to this virtual laboratory was positive. Suggestions from students provided further opportunities for improvement web based virtual laboratory and should be considered for further research.

  4. Flow Formulations for Curriculum-based Course Timetabling

    DEFF Research Database (Denmark)

    Bagger, Niels-Christian Fink; Kristiansen, Simon; Sørensen, Matias

    2017-01-01

    In this paper we present two mixed-integer programming formulations for the Curriculum based Course Timetabling Problem (CTT). We show that the formulations contain underlying network structures by dividing the CTT into two separate models and then connect the two models using flow formulation...... techniques. The first mixed-integer programming formulation is based on an underlying minimum cost flow problem, which decreases the number of integer variables significantly and improves the performance compared to an intuitive mixed-integer programming formulation. The second formulation is based...... on a multi-commodity flow problem which in general is NP-hard, however, we prove that it suffices to solve the linear programming relaxation of the model. The formulations show competitiveness with other approaches based on mixed-integer programming from the literature and improve the currently best known...

  5. A STEM-Based, High School Aviation Course

    Science.gov (United States)

    Surra, Alex; Litowitz, Len S.

    2015-01-01

    The authors describe a vocational training course that was developed to give more than just an overview of how aircraft work, or a course on how to fly. This training course was a half-year course in aviation technology. Powered flight is an area of interest for many students, and the intent of creating a curriculum rich with science, technology,…

  6. Ten practical, theory-based tips for clinical course planners

    DEFF Research Database (Denmark)

    Balslev, T.; Westphall, I.; Blichfeldt, S.

    2008-01-01

    A list of practical advice and examples are given based on the literature. E-learning with cliffhanger text-cases can activate prior knowledge, and selected examination skills can be trained with simulated patients. Patient video recordings can be used to train clinical reasoning skills, including...... and the participants. Spacing a course with intervening assignments can enable the transfer of skills to practice Udgivelsesdato: 2008/4/7...... pattern recognition and hypothetic-deductive approaches. Interactive approaches, for example, questioning, quizzes or buzz groups imply active involvement and participation. Quizzes and MCQ-testing can provide a formative 'check-up' on learning and point to gaps in understanding for the teachers...

  7. Video-based problems in introductory mechanics physics courses

    International Nuclear Information System (INIS)

    Gröber, Sebastian; Klein, Pascal; Kuhn, Jochen

    2014-01-01

    Introductory mechanics physics courses at the transition from school to university are a challenge for students. They are faced with an abrupt and necessary increase of theoretical content and requirements on their conceptual understanding of phyiscs. In order to support this transition we replaced part of the mandatory weekly theory-based paper-and-pencil problems with video analysis problems of equal content and level of difficulty. Video-based problems (VBP) are a new problem format for teaching physics from a linked sequence of theoretical and video-based experimental tasks. Experimental tasks are related to the well-known concept of video motion analysis. This introduction of an experimental part in recitations allows the establishment of theory–experiment interplay as well as connections between physical content and context fields such as nature, technique, everyday life and applied physics by conducting model-and context-related experiments. Furthermore, laws and formulas as predominantly representative forms are extended by the use of diagrams and vectors. In this paper we give general reasons for this approach, describe the structure and added values of VBP, and show that they cover a relevant part of mechanics courses at university. Emphasis is put on theory–experiment interplay as a structural added value of VBP to promote students' construction of knowledge and conceptual understanding. (paper)

  8. Microtexture diagnostics of asphalt pavement surfaces

    Science.gov (United States)

    Florková, Zuzana; Pepucha, L.'ubomír

    2017-09-01

    The microtexture of asphalt pavement surface is an essential parameter from the traffic safety point of view and it closely relates to a geometrical, petrological and physical properties of aggregate particle used in asphalt pavement. Microtexture has a significant influence for assurance basic friction values between tire and pavement in relation to a skid resistance properties. Therefore, the microtexture detecting methods are necessary. The British pendulum tester measurements have been carried out on selected sections of roads with different asphalt surfaces. Individual grains of aggregates were taken from the surface of each section from the sliding path and also from the core sample after the extraction. The laboratory profilometry measurements have been practiced on these aggregate samples and subsequently the surface microtexture was investigated based on commonly used texture characteristics and the filtration approach was applied in calculation process. The results have shown the degradation of microtexture values occurs due to polishing of aggregate under loading from traffic in relation to the type of used aggregate. Some correlation between BPN values and texture characteristics was found.

  9. Pervious Pavement System Evaluation- Abstract

    Science.gov (United States)

    Porous pavement is a low impact development stormwater control. The Urban Watershed Management Branch is evaluating interlocking concrete pavers as a popular implementation. The pavers themselves are impermeable, but the spaces between the pavers are backfilled with washed, gra...

  10. Premature asphalt concrete pavement cracking.

    Science.gov (United States)

    2015-06-01

    Recently, the Oregon Department of Transportation (ODOT) has identified hot mix asphalt concrete : (HMAC) pavements that have displayed top-down cracking within three years of construction. The objective of : the study was to evaluate the top-down cr...

  11. Pavement management using hyperspectral imagery

    Science.gov (United States)

    Ayalew, Balehager; Gomez, Richard B.; Roper, William E.; Carrasco, Oscar

    2003-08-01

    Public Works facilities require up-to-date information on the health status of the road network they maintain. However, roadway maintenance and rehabilitation involves the greatest portion of a municipality's annual operating budget. Government officials use various technologies such as a pavement management system to assist in making better decisions about their roadways systems, pavement condition, history, and projects. Traditionally, manual surveying has served as the method of obtaining this information. To better assist in decision-making, a regionally specific spectral library for urban areas is being developed and used in conjunction with hyperspecrtal imaging, to map urban materials and pavement conditions. A Geographical Information and Positioning System (GIS/GPS) will also be implemented to overlay relative locations. This paper will examine the benefits of using hyperspectral imaging over traditional methods of roadway maintenance and rehabilitation for pavement management applications. In doing so, we will identify spatial and spectral requirements for successful large-scale road feature extraction.

  12. Water quality and quantity assessment of pervious pavements performance in experimental car park areas.

    Science.gov (United States)

    Sañudo-Fontaneda, Luis A; Charlesworth, Susanne M; Castro-Fresno, Daniel; Andres-Valeri, Valerio C A; Rodriguez-Hernandez, Jorge

    2014-01-01

    Pervious pavements have become one of the most used sustainable urban drainage system (SUDS) techniques in car parks. This research paper presents the results of monitoring water quality from several experimental car park areas designed and constructed in Spain with bays made of interlocking concrete block pavement, porous asphalt, polymer-modified porous concrete and reinforced grass with plastic and concrete cells. Moreover, two different sub-base materials were used (limestone aggregates and basic oxygen furnace slag). This study therefore encompasses the majority of the materials used as permeable surfaces and sub-base layers all over the world. Effluent from the test bays was monitored for dissolved oxygen, pH, electric conductivity, total suspended solids, turbidity and total petroleum hydrocarbons in order to analyze the behaviour shown by each combination of surface and sub-base materials. In addition, permeability tests were undertaken in all car parks using the 'Laboratorio Caminos Santander' permeameter and the Cantabrian Portable Infiltrometer. All results are presented together with the influence of surface and sub-base materials on water quality indicators using bivariate correlation statistical analysis at a confidence level of 95%. The polymer-modified porous concrete surface course in combination with limestone aggregate sub-base presented the best performance.

  13. How do instructors design a WWW-based course-support environment?. Vol. 1

    NARCIS (Netherlands)

    de Boer, Willem; Collis, Betty; Oliver, Ron

    1999-01-01

    After one year (1997-1998) of working extensively with our instructors, particularly all of those responsible for our first-year courses, 17 courses required for all students and several senior elective courses (3) are now using their tailored-made Web-based course-support environments. In addition,

  14. Instructional design of WWW-based course-support environments : From case to general principles

    NARCIS (Netherlands)

    Dijkstra, Sanne; Collis, Betty; Eseryel, Deniz

    1999-01-01

    In this paper we describe the design of a WWW-based course-support environment for a course in instructional-design theories, give an overview of how the environment was used as part of the course experience, and summarize the student evaluation of the course. Our conclusion is that such a

  15. Environmentally Friendly Pavements: final report

    OpenAIRE

    Aksnes, Jostein

    2009-01-01

    This final report presents the main results, advice and recommendations from the research and development program Environmentally Friendly Pavements run by the Norwegian Public Roads Administration (NPRA) in the period 2004-2009. The main focus of the project has been to optimise the environmental properties of road surfaces with respect to low road tyre noise and road dust emissions. The project has shown that: The tested environmentally friendly pavements give an initial noise r...

  16. Intelligent system for pavement management

    Science.gov (United States)

    Ferreira Brega, Jose R.; Alba Soria, Manoel H.; Marar, Joao F.; Sementille, Antonio C.

    1998-03-01

    This paper describes a method for the evaluation of pavement condition through artificial neural networks using the MLP backpropagation technique. Two of the most used procedures for detecting the pavement conditions were applied: the 'overall severity index' and the 'irregularity index.' Tests with the model demonstrated that the simulation with the neural network gives better results than the procedures recommended by the highway officials. This network may also be applied for the construction of a graphic computer environment.

  17. Pavement maintenance optimization model using Markov Decision Processes

    Science.gov (United States)

    Mandiartha, P.; Duffield, C. F.; Razelan, I. S. b. M.; Ismail, A. b. H.

    2017-09-01

    This paper presents an optimization model for selection of pavement maintenance intervention using a theory of Markov Decision Processes (MDP). There are some particular characteristics of the MDP developed in this paper which distinguish it from other similar studies or optimization models intended for pavement maintenance policy development. These unique characteristics include a direct inclusion of constraints into the formulation of MDP, the use of an average cost method of MDP, and the policy development process based on the dual linear programming solution. The limited information or discussions that are available on these matters in terms of stochastic based optimization model in road network management motivates this study. This paper uses a data set acquired from road authorities of state of Victoria, Australia, to test the model and recommends steps in the computation of MDP based stochastic optimization model, leading to the development of optimum pavement maintenance policy.

  18. Fatigue Life Assessment of Orthotropic Steel Deck with UHPC Pavement

    Directory of Open Access Journals (Sweden)

    Xu Jiang

    2017-01-01

    Full Text Available In recent years, a number of large-span bridges with orthotropic steel decks were constructed in China. With increasing traffic volumes and higher wheel loads, many fatigue cracks developed at the welds and the edge of cut-out holes. This paper aims at presenting the numerical analysis on the fatigue performance of the orthotropic steel deck using ultrahigh performance concrete (UHPC overlay as the deck pavement instead of the conventional asphalt concrete pavement. By using finite element method (FEM model, stress distribution at fatigue sensitive locations under the action of wheel loads is characterized and the obtained stress ranges indicate that the UHPC pavement significantly reduces the magnitude of the stress peak valued. A suggested truck stream model based on the weigh-in-motion (WIM data of four bridges in China is employed to calculate the stress variation at specific fatigue details. Furthermore, the fatigue damage accumulation at fatigue details under the UHPC and conventional asphalt concrete pavement is studied based on Miner’s linear cumulative damage rule and the rain-flow method. The results indicate that the UHPC pavement on the orthotropic steel deck can extend the service lives of the concerned regions over 100 years, but the fatigue lives will reduce significantly when the elastic modulus of UHPC decreases to 50% of the original value.

  19. A User Friendly Software for Rigid Pavement Design

    Directory of Open Access Journals (Sweden)

    Aydın Kıcı

    2017-12-01

    Full Text Available Concrete pavements as concrete road slab, appear as a strong alternative for flexible superstructures especially because of their low cost for maintenance and repair and the high performance they show under heavy axle loads. The design of these concrete road slabs is quite different from the traditional concrete and reinforced concrete structures’ design. In the design for this kind of pavements, traffic conditions should be defined properly and considered an addition to the concrete and platform properties. There have been designing methods developed based on both experimental and mechanic foundations for concrete pavements. The most important ones of these methods are AASHTO (1993 and PCA (1984. In both design methods, it’s significant to know the maximum deflections and maximum strains the vehicles’ loads cause on the pavement. The calculation of this maximum deflections and maximum strains can be done via the finite element method or the closed formulas which have been developed by Westergaard. In this study, a user-friendly software has been developed based on AASHTO 1993, PCA 1984 design methods and Westergaard formulas. Thanks to this software, the user who wants to design the concrete pavement as concrete road slab can obtain the essential parameters automatically by entering the required data for the design.

  20. A "Medical Physics" Course Based Upon Hospital Field Experience

    Science.gov (United States)

    Onn, David G.

    1972-01-01

    Describes a noncalculus, medical physics'' course with a basic element of direct hospital field experience. The course is intended primarily for premedical students but may be taken by nonscience majors. (Author/PR)

  1. INTENSITY- AND TIME COURSE-BASED CLASSIFICATIONS OF OXIDATIVE STRESSES

    Directory of Open Access Journals (Sweden)

    Volodymyr Lushchak

    2015-05-01

    Full Text Available In living organisms, production of reactive oxygen species (ROS is counterbalanced by their elimination and/or prevention of formation which in concert can typically maintain a steady-state (stationary ROS level. However, this balance may be disturbed and lead to elevated ROS levels and enhanced damage to biomolecules. Since 1985, when H. Sies first introduced the definition of oxidative stress, this area has become one of the hot topics in biology and, to date, many details related to ROS-induced damage to cellular components, ROS-based signaling, cellular responses and adaptation have been disclosed. However, some basal oxidative damage always occurs under unstressed conditions, and in many experimental studies it is difficult to show definitely that oxidative stress is indeed induced by the stressor. Therefore, usually researchers experience substantial difficulties in the correct interpretation of oxidative stress development. For example, in many cases an increase or decrease in the activity of antioxidant and related enzymes are interpreted as evidences of oxidative stress. Careful selection of specific biomarkers (ROS-modified targets may be very helpful. To avoid these sorts of problems, I propose several classifications of oxidative stress based on its time-course and intensity. The time-course classification includes acute and chronic stresses. In the intensity based classification, I propose to discriminate four zones of function in the relationship between “Dose/concentration of inducer” and the measured “Endpoint”: I – basal oxidative stress zone (BOS; II – low intensity oxidative stress (LOS; III – intermediate intensity oxidative stress (IOS; IV – high intensity oxidative stress (HOS. The proposed classifications may be helpful to describe experimental data where oxidative stress is induced and systematize it based on its time course and intensity. Perspective directions of investigations in the field include

  2. Determination of Pavement Rehabilitation Activities through a Permutation Algorithm

    Directory of Open Access Journals (Sweden)

    Sangyum Lee

    2013-01-01

    Full Text Available This paper presents a mathematical programming model for optimal pavement rehabilitation planning. The model maximized the rehabilitation area through a newly developed permutation algorithm, based on the procedures outlined in the harmony search (HS algorithm. Additionally, the proposed algorithm was based on an optimal solution method for the problem of multilocation rehabilitation activities on pavement structure, using empirical deterioration and rehabilitation effectiveness models, according to a limited maintenance budget. Thus, nonlinear pavement performance and rehabilitation activity decision models were used to maximize the objective functions of the rehabilitation area within a limited budget, through the permutation algorithm. Our results showed that the heuristic permutation algorithm provided a good optimum in terms of maximizing the rehabilitation area, compared with a method of the worst-first maintenance currently used in Seoul.

  3. Calibration of PMIS pavement performance prediction models.

    Science.gov (United States)

    2012-02-01

    Improve the accuracy of TxDOTs existing pavement performance prediction models through calibrating these models using actual field data obtained from the Pavement Management Information System (PMIS). : Ensure logical performance superiority patte...

  4. Appraisal of the Causes of Pavement

    African Journals Online (AJOL)

    used environmental observations in addition to geotechnical test to study ... 1Department of Applied Geophysics, Federal University of Technology, Akure, Nigeria ... have contributed to the pavement failure. Keywords: Remote Sensing, Geotechnical Investigation, Road Pavement Failure, Basement Complex. Environment.

  5. Pervious Pavement System Evaluation-Poster

    Science.gov (United States)

    Pervious pavement is a low impact development stormwater control. The Environmental Protection Agency's Urban Watershed Management Branch is evaluating interlocking concrete pavingstone pervious pavement systems. The pavingstones themselves are impermeable, but the spaces between...

  6. Equivalent damage of loads on pavements

    CSIR Research Space (South Africa)

    Prozzi, JA

    2009-05-26

    Full Text Available This report describes a new methodology for the determination of Equivalent Damage Factors (EDFs) of vehicles with multiple axle and wheel configurations on pavements. The basic premise of this new procedure is that "equivalent pavement response...

  7. Dynamic contracting mechanism for pavement maintenance management

    NARCIS (Netherlands)

    Demirel, H.C.; De Ridder, H.A.J.

    2013-01-01

    Technological advances, financial possibilities and changes of demands have increasingly affected the pavement maintenance environment for outsourcing in recent years. This induces complexity in the contracting methods of pavement maintenance activities. Despite the fact that current contracting

  8. Minimization of reflection cracks in flexible pavements.

    Science.gov (United States)

    1977-01-01

    This report describes the performance of fabrics used under overlays in an effort to minimize longitudinal and alligator cracking in flexible pavements. It is concluded, although the sample size is small, that the treatments will extend the pavement ...

  9. Evaluation of pavement surface friction treatments.

    Science.gov (United States)

    2011-12-01

    The implementation of a pavement preservation program involves a learning curve with not only a determination to succeed, but : also the courage to fail. Also, successful implementation of pavement preservation program requires knowledge of the perfo...

  10. Serviceable pavement marking retroreflectivity levels : technical report.

    Science.gov (United States)

    2009-03-01

    This research addressed an array of issues related to measuring pavement markings retroreflectivity, factors : related to pavement marking performance, subjective evaluation process, best practices for using mobile : retroreflectometers, sampling pav...

  11. An approach to pavement management in Virginia.

    Science.gov (United States)

    1981-01-01

    The report summarizes the objectives and benefits of formal pavement management systems and outlines an approach believed by the author to be practical for Virginia. The management of Virginia interstate pavements and a proposed random-sampling plan ...

  12. Sustainable concrete pavements : a manual of practice.

    Science.gov (United States)

    2011-08-01

    Developed as a more detailed follow-up to a 2009 briefing document, Building Sustainable Pavement with Concrete, this guide provides a clear, concise, and cohesive discussion of pavement sustainability concepts and of recommended practices for maximi...

  13. Pavement performance evaluation, phase II : data collection.

    Science.gov (United States)

    2008-12-01

    Phase I and II of this study tested approximately 1500 rehabilitated pavements (asphalt and PCC) : throughout the State. These pavements ranged from 5 to 15 years old and were intended to develop a : snapshot of how various rehabilitations were perfo...

  14. Quantifying Evaporation in a Permeable Pavement System

    Science.gov (United States)

    Studies quantifying evaporation from permeable pavement systems are limited to a few laboratory studies and one field application. This research quantifies evaporation for a larger-scale field application by measuring the water balance from lined permeable pavement sections. Th...

  15. Research-Based Integrated Reading and Writing Course Development

    Science.gov (United States)

    Pierce, Calisa A.

    2017-01-01

    With the continuing national emphases on acceleration and completion, an integrated reading and writing course (a combined developmental reading and developmental writing course, with all levels compressed into a single course) is one way to move students more quickly and efficiently through the developmental sequence while still maintaining…

  16. Course-Based Undergraduate Research--It Can Be Accomplished!

    Science.gov (United States)

    Allyn, Debra A.

    2013-01-01

    This article describes a senior seminar course in the Health and Human Performance (HHP) Department at the University of Wisconsin-River Falls. All students in the HHP department are required to complete the course. The emphases within HHP include physical education, health education, and exercise and sport science. In this course students learn…

  17. Designing a Web-Based Asynchronous Innovation/Entrepreneurism Course

    Science.gov (United States)

    Ghandforoush, Parviz

    2017-01-01

    Teaching an online fully asynchronous information technology course that requires students to ideate, build an e-commerce website, and develop an effective business plan involves a well-developed and highly engaging course design. This paper describes the design, development, and implementation of such a course and presents information on…

  18. Assessment Of The Deterioration Degree Of Airfield Pavement Functional Constituents Made Of Cement Concrete

    Directory of Open Access Journals (Sweden)

    Barszcz Piotr

    2014-12-01

    Full Text Available The characteristic feature of the approach to the analysis of the airfield pavement deterioration degree as outlined in this paper is the fact that not only existing deteriorations are taken into account of but also already completed historical repairs. This approach enables determination of resources needed to conduct repairs and setting up reasonable schedules of future overhauls. The proposed index of the pavement deterioration degree, calculated on the basis of measured deficiencies and past repairs, makes it possible to assess the technical condition of the airfield pavement in a comprehensive manner. The key information indispensable to evaluate the degree of deterioration of the airfield pavement surface includes data which can be acquired from already completed stocktaking inventories. The stocktaking process is based on the catalogue of deficiencies typical for airfield pavements and the rules for stocktaking measurements.

  19. Perpetual pavement – absorbing stress and functional maintenance

    Directory of Open Access Journals (Sweden)

    Rong Gao

    2017-03-01

    Full Text Available Perpetual Pavement combines the well documented smoothness and safety advantages of asphalt with an advanced, multi-layer paving design process, that with routine maintenance, extends the useful life of a roadway. Perpetual provides long lasting road and smoothness for the construction purposes. This study has the design key points of perpetual pavement based on the idea of life cycle, which has a new direction for the new highway construction, reconstruction and expansion. First, the structure of long life pavement design is studied to analyze the effect of stress absorbing layer. Second, researches on stress absorbing layer from the aspects of raw materials, mix proportion are implemented. Third, the design index of stress absorbing layer is determined by the shear strength test. The results show that the design idea of composite perpetual pavement can be realized by reasonable design of the stress absorbing layer and carrying out the surface functional maintenance can ensure the pavement to avoid structural damage in the operation stage.

  20. High Performance Concrete Pavement in Indiana

    OpenAIRE

    Nantung, Tommy E

    2011-01-01

    Until the early 1990s, curling and warping of Portland cement concrete pavement did not concern pavement engineers in many transportation agencies. Since beginning construction of the interstate system in the United States in the late 1950s through the late 1980s, the performance of Portland cement concrete pavement has been associated with properties of concrete as a pavement material. In those years developed standards and design guidelines emphasized better concrete materials and construct...

  1. Developing an evidence-based public health informatics course.

    Science.gov (United States)

    Yu, Xinyu; Xie, Yue; Pan, Xuequn; Mayfield-Johnson, Susan; Whipple, Jessica; Azadbakht, Elena

    2015-10-01

    This study assessed the need to develop a public health informatics (PHI) introductory course and determine contents of such a course. Community assessments employing focus group interviews and an online survey were utilized to determine course need and content. Results revealed a need to provide PHI training to graduate public health students and suggested broad course content requirements. Results indicated lack of awareness of libraries and librarians as sources of public health information. A graduate PHI course was developed and delivered. Additionally, implementation of a subject guide increased the library's profile.

  2. Development of a pavement management system for Virginia : final report on phase I : application and verification of a pilot pavement condition inventory for Virginia interstate flexible pavements.

    Science.gov (United States)

    1984-01-01

    The study reported here addresses some of the earlier phases in the development of a pavement management system for the state of Virginia. Among the issues discussed are the development of an adequate data base and the implementation of a condition r...

  3. MoDOT pavement preservation research program volume II, data collection for pavement management : historical data mining and production of data.

    Science.gov (United States)

    2015-10-01

    The objective of Task 1 was to develop data for use in MoDOTs pavement preservation program based primarily on historical : information available throughout MoDOT as well as climate data from the National Oceanic and Atmospheric Administration : (...

  4. Calibration on MEPDG Low Temperature Cracking Model and Recommendation on Asphalt Pavement Structures in Seasonal Frozen Region of China

    Directory of Open Access Journals (Sweden)

    Hongyan Ma

    2015-01-01

    Full Text Available In order to implement the Mechanistic-Empirical Pavement Design Guide (MEPDG to design and maintain asphalt pavements in China, it is necessary to calibrate transfer functions of distresses in MEPDG with local conditions, including traffics, environment, and materials as well as measured pavement distresses data in field. Comprehensive single factor sensitivity analyses of factors that influence thermal cracking of asphalt pavements were conducted utilizing the MEPDG low temperature cracking (LTC model. Additionally, multiple factor sensitivity analyses were carried out as well, based on which pavement structures with sound thermal cracking resistance were recommended for seasonal frozen regions in China. Finally, the field data of thermal cracks on typical asphalt pavements in China was utilized to calibrate the LTC model in MEPDG. An improvement was proposed on MEPDG LTC model, after which was applied, the predicted thermal cracking from MEPDG LTC model agrees well with measured thermal cracking in China.

  5. Does Homework Really Matter for College Students in Quantitatively-Based Courses?

    Science.gov (United States)

    Young, Nichole; Dollman, Amanda; Angel, N. Faye

    2016-01-01

    This investigation was initiated by two students in an Advanced Computer Applications course. They sought to examine the influence of graded homework on final grades in quantitatively-based business courses. They were provided with data from three quantitatively-based core business courses over a period of five years for a total of 10 semesters of…

  6. Applying XML-Based Technologies to Developing Online Courses: The Case of a Prototype Learning Environment

    Science.gov (United States)

    Jedrzejowicz, Joanna; Neumann, Jakub

    2007-01-01

    Purpose: This paper seeks to describe XML technologies and to show how they can be applied for developing web-based courses and supporting authors who do not have much experience with the preparation of web-based courses. Design/methodology/approach: When developing online courses the academic staff has to address the following problem--how to…

  7. Business and Industry Project-Based Capstone Courses: Selecting Projects and Assessing Learning Outcomes

    Science.gov (United States)

    Maleki, Reza A.

    2009-01-01

    This is the first of two articles in which the author shares experiences gained from the development and delivery of a business/industry project-based capstone course. The course integrates research, proposal development and design experience based on knowledge and skills acquired in earlier coursework. The course also incorporates standards and…

  8. Combination of the Research-Based Learning Method with the Modern Physics Experiment Course Teaching

    Science.gov (United States)

    Liu, Xiaolai; Li, Qinghuai

    2011-01-01

    It has been the hotspot to reconstruct the education course based on the research-based learning in the course reform in many countries in recent years. The new course standard of China insists that the teaching is the interactive process that teachers and students communicate and develop together. In the teaching, the relationship between…

  9. Designing “Theory of Machines and Mechanisms” course on Project Based Learning approach

    DEFF Research Database (Denmark)

    Shinde, Vikas

    2013-01-01

    Theory of Machines and Mechanisms course is one of the essential courses of Mechanical Engineering undergraduate curriculum practiced at Indian Institute. Previously, this course was taught by traditional instruction based pedagogy. In order to achieve profession specific skills demanded by the i......Theory of Machines and Mechanisms course is one of the essential courses of Mechanical Engineering undergraduate curriculum practiced at Indian Institute. Previously, this course was taught by traditional instruction based pedagogy. In order to achieve profession specific skills demanded...... and the process followed to design a project which meets diverse objectives....

  10. Implementing Team Based Learning in an Information Literacy Course

    Directory of Open Access Journals (Sweden)

    Marijn Post

    2016-12-01

    Full Text Available Introduction: Motivating students to improve their Information Literacy (IL skills can be a challenge. As a pilot, we implemented Team Based Learning (TBL in our IL lessons. TBL is an interactive learning approach based on the “flipped classroom” concept, offering students opportunities to gather skills via immediate feedback during individual and team activities. Moreover, TBL promises to be an attractive and activating way of learning. We were interested if TBL, A indeed activates students and B improves their IL skills more than with lectures and self-tuition. Methods: TBL was implemented in a first year bachelor IL course in the year 2015-2016. Student were asked to study three IL e-learning modules before class. The obtained knowledge was assessed individually during an Individual Readiness Assessment test (IRAT and in a team via a Team Readiness Assessment test (TRAT using “scratch and win cards”. After this, teams were given an IL case and the members had to come to a consensus about the best solution out of a couple options provided. Finally, students took a written exam, which was the same as used in this course in the year 2014-2015, when TBL was not applied yet. We compared the grades of the written exam between the two academic years using a Mann Whitney U test (P<0.05. Students’ opinion about TBL was polled using a 34 question student survey. Results: The mean written exam grades were significantly higher in the TBL year than in the preceding year without TBL (respectively, 7.6 ± 1.42 vs 6.5 ± 1.31, P<0.001. The student survey showed that students were positive about the IRATs and TRATs, but neutral about other TBL parts. Conclusion: TBL seems to be a good didactical method to motivate students and enhance their IL skills.

  11. Impact of the variation in dynamic vehicle load on flexible pavement responses

    Science.gov (United States)

    Ahsanuzzaman, Md

    The purpose of this research was to evaluate the dynamic variation in asphalt pavement critical responses due to dynamic tire load variations. An attempt was also made to develop generalized regression equations to predict the dynamic response variation in flexible pavement under various dynamic load conditions. The study used an extensive database of computed pavement response histories for five different types of sites (smooth, rough, medium rough, very rough and severely rough), two different asphalt pavement structures (thin and thick) at two temperatures (70 °F and 104 °F), subjected to a tandem axle dual tire at three speeds 25, 37 and 50 mph (40, 60 and 80 km/h). All pavement responses were determined using the 3D-Move Analysis program (Version 1.2) developed by University of Nevada, Reno. A new term called Dynamic Response Coefficient (DRC) was introduced in this study to address the variation in critical pavement responses due to dynamic loads as traditionally measured by the Dynamic Load Coefficient (DLC). While DLC represents the additional varying component of the tire load, DRC represents the additional varying component of the response value (standard deviation divided by mean response). In this study, DRC was compared with DLC for five different sites based on the roughness condition of the sites. Previous studies showed that DLC varies with vehicle speed and suspension types, and assumes a constant value for the whole pavement structure (lateral and vertical directions). On the other hand, in this study, DRC was found to be significantly varied with the asphalt pavement and function of pavement structure, road roughness conditions, temperatures, vehicle speeds, suspension types, and locations of the point of interest in the pavement. A major contribution of the study is that the variation of pavement responses due to dynamic load in a flexible pavement system can be predicted with generalized regression equations. Fitting parameters (R2) in the

  12. Enhancement of Learning Process in Web-Based Courses Using Combined Media Components

    National Research Council Canada - National Science Library

    Georgios, Desypris

    2002-01-01

    .... Two approaches were studied for the development of a part of a web-based course. The first is the instructional design approach and how an instructor will implement the best course possible applying the more suitable instructional strategies...

  13. Effectiveness of inquiry-based learning in an undergraduate exercise physiology course

    DEFF Research Database (Denmark)

    Nybo, Lars; May, Michael

    2015-01-01

    (individual subject-specific tests and group interviews) were performed for a laboratory course in cardiorespiratory exercise physiology that was conducted in one year with a traditional step-by-step guided manual (traditional course) and the next year completed with an inquiry-based structure (I-based course......). The I-based course was a guided inquiry course where students had to design the experimental protocol and conduct their own study on the basis of certain predefined criteria (i.e., they should evaluate respiratory responses to submaximal and maximal exercise and provide indirect and direct measures...... of aerobic exercise capacity). The results indicated that the overall time spent on the experimental course as well as self-evaluated learning outcomes were similar across groups. However, students in the I-based course used more time in preparation (102 ± 5 min) than students in the traditional course (42...

  14. Pavement Subgrade Performance Study in the Danish Road Testing Machine

    DEFF Research Database (Denmark)

    Ullidtz, Per; Ertman Larsen, Hans Jørgen

    1997-01-01

    Most existing pavement subgrade criteria are based on the AASHO Road Test, where only one material was tested and for only one climatic condition. To study the validity of these criteria and to refine the criteria a co-operative research program entitled the "International Pavement Subgrade...... Performance Study" was sponsored by the FHWA with American, Finnish and Danish partners. This paper describes the first test series which was carried out in the Danish Road Testing Machine (RTM).The first step in this program is a full scale test on an instrumented pavement in the Danish Road Testing Machine....... Pressure gauges and strain cells were installed in the upper part of the subgrade, for measuring stresses and strains in all three directions. During and after construction FWD testing was carried out to evaluate the elastic parameters of the materials. These parameters were then used with the theory...

  15. Effects of Pavement Skid Resistance on Traffic Accidents

    Directory of Open Access Journals (Sweden)

    Abdullah I. Al-Mansour

    2006-12-01

    Full Text Available The Ministry of Transport (MOT in the Kingdom of Saudi Arabia had collected a massive amount of friction measurements using a Mu-meter covering most of the major highway network in the kingdom. Traffic accident data of 89 high accident rate locations from four main different highway classes were extracted from the MOT accident records. Pavement skid resistance for the selected locations was determined from the pavement skid resistance records. The objective of this paper is to utilize these data to investigate the effects of pavement skid resistance on traffic accidents. The analysis included establishing relationships between skid resistance and accident number, accident significance and accident density. It was determined that a decreasing skid resistance leads to an increase in traffic accidents. Acritical value of skid resistance was also established based on number, significance and density of accidents.

  16. Modern field courses and problem-based learning; a comparison between industry and academia

    OpenAIRE

    Hesthammer, Jonny; Fossen, Haakon

    2006-01-01

    Problem-based learning (PBL) can provide an attractive learning situation in relation to field courses. Combined with information technology, the learning effect can be enhanced compared with more traditional courses that use lecture-based learning and no advanced technological aids. However, the use of information technology in field courses requires the consideration of fundamental pedagogic principles. In May 2003, two separate geological field courses were run at locations ...

  17. Pavement noise measurements in Poland

    Science.gov (United States)

    Zofka, Ewa; Zofka, Adam; Mechowski, Tomasz

    2017-09-01

    The objective of this study is to investigate the feasibility of the On-Board Sound Intensity (OBSI) system to measure tire-pavement noise in Poland. In general, sources of noise emitted by the modern vehicles are the propulsion noise, aerodynamic resistance and noise generated at the tire-pavement interface. In order to capture tire-pavement noise, the OBSI system uses a noise intensity probe installed in the close proximity of that interface. In this study, OBSI measurements were performed at different types of pavement surfaces such as stone mastic asphalt (SMA), regular asphalt concrete (HMA) as well as Portland cement concrete (PCC). The influence of several necessary OBSI measurement conditions were recognized as: testing speed, air temperature, tire pressure and tire type. The results of this study demonstrate that the OBSI system is a viable and robust tool that can be used for the quality evaluation of newly built asphalt pavements in Poland. It can be also applied to generate reliable input parameters for the noise propagation models that are used to assess the environmental impact of new and existing highway corridors.

  18. Use of Ground Penetrating Radar at the FAA's National Airport Pavement Test Facility

    Science.gov (United States)

    Injun, Song

    2015-04-01

    The Federal Aviation Administration (FAA) in the United States has used a ground-coupled Ground Penetrating Radar (GPR) at the National Airport Pavement Test Facility (NAPTF) since 2005. One of the primary objectives of the testing at the facility is to provide full-scale pavement response and failure information for use in airplane landing gear design and configuration studies. During the traffic testing at the facility, a GSSI GPR system was used to develop new procedures for monitoring Hot Mix Asphalt (HMA) pavement density changes that is directly related to pavement failure. After reviewing current setups for data acquisition software and procedures for identifying different pavement layers, dielectric constant and pavement thickness were selected as dominant parameters controlling HMA properties provided by GPR. A new methodology showing HMA density changes in terms of dielectric constant variations, called dielectric sweep test, was developed and applied in full-scale pavement test. The dielectric constant changes were successfully monitored with increasing airplane traffic numbers. The changes were compared to pavement performance data (permanent deformation). The measured dielectric constants based on the known HMA thicknesses were also compared with computed dielectric constants using an equation from ASTM D4748-98 Standard Test Method for Determining the Thickness of Bound Pavement Layers Using Short-Pulse Radar. Six inches diameter cylindrical cores were taken after construction and traffic testing for the HMA layer bulk specific gravity. The measured bulk specific gravity was also compared to monitor HMA density changes caused by aircraft traffic conditions. Additionally this presentation will review the applications of the FAA's ground-coupled GPR on embedded rebar identification in concrete pavement, sewer pipes in soil, and gage identifications in 3D plots.

  19. Development, deployment, and assessment of activity-based transportation courses.

    Science.gov (United States)

    2012-12-01

    This project developed four new activitybased transportation courses including Traffic Signal Systems Operations and : Design, Understanding and Communicating Transportation Data, Introduction to Freight Transportation, and Ru...

  20. Geo synthetic-reinforced Pavement systems

    International Nuclear Information System (INIS)

    Zornberg, J. G.

    2014-01-01

    Geo synthetics have been used as reinforcement inclusions to improve pavement performance. while there are clear field evidence of the benefit of using geo synthetic reinforcements, the specific conditions or mechanisms that govern the reinforcement of pavements are, at best, unclear and have remained largely unmeasured. Significant research has been recently conducted with the objectives of: (i) determining the relevant properties of geo synthetics that contribute to the enhanced performance of pavement systems, (ii) developing appropriate analytical, laboratory and field methods capable of quantifying the pavement performance, and (iii) enabling the prediction of pavement performance as a function of the properties of the various types of geo synthetics. (Author)

  1. Integrating the Problem-Based Learning Approach into a Web-Based English Reading Course

    Science.gov (United States)

    Lin, Lu-Fang

    2018-01-01

    This study incorporated the problem-based learning (PBL) approach into a web-based English reading course. The purpose of the study was to examine the impact of PBL on the participants' English reading comprehension (RC) and to explore the participants' perceptions of PBL. The present study conducted a comparison of two teaching methods. Two…

  2. Statmaster and HEROS - web-based courses first and second generation

    DEFF Research Database (Denmark)

    Larsen, Pia Veldt; Rootzen, Helle

    2008-01-01

    With the increasing focus on life-long learning, and with the convenience and accessibility of the Internet, the market for web-based courses has expanded vastly in recent times–in particular in connection with continuing education. However, teaching web-based courses presents various technical...... as well as pedagogical challenges. Some of these challenges are addressed, and means to dealing with them are suggested. A second generation of web-based courses is comprised of learning objects, which allows for tailoring courses for specialized groups of students, and accommodate individualized learning....... The concept of learning objects and how they are used to form new courses are discussed....

  3. Inquiry-based course in physics and chemistry for preservice K-8 teachers

    Directory of Open Access Journals (Sweden)

    Michael E. Loverude

    2011-05-01

    Full Text Available We describe an inquiry-based course in physics and chemistry for preservice K-8 teachers developed at California State University Fullerton. The course is one of three developed primarily to enhance the science content understanding of prospective teachers. The course incorporates a number of innovative instructional strategies and is somewhat unusual for its interdisciplinary focus. We describe the course structure in detail, providing examples of course materials and assessment strategies. Finally, we provide research data illustrating both the need for the course and the effectiveness of the course in developing student understanding of selected topics. Student responses to various questions reflect a lack of understanding of many relatively simple physical science concepts, and a level of performance that is usually lower than that in comparable courses serving a general education audience. Additional data suggest that course activities improve student understanding of selected topics, often dramatically.

  4. Differentiating Biochemistry Course Laboratories Based on Student Experience

    Science.gov (United States)

    Jakubowski, Henry V.

    2011-01-01

    Content and emphases in undergraduate biochemistry courses can be readily tailored to accommodate the standards of the department in which they are housed, as well as the backgrounds of the students in the courses. A more challenging issue is how to construct laboratory experiences for a class with both chemistry majors, who usually have little or…

  5. Evaluating an Inquiry-Based Bioinformatics Course Using Q Methodology

    Science.gov (United States)

    Ramlo, Susan E.; McConnell, David; Duan, Zhong-Hui; Moore, Francisco B.

    2008-01-01

    Faculty at a Midwestern metropolitan public university recently developed a course on bioinformatics that emphasized collaboration and inquiry. Bioinformatics, essentially the application of computational tools to biological data, is inherently interdisciplinary. Thus part of the challenge of creating this course was serving the needs and…

  6. Determination of mechanical properties for cement-treated aggregate base : final report.

    Science.gov (United States)

    2017-06-01

    The Virginia Department of Transportation (VDOT) currently follows pavement design procedures for all new and rehabilitated pavements based on the 1993 AASHTO Guide for Design of Pavement Structures. VDOTs Materials Division is in the process of i...

  7. Quantitative Assessment of a Field-Based Course on Integrative Geology, Ecology and Cultural History

    Science.gov (United States)

    Sheppard, Paul R.; Donaldson, Brad A.; Huckleberry, Gary

    2010-01-01

    A field-based course at the University of Arizona called Sense of Place (SOP) covers the geology, ecology and cultural history of the Tucson area. SOP was quantitatively assessed for pedagogical effectiveness. Students of the Spring 2008 course were given pre- and post-course word association surveys in order to assess awareness and comprehension…

  8. Competency-Based Course Outlines for Business and Office Education. Secretarial, Stenographic, Typewriting and Related Occupations.

    Science.gov (United States)

    Ricks, Betty R., Ed.; Schmidt, B. June, Ed.

    This guide contains course outlines designed to assist teachers with the identification of research-based competencies for courses in business and office education. Outlines are provided for seven courses: typewriting, clerk typist one, clerk typist two, stenography one, stenography two, beginning shorthand, and advanced shorthand. Following a…

  9. Specialized Courses Teaching Mode Innovation of the Independent College Based on MOOCS

    Science.gov (United States)

    Hongxia, Sun; Na, Zhao; Zhixiang, Zhang; Feng, Li; Pengcheng, Zhu

    2017-01-01

    Independent college is a new kind of school-running pattern, on the basis of independent college computer professional course teaching, based on the background of MOOCS, specialized course teaching mode principle, on the basis of design is given priority to, the class online course of classroom teaching mode. To a certain extent can motivate we…

  10. Integration of Information Literacy Components into a Large First-Year Lecture-Based Chemistry Course

    Science.gov (United States)

    Locknar, Angela; Mitchell, Rudolph; Rankin, Janet; Sadoway, Donald R.

    2012-01-01

    A first-year chemistry course is ideal for introducing students to finding and using scholarly information early in their academic careers. A four-pronged approach (lectures, homework problems, videos, and model solutions) was used to incorporate library research skills into a large lecture-based course. Pre- and post-course surveying demonstrated…

  11. Assessment of Problem-Based Learning in the Undergraduate Statistics Course

    Science.gov (United States)

    Karpiak, Christie P.

    2011-01-01

    Undergraduate psychology majors (N = 51) at a mid-sized private university took a statistics examination on the first day of the research methods course, a course for which a grade of "C" or higher in statistics is a prerequisite. Students who had taken a problem-based learning (PBL) section of the statistics course (n = 15) were compared to those…

  12. Effectiveness of inquiry-based learning in an undergraduate exercise physiology course.

    Science.gov (United States)

    Nybo, Lars; May, Michael

    2015-06-01

    The present study was conducted to investigate the effects of changing a laboratory physiology course for undergraduate students from a traditional step-by-step guided structure to an inquiry-based approach. With this aim in mind, quantitative and qualitative evaluations of learning outcomes (individual subject-specific tests and group interviews) were performed for a laboratory course in cardiorespiratory exercise physiology that was conducted in one year with a traditional step-by-step guided manual (traditional course) and the next year completed with an inquiry-based structure (I-based course). The I-based course was a guided inquiry course where students had to design the experimental protocol and conduct their own study on the basis of certain predefined criteria (i.e., they should evaluate respiratory responses to submaximal and maximal exercise and provide indirect and direct measures of aerobic exercise capacity). The results indicated that the overall time spent on the experimental course as well as self-evaluated learning outcomes were similar across groups. However, students in the I-based course used more time in preparation (102 ± 5 min) than students in the traditional course (42 ± 3 min, P physiology and the experimental methods before the course, it appears that an inquiry-based approach rather than one that provides students with step-by-step instructions may benefit learning outcomes in a laboratory physiology course. Copyright © 2015 The American Physiological Society.

  13. Effect of interlayer bonding quality of asphalt layers on pavement performance

    Science.gov (United States)

    Jaskula, Piotr; Rys, Dawid

    2017-09-01

    The quality of interlayer bonding at the interfaces between the asphalt layers in flexible pavements affects the overall pavement performance. Lack or partial lack of interlayer bonding between asphalt layers can cause pavement’s premature failures such as rutting, slippage of the wearing course, cracking or simply a reduction in the calculated fatigue life of the pavement structure. This paper shows the case studies of investigation of actual or potential premature failure of newly reconstructed and constructed pavements where low quality of interlayer bonding has a dominant meaning. In situ and laboratory tests were performed and followed by analytical calculation of pavement structure where thicknesses of layers and maximum shear strengths obtained from the tests were used. During the investigation it was found out that a low quality of tack coat as well as the same aggregate gradation in the bonded asphalt mixtures were the main reasons behind the weak quality of interlayer bonding. Partial interlayer bonding has a strong influence on reduction of calculated fatigue life of pavement. The summary of the paper includes recommendations on how to avoid the low quality of interlayer bonding of asphalt layers.

  14. Greenhouse Gas Emissions from Asphalt Pavement Construction: A Case Study in China.

    Science.gov (United States)

    Ma, Feng; Sha, Aimin; Lin, Ruiyu; Huang, Yue; Wang, Chao

    2016-03-22

    In China, the construction of asphalt pavement has a significant impact on the environment, and energy use and greenhouse gas (GHG) emissions from asphalt pavement construction have been receiving increasing attention in recent years. At present, there is no universal criterion for the evaluation of GHG emissions in asphalt pavement construction. This paper proposes to define the system boundaries for GHG emissions from asphalt pavement by using a process-based life cycle assessment method. A method for evaluating GHG emissions from asphalt pavement construction is suggested. The paper reports a case study of GHG emissions from a typical asphalt pavement construction project in China. The results show that the greenhouse gas emissions from the mixture mixing phase are the highest, and account for about 54% of the total amount. The second highest GHG emission phase is the production of raw materials. For GHG emissions of cement stabilized base/subbase, the production of raw materials emits the most, about 98%. The GHG emission for cement production alone is about 92%. The results indicate that any measures to reduce GHG emissions from asphalt pavement construction should be focused on the raw materials manufacturing stage. If the raw materials production phase is excluded, the measures to reduce GHG emissions should be aimed at the mixture mixing phase.

  15. Inferring pavement layer properties from a moving measurement platform

    DEFF Research Database (Denmark)

    Andersen, Sebastian; Levenberg, Eyal; Andersen, M.B.

    2017-01-01

    was achieved when the correct pavement model and accurate input data were employed. Also, when artificial errors were introduced for assessing sensitivities, only small deviations were generated. Based on these promising outcomes the method will be further studied and developed to support the construction...

  16. Re-use of stabilised flue gas ashes from solid waste incineration in cement-treated base layers for pavements

    DEFF Research Database (Denmark)

    Cai, Zuansi; Jensen, Dorthe Lærke; Christensen, Thomas Højlund

    2003-01-01

    Fly ash from coal-burning power plants has been used extensively as a pozzolan and fine filter in concrete for many years. Laboratory experiments were performed investigating the effect of substituting the coal-based fly ash with chemically stabilised flue gas ashes (FGA) from waste incineration...... would teach during a 100-year period from a 0.5 m thick concrete stab exposed to water on one side. Leaching of the common ions Ca, Cl, Na and SO4 was increased 3-20 times from the specimens with chemically stabilised flue gas ashes from waste incineration. However, the quantities leached were still...... modest. These experiments suggest that FGA from waste incineration after Ferrox-treatment could be re-used in CTB without compromising the strength and teaching from the base layer....

  17. Fuzzy logic inference-based Pavement Friction Management and real-time slippery warning systems: A proof of concept study.

    Science.gov (United States)

    Najafi, Shahriar; Flintsch, Gerardo W; Khaleghian, Seyedmeysam

    2016-05-01

    Minimizing roadway crashes and fatalities is one of the primary objectives of highway engineers, and can be achieved in part through appropriate maintenance practices. Maintaining an appropriate level of friction is a crucial maintenance practice, due to the effect it has on roadway safety. This paper presents a fuzzy logic inference system that predicts the rate of vehicle crashes based on traffic level, speed limit, and surface friction. Mamdani and Sugeno fuzzy controllers were used to develop the model. The application of the proposed fuzzy control system in a real-time slippery road warning system is demonstrated as a proof of concept. The results of this study provide a decision support model for highway agencies to monitor their network's friction and make appropriate judgments to correct deficiencies based on crash risk. Furthermore, this model can be implemented in the connected vehicle environment to warn drivers of potentially slippery locations. Published by Elsevier Ltd.

  18. Evaluating a problem based learning course: an action research study.

    Science.gov (United States)

    Walker, J; Bailey, S; Brasell-Brian, R; Gould, S

    2001-03-01

    Problem based learning (PBL) has been widely used in the United States, United Kingdom and Australasia in undergraduate nursing education to develop critical thinking and problem solving skills. PBL has been used since 1996 in a Bachelor of Nursing course at a New Zealand tertiary institution, and several modifications have been made to foster effective learning. The 'pure' PBL process has been adapted to move students gradually from teacher direction to taking responsibility for their learning. This has provided the opportunity for students to develop critical thinking, problem solving, information retrieval and evaluation skills, and group process skills over an 18-week period. Because rigorous evaluation of these changes had not been formally undertaken, the purpose of this study was to evaluate how the current format was developing students' understanding and integration of knowledge. Two cycles of the action research method (Cardno and Piggot-Irvine, 1994) were used, involving 4 lecturers and 17 students. Data was collected both quantitatively and qualitatively over a 16-week period. Findings indicated the importance of: explaining the purpose and process of PBL; communicating in detail the role of both students and lecturers; keeping communication lines open; addressing timetabling issues and valuing this method of learning for nursing practice. Implications for nursing education are addressed.

  19. Generating enhanced site topography data to improve permeable pavement performance assessment methods - presentation

    Science.gov (United States)

    Permeable pavement surfaces are infiltration based stormwater control measures (SCM) commonly applied in parking lots to decrease impervious area and reduce runoff volume. Many are not optimally designed however, as little attention is given to draining a large enough contributin...

  20. Selection of pavement foundation geomaterials for the construction of a new runway

    CSIR Research Space (South Africa)

    Anochie-Boateng, Joseph

    2011-07-01

    Full Text Available The selection of foundation geomaterials including base/subbase unbound granular aggregate is critical for the design of flexible airfield pavements in the United States. These materials must meet the Federal Aviation Administration (FAA) selection...

  1. Cone penetrometer equipped with piezoelectric sensors for measurement of soil stiffness in highway pavement.

    Science.gov (United States)

    2005-11-01

    The stiffness (elastic modulus and shear modulus) and Poisson's ratio of the base and sublayers are important parameters in the design and quality assurance during construction of highway pavements. The new highway construction guide proposed by AASH...

  2. Development of a validation process for parameters utilized in optimizing construction quality management of pavements.

    Science.gov (United States)

    2006-01-01

    The implementation of an effective performance-based construction quality management requires a tool for determining impacts of construction quality on the life-cycle performance of pavements. This report presents an update on the efforts in the deve...

  3. Development of field performance evaluation tools and program for pavement marking materials : technical report

    Science.gov (United States)

    2011-03-01

    Historically the prequalification or selection of pavement marking materials (PMMs) is mainly based on : product specifications and lab testing, which do not correlate well with the field performance of the products. : On the other hand, there is no ...

  4. The evaluation of epoxy thermoplastic pavement marking material in Virginia : the application : interim report.

    Science.gov (United States)

    1983-01-01

    Epoxy Thermoplastic (ETP) is a recently developed epoxy-resin-based thermoplastic pavement marking material being promoted by the Federal Highway Administration as a possible substitute for conventional traffic paints and thermoplastics. Its reported...

  5. Re-use of stabilised flue gas ashes from solid waste incineration in cement-treated base layers for pavements

    DEFF Research Database (Denmark)

    Cai, Zuansi; Jensen, Dorthe Lærke; Christensen, Thomas Højlund

    2003-01-01

    Fly ash from coal-burning power plants has been used extensively as a pozzolan and fine filter in concrete for many years. Laboratory experiments were performed investigating the effect of substituting the coal-based fly ash with chemically stabilised flue gas ashes (FGA) from waste incineration...... weeks. Cylinders (diameter 100 mm, length 150 mm) were drilled from these cubes for tank leaching experiments. Duplicate specimens were subject to compression strength testing and to tank leaching experiments. The compressive strength of the CTB fulfilled the Danish requirements for CTB, i.e. strength...... more than 5 MPa after 7 days. The tank leaching tests revealed that leaching of heavy metals was not significantly affected by the use of chemically stabilised flue gas ashes from waste incineration. Assuming that diffusion controls the leaching process it was calculated that less than 1% of the metals...

  6. EVALUATION MODEL FOR PAVEMENT SURFACE DISTRESS ON 3D POINT CLOUDS FROM MOBILE MAPPING SYSTEM

    Directory of Open Access Journals (Sweden)

    K. Aoki

    2012-07-01

    Full Text Available This paper proposes a methodology to evaluate the pavement surface distress for maintenance planning of road pavement using 3D point clouds from Mobile Mapping System (MMS. The issue on maintenance planning of road pavement requires scheduled rehabilitation activities for damaged pavement sections to keep high level of services. The importance of this performance-based infrastructure asset management on actual inspection data is globally recognized. Inspection methodology of road pavement surface, a semi-automatic measurement system utilizing inspection vehicles for measuring surface deterioration indexes, such as cracking, rutting and IRI, have already been introduced and capable of continuously archiving the pavement performance data. However, any scheduled inspection using automatic measurement vehicle needs much cost according to the instruments’ specification or inspection interval. Therefore, implementation of road maintenance work, especially for the local government, is difficult considering costeffectiveness. Based on this background, in this research, the methodologies for a simplified evaluation for pavement surface and assessment of damaged pavement section are proposed using 3D point clouds data to build urban 3D modelling. The simplified evaluation results of road surface were able to provide useful information for road administrator to find out the pavement section for a detailed examination and for an immediate repair work. In particular, the regularity of enumeration of 3D point clouds was evaluated using Chow-test and F-test model by extracting the section where the structural change of a coordinate value was remarkably achieved. Finally, the validity of the current methodology was investigated by conducting a case study dealing with the actual inspection data of the local roads.

  7. Flow Formulation-based Model for the Curriculum-based Course Timetabling Problem

    DEFF Research Database (Denmark)

    Bagger, Niels-Christian Fink; Kristiansen, Simon; Sørensen, Matias

    2015-01-01

    In this work we will present a new mixed integer programming formulation for the curriculum-based course timetabling problem. We show that the model contains an underlying network model by dividing the problem into two models and then connecting the two models back into one model using a maximum ow...

  8. Comparison of winter temperature profiles in asphalt and concrete pavements.

    Science.gov (United States)

    2014-06-01

    The objectives of this research were to 1) determine which pavement type, asphalt or concrete, has : higher surface temperatures in winter and 2) compare the subsurface temperatures under asphalt and : concrete pavements to determine the pavement typ...

  9. Minnesota Local Agency Pavement Marking : Mining Existing Data

    Science.gov (United States)

    2017-11-01

    Pavement marking is important for safety. Maximizing pavement marking performance in terms of increased retroreflectivity, within limited budget constraints, allows agencies to make better decisions toward providing more effective pavement marking pe...

  10. Texas flexible pavements overlays : review and analysis of existing databases.

    Science.gov (United States)

    2011-12-01

    Proper calibration of pavement design and rehabilitation performance models to : conditions in Texas is essential for cost-effective flexible pavement design. The degree of : excellence with which TxDOTs pavement design models is calibrated will d...

  11. Do sediment type and test durations affect results of laboratory-based, accelerated testing studies of permeable pavement clogging?

    Science.gov (United States)

    Nichols, Peter W B; White, Richard; Lucke, Terry

    2015-04-01

    Previous studies have attempted to quantify the clogging processes of Permeable Interlocking Concrete Pavers (PICPs) using accelerated testing methods. However, the results have been variable. This study investigated the effects that three different sediment types (natural and silica), and different simulated rainfall intensities, and testing durations had on the observed clogging processes (and measured surface infiltration rates) of laboratory-based, accelerated PICP testing studies. Results showed that accelerated simulated laboratory testing results are highly dependent on the type, and size of sediment used in the experiments. For example, when using real stormwater sediment up to 1.18 mm in size, the results showed that neither testing duration, nor stormwater application rate had any significant effect on PICP clogging. However, the study clearly showed that shorter testing durations generally increased clogging and reduced the surface infiltration rates of the models when artificial silica sediment was used. Longer testing durations also generally increased clogging of the models when using fine sediment (<300 μm). Results from this study will help researchers and designers better anticipate when and why PICPs are susceptible to clogging, reduce maintenance and extend the useful life of these increasingly common stormwater best management practices. Copyright © 2015 Elsevier B.V. All rights reserved.

  12. Tuning in to pavement radio

    NARCIS (Netherlands)

    Ellis, S.D.K.

    1989-01-01

    This article describes a phenomenon known all over Africa, for which there is no really satisfactory term in English but which is summed up in the French term 'radio trottoir', literally 'pavement radio'. It may be defined as the popular and unofficial discussion of current affairs in Africa,

  13. The Concrete and Pavement Challenge

    Science.gov (United States)

    Roman, Harry T.

    2012-01-01

    The modern world is characterized by the extensive use of concrete and asphalt pavement. Periodically, these materials are replaced and the old materials disposed of. In this challenge, students will be asked to develop ways to reuse the old materials. It is important for students to understand how concrete and asphalt are made and applied, as…

  14. Feasibility of reclaimed asphalt pavement as aggregate in portland cement concrete pavements.

    Science.gov (United States)

    2013-11-01

    This research effort was focused on evaluating the feasibility of using minimally processed reclaimed : asphalt pavement (RAP) as aggregate replacement in concrete pavements. This research demonstrated : that concretes with up to 50 percent of the fi...

  15. Comparison of accelerated pavement test results with long term pavement behaviour and performance

    CSIR Research Space (South Africa)

    Jooste, FJ

    1997-08-01

    Full Text Available The aim of this study was to investigate the following:how accelerated pavement testing predictions compare with actual road behaviour and performance the relative influences of load and environmental factors on pavement deterioration and how well...

  16. An integrated pavement data management and feedback system (PAMS) : evaluation of pavement condition rating procedure.

    Science.gov (United States)

    1984-08-01

    This report describes an evaluation of a method for use in the Highway Needs Study pavement condition rating. The methods by which the Department generates and manages pavement condition data in the overall process of providing a network of highways ...

  17. Integration and Evaluation of Automated Pavement Distress Data in INDOT’s Pavement Management System

    Science.gov (United States)

    2017-05-01

    This study was in two parts. The first part established and demonstrated a framework for pavement data integration. This is critical for fulfilling QC/QA needs of INDOTs pavement management system, because the precision of the physical location re...

  18. Long-term pavement performance information management system : pavement performance database user reference guide

    Science.gov (United States)

    2003-11-01

    This document provides information to aid in understanding and using the Long-Term Pavement Performance (LTPP) program pavement performance database. This document provides an introduction to the structure of the LTPP program, the relational structur...

  19. Application of the portable pavement seismic analyser (PSPA) for pavement analysis

    CSIR Research Space (South Africa)

    Steyn, WJVDM

    2007-07-01

    Full Text Available of pavement types, including Long-Term Pavement Performance (LTPP) sections and Heavy Vehicle Simulator (HVS) test sites. The data are analysed for repeatability, variability, isotropy, and ranges of seismic stiffness values. Information is provided...

  20. Advanced Pavement Design: Finite Element Modeling for Rigid Pavement Joints, Report II: Model Development

    National Research Council Canada - National Science Library

    Hammons, Michael

    1998-01-01

    .... The objective of this research was to obtain data on the response of the ng'id pavement slab-joint-foundation system by conducting laboratory-scale experiments on jointed rigid pavement models...

  1. MoDOT pavement preservation research program volume IV, pavement evaluation tools-data collection methods.

    Science.gov (United States)

    2015-10-01

    The overarching goal of the MoDOT Pavement Preservation Research Program, Task 3: Pavement Evaluation Tools Data : Collection Methods was to identify and evaluate methods to rapidly obtain network-level and project-level information relevant to :...

  2. Modelling of pavement materials on steel decks using the five-point bending test: Thermo mechanical evolution and fatigue damage

    International Nuclear Information System (INIS)

    Arnaud, L; Houel, A

    2010-01-01

    This paper deals with the modelling of wearing courses on steel orthotropic decks such as the Millau viaduct in France. This is of great importance when dealing with durability: due to the softness of such a support, the pavement is subjected to considerable strains that may generate top-down cracks in the layer at right angles of the orthotropic plate stiffeners and shear cracks at the interface between pavement and steel. Therefore, a five-point bending fatigue test was developed and improved since 2003 at the ENTPE laboratory, to test different asphalt concrete mixes. This study aims at modelling the mechanical behavior of the wearing course throughout the fatigue test by a finite element method (Comsol Multiphysics software). Each material - steel, sealing sheet, asphalt concrete layer - is considered and modelled. The modelling of asphalt concrete is complex since it is a heterogeneous material, a viscoelastic medium and it thermosensitive. The actual characteristics of the asphalt concrete (thermo physical parameter and viscoelastic complex modulus) are determined experimentally on cylindrical cores. Moreover, a damage law based on Miner's damage is included in the model. The modelling of the fatigue test leads to encouraging results. Finally, results from the model are compared to the experimental data obtained from the five-point bending fatigue test device. The experimental data are very consistent with the numerical simulation.

  3. DOE contractor radiation safety CBT [computer based training] course

    International Nuclear Information System (INIS)

    Gardner, P.R.

    1986-01-01

    Westinghouse Hanford Company developed a generic Radiation Worker safety CBT course for Department of Energy contractors. Task analysis concentrated on actual and potential tasks and included visits to fourteen different contractor sites. Team Design and Prototype verification formed the major portion of the development phase. Lesson entry was accomplished using the WISE author system from WICAT Systems, Inc. The course features graded task simulations for both Pretest and Final; fourteen Topics in five Lessons, each Topic keyed to ''Critical Acts'' and Questions in the Pretest and Final; Automatic, Intensive, and Manual modes of instruction available for each Lesson; Practical Problems and Sample Questions associated with each Topic; and provisions for local configuration in several areas. The course is deliverable on IBM PC compatible equipment. 2 refs

  4. Performance evaluation of thin wearing courses through scaled accelerated trafficking.

    Science.gov (United States)

    2014-01-01

    The primary objective of this study was to evaluate the permanent deformation (rutting) and fatigue performance of : several thin asphalt concrete wearing courses using a scaled-down accelerated pavement testing device. The accelerated testing : was ...

  5. Recyclability of Concrete Pavement Incorporating High Volume of Fly Ash

    Science.gov (United States)

    Yoshitake, Isamu; Ishida, Takeo; Fukumoto, Sunao

    2015-01-01

    Recyclable concrete pavement was made from fly ash and crushed limestone sand and gravel as aggregates so that the concrete pavement could be recycled to raw materials for cement production. With the aim to use as much fly ash as possible for the sustainable development of society, while achieving adequate strength development, pavement concrete having a cement-replacement ratio of 40% by mass was experimentally investigated, focusing on the strength development at an early age. Limestone powder was added to improve the early strength; flexural strength at two days reached 3.5 MPa, the minimum strength for traffic service in Japan. The matured fly ash concrete made with a cement content of 200 kg/m3 achieved a flexural strength almost equal to that of the control concrete without fly ash. Additionally, Portland cement made from the tested fly ash concrete was tested to confirm recyclability, with the cement quality meeting the Japanese classification of ordinary Portland cement. Limestone-based recyclable fly ash concrete pavement is, thus, a preferred material in terms of sustainability. PMID:28793518

  6. ANALYSES OF THE INFLUENCE OF MATERIAL CHARACTERISTICS ON PAVEMENT DESIGN

    Directory of Open Access Journals (Sweden)

    Nino Vukobratović

    2017-01-01

    Full Text Available Currently, only empirical design methods are used in the application of well-known standards for pavement structure design. Given this fact, it is assumed that material characteristics correspond to average quality materials. Thus, the aim of this study included examining the influence of material characteristics on pavement design analyzing changes in the cement bound base layer (CBL characteristics with respect to the occurrence of cracks and changes in the asphalt layer given typical seasonal changes. The study involved varying CBL modulus as 15 GPa, 10 GPa, and 5 GPa. Additionally, the moduli of asphalt layers were varied from 6 MPa to 2 MPa to simulate real conditions in pavement structure life. The analyses indicated that there was a significant difference in pavement behavior with respect to changes in material characteristics. Given these significant differences, it is extremely important to properly define material characteristics while using empirical design methods. Proper material characterization combined with the utilization of empirical and analytical methods increases the possibility of reducing layers thickness to design cost-effective structures.

  7. Experimental continuously reinforced concrete pavement parameterization using nondestructive methods

    Directory of Open Access Journals (Sweden)

    L. S. Salles

    Full Text Available ABSTRACT Four continuously reinforced concrete pavement (CRCP sections were built at the University of São Paulo campus in order to analyze the pavement performance in a tropical environment. The sections short length coupled with particular project aspects made the experimental CRCP cracking be different from the traditional CRCP one. After three years of construction, a series of nondestructive testing were performed - Falling Weight Deflectometer (FWD loadings - to verify and to parameterize the pavement structural condition based on two main properties: the elasticity modulus of concrete (E and the modulus of subgrade reaction (k. These properties estimation was obtained through the matching process between real and EverFE simulated basins with the load at the slab center, between two consecutive cracks. The backcalculation results show that the lack of anchorage at the sections end decreases the E and k values and that the longitudinal reinforcement percentage provides additional stiffness to the pavement. Additionally, FWD loadings tangential to the cracks allowed the load transfer efficiency (LTE estimation determination across cracks. The LTE resulted in values above 90 % for all cracks.

  8. Recyclability of Concrete Pavement Incorporating High Volume of Fly Ash

    Directory of Open Access Journals (Sweden)

    Isamu Yoshitake

    2015-08-01

    Full Text Available Recyclable concrete pavement was made from fly ash and crushed limestone sand and gravel as aggregates so that the concrete pavement could be recycled to raw materials for cement production. With the aim to use as much fly ash as possible for the sustainable development of society, while achieving adequate strength development, pavement concrete having a cement-replacement ratio of 40% by mass was experimentally investigated, focusing on the strength development at an early age. Limestone powder was added to improve the early strength; flexural strength at two days reached 3.5 MPa, the minimum strength for traffic service in Japan. The matured fly ash concrete made with a cement content of 200 kg/m3 achieved a flexural strength almost equal to that of the control concrete without fly ash. Additionally, Portland cement made from the tested fly ash concrete was tested to confirm recyclability, with the cement quality meeting the Japanese classification of ordinary Portland cement. Limestone-based recyclable fly ash concrete pavement is, thus, a preferred material in terms of sustainability.

  9. Recyclability of Concrete Pavement Incorporating High Volume of Fly Ash.

    Science.gov (United States)

    Yoshitake, Isamu; Ishida, Takeo; Fukumoto, Sunao

    2015-08-21

    Recyclable concrete pavement was made from fly ash and crushed limestone sand and gravel as aggregates so that the concrete pavement could be recycled to raw materials for cement production. With the aim to use as much fly ash as possible for the sustainable development of society, while achieving adequate strength development, pavement concrete having a cement-replacement ratio of 40% by mass was experimentally investigated, focusing on the strength development at an early age. Limestone powder was added to improve the early strength; flexural strength at two days reached 3.5 MPa, the minimum strength for traffic service in Japan. The matured fly ash concrete made with a cement content of 200 kg/m3 achieved a flexural strength almost equal to that of the control concrete without fly ash. Additionally, Portland cement made from the tested fly ash concrete was tested to confirm recyclability, with the cement quality meeting the Japanese classification of ordinary Portland cement. Limestone-based recyclable fly ash concrete pavement is, thus, a preferred material in terms of sustainability.

  10. Automated management for pavement inspection system (AMPIS)

    Science.gov (United States)

    Chung, Hung Chi; Girardello, Roberto; Soeller, Tony; Shinozuka, Masanobu

    2003-08-01

    An automated in-situ road surface distress surveying and management system, AMPIS, has been developed on the basis of video images within the framework of GIS software. Video image processing techniques are introduced to acquire, process and analyze the road surface images obtained from a moving vehicle. ArcGIS platform is used to integrate the routines of image processing and spatial analysis in handling the full-scale metropolitan highway surface distress detection and data fusion/management. This makes it possible to present user-friendly interfaces in GIS and to provide efficient visualizations of surveyed results not only for the use of transportation engineers to manage road surveying documentations, data acquisition, analysis and management, but also for financial officials to plan maintenance and repair programs and further evaluate the socio-economic impacts of highway degradation and deterioration. A review performed in this study on fundamental principle of Pavement Management System (PMS) and its implementation indicates that the proposed approach of using GIS concept and its tools for PMS application will reshape PMS into a new information technology-based system providing a convenient and efficient pavement inspection and management.

  11. Cracking of open traffic rigid pavement

    OpenAIRE

    Niken Chatarina; Siswanto Yudi; Widodo; Tjahjono Elly

    2017-01-01

    The research is done by observing the growth of real structure cracking in Natar, Lampung, Indonesia compared to C. Niken’s et al research and literature study. The rigid pavement was done with open traffic system. There are two main crack types on Natar rigid pavement: cracks cross the road, and cracks spreads on rigid pavement surface. The observation of cracks was analyzed by analyzing material, casting, curing, loading and shrinkage mechanism. The relationship between these analysis and s...

  12. Nutrient infiltrate concentrations from three permeable pavement types.

    Science.gov (United States)

    Brown, Robert A; Borst, Michael

    2015-12-01

    While permeable pavement is increasingly being used to control stormwater runoff, field-based, side-by-side investigations on the effects different pavement types have on nutrient concentrations present in stormwater runoff are limited. In 2009, the U.S. EPA constructed a 0.4-ha parking lot in Edison, New Jersey, that incorporated permeable interlocking concrete pavement (PICP), pervious concrete (PC), and porous asphalt (PA). Each permeable pavement type has four, 54.9-m(2), lined sections that direct all infiltrate into 5.7-m(3) tanks enabling complete volume collection and sampling. This paper highlights the results from a 12-month period when samples were collected from 13 rainfall/runoff events and analyzed for nitrogen species, orthophosphate, and organic carbon. Differences in infiltrate concentrations among the three permeable pavement types were assessed and compared with concentrations in rainwater samples and impervious asphalt runoff samples, which were collected as controls. Contrary to expectations based on the literature, the PA infiltrate had significantly larger total nitrogen (TN) concentrations than runoff and infiltrate from the other two permeable pavement types, indicating that nitrogen leached from materials in the PA strata. There was no significant difference in TN concentration between runoff and infiltrate from either PICP or PC, but TN in runoff was significantly larger than in the rainwater, suggesting meaningful inter-event dry deposition. Similar to other permeable pavement studies, nitrate was the dominant nitrogen species in the infiltrate. The PA infiltrate had significantly larger nitrite and ammonia concentrations than PICP and PC, and this was presumably linked to unexpectedly high pH in the PA infiltrate that greatly exceeded the optimal pH range for nitrifying bacteria. Contrary to the nitrogen results, the PA infiltrate had significantly smaller orthophosphate concentrations than in rainwater, runoff, and infiltrate from PICP

  13. Construction of Course Ubiquitous Learning Based on Network

    Science.gov (United States)

    Wang, Xue; Zhang, Wei; Yang, Xinhui

    2017-01-01

    Ubiquitous learning has been more and more recognized, which describes a new generation of learning from a new point of view. Ubiquitous learning will bring the new teaching practice and teaching reform, which will become an essential way of learning in 21st century. Taking translation course as a case study, this research constructed a system of…

  14. Relationship between Nursing Students' Views about Web-Based Patient Education Course and Anxiety in Turkey

    Science.gov (United States)

    Tasocak, Gülsün; Kaya, Hülya; Senyuva, Emine; Isik, Burçin; Bodur, Gönül

    2014-01-01

    The study was designed as descriptive and cross-sectional to determine the relation between students' views about web-based Patient Education course and anxiety. The study group consisted of all students registered the web-based Patient Education course (N: 148) at 2010-2011 semester at a nursing school. Data were collected using "Information…

  15. Business and Industry Project-Based Capstone Courses: A Reflection on the Performance of Student Teams

    Science.gov (United States)

    Maleki, Reza A.

    2009-01-01

    This is the second of two articles in which the author shares experiences gained from the development and delivery of a business/industry project-based capstone course. The course integrates research, proposal development and design experience based on knowledge and skills acquired in earlier coursework. It also incorporates standards and…

  16. The Merits of a Two-Day Evidence-Based Medicine Course for Surgical Residents

    NARCIS (Netherlands)

    Ubbink, Dirk T.; Legemate, Dink A.; Koelemay, Mark J.

    2016-01-01

    Over 10 years ago, we introduced a two-day, evidence-based surgery course for surgical residents. During the last 4 years, we evaluated its effect on the participants' evidence-based medicine (EBM) knowledge and skills. Between 2012 and 2015, six courses were organised for residents of various

  17. Preliminary evaluation of the lifecycle costs and market barriers of reflective pavements; TOPICAL

    International Nuclear Information System (INIS)

    Ting, M.; Koomey, J.G.; Pomerantz, M.

    2001-01-01

    , which we call the chipping and aggregate methods, and calculated their potential life cycle costs. By analyzing the potential for increased pavement durability resulting from these conceptual approaches, we then estimated the incremental costs that would allow them to be cost-effective compared to conventional AC. For our example case of Los Angeles, we found that those allowable incremental costs range from less than dollar 1 to more than dollar 11 per square yard (dollar 1 to dollar 13 per square meter) depending on street type and the condition of the original pavement. Finally, we evaluated the main actors in the pavement market and the existing and potential market barriers associated with reflective pavements. Apart from situations where lifecycle costs are high compared to conventional AC, all reflective paving technologies face a cultural barrier based on the belief that black is better. For PCC, high first costs were found to be the most significant economic barrier, particularly where agencies are cons trained by first cost. Lack of developer standards was found to be a significant institutional barrier to PCC since developers are often not held accountable for the long-term maintenance of roads after initial construction, which creates a misplaced incentive to build low first-cost pavements. PCC also faces site-specific barriers such as poorly compacted base soils and proximity to areas of frequent utility cutting

  18. Preliminary evaluation of the lifecycle costs and market barriers of reflective pavements

    Energy Technology Data Exchange (ETDEWEB)

    Ting, M.; Koomey, J.G.; Pomerantz, M.

    2001-11-21

    , which we call the chipping and aggregate methods, and calculated their potential life cycle costs. By analyzing the potential for increased pavement durability resulting from these conceptual approaches, we then estimated the incremental costs that would allow them to be cost-effective compared to conventional AC. For our example case of Los Angeles, we found that those allowable incremental costs range from less than dollar 1 to more than dollar 11 per square yard (dollar 1 to dollar 13 per square meter) depending on street type and the condition of the original pavement. Finally, we evaluated the main actors in the pavement market and the existing and potential market barriers associated with reflective pavements. Apart from situations where lifecycle costs are high compared to conventional AC, all reflective paving technologies face a cultural barrier based on the belief that black is better. For PCC, high first costs were found to be the most significant economic barrier, particularly where agencies are cons trained by first cost. Lack of developer standards was found to be a significant institutional barrier to PCC since developers are often not held accountable for the long-term maintenance of roads after initial construction, which creates a misplaced incentive to build low first-cost pavements. PCC also faces site-specific barriers such as poorly compacted base soils and proximity to areas of frequent utility cutting.

  19. Prediction of performance and evaluation of flexible pavement rehabilitation strategies

    Directory of Open Access Journals (Sweden)

    Kang-Won Wayne Lee

    2017-04-01

    Full Text Available Five test sections with different additives and strategies were established to rehabilitate a State-maintained highway more effectively in Rhode Island (RI: control, calcium chloride, asphalt emulsion, Portland cement and geogrid. Resilient moduli of subgrade soils and subbase materials before and after full depth rehabilitation were employed as input parameters to predict the performance of pavement structures using AASHTOWare Pavement ME Design (Pavement ME software in terms of rutting, cracking and roughness. It was attempted to use Level 1 input (which includes traffic full spectrum data, climate data and structural layer properties for Pavement ME. Traffic data was obtained from a Weigh-in-Motion (WIM instrument and Providence station was used for collecting climatic data. Volumetric properties, dynamic modulus and creep compliance were used as input parameters for 19 mm (0.75 in. warm mix asphalt (WMA base and 12.5 mm (0.5 in. WMA surface layer. The results indicated that all test sections observed AC top-down (longitudinal cracking except Portland cement section which passed for all criteria. The order in terms of performance (best to worst for all test sections by Pavement ME was Portland cement, calcium chloride, control, geogrid, and asphalt emulsion. It was also observed that all test sections passed for both bottom up and top down fatigue cracking by increasing thickness of either of the two top asphalt layers. Test sections with five different base/subbase materials were evaluated in last two years through visual condition survey and measurements of deflection and roughness to confirm the prediction, but there was no serious distress and roughness. Thus these experiments allowed selecting the best rehabilitation/reconstruction techniques for the particular and/or similar highway, and a framework was formulated to select an optimal technique and/or strategy for future rehabilitation/reconstruction projects. Finally, guidelines for

  20. Do evidence-based active-engagement courses reduce the gender gap in introductory physics?

    Science.gov (United States)

    Karim, Nafis I.; Maries, Alexandru; Singh, Chandralekha

    2018-03-01

    Prior research suggests that using evidence-based pedagogies can not only improve learning for all students, it can also reduce the gender gap. We describe the impact of physics education research-based pedagogical techniques in flipped and active-engagement non-flipped courses on the gender gap observed with validated conceptual surveys. We compare male and female students’ performance in courses which make significant use of evidence-based active-engagement (EBAE) strategies with courses that primarily use lecture-based (LB) instruction. All courses had large enrolment and often had more than 100 students. The analysis of data for validated conceptual surveys presented here includes data from two-semester sequences of algebra-based and calculus-based introductory physics courses. The conceptual surveys used to assess student learning in the first and second semester courses were the force concept inventory and the conceptual survey of electricity and magnetism, respectively. In the research discussed here, the performance of male and female students in EBAE courses at a particular level is compared with LB courses in two situations: (I) the same instructor taught two courses, one of which was an EBAE course and the other an LB course, while the homework, recitations and final exams were kept the same; (II) student performance in all of the EBAE courses taught by different instructors was averaged and compared with LB courses of the same type also averaged over different instructors. In all cases, on conceptual surveys we find that students in courses which make significant use of active-engagement strategies, on average, outperformed students in courses of the same type using primarily lecture-based instruction even though there was no statistically significant difference on the pre-test before instruction. However, the gender gap persisted even in courses using EBAE methods. We also discuss correlations between the performance of male and female students on

  1. The impact of team-based learning on a foundational pharmacokinetics course.

    Science.gov (United States)

    Persky, Adam M

    2012-03-12

    To assess the impact of team-based learning (TBL) in a foundational pharmacokinetics course. The course was arranged into 5 modules based on the TBL format. Each module contained preclass preparation; readiness-assurance process; and in-class, clinical cases. Survey instruments on professionalism and attitudes of team learning were administered pre- and post-course. Examination grades focused at the evaluation/creation level were significantly higher in the TBL format compared with the previous year. Professionalism scores increased over the course of the semester, particularly in altruism and honesty. Other measures of team-learning attitudes significantly increased over time, although there was no change in major subscales. End-of-semester course evaluations showed improvements in active engagement and in various areas of skill development. The TBL format can be used successfully in a foundational pharmacokinetics course to increase higher levels of learning, team-learning skills, and professionalism in pharmacy students.

  2. NARROW READING IN AN EXTENSIVE READING COURSE: LEXICALLY-BASED

    Directory of Open Access Journals (Sweden)

    Siusana Kweldju

    2016-02-01

    Full Text Available One shot case study was conducted in one semester to undergraduate English majors who were preparing themselves to become English teachers at high school level. This study was to find out whether or not students had positive attitudes towards narrow reading, how high narrow reading helped them improve their English proficiency, and what problems students might have with narrow reading. Four questionnaires were completed during the case study to discover how students felt and thought about the course and how the course improved their English. It was found out that narrow reading not only improved students' language proficiency but also helped students develop their general knowledge, the love of reading and the appreciation on literary work.

  3. The use of accelerometers in the pavement performance monitoring and analysis

    International Nuclear Information System (INIS)

    Ryynaenen, T; Belt, J; Pellinen, T

    2010-01-01

    This study investigated the use of sensor technology to enhance the management of highway infrastructure. With the help of monitoring data, it is possible to assess the current analytical pavement analysis method, which is based on multi-layered elastic analysis, and, thus enhance the pavement design practices in use. Pavement response was measured using different sensors, installed at various depths. Most promising sensors for the continuous monitoring purposes were the accelerometers. The drawback of these sensors is that the measured quantity is acceleration, which must be converted to the deflection via mathematical integration. In this paper some issues related to the manipulation of accelerometer data is presented and discussed, in addition of the discussion of the calculated and measured pavement response.

  4. The use of accelerometers in the pavement performance monitoring and analysis

    Science.gov (United States)

    Ryynänen, T.; Pellinen, T.; Belt, J.

    2010-06-01

    This study investigated the use of sensor technology to enhance the management of highway infrastructure. With the help of monitoring data, it is possible to assess the current analytical pavement analysis method, which is based on multi-layered elastic analysis, and, thus enhance the pavement design practices in use. Pavement response was measured using different sensors, installed at various depths. Most promising sensors for the continuous monitoring purposes were the accelerometers. The drawback of these sensors is that the measured quantity is acceleration, which must be converted to the deflection via mathematical integration. In this paper some issues related to the manipulation of accelerometer data is presented and discussed, in addition of the discussion of the calculated and measured pavement response.

  5. The numerical model for parametric studies of forest haul roads pavements

    Directory of Open Access Journals (Sweden)

    Lenka Ševelová

    2010-01-01

    Full Text Available Forest roads pavement structures are considered to be low volume roads. These roads serve as a mean of transport of wood and people. Besides they are currently often used for recreational purpose. The construction of the pavements should be suitable for forest transportation irrespective of their low bearing capacity. These pavement structures are very specific for special unbound materials that are used in their construction. To meet the requirements of the pavement designs and simulation analysis the FEM model in the software ANSYS was created.This paper compares two material models used for the description of the behaviour of unbound materials. The first is linear elastic according to Hook theory (H model and the second one is nonlinear plastic model Drucker-Prager (D–P model. ANSYS software has been used to create flexible model based on the parametrers of variable principle. The flexible model is parametric to realize repeated calculations useful for optimization analysis.

  6. Application of Finite Layer Method in Pavement Structural Analysis

    Directory of Open Access Journals (Sweden)

    Pengfei Liu

    2017-06-01

    Full Text Available The finite element (FE method has been widely used in predicting the structural responses of asphalt pavements. However, the three-dimensional (3D modeling in general-purpose FE software systems such as ABAQUS requires extensive computations and is relatively time-consuming. To address this issue, a specific computational code EasyFEM was developed based on the finite layer method (FLM for analyzing structural responses of asphalt pavements under a static load. Basically, it is a 3D FE code that requires only a one-dimensional (1D mesh by incorporating analytical methods and using Fourier series in the other two dimensions, which can significantly reduce the computational time and required resources due to the easy implementation of parallel computing technology. Moreover, a newly-developed Element Energy Projection (EEP method for super-convergent calculations was implemented in EasyFEM to improve the accuracy of solutions for strains and stresses over the whole pavement model. The accuracy of the program is verified by comparing it with results from BISAR and ABAQUS for a typical asphalt pavement structure. The results show that the predicted responses from ABAQUS and EasyFEM are in good agreement with each other. The EasyFEM with the EEP post-processing technique converges faster compared with the results derived from ordinary EasyFEM applications, which proves that the EEP technique can improve the accuracy of strains and stresses from EasyFEM. In summary, the EasyFEM has a potential to provide a flexible and robust platform for the numerical simulation of asphalt pavements and can easily be post-processed with the EEP technique to enhance its advantages.

  7. Evaluating life cycle costs of perpetual pavements in China using operational pavement management system

    Directory of Open Access Journals (Sweden)

    Saud A. Sultan

    2016-10-01

    Full Text Available Highway transportation is considered as vital factor in China’s economic growth; many high grade highways have been constructed in China during the last decades. The research and application of perpetual asphalt pavement (PP technology have been deployed in China since 2000. The semi-rigid pavement has been normally considered as typical pavement of high class highways in the design according to the Chinese experience. The objective of this research is to evaluate the performance of different Chinese perpetual pavements using operational pavement management system and to examine its suitability for use in the design and construction of more economical and durable pavements. It has been found that the use of thin asphalt layers over semi-rigid pavement foundation in PP structure will create more sustainable, economical, and durable PP structures in comparison with typical thick asphalt layers PP structures.

  8. A comparison of student characteristics in traditional and Web-based college science courses

    Science.gov (United States)

    Andrikanich, Meghan

    Distance learning options at colleges and universities are increasing dramatically (e.g. National Center for Educational Statistics [NCES], 1998; NCES, 2001). Web-based courses create an interesting learning environment for study (e.g., Dupin-Bryant, 2004; Maki & Maki, 2003). Because science is a topic that induces anxiety for many students (e.g., Brownlow, et al., 2000; Greenburg & Mallow, 1982), and test anxiety has been linked to reduced academic performance (e.g., Bruch, 1981; Spielberger, 1979), the intersection of course format, science, and test anxiety is an area in need of research. This study used an explanatory mixed method design. One hundred and seven web-based science students and 110 students enrolled in traditional courses completed a questionnaire regarding demographic and personal factors, the Reduced Reaction to Tests (RTT) (Benson & Bandalos, 1992) and the Locus of Control of Behavior Scale (Craig, Franklin, & Andrews, 1984). Ten students participated in a follow-up interview. Quantitative results found no significant difference between age, racial/ethnic background, student status (full-time or part-time), or degree program being pursued between traditional and web-based science courses. Significantly more females, more students employed full-time, and with an external locus of control enrolled in web-based courses. Students in traditional courses experienced more test anxiety due to test-irrelevant thoughts. Traditional students experienced more anxiety in traditional science courses, while nontraditional students experienced more anxiety in web-based science courses. Expected course grade and locus of control predicted test anxiety in traditional courses, and previous web experience, expected grade, and locus of control predicted test anxiety for web-based courses. Qualitative data indicated that students in both formats expressed opinions regarding course format, studying and test preparation methods, test-taking, communication with

  9. Combining Project-Based Learning and Community-Based Research in a Research Methodology Course: The Lessons Learned

    Science.gov (United States)

    Arantes do Amaral, João Alberto; Lino dos Santos, Rebeca Júlia Rodrigues

    2018-01-01

    In this article, we present our findings regarding the course "Research Methodology," offered to 22 first-year undergraduate students studying Administration at the Federal University of São Paulo, Osasco, Brazil. The course, which combined community-based research and project-based learning, was developed during the second semester of…

  10. Rationale for the Design of a Web-based Programming Course for Adults

    DEFF Research Database (Denmark)

    Bennedsen, Jens; Caspersen, Michael Edelgaard

    2003-01-01

    for choosing technologies and organizing the course in order to compensate for the drawbacks inherent in this kind of teaching. Our conclusions, although presented in the context of an introductory programming course, holds for most other construction-based courses as well. In the first part we set the stage......Web-based distance education is becoming more and more popular in particular for part-time educations primarily because it flexibly adapts to a busy life where family and work has first priority. Students can follow the course without wasting precious time traveling to and from campus several...... assistant as well as the other students. Another serious drawback is the reduced bandwidth in communication among the different actors. Precautions have to be taken in order to compensate for these and other drawbacks. We describe a web-based introductory programming course for adults and the rationale...

  11. A Wiki-Based Group Project in an Inorganic Chemistry Foundation Course

    Science.gov (United States)

    Kristian, Kathleen E.

    2015-01-01

    A semester-long group project that utilizes wiki sites to enhance collaboration was developed for a foundation course in inorganic chemistry. Through structured assignments, student groups use metal-based or metal-combating therapeutic agents as a model for applying and understanding course concepts; they also gain proficiency with scientific- and…

  12. Development and Evaluation of a Multi-Institutional Case Studies-Based Course in Food Safety

    Science.gov (United States)

    Pleitner, Aaron M.; Chapin, Travis K.; Hammons, Susan R.; Stelten, Anna Van; Nightingale, Kendra K.; Wiedmann, Martin; Johnston, Lynette M.; Oliver, Haley F.

    2015-01-01

    Developing novel, engaging courses in food safety is necessary to train professionals in this discipline. Courses that are interactive and case-based encourage development of critical thinking skills necessary for identifying and preventing foodborne disease outbreaks. The purpose of this study was to assess the efficacy of a case study…

  13. Computer Controlled Test Systems. Introduction. A Course Based on the IEEE 488 Bus.

    Science.gov (United States)

    Herrmann, Eric J.

    An introductory course in computer automated tests and measurement systems based on the International Test Instrument-Computer Interface Standard, the IEEE (Institute of Electrical and Electronics Engineers)-488, is presented in this study guide. This course is designed to: (1) introduce the electronics engineering technician to the functional…

  14. The Impact of Task-Based Approach on Vocabulary Learning in ESP Courses

    Science.gov (United States)

    Sarani, Abdullah; Sahebi, Leila Farzaneh

    2012-01-01

    This study investigates the teaching of vocabulary in ESP courses within the paradigm of task-based language teaching, concentrating on Persian literature students at Birjand University in Iran. Two homogenous groups of students who were taking their ESP courses participated in the study as a control and an experimental group. A teacher-made test…

  15. A Theme-Based Course: Hydrogen as the Fuel of the Future

    Science.gov (United States)

    Shultz, Mary Jane; Kelly, Matthew; Paritsky, Leonid; Wagner, Julia

    2009-01-01

    A theme-based course focusing on the potential role of hydrogen as a future fuel is described. Numerous topics included in typical introductory courses can be directly related to the issue of hydrogen energy. Beginning topics include Avogadro's number, the mole, atomic mass, gas laws, and the role of electrons in chemical transformations. Reaction…

  16. Transitioning from Expository Laboratory Experiments to Course-Based Undergraduate Research in General Chemistry

    Science.gov (United States)

    Clark, Ted M.; Ricciardo, Rebecca; Weaver, Tyler

    2016-01-01

    General chemistry courses predominantly use expository experiments that shape student expectations of what a laboratory activity entails. Shifting within a semester to course-based undergraduate research activities that include greater decision-making, collaborative work, and "messy" real-world data necessitates a change in student…

  17. Lessons Learned from Undergraduate Students in Designing a Science-Based Course in Bioethics

    Science.gov (United States)

    Loike, John D.; Rush, Brittany S.; Schweber, Adam; Fischbach, Ruth L.

    2013-01-01

    Columbia University offers two innovative undergraduate science-based bioethics courses for student majoring in biosciences and pre-health studies. The goals of these courses are to introduce future scientists and healthcare professionals to the ethical questions they will confront in their professional lives, thus enabling them to strategically…

  18. Engaging a "Pedagogy of Discomfort": Emotion as Critical Inquiry in Community-Based Writing Courses

    Science.gov (United States)

    Prebel, Julie

    2016-01-01

    This article revisits the scholarship on emotion in composition studies and extends this work through a consideration of emotion in community-based writing courses. With examples from student reflection essays from one such course, Writing With the Community, I explore emotion as a generative aspect of the students' semester writing projects for…

  19. Known Structure, Unknown Function: An Inquiry-Based Undergraduate Biochemistry Laboratory Course

    Science.gov (United States)

    Gray, Cynthia; Price, Carol W.; Lee, Christopher T.; Dewald, Alison H.; Cline, Matthew A.; McAnany, Charles E.; Columbus, Linda; Mura, Cameron

    2015-01-01

    Undergraduate biochemistry laboratory courses often do not provide students with an authentic research experience, particularly when the express purpose of the laboratory is purely instructional. However, an instructional laboratory course that is inquiry- and research-based could simultaneously impart scientific knowledge and foster a student's…

  20. The Views of Undergraduates about Problem-Based Learning Applications in a Biochemistry Course

    Science.gov (United States)

    Tarhan, Leman; Ayyildiz, Yildizay

    2015-01-01

    The effect of problem-based learning (PBL) applications in an undergraduate biochemistry course on students' interest in this course was investigated through four modules during one semester. Students' views about active learning and improvement in social skills were also collected and evaluated. We conducted the study with 36 senior students from…

  1. Web-Based Social Work Courses: Guidelines for Developing and Implementing an Online Environment

    Science.gov (United States)

    Dawson, Beverly Araujo; Fenster, Judy

    2015-01-01

    Although web-based courses in schools of social work have proliferated over the past decade, the literature contains few guidelines on steps that schools can take to develop such courses. Using Knowles's framework, which delineates tasks and themes involved in implementing e-learning in social work education, this article describes the cultivation…

  2. Fostering Critical Reflection in a Computer-Based, Asynchronously Delivered Diversity Training Course

    Science.gov (United States)

    Givhan, Shawn T.

    2013-01-01

    This dissertation study chronicles the creation of a computer-based, asynchronously delivered diversity training course for a state agency. The course format enabled efficient delivery of a mandatory curriculum to the Massachusetts Department of State Police workforce. However, the asynchronous format posed a challenge to achieving the learning…

  3. Application of Problem Based Learning ((PBL) in a Course on Financial Accounting Principles

    Science.gov (United States)

    Manaf, Nor Aziah Abdul; Ishak, Zuaini; Hussin, Wan Nordin Wan

    2011-01-01

    Purpose: This paper aims to share experiences in teaching a Financial Accounting Principles course using a hybrid problem based learning (PBL) method. The three specific objectives of this paper are to document how the PBL project for this course was developed and managed in class, to compare the academic performance of PBL students with non-PBL…

  4. Teaching Research Methodology Using a Project-Based Three Course Sequence Critical Reflections on Practice

    Science.gov (United States)

    Braguglia, Kay H.; Jackson, Kanata A.

    2012-01-01

    This article presents a reflective analysis of teaching research methodology through a three course sequence using a project-based approach. The authors reflect critically on their experiences in teaching research methods courses in an undergraduate business management program. The introduction of a range of specific techniques including student…

  5. The Robotic Decathlon: Project-Based Learning Labs and Curriculum Design for an Introductory Robotics Course

    Science.gov (United States)

    Cappelleri, D. J.; Vitoroulis, N.

    2013-01-01

    This paper presents a series of novel project-based learning labs for an introductory robotics course that are developed into a semester-long Robotic Decathlon. The last three events of the Robotic Decathlon are used as three final one-week-long project tasks; these replace a previous course project that was a semester-long robotics competition.…

  6. Reality-Based Learning: Outbreak, an Engaging Introductory Course in Public Health and Epidemiology

    Science.gov (United States)

    Calonge, David Santandreu; Grando, Danilla

    2013-01-01

    Objective: To develop a totally online reality-based course that engages students and enables the development of enhanced teamwork and report-writing skills. Setting: Outbreaks of infectious diseases impacts upon commerce, trade and tourism as well as placing strains on healthcare systems. A general course introducing university students to…

  7. Introducing Problem-Based Learning to Undergraduate IT Service Management Course: Student Satisfaction and Work Performance

    Science.gov (United States)

    Anicic, Katarina Pažur; Mekovec, Renata

    2016-01-01

    This paper describes the implementation of problem-based learning (PBL) principles in an undergraduate IT service management course, followed by the results about student satisfaction and work performance. The results indicate the students' general satisfaction with the course implementation, as well as some challenges regarding the…

  8. Appraisal of the Causes of Pavement

    African Journals Online (AJOL)

    INTRODUCTION. Pavement failures are very common features on. Nigeria in roads after few years of performance and often before attaining the design age. These roads are continuously reconstructed or rehabilitated without any effort made to identify factor(s) responsible for their perpetual failure. Pavement failures can ...

  9. Pervious Pavement System Evaluation-Paper

    Science.gov (United States)

    The use of a pervious pavement can be effective as a low impact development stormwater control. The Urban Watershed Management Branch is evaluating interlocking concrete paver systems as a type of porous pavement. Although the pavers are impermeable, the spaces between the pave...

  10. Numerical Simulation of Tire-Pavement Interaction

    NARCIS (Netherlands)

    Srirangam, S.K.

    2015-01-01

    Good skid resistance of a pavement surface is essential for road safety. Loss of skid resistance can lead to property damage and loss of lives. Ever increasing need of driver safety poses challenges to the highway authorities to evaluate pavement conditions even more precisely under different

  11. Crackscope : automatic pavement cracking inspection system.

    Science.gov (United States)

    2008-08-01

    The CrackScope system is an automated pavement crack rating system consisting of a : digital line scan camera, laser-line illuminator, and proprietary crack detection and classification : software. CrackScope is able to perform real-time pavement ins...

  12. Modelling Flexible Pavement Response and Performance

    DEFF Research Database (Denmark)

    Ullidtz, Per

    This textbook is primarily concerned with models for predicting the future condition of flexible pavements, as a function of traffic loading, climate, materials, etc., using analytical-empirical methods.......This textbook is primarily concerned with models for predicting the future condition of flexible pavements, as a function of traffic loading, climate, materials, etc., using analytical-empirical methods....

  13. Accelerated testing for studying pavement design and performance (FY 2001) : evaluation of the performance of permeable and semi-permeable unbound granular bases under Portland Cement Concrete Pavement (PCCP) slabs and alternate load transfer devices for

    Science.gov (United States)

    2003-11-01

    The objectives of this research are to determine the effect of unbound drainable base types on the performance of PCCP and the efficiency of fiber-reinforced polymer (FRP) dowels, compared to epoxy coated steel dowels, when retrofitted to re-establis...

  14. ANALYSIS OF STRESS STATE IN UPPER LAYER OF ROAD CONCRETE PAVEMENT WITH TEMPERATURE ACTION

    Directory of Open Access Journals (Sweden)

    M. K. Pshembaev

    2017-01-01

    Full Text Available While being operated auto-road pavements are subjected to intensive mechanical impacts, ultraviolet ray irradiation, freeze-thaw temperatures, freezing and thawing, drying and moistening. Due to these actions various types of pavement distresses appear on the road pavement. The most significant and dangerous type of distresses is micro-cracks on the road surface. One of the main reasons for their formation is an action of weather and climatic factors that initiate large changes in temperature of coating surface and occurrence of large temperature gradients in the upper layer. In this context while designing and operating auto-roads it is rather essential to investigate a stress state in road surface which is caused by temperature action. Purpose of the described investigations is to determine permissible temperature gradients for cement-concrete pavements that exclude formation of micro-cracks on their surface and thickness of damaged surface layer. Calculations of road pavement have been carried out at various laws for temperature distribution in its depth. A finite difference method realized in PARUS software has been used for studying a stress state of cement-concrete auto-roads. Regularities for distribution of stresses in cement-concrete pavement of auto-roads have been obtained at various surface temperatures. Permissible temperature gradients in the upper pavement layer have been determined and thickness of the layer where micro-cracks are formed has been assessed in the paper. Strength criterion based on the process of micro-crack formation and development in the concrete has been used for calculations. Risk of micro-crack formation on the auto-road pavement depends on material strength, conditions of plate fixing and temperature gradients.

  15. Skid resistance determination for pavement management and wet-weather road safety

    Directory of Open Access Journals (Sweden)

    T.F. Fwa

    2017-09-01

    Full Text Available Road accidents during wet weather have been a topic of major concern of road engineers in regions of wet-tropical climate and in other parts of the world during the wet season of the year. Road safety studies indicate that approximately 20% of all road accidents occurred during wet weather, and that the skid resistance of wet pavements have a major influence on the occurrences of wet-weather accidents. Monitoring of wet pavement skid resistance has been an integral part of a typical pavement management system. However, because of the lack of prediction capability of pavement skid resistance under various rainfall intensities, the minimum skid resistance threshold for safe wet-weather driving has been specified by highway agencies based on either engineering judgement or past experience. It is shown in this paper that the single-point minimum skid resistance threshold is inadequate to offer a complete description of the skid resistance performance of the pavement sections in question for effective management of a road network. It is unable to assess the risk involved in an actual wet-weather condition where the pavement surface water-film thickness and vehicle speed are different from standard test conditions. This limitation of the current system of specifying a minimum skid resistance threshold can be overcome by adopting a theoretically sound approach to represent pavement skid resistance under different conditions of water-film thickness and vehicle speed. This paper describes the theoretical basis of the approach and the development of a mechanistically derived three-dimensional finite-element skid resistance simulation model to predict skid resistance. The application of the proposed approach and the skid resistance prediction procedure in pavement management system and wet-weather driving safety assessment is presented.

  16. Automatic extraction of pavement markings on streets from point cloud data of mobile LiDAR

    Science.gov (United States)

    Gao, Yang; Zhong, Ruofei; Tang, Tao; Wang, Liuzhao; Liu, Xianlin

    2017-08-01

    Pavement markings provide an important foundation as they help to keep roads users safe. Accurate and comprehensive information about pavement markings assists the road regulators and is useful in developing driverless technology. Mobile light detection and ranging (LiDAR) systems offer new opportunities to collect and process accurate pavement markings’ information. Mobile LiDAR systems can directly obtain the three-dimensional (3D) coordinates of an object, thus defining spatial data and the intensity of (3D) objects in a fast and efficient way. The RGB attribute information of data points can be obtained based on the panoramic camera in the system. In this paper, we present a novel method process to automatically extract pavement markings using multiple attribute information of the laser scanning point cloud from the mobile LiDAR data. This method process utilizes a differential grayscale of RGB color, laser pulse reflection intensity, and the differential intensity to identify and extract pavement markings. We utilized point cloud density to remove the noise and used morphological operations to eliminate the errors. In the application, we tested our method process on different sections of roads in Beijing, China, and Buffalo, NY, USA. The results indicated that both correctness (p) and completeness (r) were higher than 90%. The method process of this research can be applied to extract pavement markings from huge point cloud data produced by mobile LiDAR.

  17. Greenhouse gas emissions of alternative pavement designs: framework development and illustrative application.

    Science.gov (United States)

    Liu, Xiaoyu; Cui, Qingbin; Schwartz, Charles

    2014-01-01

    Pavement rehabilitation is carbon intensive and the choice of pavement type is a critical factor in controlling greenhouse gas (GHG) emissions. The existing body of knowledge is not able to support decision-making on pavement choice due to a lack of consensus on the system boundaries, the functional units and the estimation periods. Excessive data requirements further inhibit the generalization of the existing methodologies for design evaluation at the early planning stage. This study proposes a practical life-cycle GHG estimation approach, which is arguably effective to benchmark pavement emissions given project bid tabulation. A set of case studies conducted for this study suggest that recycled asphalt pavement (e.g., foam stabilized base (FSB), and warm mix asphalt (WMA)) would prevent up to 50% of GHGs from the initial construction phase. However, from a life-cycle perspective, pavement emissions are dictated largely by the traffic characteristics and the analysis period for the use phase. The benefits from using recycled materials (e.g., FSB) are likely to diminish if the recycled products do not perform as well as those properly proportioned with less recycled materials, or if the recycled materials are locally unavailable. When the AADT reaches 10,000, use phase releases more than 97% of the life cycle emissions and the emissions difference among alternative designs will be within 1%. Copyright © 2013 Elsevier Ltd. All rights reserved.

  18. Continuous monitoring of mining induced strain in a road pavement using fibre Bragg grating sensors

    Science.gov (United States)

    Whelan, B. E.; Brunton, M.; Nosenzo, Giorgio; Kay, Daryl; Buys, Henk

    2012-02-01

    This paper describes the application of Fibre Bragg Grating (FBG) based sensors for monitoring road pavement strains caused by mining induced ground subsidence as a result of underground longwall coal mining beneath a major highway in New South Wales, Australia. After a lengthy planning period, the risks to the highway pavement were successfully managed by the highway authority and the mining company through a technical committee. The technical committee comprised representatives of the mining company, the highway authority and specialists in the fields of pavement engineering, geotechnical engineering and subsidence. An important component of the management strategy is the installation of a total of 840 strain and temperature sensors in the highway pavement using FBG arrays encapsulated in glass-fibre composite cables. The sensors and associated demodulation equipment provide continuous strain measurements along the pavement, enabling on-going monitoring of the effects of mining subsidence on the pavement and timely implementation of planned mitigation and response measures to ensure the safety and serviceability of the highway throughout the mining period.

  19. Continuous monitoring of mining induced strain in a road pavement using fiber Bragg grating sensors

    Science.gov (United States)

    Nosenzo, Giorgio; Whelan, B. E.; Brunton, M.; Kay, Daryl; Buys, Henk

    2013-06-01

    This paper describes the application of fiber Bragg grating (FBG) based sensors for monitoring road pavement strains caused by mining induced ground subsidence as a result of underground longwall coal mining beneath a major highway in New South Wales, Australia. After a lengthy planning period, the risks to the highway pavement were successfully managed by the highway authority and the mining company through a technical committee. The technical committee comprised representatives of the mining company, the highway authority and specialists in the fields of pavement engineering, geotechnical engineering and subsidence. An important component of the management strategy is the installation of a total of 840 strain and temperature sensors in the highway pavement using FBG arrays encapsulated in glass-fiber composite cables. The sensors and associated demodulation equipment provide continuous strain measurements along the pavement, enabling on-going monitoring of the effects of mining subsidence on the pavement and timely implementation of planned mitigation and response measures to ensure the safety and serviceability of the highway throughout the mining period.

  20. Nursing Librarians Cultivating Evidence-Based Practice Through an Asynchronous Online Course.

    Science.gov (United States)

    Mears, Kim; Blake, Lindsay

    2017-09-01

    In response to a request from the Nursing Shared Governance Evidence-Based Practice Council, librarians created an online evidence-based practice (EBP) continuing education course for clinical nurses. The curriculum was adapted from a previously created face-to-face course and was offered online through a learning management system. Although many nurses registered for the course, only a small sample was able to complete all modules. Feedback revealed that nurses appreciated the ease of online use, but they experienced technical barriers. Overall, nurses completing the course agreed that all learning objectives were met. An online asynchronous course for nurses is a viable option for teaching EBP, but hospital computer limitations must be taken into account to allow for participants' full immersion into the material. J Contin Educ Nurs. 2017;48(9):420-424. Copyright 2017, SLACK Incorporated.

  1. Review of the centre for evidence-based veterinary medicine's "using an evidence-based approach in your practice" course

    OpenAIRE

    Buckley, LA; Hall, EJ

    2017-01-01

    The practice of evidence–based veterinary nursing is a day one skill expected of veterinary nurses, and veterinary nursing educators are required to prepare student veterinary nurses to meet this competency. This article reviewed the Centre for Evidence – based Veterinary Medicine's course "Using an evidence – based approach in your practice" from the perspective of two Veterinary nursing educators. This four month blended learning course covered the importance of evidence based medicine (EBV...

  2. Post-graduate art therapy training in Israel: personal and professional transformation through dynamic artwork-based experiential transformative courses

    OpenAIRE

    Honig, Ofira

    2014-01-01

    Art therapy training programmes around the world feature a unique type of course based on dynamic art-work experience and conducted in the context of a core student group. The course is usually called an 'experiential group course'. There is world-wide practical recognition in the professional art therapy literature of the need for dynamic experiential artwork-based courses in art therapy training. What is new is that Israeli lecturers have extended this 'experiential group course' into what ...

  3. Developing learning material of introduction to operation research course based on problem-based learning

    Science.gov (United States)

    Yerizon; Jazwinarti; Yarman

    2018-01-01

    Students have difficulties experience in the course Introduction to Operational Research (PRO). The purpose of this study is to analyze the requirement of students in the developing lecturing materials PRO based Problem Based Learning which is valid, practice, and effective. Lecture materials are developed based on Plomp’s model. The development process of this device consists of 3 phases: front-end analysis/preliminary research, development/prototype phase and assessment phase. Preliminary analysis was obtained by observation and interview. From the research, it is found that students need the student’s worksheet (LKM) for several reasons: 1) no LKM available, 2) presentation of subject not yet based on real problem, 3) experiencing difficulties from current learning source.

  4. A historical overview of interdisciplinary family health: a community-based interprofessional health professions course.

    Science.gov (United States)

    Davidson, Richard A; Waddell, Rhondda

    2005-04-01

    The Interdisciplinary Family Health course at the University of Florida Health Science Center is a course for beginning health profession students designed to teach core values, such as community-based family health, health promotion and disease prevention, and teamwork in the context of home visits. In addition, the course provides a valuable service to volunteer families by helping them identify useful community resources, and by formulating wellness care plans for prevention of illness and stabilization of chronic illness. In this article, the authors describe the historical development of the course, which began as a grant-supported pilot course for 20 medical students in 1996. After several additional grants helped fund an expansion involving other colleges, the course was given institutional support in 2001 and currently includes over 400 students and 70 faculty from four colleges working to improve the health status of over 150 local volunteer families. The theoretical constructs and objectives of the course were developed collaboratively by dedicated faculty from five Health Science Center colleges over seven years. In addition to benefiting the community and students, the course has encouraged an atmosphere of collaboration among faculty and colleges that has been a tangible benefit to the academic health center. The development and continuing support of this course demonstrates that barriers to such efforts can be overcome by dedicated faculty and administration.

  5. Theoretical Relationships Between Moduli for Soil Layers Beneath Concrete Pavements.

    Science.gov (United States)

    method of analysis used for rigid pavements and the elastic layer method of analysis used for both rigid and flexible pavements. Twenty-three pavement sections were selected to illustrate the usage of these relationships. These sections represent the widest possible variation of rigid pavement types for which sufficient materials data was available. For the sections studied and within the context of linear analysis, these relationships demonstrate that the peak pavement stress can usually be computed by either method

  6. DETECTION OF CRACKS IN ASPHALT PAVEMENT DURING ROAD INSPECTION PROCESSES

    Directory of Open Access Journals (Sweden)

    Marcin STANIEK

    2017-09-01

    Full Text Available Road inspection is one of key processes of a pavement management system, whose function is to examine and describe the road infrastructure condition. When thoroughly performed, it provides the information required to implement an adequate road infrastructure maintenance policy and plan ad hoc repairs or refurbishments. This article discusses a solution for automatic asphalt pavement cracking detection, based on image-processing technology. This solution makes it possible to identify different crack types, i.e., transverse, longitudinal, alligator-type and technological cracks. The detection process is based on the application of various methods, including statistical difference identification for pre-assumed image analysis directions, i.e., in and opposite to the test vehicle running direction. The purpose of the morphological and filtering operations applied was to reduce the image noise level. The solution proposed was verified using video material in the form of a sequence of images recorded using the test vehicle.

  7. Automatic Road Pavement Assessment with Image Processing: Review and Comparison

    Directory of Open Access Journals (Sweden)

    Sylvie Chambon

    2011-01-01

    Full Text Available In the field of noninvasive sensing techniques for civil infrastructures monitoring, this paper addresses the problem of crack detection, in the surface of the French national roads, by automatic analysis of optical images. The first contribution is a state of the art of the image-processing tools applied to civil engineering. The second contribution is about fine-defect detection in pavement surface. The approach is based on a multi-scale extraction and a Markovian segmentation. Third, an evaluation and comparison protocol which has been designed for evaluating this difficult task—the road pavement crack detection—is introduced. Finally, the proposed method is validated, analysed, and compared to a detection approach based on morphological tools.

  8. Integration of problem-based learning and innovative technology into a self-care course.

    Science.gov (United States)

    McFalls, Marsha

    2013-08-12

    To assess the integration of problem-based learning and technology into a self-care course. Problem-based learning (PBL) activities were developed and implemented in place of lectures in a self-care course. Students used technology, such as computer-generated virtual patients and iPads, during the PBL sessions. Students' scores on post-case quizzes were higher than on pre-case quizzes used to assess baseline knowledge. Student satisfaction with problem-based learning and the use of technology in the course remained consistent throughout the semester. Integrating problem-based learning and technology into a self-care course enabled students to become active learners.

  9. Problem-Based Learning in a Natural Resources Conservation and Management Curriculum: A Capstone Course.

    Science.gov (United States)

    Arthur, M. A.; Thompson, J. A.

    1999-01-01

    Presents a course for natural resource conservation and management students that explicitly teaches integration of disciplinary knowledge using an internet-based approach to natural resource issues. (Author/CCM)

  10. Preliminary Evaluation of the Computer-Based Tactics Certification Course--Principles of War Module

    National Research Council Canada - National Science Library

    Pleban, Robert

    1997-01-01

    This report describes a portion of the U.S. Army Research Institute for the Behavioral and Social Sciences Infantry Forces Research Unit's work in the formative evaluation of the computer based Tactics Certification Course (TCC...

  11. Combination of graph heuristics in producing initial solution of curriculum based course timetabling problem

    Science.gov (United States)

    Wahid, Juliana; Hussin, Naimah Mohd

    2016-08-01

    The construction of population of initial solution is a crucial task in population-based metaheuristic approach for solving curriculum-based university course timetabling problem because it can affect the convergence speed and also the quality of the final solution. This paper presents an exploration on combination of graph heuristics in construction approach in curriculum based course timetabling problem to produce a population of initial solutions. The graph heuristics were set as single and combination of two heuristics. In addition, several ways of assigning courses into room and timeslot are implemented. All settings of heuristics are then tested on the same curriculum based course timetabling problem instances and are compared with each other in terms of number of population produced. The result shows that combination of saturation degree followed by largest degree heuristic produce the highest number of population of initial solutions. The results from this study can be used in the improvement phase of algorithm that uses population of initial solutions.

  12. Un Cours de composition francaise par ordinateur (A Computer-Based Course in French Composition).

    Science.gov (United States)

    Landes, Anne; Kaplan, Alice

    1988-01-01

    The origins, organization, and methods of a Columbia University course offering computer-based instruction in French composition are outlined, and the progress of four individual students is described. (MSE)

  13. Determinants of knowledge gain in evidence-based medicine short courses: an international assessment

    DEFF Research Database (Denmark)

    Witt, Klaus; Kunz, Regina; Wegscheider, Karl

    2010-01-01

    Background: Health care professionals worldwide attend courses and workshops to learn evidence-based medicine (EBM), but evidence regarding the impact of these educational interventions is conflicting and of low methodologic quality and lacks generalizability. Furthermore, little is known about...

  14. Incorporation of Blended Learning in Introductory Courses: A Research-Based Approach to Evaluation

    Science.gov (United States)

    Strey, S. T.; Charlevoix, D. J.; Guarente, B. A.; Snodgrass, E. R.

    2008-12-01

    We evaluate the learning outcomes of students in large enrollment classes comparing a blended learning course format and a traditional lecture section. Blended learning, here, describes instruction that is a combination of face-to-face meeting with asynchronous online learning, resulting in reduced class time. The course, Severe and Hazardous Weather, relies heavily on graphics and animations of weather events available online, both current and archived, and thereby lends itself well to a blended format. Severe and Hazardous Weather is a popular general education requirement course at the University of Illinois with consistently high enrollments (greater than 200 students per section) and classes at capacity. Unlike many past studies, this blended learning format is applied to a large-enrollment course of approximately 100 students. Curriculum was redesigned during fall 2007 from typical lecture to the blended format. The redesign process followed best practices grounded in peer-reviewed literature on blended and online learning. We will provide a brief overview of the course structure, but focus on the evaluation of both the curriculum design and student outcomes as compared to the traditional lecture-based course. Evaluation is based on course objectives stated in the course syllabus and is conducted following best practices; the research project received University Institutional Review Board approval prior to the start of the study.

  15. The Impact of a Participant-Based Accounting Cycle Course on Student Performance in Intermediate Financial Accounting I

    Science.gov (United States)

    Siagian, Ferdinand T.; Khan, Mohammad

    2016-01-01

    The authors investigated whether students in an Intermediate Financial Accounting I course who took a 1-credit, participant-based accounting cycle course performed better than students who did not take the accounting cycle course. Results indicate a higher likelihood of earning a better grade for students who took the accounting cycle course even…

  16. How to Mutually Advance General Education and Major-Based Education: A Grounded Theory Study on the Course Level

    Science.gov (United States)

    Fang, Hualiang

    2018-01-01

    The author employs grounded theory to investigate the teaching process of an interdisciplinary general education course at A University as a case. The author finds that under the condition of rather concrete relations between the subject of a major-based course and that of an elected general education course, if the major course is taught with a…

  17. Problem-based learning in upper division courses: Student successes, perceptions, and reactions

    Science.gov (United States)

    Duda, Gintaras; Ross, James

    2012-02-01

    This paper presents an experiment in project/problem-based learning (PBL) in an upper division mathematical physics course. The group project in the course involved modeling a zombie outbreak of the type seen in AMC's The Walking Dead. Students researched, devised, and solved their mathematical models for the spread of a zombie-like infection. Students independently learned and utilized numerical methods to solve highly coupled systems of differential equations. This work explores student perceptions and reactions to problem-based learning, and the feasibility of using PBL as the sole pedagogy in upper division physics courses.

  18. Deformation-strength Characteristics of Unsaturated Granular Subbase Course Material under Monotonic and Cyclic Loading

    OpenAIRE

    張, 媛

    2014-01-01

    Throughout a year, climatic changes highly influence the degree of saturation of subbase course layer inside pavement structures in cold snowy regions, such as Hokkaido, Japan. Besides, pavements have to transfer traffic loads from the asphalt-mixture layer to the subbase course layer. Accordingly, it is necessary to understand the mechanical behaviors of the subbase course layer effected by seasonal variations of degree of saturation and traffic loads. In this study, a series of monotonic an...

  19. Implementation of a team-based learning course: Work required and perceptions of the teaching team.

    Science.gov (United States)

    Morris, Jenny

    2016-11-01

    Team-based learning was selected as a strategy to help engage pre-registration undergraduate nursing students in a second-year evidence-informed decision making course. To detail the preparatory work required to deliver a team-based learning course; and to explore the perceptions of the teaching team of their first experience using team-based learning. Descriptive evaluation. Information was extracted from a checklist and process document developed by the course leader to document the work required prior to and during implementation. Members of the teaching team were interviewed by a research assistant at the end of the course using a structured interview schedule to explore perceptions of first time implementation. There were nine months between the time the decision was made to use team-based learning and the first day of the course. Approximately 60days were needed to reconfigure the course for team-based learning delivery, develop the knowledge and expertise of the teaching team, and develop and review the resources required for the students and the teaching team. This reduced to around 12days for the subsequent delivery. Interview data indicated that the teaching team were positive about team-based learning, felt prepared for the course delivery and did not identify any major problems during this first implementation. Implementation of team-based learning required time and effort to prepare the course materials and the teaching team. The teaching team felt well prepared, were positive about using team-based learning and did not identify any major difficulties. Crown Copyright © 2016. Published by Elsevier Ltd. All rights reserved.

  20. Developing a Problem-Based Course Based on Needs Analysis to Enhance English Reading Ability of Thai Undergraduate Students

    Science.gov (United States)

    Bosuwon, Takwa; Woodrow, Lindy

    2009-01-01

    This paper reports on a needs analysis underlying a proposed business English reading course using a problem-based learning approach designed to enhance English reading abilities of Thai undergraduate students. As part of a work in progress, the needs analysis survey was done prior to the course design with the major stakeholders in business and…

  1. Drugs & the Brain: Case-based Instruction for an Undergraduate Neuropharmacology Course.

    Science.gov (United States)

    Nagel, Anastasia; Nicholas, Andrea

    2017-01-01

    In order to transform a traditional large non-majors general education (GE) neurobiology lecture (Drugs & the Brain) into an active learning course, we developed a series of directed mini-cases targeting major drug classes. Humorous and captivating case-based situations were used to better engage and motivate students to solve problems related to neuropharmacology and physiology. Here we provide directed cases, questions and learning outcomes for our opiates mini-cases. In addition, we describe how case studies were incorporated into our course and assessed using peer review and online quizzing. An in-depth analysis of the overall course transformation on student exam performance, opinions and instructor evaluations can be found in the JUNE article Don't Believe the Gripe! Increasing Course Structure in a Large Non-majors Neuroscience Course.

  2. Factors influencing a problem-based learning implementation: A case study of IT courses

    Science.gov (United States)

    Darus, Norida Muhd; Mohd, Haslina; Baharom, Fauziah; Saip, Mohamed Ali; Puteh, Nurnasran; Marzuki @ Matt, Zaharin; Husain, Mohd Zabidin; Yasin, Azman

    2016-08-01

    IT students must be trained to work efficiently as teamwork. One of the techniques that can be used to train them is through Problem-Based Learning (PBL) approach. The PBL implementation can be influenced by various factors depending on the ultimate goal of the study. This study is focusing on the IT students' perception of the PBL implementation. The student's perception is important to ensure the successfulness of the PBL implementation. Therefore, it is important to identify the factors that might influence the implementation of PBL of IT courses. This study aims to identify some catalyst factors that may influence the PBL implementation of IT courses. The study involved three (3) main phases: identifying PBL implementation factors, constructing a PBL model, and PBL model validation using statistical analysis. Four main factors are identified: PBL Characteristics, PBL Course Assessment, PBL Practices, and PBL Perception. Based on these four factors, a PBL model is constructed. Then, based on the proposed PBL model, four hypotheses are formulated and analyzed to validate the model. All hypotheses are significantly acceptable. The result shows that the PBL Characteristics and PBL Course Assessment factors are significantly influenced the PBL Practices and indirectly influenced the Students' Perception of the PBL Implementation for IT courses. This PBL model can assist decision makers in enhancing the PBL teaching and learning strategy for IT courses. It is also can be tested to other courses in the future.

  3. Estimation of doses from radioactively contaminated disaster wastes reused for pavements

    International Nuclear Information System (INIS)

    Sawaguchi, Takuma; Takeda, Seiji; Kimura, Hideo; Tanaka, Tadao

    2015-01-01

    It is desirable that the disaster wastes contaminated by radioactive cesium after the severe accident at the Fukushima Nuclear Plant are reused as much as possible in order to minimize the quantity to be disposed of. Ministry of the Environment showed the policy that the wastes containing cesium of higher concentration than the clearance level (100 Bq/kg) were reusable as materials of construction such as subbase course materials of pavements under controlled condition with measures to lower exposure doses. In this study, in order to provide technical information for making a guideline on the use of contaminated concrete materials recycled from disaster wastes as pavement, doses for workers and the public were estimated, and the reusable concentration of radioactive cesium in the wastes was evaluated. It was shown that the external exposure of the public (children) residing near the completed pavement gave the minimum radiocesium concentration in order to comply with the dose criteria. The recycled concrete materials whose average concentration of cesium lower than 2,700 Bq/kg can be used as the subbase course materials of pavements. (author)

  4. Implementing Project Based Learning Approach to Graphic Design Course

    Science.gov (United States)

    Riyanti, Menul Teguh; Erwin, Tuti Nuriah; Suriani, S. H.

    2017-01-01

    The purpose of this study was to develop a learning model based Commercial Graphic Design Drafting project-based learning approach, was chosen as a strategy in the learning product development research. University students as the target audience of this model are the students of the fifth semester Visual Communications Design Studies Program…

  5. Cone penetrometer equipped with piezoelectric sensors for measurement of soil stiffness in highway pavement : executive summary report.

    Science.gov (United States)

    2005-11-01

    The stiffness (elastic modulus and shear modulus) and Poissons ratio of the base and : sublayers are important parameters in the design and quality assurance during construction of : highway pavements. During and after the construction of a paveme...

  6. Measuring Carbon Emissions of Pavement Construction in China

    Directory of Open Access Journals (Sweden)

    Youliang Huang

    2016-07-01

    Full Text Available While various methodologies for quantifying carbon emissions of pavement construction are developed worldwide, adopting and promoting the existing tools to China’s market is found fairly challenging due to institutional constraints. Therefore, the objectives of this study are to propose a methodology for measuring carbon emissions of pavement construction compatible with the fixed pricing systems prevalent in China; and develop an automatic tool for carbon estimations. The total carbon emissions are measured by aggregating emissions of energy consumption and materials used along with four stages, namely material manufacture, transportation, construction, and disposal. A set of composite carbon emission factors for energy and materials was calculated based on existing emission factors with the consideration of the boundaries concerned. The quantity of energy and materials used in pavement construction are obtained through bills of quantity and the fixed price system. The database of the emission factors for energy and materials was embedded into a C# based tool, and validated in a real case.

  7. Initial experience with a calculus-based IPLS course at Vanderbilt

    Science.gov (United States)

    Hutson, M. Shane; Rericha, Erin C.

    2014-03-01

    By implementing research results from the PER community, we have designed a new calculus-based IPLS course and began teaching two sections of this course in Fall 2013, both taught by biological physicists. This course differs from Vanderbilt's other introductory physics offerings in two major ways. First, it seeks to implement PER-based active learning strategies including just-in-time teaching, peer instruction and context-rich problems. The latter are specifically designed within biomedical contexts. Second, the course content has been chosen to closely align with the core competencies delineated in the HHMI-AAMC report Scientific Foundations for Future Physicians. We provide students with a very explicit accounting (in the syllabus) of how this course will contribute to 5 of the 8 SFFP-competencies and 21 of its 37 learning objectives. Throughout the course and associated labs, we make repeated, explicit and hopefully authentic connections between physics and the life sciences. The chosen text reinforces our approach through well-developed biomedical applications of physics concepts. We will report what we've seen work and not work in our first implementation of an IPLS course and detail results regarding student learning and student attitudes towards physics.

  8. Reforming a large lecture modern physics course for engineering majors using a PER-based design

    Science.gov (United States)

    McKagan, S. B.; Perkins, K. K.; Wieman, C. E.

    2007-01-01

    We have reformed a large lecture modern physics course for engineering majors by radically changing both the content and the learning techniques implemented in lecture and homework. Traditionally this course has been taught in a manner similar to the equivalent course for physics majors, focusing on mathematical solutions of abstract problems. Based on interviews with physics and engineering professors, we developed a syllabus and learning goals focused on content that was more useful to our actual student population: engineering majors. The content of this course emphasized reasoning development, model building, and connections to real world applications. In addition we implemented a variety of PER-based learning techniques, including peer instruction, collaborative homework sessions, and interactive simulations. We have assessed the effectiveness of reforms in this course using pre/post surveys on both content and beliefs. We have found significant improvements in both content knowledge and beliefs compared with the same course before implementing these reforms and a corresponding course for physics majors.

  9. Development of a Full-Depth Wheel Tracking Test for Asphalt Pavement Structure: Methods and Performance Evaluation

    Directory of Open Access Journals (Sweden)

    Hui Wang

    2016-01-01

    Full Text Available The rutting performance of asphalt pavement structure relies on the high temperature properties of asphalt mixture as well as the pavement structure and thickness. In order to investigate the influence of the structure and thickness, a full-depth wheel tracking test is developed in this research by improving the conventional wheel tracking test apparatus. The newly proposed test method is capable of varying its load speed and load size, controlling its specimen temperature gradient, and simulating the support conditions of actual asphalt pavement. The full-depth wheel tracking test based rutting performance evaluation of different asphalt pavement structures indicates that it is not reasonable to explain the rutting performance of asphalt pavement structure from the point of view of single-layer asphalt mixture rutting performance. The developed full-depth wheel tracking test can be used to distinguish rutting performance of different asphalt pavement structures, and two of five typical asphalt pavement structures commonly used in Shanxi Province were suggested for use in practical engineering.

  10. Integration of Problem-Based Learning and Web-Based Multimedia to Enhance Soil Management Course

    Science.gov (United States)

    Strivelli, R.; Krzic, M.; Crowley, C.; Dyanatkar, S.; Bomke, A.; Simard, S.; Grand, S.

    2012-04-01

    In an attempt to address declining enrolment in soil science programs and the changing learning needs of 21st century students, several universities in North America and around the world have re-organized their soil science curriculum and adopted innovative educational approaches and web-based teaching resources. At the University of British Columbia, Canada, an interdisciplinary team set out to integrate teaching approaches to address this trend. The objective of this project was to develop an interactive web-based teaching resource, which combined a face-to-face problem-based learning (PBL) case study with multimedia to illustrate the impacts of three land-uses on soil transformation and quality. The Land Use Impacts (LUI) tool (http://soilweb.landfood.ubc.ca/luitool/) was a collaborative and concentrated effort to maximize the advantages of two educational approaches: (1) the web's interactivity, flexibility, adaptability and accessibility, and (2) PBL's ability to foster an authentic learning environment, encourage group work and promote the application of core concepts. The design of the LUI case study was guided by Herrington's development principles for web-based authentic learning. The LUI tool presented students with rich multimedia (streaming videos, text, data, photographs, maps, and weblinks) and real world tasks (site assessment and soil analysis) to encourage students to utilize knowledge of soil science in collaborative problem-solving. Preliminary student feedback indicated that the LUI tool effectively conveyed case study objectives and was appealing to students. The resource is intended primarily for students enrolled in an upper level undergraduate/graduate university course titled Sustainable Soil Management but it is flexible enough to be adapted to other natural resource courses. Project planning and an interactive overview of the tool will be given during the presentation.

  11. Math remediation intervention for student success in the algebra-based introductory physics course

    Science.gov (United States)

    Forrest, Rebecca L.; Stokes, Donna W.; Burridge, Andrea B.; Voight, Carol D.

    2017-12-01

    Pretesting and early intervention measures to identify and remediate at-risk students were implemented in algebra-based introductory physics to help improve student success rates. Pretesting via a math and problem-solving diagnostic exam administered at the beginning of the course was employed to identify at-risk students based on their scores. At-risk students were encouraged to utilize an online math tutorial to increase their chances of passing the course. The tutorial covers the same math topics covered by the diagnostic exam. Results from 643 students enrolled in the course showed that the 61 at-risk students who successfully completed the math tutorial increased their odds of passing the course by roughly 4 times those of the at-risk students who did not. This intervention is easily implemented, short term, and can be administered concurrently with the course. Based on these results, the Department of Physics has implemented the math tutorials in all sections of the introductory algebra as well as the calculus-based physics courses.

  12. Use of Shadowing-Based Learning in an Allied Health Microbiology Course

    Directory of Open Access Journals (Sweden)

    Alex A. Lowrey

    2016-05-01

    Full Text Available Students in an undergraduate microbiology course for health professions majors perform a shadowing-based learning exercise for their course project. Students accomplish this by shadowing a health care professional of their choice, specifically incorporating basic microbiological concept themes into their observations. These concept themes include the biological nature, health effects, detection, and control of microorganisms. Upon completion of the shadowing experience, students present a concise report, which is graded on how well the students connect course scientific concepts with actual clinical practice.

  13. Determinants of knowledge gain in evidence-based medicine short courses: an international assessment

    DEFF Research Database (Denmark)

    Witt, Klaus; Kunz, Regina; Wegscheider, Karl

    2010-01-01

    Background: Health care professionals worldwide attend courses and workshops to learn evidence-based medicine (EBM), but evidence regarding the impact of these educational interventions is conflicting and of low methodologic quality and lacks generalizability. Furthermore, little is known about...... the course. Results: A total of 15 centres participated in the study and 420 learners from North America and Europe completed the study. The baseline score across courses was 7.49 points (range 3.97–10.42 points) out of a possible 15 points. The average increase in score was 1.40 points (95% confidence...

  14. Exercise in Inquiry: Critical Thinking in an Inquiry-Based Exercise Physiology Laboratory Course.

    Science.gov (United States)

    DiPasquale, Dana M.; Mason, Cheryl L.; Kolkhorst, Fred W.

    2003-01-01

    Describes an inquiry-based teaching method implemented in an undergraduate exercise physiology laboratory course. Indicates students' strong, positive feelings about the inquiry-based teaching method and shows that inquiry-based learning results in a higher order of learning not typically observed in traditional style classes. This teaching method…

  15. The use of virtual laboratories and other web-based tools in a drug assay course.

    Science.gov (United States)

    Dunham, Marissa Waldman; Ghirtis, Konstantine; Beleh, Mustapha

    2012-06-18

    To determine students' perceptions of and performance in a drug assay laboratory course after the addition of Web-based multimedia tools. Video modules and other Web-based tools to deliver instructions and emulate the laboratory set up for experiments were implemented in 2005 to improve student preparation for laboratory sessions and eliminate the need for graduate students to present instructions live. Data gathered from quizzes, final examinations, and post-course surveys administered over 6 years were analyzed. Students' scores on online quizzes after implementation of the virtual laboratories reflected improved student understanding and preparation. Students' perception of the course improved significantly after the introduction of the tools and the new teaching model. Implementation of an active-learning model in a laboratory course led to improvement in students' educational experience and satisfaction. Additional benefits included improved resource use, student exposure to a variety of educational methods, and having a highly structured laboratory format that reduced inconsistencies in delivered instructions.

  16. EFL Students’ Perceptions about a Web-Based English Reading Comprehension Course

    Directory of Open Access Journals (Sweden)

    Érica Gómez Flórez

    2012-07-01

    Full Text Available Web-based distance education is an innovative modality of instruction in Colombia. It is characterized by the separation of the teacher and learners, the use of technological tools and the students’ autonomy development. This paper reports the findings of a case study that explores students’ perceptions about an English reading comprehension course in a web-based modality. Findings show that students have different opinions about the course, its content and objectives, its level of difficulty, the time students invested in the course, adults’ learning, and the role of the teacher. We perceived that this course represents an academic challenge; it is conducive to learning, and favors students’ autonomous use of time.

  17. Evaluation of an interactive web-based nursing course with streaming videos for medication administration skills.

    Science.gov (United States)

    Sowan, Azizeh K; Idhail, Jamila Abu

    2014-08-01

    Nursing students should exhibit competence in nursing skills in order to provide safe and quality patient care. This study describes the design and students' response to an interactive web-based course using streaming video technology tailored to students' needs and the course objectives of the fundamentals of nursing skills clinical course. A mixed-methodology design was used to describe the experience of 102 first-year undergraduate nursing students at a school of nursing in Jordan who were enrolled in the course. A virtual course with streaming videos was designed to demonstrate medication administration fundamental skills. The videos recorded the ideal lab demonstration of the skills, and real-world practice performed by registered nurses for patients in a hospital setting. After course completion, students completed a 30-item satisfaction questionnaire, 8 self-efficacy scales, and a 4-item scale solicited their preferences of using the virtual course as a substitute or a replacement of the lab demonstration. Students' grades in the skill examination of the procedures were measured. Relationships between the main variables and predictors of satisfaction and self-efficacy were examined. Students were satisfied with the virtual course (3.9 ± 0.56, out of a 5-point scale) with a high-perceived overall self-efficacy (4.38 ± 0.42, out of a 5-point scale). Data showed a significant correlation between student satisfaction, self-efficacy and achievement in the virtual course (r = 0.45-0.49, p streaming videos for clinical courses is a complex process that should be carefully designed to positively influence the learning experience. However, the learning benefits gained from such pedagogical approach are worth faculty, institution and students' efforts. Published by Elsevier Ireland Ltd.

  18. Introducing problem-based learning to undergraduate IT service management course: student satisfaction and work performance

    OpenAIRE

    Katarina Pažur Aničić; Renata Mekovec

    2016-01-01

    This paper describes the implementation of problem-based learning (PBL) principles in an undergraduate IT service management course, followed by the results about student satisfaction and work performance. The results indicate the students’ general satisfaction with the course implementation, as well as some challenges regarding the self-assessment and peer assessment of their work. The findings also reveal the students’ better work performance in project results than in traditional knowledge...

  19. Team-Based Learning Improves Course Outcomes in Introductory Psychology

    Science.gov (United States)

    Travis, Lisa L.; Hudson, Nathan W.; Henricks-Lepp, Genevieve M.; Street, Whitney S.; Weidenbenner, Jennifer

    2016-01-01

    This study investigated the influence of team-based learning (TBL) methods on exam performance and student satisfaction in an introductory psychology class. Fifteen instructors teaching 29 sections (with a combined enrollment of approximately 1,130 students) were randomly assigned to use TBL for 7 of 12 major topics or to use lecture. All students…

  20. Development of a Knowledge Base for Incorporating Technology into Courses

    Science.gov (United States)

    Rath, Logan

    2013-01-01

    This article discusses a project resulting from the request of a group of faculty at The College at Brockport to create a website for best practices in teaching and technology. The project evolved into a knowledge base powered by WordPress. Installation and configuration of WordPress resulted in the creation of custom taxonomies and post types,…

  1. On Interactive Teaching Model of Translation Course Based on Wechat

    Science.gov (United States)

    Lin, Wang

    2017-01-01

    Constructivism is a theory related to knowledge and learning, focusing on learners' subjective initiative, based on which the interactive approach has been proved to play a crucial role in language learning. Accordingly, the interactive approach can also be applied to translation teaching since translation itself is a bilingual transformational…

  2. Teaching Construction: A Design-Based Course Model

    Science.gov (United States)

    Love, Tyler S.; Salgado, Carlos A.

    2016-01-01

    The focus on construction in T&E education has drastically changed. This article presents a series of topics and design-based labs that can be taught at various grade levels to integrate STEM concepts while also increasing students' overall awareness of construction and structural technologies.

  3. Pedagogy for teaching and learning cooperatively on the Web: a Web-based pharmacology course.

    Science.gov (United States)

    Tse, Mimi M Y; Pun, Sandra P Y; Chan, Moon Fai

    2007-02-01

    The Internet is becoming a preferred place to find information. Millions of people go online in the search of health and medical information. Likewise, the demand for Web-based courses grows. This article presents the development, utilization and evaluation of a web-based pharmacology course for nursing students. The course was developed based on 150 commonly used drugs. There were 110 year 1 nursing students took part in the course. After attending six hours face to face lecture of pharmacology over three weeks, students were invited to complete a questionnaire (pre-test) about learning pharmacology. The course materials were then uploaded to a WebCT for student's self-directed learning and attempts to pass two scheduled online quizzes. At the end of the semester, students were given the same questionnaire (post-test). There were a significant increase in the understanding compared with memorizing the subject content, the development of problem solving ability in learning pharmacology and becoming an independent learner (p ,0.05). Online quizzes yielded satisfactory results. In the focused group interview, students appreciated the time flexibility and convenience associated with web-based learning, also, they had made good suggestions in enhancing web-based learning. Web-based approach is promising for teaching and learning pharmacology for nurses and other health-care professionals.

  4. Factors affecting progress of Australian and international students in a problem-based learning medical course.

    Science.gov (United States)

    Treloar, C; McCall, N; Rolfe, I; Pearson, S A; Garvey, G; Heathcote, A

    2000-09-01

    Research on the factors affecting progress in medical schools has typically focused on mainstream (non-Indigenous Australian, non-international) students in traditional, didactic programmes. These results may not be applicable to students, particularly those from culturally diverse backgrounds, undertaking problem-based learning courses. This study used qualitative methodology to explore and compare factors affecting progress for mainstream Australian students (non-Indigenous Australian, non-international) and international students (full fee-paying students who had relocated countries to study) in a problem-based learning medical course. Intervention strategies were devised on the basis of the participants' experiences. Six focus group discussions were conducted (three with mainstream Australian and three with international participants). Transcripts of these discussions were coded and analysed independently by two researchers and discussed until consensus was attained. Participants identified both positive and negative experiences related to the course structure, which were consistent with previous findings. The participants' experiences demonstrated a relationship between sense of 'belongingness' to the medical school community, participation in learning opportunities and progress through the course. The results suggest that interventions aimed at reducing barriers to progress need to promote students' confidence, motivation and subsequent participation in course learning opportunities. These results have application to other problem-based learning courses particularly those which face the challenge of providing an optimal learning environment for students from diverse backgrounds.

  5. Generator of text-based assignments for programming courses

    OpenAIRE

    Jager, Mojca

    2013-01-01

    Verifying and assessing of knowledge represent important part of education. A teacher can verify knowledge on different ways, like classically oral and written, which are in majority still dominant types, and alternatively, which is based on student's current activities. During assembling the questions for written verification, many teachers nowadays help themselves using different test generators like Hot Potatoes, Moodle, Test Pilot, and others, they are all available on internet. At t...

  6. Effects on evaporation rates from different water-permeable pavement designs.

    Science.gov (United States)

    Starke, P; Göbel, P; Coldewey, W G

    2011-01-01

    The urban water balance can be attenuated to the natural by water-permeable pavements (WPPs). Furthermore, WPPs have a 16% higher evaporation rate than impermeable pavements, which can lead to a better urban climate. Evaporation rates from pavements are influenced by the pavement surface and by the deeper layers. By a compared evaporation measurement between different WPP designs, the grain size distribution of the sub-base shows no influence on the evaporation rates in a significant way. On the contrary, a sub-base made of a twin-layer decreases the evaporation by 16% compared to a homogeneous sub-base. By a change in the colour of the paving stone, 19% higher evaporation rates could be achieved. A further comparison shows that the transpiration-effect of the grass in grass pavers increases the evaporation rates more than threefold to pervious concrete pavements. These high evapotranspiration rates can not be achieved with a pervious concrete paving stone. In spite of this, the broad field of application of the pervious concrete paving stone increases the importance in regard to the urban climate.

  7. A project-based course about outreach in a physics curriculum

    Science.gov (United States)

    Bobroff, Julien; Bouquet, Frédéric

    2016-07-01

    We describe an undergraduate course where physics students are asked to conceive an outreach project of their own. This project-based-learning course alternates between the project conception and teaching activities about outreach. It ends in a public show. Students decide the topic and format on their own. An analysis of the students’ productions over three years shows that all physics fields were equally covered, and various formats were used (experimental devices, animation or fiction movies, games, live events, photography). Some typical examples are described. We also analyse the benefits of this approach from the students’ perspective, through a survey done over three classes. Students showed an overall very good assessment of the course (average of 4.5(0.6) on an appreciation scale from 1 to 5) and recognised having developed outreach skills but also project-management and group-work know-how. They acknowledged this course to be a unique opportunity to share with an audience their interest in physics compared to other courses. They further mentioned that it served as an intermission in a classical academic curriculum. They also point out some challenges, especially the time-consuming issue. This survey together with the practical description of the course implementation should help other universities develop similar courses.

  8. User's guide : pavement marking management system database.

    Science.gov (United States)

    2011-12-01

    Pavement markings play a critical role in maintaining a safe and efficient driving environment for road users, especially during nighttime conditions. The Texas Department of Transportation (TxDOT) spends millions of dollars each year for installatio...

  9. Permeable Pavement Research - Edison, New Jersey

    Science.gov (United States)

    This presentation provides the background and summary of results collected at the permeable pavement parking lot monitored at the EPA facility in Edison, NJ. This parking lot is surfaced with permeable interlocking concrete pavers (PICP), pervious concrete, and porous asphalt. ...

  10. Class C fly ash in pavements.

    Science.gov (United States)

    2010-07-01

    Portland cement is the most dominant material used in concrete pavements in the state of Nebraska. In order to improve performance, reduce cost, and advance sustainability, a percentage of the Portland cement is replaced with a recycled material know...

  11. Performance of I-57 recycled concrete pavements.

    Science.gov (United States)

    2009-01-01

    In 1986-1987 the Illinois Department of Transportation (IDOT) constructed a demonstration project on I-57 near Effingham, Illinois to evaluate the viability : of recycling an existing jointed reinforced concrete pavement for use as its primary aggreg...

  12. Pervious Pavement System Evaluation- Abstract 1

    Science.gov (United States)

    Porous pavement is a low impact development stormwater control. The Urban Watershed Management Branch is evaluating interlocking concrete pavers as a popular implementation. The pavers themselves are impermeable, but the spaces between the pavers are backfilled with washed, gra...

  13. Long term monitoring of moisture under pavements.

    Science.gov (United States)

    2010-01-01

    Monitoring of the environmental instrumentation installed under select pavement sections constructed : by the Ohio Department of Transportation (ODOT) in 1995 on US 23 in Delaware County, Ohio was : continued. The measurements made consisted of soil ...

  14. Concrete pavement construction basics : tech notes.

    Science.gov (United States)

    2006-08-01

    This tech note has been produced for developers, consultants, and engineers planning concrete pavement construction projects, superintendents and supervisors who want a basic training aid and reference, and crew members new to the concrete paving ind...

  15. Noise measurements of highway pavements in Texas.

    Science.gov (United States)

    2009-10-01

    This report presents the results of noise testing performed on Texas pavements between May of 2006 and the : summer of 2008. Two field test methodologies were used: roadside noise measurement with SPL meters and onvehicle : sound intensity measuremen...

  16. Improving safety in pavement field testing.

    Science.gov (United States)

    2017-09-15

    The Florida Department of Transportation (FDOT) collects pavement condition and performance data each year, using both site-specific equipment that requires temporary traffic control (TTC) operations (either moving or closed operations) and full-size...

  17. Reformulated pavement remaining service life framework.

    Science.gov (United States)

    2013-11-01

    "Many important decisions are necessary in order to effectively provide and manage a pavement network. At the heart : of this process is the prediction of needed future construction events. One approach to providing a single numeric on : the conditio...

  18. Optimization of safety on pavement preservation projects.

    Science.gov (United States)

    2011-01-01

    To achieve a goal of reducing highway crash fatalities by 4% each year to improve roadway safety, the Georgia Department of Transportation (GDOT) is actively seeking opportunities to incorporate safety improvements into its current pavement preservat...

  19. On-road Bicycle Pavement Markings

    Data.gov (United States)

    Allegheny County / City of Pittsburgh / Western PA Regional Data Center — A mile by mile breakdown of the on-street bicycle pavement markings installed within the City of Pittsburgh. These include bike lanes, shared lane markings...

  20. Revision of South African pavement design method

    CSIR Research Space (South Africa)

    Kannemeyer, L

    2015-08-01

    Full Text Available South Africa has a long pavement engineering history in terms of developing methodologies and solutions for supporting the local economy using available materials under specific environmental and socio-economic conditions. Over the past 10 years...

  1. Mechanistic flexible pavement overlay design program.

    Science.gov (United States)

    2009-07-01

    The current Louisiana Department of Transportation and Development (LADOTD) overlay thickness design method follows the Component : Analysis procedure provided in the 1993 AASHTO pavement design guide. Since neither field nor laboratory tests a...

  2. Life cycle assessment of asphalt pavement maintenance.

    Science.gov (United States)

    2014-01-01

    This study aims at developing a life cycle assessment (LCA) model to quantify the impact of pavement preservation on energy consumption and greenhouse gas (GHG) emissions. The construction stage contains material, manufacture, transportation and plac...

  3. Performance evaluation of precast prestressed concrete pavement.

    Science.gov (United States)

    2007-11-01

    This report describes in detail an experimental investigation of an innovative precast prestressed concrete pavement (PPCP) system used to rehabilitate a 1,000 ft. section of interstate highway located on the northbound lanes of I-57 near Charleston,...

  4. Ten practical, theory-based tips for clinical course planners

    DEFF Research Database (Denmark)

    Balslev, T.; Westphall, I.; Blichfeldt, S.

    2008-01-01

    A list of practical advice and examples are given based on the literature. E-learning with cliffhanger text-cases can activate prior knowledge, and selected examination skills can be trained with simulated patients. Patient video recordings can be used to train clinical reasoning skills, including...... pattern recognition and hypothetic-deductive approaches. Interactive approaches, for example, questioning, quizzes or buzz groups imply active involvement and participation. Quizzes and MCQ-testing can provide a formative 'check-up' on learning and point to gaps in understanding for the teachers...

  5. Achieving generic competences through a cross-disciplinary research based course in Arctic Technology

    DEFF Research Database (Denmark)

    Kirkelund, Gunvor Marie; Hansen, Claus Thorp; Jensen, Pernille Erland

    2014-01-01

    successful in achieving both the scientific and generic competences than the students who did not. The students evaluate the course as being highly motivating for further learning and they get confident by successfully having executed a research based project in a new context. The project and field work...... engineering competences, so they are more aware of this, instead of just focussing on improving their scientific competences.......In a research based course in Arctic Technology, different teaching activities were used to support learning of both technical and generic competences. The active learning was based around a 3-weeks field work period in Greenland in combination with lectures, assignments, project and peer group...

  6. Oxygen demand of aircraft and airfield pavement deicers and alternative freezing point depressants

    Science.gov (United States)

    Corsi, Steven R.; Mericas, Dean; Bowman, George

    2012-01-01

    Aircraft and pavement deicing formulations and other potential freezing point depressants were tested for biochemical oxygen demand (BOD) and chemical oxygen demand (COD). Propylene glycol-based aircraft deicers exhibited greater BOD5 than ethylene glycol-based aircraft deicers, and ethylene glycol-based products had lower degradation rates than propylene glycol-based products. Sodium formate pavement deicers had lower COD than acetate-based pavement deicers. The BOD and COD results for acetate-based pavement deicers (PDMs) were consistently lower than those for aircraft deicers, but degradation rates were greater in the acetate-based PDM than in aircraft deicers. In a 40-day testing of aircraft and pavement deicers, BOD results at 20°C (standard) were consistently greater than the results from 5°C (low) tests. The degree of difference between standard and low temperature BOD results varied among tested products. Freshwater BOD test results were not substantially different from marine water tests at 20°C, but glycols degraded slower in marine water than in fresh water for low temperature tests. Acetate-based products had greater percentage degradation than glycols at both temperatures. An additive component of the sodium formate pavement deicer exhibited toxicity to the microorganisms, so BOD testing did not work properly for this formulation. BOD testing of alternative freezing point depressants worked well for some, there was little response for some, and for others there was a lag in response while microorganisms acclimated to the freezing point depressant as a food source. Where the traditional BOD5 test performed adequately, values ranged from 251 to 1,580 g/kg. Where the modified test performed adequately, values of BOD28 ranged from 242 to 1,540 g/kg.

  7. Determinants of knowledge gain in evidence-based medicine short courses: an international assessment.

    Science.gov (United States)

    Kunz, Regina; Wegscheider, Karl; Fritsche, Lutz; Schünemann, Holger J; Moyer, Virginia; Miller, Donald; Boluyt, Nicole; Falck-Ytter, Yngve; Griffiths, Peter; Bucher, Heiner C; Timmer, Antje; Meyerrose, Jana; Witt, Klaus; Dawes, Martin; Greenhalgh, Trisha; Guyatt, Gordon H

    2010-01-01

    Health care professionals worldwide attend courses and workshops to learn evidence-based medicine (EBM), but evidence regarding the impact of these educational interventions is conflicting and of low methodologic quality and lacks generalizability. Furthermore, little is known about determinants of success. We sought to measure the effect of EBM short courses and workshops on knowledge and to identify course and learner characteristics associated with knowledge acquisition. Health care professionals with varying expertise in EBM participated in an international, multicentre before-after study. The intervention consisted of short courses and workshops on EBM offered in diverse settings, formats and intensities. The primary outcome measure was the score on the Berlin Questionnaire, a validated instrument measuring EBM knowledge that the participants completed before and after the course. A total of 15 centres participated in the study and 420 learners from North America and Europe completed the study. The baseline score across courses was 7.49 points (range 3.97-10.42 points) out of a possible 15 points. The average increase in score was 1.40 points (95% confidence interval 0.48-2.31 points), which corresponded with an effect size of 0.44 standard deviation units. Greater improvement in scores was associated (in order of greatest to least magnitude) with active participation required of the learners, a separate statistics session, fewer topics, less teaching time, fewer learners per tutor, larger overall course size and smaller group size. Clinicians and learners involved in medical publishing improved their score more than other types of learners; administrators and public health professionals improved their score less. Learners who perceived themselves to have an advanced knowledge of EBM and had prior experience as an EBM tutor also showed greater improvement than those who did not. EBM course organizers who wish to optimize knowledge gain should require learners

  8. Evaluation of medical students of teacher-based and student-based teaching methods in Infectious diseases course.

    Science.gov (United States)

    Ghasemzadeh, I; Aghamolaei, T; Hosseini-Parandar, F

    2015-01-01

    Introduction: In recent years, medical education has changed dramatically and many medical schools in the world have been trying for expand modern training methods. Purpose of the research is to appraise the medical students of teacher-based and student-based teaching methods in Infectious diseases course, in the Medical School of Hormozgan Medical Sciences University. Methods: In this interventional study, a total of 52 medical scholars that used Section in this Infectious diseases course were included. About 50% of this course was presented by a teacher-based teaching method (lecture) and 50% by a student-based teaching method (problem-based learning). The satisfaction of students regarding these methods was assessed by a questionnaire and a test was used to measure their learning. information are examined with using SPSS 19 and paired t-test. Results: The satisfaction of students of student-based teaching method (problem-based learning) was more positive than their satisfaction of teacher-based teaching method (lecture).The mean score of students in teacher-based teaching method was 12.03 (SD=4.08) and in the student-based teaching method it was 15.50 (SD=4.26) and where is a considerable variation among them (p<0.001). Conclusion: The use of the student-based teaching method (problem-based learning) in comparison with the teacher-based teaching method (lecture) to present the Infectious diseases course led to the student satisfaction and provided additional learning opportunities.

  9. Using Debates to Teach Evidence-Based Practice in Large Online Courses.

    Science.gov (United States)

    Boyd, Mary R; Baliko, Beverly; Polyakova-Norwood, Vera

    2015-10-01

    To engage in evidence-based practice (EBP), baccalaureate nursing graduates' competencies must include locating, interpreting, appraising, and applying research findings. Faculty are challenged to find effective ways to incorporate this content in large online courses. Faculty in a thriving college of nursing used interactive debates to teach EBP skills in a large (200+ students) online undergraduate course. Students remain highly engaged while practicing critical thinking, team-work, leadership, delegation, communication skills, and peer evaluation through participation in a series of faculty-facilitated online debates. Meticulous course organization and use of structured debates allows one instructor to teach skills for EBP, while keeping students engaged with each other, the instructor, and the material. Use of debates and the amount of engagement among students and faculty achieved could not be accomplished in a large face-to-face course. Copyright 2015, SLACK Incorporated.

  10. Construction and Implementation of Teaching Mode for Digital Mapping based on Interactive Micro-course Technology

    Directory of Open Access Journals (Sweden)

    Ning Gao

    2018-02-01

    Full Text Available The era of “Internet + education” has caused reforms in teaching ideas, teaching modes, and learning styles. The emergence of micro-course technology provides new strategies for integrating learning styles. Task-driven digital mapping teaching, known as traditional classroom organization, has poor teaching effect due to single learning style and strategy. A new teaching mode for digital mapping was constructed in this study based on micro-course technology by combining interactive micro-course technology and digital mapping teaching to adapt to the demands of modern teaching. This teaching mode mainly included four modules, namely, micro-courseware, micro-video, micro-exercise, and micro-examination. It realized the hierarchical teaching of knowledge points in digital mapping course, simplification of basic principles, simulation of engineering cases, and self-evaluation of learning outcomes. The teaching mode was applied to 114 students from the Mapping Engineering Department of Henan University of Urban Construction. Results indicate that the proposed teaching mode based on interactive micro-course technology promoting the independent after-class learning of the students, stimulating their learning enthusiasm, enhancing their practical abilities of the students, and improving the effect of teaching. This mode of teaching provides a new concept for the teaching mode reform of other courses in mapping engineering.

  11. Difference in First Aid Activity During Mass Casualty Training Based on Having Taken an Educational Course.

    Science.gov (United States)

    Yanagawa, Youichi; Omori, Kazuhiko; Ishikawa, Kouhei; Takeuchi, Ikuto; Jitsuiki, Kei; Yoshizawa, Toshihiko; Sato, Jun; Matsumoto, Hideyuki; Tsuchiya, Masaru; Osaka, Hiromichi

    2017-11-20

    The Japanese Association for Disaster Medicine developed a mass casualty life support (MCLS) course to improve cooperation among medical practitioners during a disaster, which is essential for reducing the rates of preventable disaster death. We investigated whether there was difference in first aid activity among members of the ambulance service during mass casualty training based on having taken the MCLS course. Mass casualty training was held at the fire department of Numazu City. Twenty-one ambulance service parties participated in this training. They first evaluated the mass casualty situation, performed the appropriate services at the scene during the initial period, and then provided START triage for mock wounded patients. Throughout the training, 5 examiners evaluated their performance. Regarding the difference in first aid activity based on MCLS course attendance among the ambulance service members, the cooperative management (scored on a scale of 1 to 5) among the members who had taken the MCLS course was significantly better than that among those who had not taken the course (median [interquartile range]: 5 [0.5] vs. 4 [1.75], P<0.05). Attending an MCLS course may help to improve outcomes in the face of an actual mass casualty incident. (Disaster Med Public Health Preparedness. 2017;page 1 of 4).

  12. Student Self-Efficacy in Introductory Project-Based Learning Courses

    Science.gov (United States)

    Pleiss, Geoffrey; Zastavker, Yevgeniya V.

    2012-02-01

    This study investigates first-year engineering students' self-efficacy in two introductory Project-Based Learning (PjBL) courses -- Physics (Mechanics) Laboratory and Engineering Design -- taught at a small technical institution. Twelve students participated in semi-structured open-ended interviews about their experiences in both courses. Analysis was performed using grounded theory. Results indicate that students had lower self-efficacy in Physics Lab than in Engineering Design. In Physics Lab, students reported high levels of faculty-supported scaffolding related to final project deliverables, which in turn established perceptions of an outcome-based course emphasis. Conversely, in Engineering Design, students observed high levels of scaffolding related to the intermediate project deliverables, highlighting process-centered aspects of the course. Our analyses indicate that this difference in student perceptions of course emphases -- resulting from the differences in scaffolding -- is a primary factor for the discrepancy in self-efficacy between Physics Lab and Engineering Design. Future work will examine how other variables (e.g., academic background, perception of community, gender) affect students' self-efficacy and perception of scaffolding in these PjBL courses.

  13. Development of Pavement Condition Index Model Using PAVER 6.5.7 for Flexible Pavement Urban Roads in Kerbala City

    OpenAIRE

    Hussein Ali Ewadh; Raid Rahman Almuhanna; Saja Jasim Alasadi

    2017-01-01

    The pavement condition index (PCI) is an important factor indicating pavement condition of roads. The pavement is one of the basic parts of the road infrastructure. Accordingly the aim of this paper is to develop a pavement condition index model using PAVER 6.5.7 for a flexible pavement urban roads in the Kerbala city center. The development model is depending on the PCI value of 109 sample sections having 57.8 km length, Data collected for pavement distress (type, dimension, and severity) w...

  14. Students' Perceptions of Their ICT-Based College English Course in China: A Case Study

    Science.gov (United States)

    Zinan, Wen; Sai, George Teoh Boon

    2017-01-01

    This study investigated foreign language students' perceptions about their Information and Communication Technology (ICT)-based College English Course (CEC) in China. The research used a five-point Likert-scale questionnaire based on Simsek (2008). A factor analysis confirmed the construct validity of the questionnaire and 6 factors were…

  15. Spiral and Project-Based Learning with Peer Assessment in a Computer Science Project Management Course

    Science.gov (United States)

    Jaime, Arturo; Blanco, José Miguel; Domínguez, César; Sánchez, Ana; Heras, Jónathan; Usandizaga, Imanol

    2016-01-01

    Different learning methods such as project-based learning, spiral learning and peer assessment have been implemented in science disciplines with different outcomes. This paper presents a proposal for a project management course in the context of a computer science degree. Our proposal combines three well-known methods: project-based learning,…

  16. Outcomes-Based Assessment and Learning: Trialling Change in a Postgraduate Civil Engineering Course

    Science.gov (United States)

    El-Maaddawy, Tamer; Deneen, Christopher

    2017-01-01

    This paper aims to demonstrate how assessment tasks can function within an outcomes-based learning framework to evaluate student attainment of learning outcomes. An outcomes-based learning framework designed to integrate teaching, learning, and assessment activities was developed and implemented in a civil engineering master-level course. The…

  17. Activity Based Learning in a Freshman Global Business Course: Analyses of Preferences and Demographic Differences

    Science.gov (United States)

    Levine, Mark F.; Guy, Paul W.

    2007-01-01

    The present study investigates pre-business students' reaction to Activity Based Learning in a lower division core required course entitled Introduction to Global Business in the business curriculum at California State University Chico. The study investigates students' preference for Activity Based Learning in comparison to a more traditional…

  18. Math Remediation Intervention for Student Success in the Algebra-Based Introductory Physics Course

    Science.gov (United States)

    Forrest, Rebecca L.; Stokes, Donna W.; Burridge, Andrea B.; Voight, Carol D.

    2017-01-01

    Pretesting and early intervention measures to identify and remediate at-risk students were implemented in algebra-based introductory physics to help improve student success rates. Pretesting via a math and problem-solving diagnostic exam administered at the beginning of the course was employed to identify at-risk students based on their scores.…

  19. Meta-Assessment in a Project-Based Systems Engineering Course

    Science.gov (United States)

    Wengrowicz, Niva; Dori, Yehudit Judy; Dori, Dov

    2017-01-01

    Project-based learning (PBL) facilitates significant learning, but it poses a major assessment challenge for assessing individual content knowledge. We developed and implemented an assessment approach and tool for a mandatory undergraduate systems engineering PBL-based course. We call this type of assessment "student-oriented"…

  20. Successful Implementation of Inquiry-Based Physiology Laboratories in Undergraduate Major and Nonmajor Courses

    Science.gov (United States)

    Casotti, G.; Rieser-Danner, L.; Knabb, M. T.

    2008-01-01

    Recent evidence has demonstrated that inquiry-based physiology laboratories improve students' critical- and analytical-thinking skills. We implemented inquiry-based learning into three physiology courses: Comparative Vertebrate Physiology (majors), Human Physiology (majors), and Human Anatomy and Physiology (nonmajors). The aims of our curricular…

  1. Pre-Service Teachers' TPACK Development and Conceptions through a TPACK-Based Course

    Science.gov (United States)

    Durdu, Levent; Dag, Funda

    2017-01-01

    This study examines pre-service teachers' Technological Pedagogical Content Knowledge (TPACK) development and analyses their conceptions of learning and teaching with technology. With this aim in mind, researchers designed and implemented a computer-based mathematics course based on a TPACK framework. As a research methodology, a parallel mixed…

  2. How to reduce tire-pavement noise : better practices for constructing and texturing concrete pavement surfaces.

    Science.gov (United States)

    2012-08-01

    Concrete pavements can be designed and constructed to be as quiet as any other conventional pavement type in use today. This report : provides an overview of how this can be doneand done consistently. : In order to construct a quieter concrete pav...

  3. Investigating elementary education and physical therapy majors' perceptions of an inquiry-based physics content course

    Science.gov (United States)

    Hilton, John Martin

    This study investigates why physical therapy assistant majors engage and perform better than elementary education majors in an inquiry-based conceptual physics course at Mid-Atlantic Community College. The students from each major are demographically similar, both courses are similar in depth and structure, and each course supports the students' program. However, there is an observed difference in the levels of engagement with the curriculum and performance on writing-based assessments between the two groups. To explore possible explanations for the difference, I examine students' affinity for science, their beliefs about the nature of science and scientific knowledge in the classroom, and their perception of the usefulness of science to their program. During semi-structured interviews, students from both majors displayed nearly identical weak affinities for science, epistemological beliefs, and uncertainty about the usefulness of the class. However, the physical therapy majors' ability to see the relevance of the physics course experience to their program enhanced their interest and motivation. In contrast, the elementary education students do not see connections between the course and their program, and do not see a purpose for their learning of physics content. To improve the program, I propose a two-pronged approach - designing a faded-scaffolded-inquiry approach for both classes, and developing a field-based/seminar class for the elementary education majors. The scaffolded inquiry will help both groups develop better orientations toward lab activities, and the structured observations and reflection will help the elementary group connect the material to their program.

  4. Demonstration of using quieter pavement in Death Valley National Park

    Science.gov (United States)

    2013-06-01

    Death Valley National Park provided an environment that allowed a demonstration of : quieter pavement use. Sound measurements near the tire-pavement interface, near the : road, and in areas of frequent human use were conducted and analyses performed ...

  5. Continuous real time measurement of pavement quality during construction.

    Science.gov (United States)

    2010-12-01

    Intelligent Compaction has been investigated as a means of improving the quality of asphalt pavements during their : construction. The long term performance of an asphalt pavement is directly related to its load bearing capability and : is determined...

  6. Laboratory fatigue evaluation of continuously fiber-reinforced concrete pavement.

    Science.gov (United States)

    2013-09-01

    Portland cement concrete (PCC) is the worlds most versatile construction material. PCC has : been in use in the United States for over 100 years. PCC pavement is generally constructed as : either continually reinforced concrete pavement (CRCP) or ...

  7. Evaluation of recycled concrete as aggregate in new concrete pavements.

    Science.gov (United States)

    2014-04-01

    This study evaluated the use of recycled concrete as coarse aggregate in new concrete pavements. : Recycled concrete aggregate (RCA) produced from demolished pavements in three geographically dispersed locations in Washington state were used to perfo...

  8. Mobile geographic information system solution for pavement condition surveys [summary].

    Science.gov (United States)

    2012-01-01

    The State Materials Office (SMO) of the Florida : Department of Transportation (FDOT) performs : annual Pavement Condition Surveys (PCS) of : the Departments extensive pavement network. : This work is performed by single-person crews in : inertial...

  9. Guidelines for PCC inputs to AASHTOWare Pavement ME.

    Science.gov (United States)

    2014-12-01

    The objective of this research study was to develop guidelines for portland cement concrete (PCC) material inputs to the : AASHTOWare Pavement ME Design program. The AASHTOWare Pavement ME Design is the software program used by the : Mississippi Depa...

  10. Long term pavement performance computed parameter : frost penetration

    Science.gov (United States)

    2008-11-01

    As the pavement design process moves toward mechanistic-empirical techniques, knowledge of seasonal changes in pavement structural characteristics becomes critical. Specifically, frost penetration information is necessary for determining the effect o...

  11. Predicting low-temperature cracking in asphalt pavements : [research brief].

    Science.gov (United States)

    2011-12-01

    In Wisconsin's winter climate, low temperatures can cause asphalt pavements to contract and crack, reducing their ride quality and service lives. To help engineers more accurately determine how well certain pavement designs will fare in such conditio...

  12. Effect of friction on rolling tire-pavement interaction

    Science.gov (United States)

    2010-11-01

    In this research, a three-dimensional (3-D) tire-pavement interaction model is developed using FEM to analyze the tire-pavement contact stress distributions at various rolling conditions (free rolling, braking/accelerating, and cornering). In additio...

  13. Precision and accuracy of mechanistic-empirical pavement design

    CSIR Research Space (South Africa)

    Theyse, HL

    2006-09-01

    Full Text Available The availability of mechanistic-empirical pavement design methods is increasing internationally. Although mechanistic-empirical design does offer some insight into pavement behaviour and performance, at least more so than empirical design methods...

  14. Advanced Automated Detection Analysis and Classification of Cracks in Pavement

    OpenAIRE

    Scott, Dennis

    2014-01-01

    Functional Session 5: Pavement Management Moderated by Akyiaa Hosten This presentation was held at the Pavement Evaluation 2014 Conference, which took place from September 15-18, 2014 in Blacksburg, Virginia. Presentation only

  15. Investigation clogging dynamic of permeable pavement systems using embedded sensors

    Science.gov (United States)

    Permeable pavement is a stormwater control measure commonly selected in both new and retrofit applications. However, there is limited information about the clogging mechanism of these systems that effects the infiltration. A permeable pavement site located at the Seitz Elementary...

  16. Mechanistic flexible pavement overlay design program : tech summary.

    Science.gov (United States)

    2009-07-01

    The Louisiana Department of Transportation and Development (LADOTD) currently follows the 1993 : AASHTO pavement design guides component analysis method in its fl exible pavement overlay thickness : design. Such an overlay design method, how...

  17. Software offers transparent, straightforward assessment of pavement additives : research spotlight.

    Science.gov (United States)

    2015-04-01

    Adding new materials to pavement layers is a proven technique to : improve performance. Many types of additivesfrom engineered : polymers and acids to recycled pavement, crumb rubber, shingles : and glasshave been used to help construct better ...

  18. AASHTO mechanistic-empirical pavement design guide parametric study.

    Science.gov (United States)

    2012-03-01

    This study focuses on assessing the robustness of the AASHTO Mechanistic-Empirical Pavement Design Guide (MEPDG v 1.1) for rigid pavement : design projects in Wisconsin. The primary tasks conducted in this study included performing sensitivity analys...

  19. Overview of the South African mechanistic pavement design analysis method

    CSIR Research Space (South Africa)

    Theyse, HL

    1996-01-01

    Full Text Available A historical overview of the South African mechanistic pavement design method, from its development in the early 1970s to the present, is presented. Material characterization, structural analysis, and pavement life prediction are discussed...

  20. The identification and treatment of poor durability Karoo dolerite base course aggregate – evidence from case studies

    CSIR Research Space (South Africa)

    Leyland, RC

    2016-03-01

    Full Text Available , but rapid pavement failures continue to occur. A study was recently undertaken to identify cases where degradation of Karoo dolerite was the cause of pavement failure. A secondary objective of the study was to determine if any observed degradation could have...

  1. Evaluation of a novel Web-based pediatric advanced life support course.

    Science.gov (United States)

    Gerard, James M; Scalzo, Anthony J; Laffey, Steven P; Sinks, Glen; Fendya, Diana; Seratti, Patrice

    2006-06-01

    To assess the educational efficacy of a Web-based pediatric advanced life support course (Web-PALS). Nonrandomized, prospective, cohort study. University medical center. Health care providers (includes physicians, nurses, paramedics, and respiratory therapists) taking either the Web-PALS or a traditional PALS course (Trad-PALS). Web-PALS. Postcourse written examination scores and scored videotapes of students performing 5 PALS procedures were compared between study groups. Students completed precourse and postcourse questionnaires, rating on a 5-point Likert scale their self-confidence to perform PALS assessments and procedures. A structured, course satisfaction survey was given after students had taken the Web-PALS course. Eighty-six students completed the study (44 Web-PALS and 42 Trad-PALS). All students achieved a passing score on the written examination on their first attempt. Compared with students in the Trad-PALS group, students in the Web-PALS group scored slightly lower (97.1% vs 95.4%; difference, 1.7%; 95% confidence interval, 0.1-3.2). Mean overall videotape scores were similar among the Web-PALS and Trad-PALS groups (75.0% vs 73.0%; difference, 2.0%; 95% confidence interval, -2.0 to 6.0). After completing the Web-PALS course, the mean level of confidence improved from 3.77 to 4.28 (difference, 0.51; 95% confidence interval, 0.33-0.69). Ninety-six percent of respondents indicated that Web-PALS met all of the stated objectives of the PALS course. All respondents indicated that they would recommend Web-PALS to a colleague. Students perceive Web-PALS as a positive educational experience. Though not identical to students taking the Trad-PALS course, they performed well on postcourse cognitive and psychomotor testing. These findings support Web-PALS as an acceptable format for administering the PALS course.

  2. Experience teaching CD-ROM-based course on CANDU nuclear-power-plant systems and operation

    International Nuclear Information System (INIS)

    Rouben, Benjamin

    2008-01-01

    This paper presents personal experience garnered from teaching a CD-ROM-based course on CANDU Power-Plant Systems and Operation. This course was originally developed by Prof. G.T. Bereznai as research in distance-learning techniques when he was directing the Thai-Canadian Human Resources Development Project at Chulalongkorn University in Bangkok. The course has been offered in a number of universities, including McMaster University and the University of Ontario Institute of Technology. All the course material, including lectures, assignments, and a simulator, is provided on a CD-ROM. Lectures include a spoken soundtrack covering the material. The class often includes both undergraduate and graduate students. I found that most students appreciate having the material on electronic format, which they can view and review at will and on their own time. Students find this course quite intensive - it covers all major systems in the CANDU reactor and power plant in detail. A very important component of the course is the simulator, which teaches students how systems operate in normal operation, in power manoeuvres, and during process-system malfunctions. Effort in absorbing the material and performing assignments can often exceed 10 hours per week. Some of the simulator assignments involve tricky manoeuvres, requiring several tries to achieve the expected result. Some assignments may take several hours, especially if the manoeuvres requiring repetition take 30 minutes or more in real time. I found that some instruction in the basic theory of reactor physics and systems is appreciated by students. A few possible enhancements to the simulator model were identified. Graduate students taking the course are required to do an additional project; I assigned an investigation of the effects of xenon-concentration changes during 1 week of load cycling. In summary, this course provides to students the opportunity to learn a great deal about the workings of CANDU-plant systems. (author)

  3. Factors Influencing Stormwater Mitigation in Permeable Pavement

    Directory of Open Access Journals (Sweden)

    Chun Yan Liu

    2017-12-01

    Full Text Available Permeable pavement (PP is used worldwide to mitigate surface runoff in urban areas. Various studies have examined the factors governing the hydrologic performance of PP. However, relatively little is known about the relative importance of these governing factors and the long-term hydrologic performance of PP. This study applied numerical models—calibrated and validated using existing experimental results—to simulate hundreds of event-based and two long-term rainfall scenarios for two designs of PP. Based on the event-based simulation results, rainfall intensity, rainfall volume, thickness of the storage layer and the hydraulic conductivity of the subgrade were identified as the most influential factors in PP runoff reduction. Over the long term, PP performed significantly better in a relatively drier climate (e.g., New York, reducing nearly 90% of runoff volume compared to 70% in a relatively wetter climate (e.g., Hong Kong. The two designs of PP examined performed differently, and the difference was more apparent in the relatively wetter climate. This study generated insights that will help the design and implementation of PP to mitigate stormwater worldwide.

  4. Basic Performance of Fibre Reinforced Asphalt Concrete with Reclaimed Asphalt Pavement Produced In Low Temperatures with Foamed Bitumen

    Science.gov (United States)

    Chomicz-Kowalska, Anna; Iwański, Mateusz M.; Mrugała, Justyna

    2017-10-01

    During the reconstruction of road pavements, the reclaimed asphalt pavement (RAP), which is obtained through milling of the worn out existing asphalt, is commonly used for producing new base courses in cold recycling processes. Two of these techniques are most popular: one using mineral-cement-emulsion mixes and one utilizing mineral cement mixes with foamed bitumen. Additionally, some amounts of RAP can be incorporated into traditional hot mix asphalt. The demand for energy efficient and environmentally friendly solutions however, results in a need for development of new techniques that would result in cheaper and more reliable solutions with smaller carbon footprint. The reduction of processing temperatures with simultaneous incorporation of reclaimed material is the most efficient way of obtaining these objectives, but it often results in the overall decrease of bituminous mix quality. The paper presents the possibility of using RAP for producing asphalt concrete in warm mix asphalt (WMA) production process by the use of foamed bitumen modified with Fischer-Tropsch synthetic wax and polymer-basalt fibers. Additionally, a series of reference mixtures were produced to investigate the effects of the additives and of the warm process. The carried out analyses and tests shown that the experimental warm mix asphalt produced with RAP and foamed bitumen returned satisfactory performance. The introduction of synthetic F-T wax in the warm foam bitumen mixes resulted in a significantly improved compaction levels and moisture and frost resistance and the addition of polymer-basalt fibers has further improved the permanent deformation resistance of the mixes. All of the designed and tested mixes have fulfilled the requirements for binding course asphalt concrete with medium traffic loads.

  5. Using Zebrafish to Implement a Course-Based Undergraduate Research Experience to Study Teratogenesis in Two Biology Laboratory Courses

    Science.gov (United States)

    Chism, Grady W.; Vaughan, Martin A.; Muralidharan, Pooja; Marrs, Jim A.

    2016-01-01

    Abstract A course-based undergraduate research experience (CURE) spanning three semesters was introduced into freshman and sophomore biology classes, with the hypothesis that participation in a CURE affects skills in research, communication, and collaboration, which may help students persist in science. Student research projects were centered on the hypothesis that nicotine and caffeine exposure during early development affects gastrulation and heart development in zebrafish. First, freshmen generated original data showing distinct effects of embryonic nicotine and caffeine exposure on zebrafish heart development and function. Next, Cell Biology laboratory students continued the CURE studies and identified novel teratogenic effects of nicotine and caffeine during gastrulation. Finally, new freshmen continued the CURE research, examining additional toxicant effects on development. Students designed new protocols, made measurements, presented results, and generated high-quality preliminary data that were studied in successive semesters. By implementing this project, the CURE extended faculty research and provided a scalable model to address national goals to involve more undergraduates in authentic scientific research. In addition, student survey results support the hypothesis that CUREs provide significant gains in student ability to (1) design experiments, (2) analyze data, and (3) make scientific presentations, translating into high student satisfaction and enhanced learning. PMID:26829498

  6. A real-time 3D scanning system for pavement distortion inspection

    International Nuclear Information System (INIS)

    Li, Qingguang; Yao, Ming; Yao, Xun; Xu, Bugao

    2010-01-01

    Pavement distortions, such as rutting and shoving, are the common pavement distress problems that need to be inspected and repaired in a timely manner to ensure ride quality and traffic safety. This paper introduces a real-time, low-cost inspection system devoted to detecting these distress features using high-speed 3D transverse scanning techniques. The detection principle is the dynamic generation and characterization of the 3D pavement profile based on structured light triangulation. To improve the accuracy of the system, a multi-view coplanar scheme is employed in the calibration procedure so that more feature points can be used and distributed across the field of view of the camera. A sub-pixel line extraction method is applied for the laser stripe location, which includes filtering, edge detection and spline interpolation. The pavement transverse profile is then generated from the laser stripe curve and approximated by line segments. The second-order derivatives of the segment endpoints are used to identify the feature points of possible distortions. The system can output the real-time measurements and 3D visualization of rutting and shoving distress in a scanned pavement

  7. Framework for incorporating nondestructive evaluation (NDE) into pavement and bridge management systems

    Science.gov (United States)

    Sobanjo, John O.; Tawfiq, Kamal S.

    1999-02-01

    One of the major components of an infrastructure management system is the condition assessment or deterioration modeling. With application to highway pavements and bridges, this paper presents conceptually how nondestructive evaluation (NDE) results can be utilized to provide a quantitative assessment of the infrastructure condition in a format usable for network-level pavement management systems and bridge management systems. NDE techniques typically applied to pavements include Visual Rating, Falling Weight Deflectometer, Dynaflect, Seismic Pavement Analyzer, and the Ground Penetrating Radar (GPR). Bridges can also be evaluated using the GPR. NDE is particularly useful at the network level of infrastructure management because of the mobility of conducting the tests. Detailed mechanistic methods have been suggested for NDE interpretation but this method may not be practical at network level. Interpretation of NDE results, through knowledge-based systems and intelligent databases indicate the defects and residual capacity of infrastructures. Measured physical properties and defects in the infrastructure component materials can be correlated to existing scales of condition assessment such as in the NBI and PONTIS formats for bridge management and also to an index or rating such as the PSI in highway pavements.

  8. Auto-synchronized laser scanning range sensor for thermoplastic pavement marking material thickness measurement

    Science.gov (United States)

    Sun, Wei; Chen, Xuemin; Chen, Yuanhang; Ekbote, Aditya; Liu, Richard Ce

    2006-03-01

    Pavement marking materials provide delineation on highways around the world. The condition of the marking materials is very important for the driver's safety as well as the comfort and the driving expenses. Currently thermoplastic pavement marking materials (TPMM) are widely used in states. Measuring the thickness of TPMM on pavement is an essential index to monitor the contractors, calculate durability of marking materials, and provide better information for the pavement marking evaluation. In recent years to measure the thickness of TPMM, a procedure involving pre-embedded plates sprayed with the marking materials has been widely accepted. This method is labor intensive, and cannot obtain a continuous-thickness profile. Therefore there are demands to develop a high-speed automatic measuring system for determining the thickness and uniformity of marking materials. In this paper, a laser range sensor based on auto-synchronized laser scanning is proposed for the thermoplastic pavement marking material thickness measurement. Compare to classical triangulation method, this approach doesn't scarify the system resolution for large field of view and it is more suitable for highway speed measurement. To achieve high speed measurement, PSD (Position Sensitive Detector) is used in the prototype system instead of CCD (Charge Couple Device) in traditional auto-synchronized system. The standoff distance and transverse scan range of the prototype system both are 1 foot. The lab test results show that the prototype system can measure the thermoplastic type thickness with error in 5mil at laser scanning rate up to 50Hz.

  9. Guidelines for Preparing High School Psychology Teachers: Course-Based and Standards-Based Approaches

    Science.gov (United States)

    American Psychologist, 2013

    2013-01-01

    Psychology is one of the most popular elective high school courses. The high school psychology course provides the foundation for students to benefit from psychological perspectives on personal and contemporary issues and learn the rules of evidence and theoretical frameworks of the discipline. The guidelines presented here constitute the second…

  10. Student Views Based A Proposal for First Reading and Writing Teaching Course of Classroom Teaching Department

    Directory of Open Access Journals (Sweden)

    Nail YILDIRIM

    2010-12-01

    Full Text Available Reading and writing teaching is very important for a person’s life. Reading and writing teaching begins in the first class of primary education and it is delivered by classroom teachers. Classroom teachers get prepared for teaching with the “first reading and writing teaching course” given in their undergraduate education. As the content of the course is analyzed, first reading and writing teaching has three theoretical credit hours per week. It is indicated that exercises should be included in the content of the course, however, the exercises stay in the university environment and a real reading and writing exercise cannot be realized. Based on this fact, the purpose of this study is to state that reading and writing teaching course should not be theoretical, contrarily, it should be exercises based. The study conducts an action research to achieve this purpose. Descriptive method is used in the research to establish the current status. In this research, to determine the factors which affect the success of methodology in the content of first reading and writing teaching course of classroom teaching departments, one of the qualitative research methods, a semistructured interview technique is applied. Reading and writing teaching is realized in Tokat city, central district by using voice based sentence method on 40 adults who knew neither reading nor writing. The population of the research is composed of 40 junior students of classroom teaching department who taught reading and writing to 40 adults and 30 students who were enrolled to theoretical reading and writing teaching course. Students, who participated in the first reading and writing teaching exercise, indicate that they feel more comfortable about reading and writing teaching, from now on, they know what to do, and they assert that applied reading and writing teaching is more useful. Those students who are enrolled to theoretical first reading and writing course state that they

  11. Light-based science and technologies and human civilization: an optical course for general education

    Science.gov (United States)

    Li, Xiaotong; Wang, Kaiwei; Yang, Qing; Si, Ke

    2017-08-01

    Starting from 2015, a general education course named "Light-based science and technologies and human civilization" has been offered in Zhejiang University. We try to give a humanism view angle to observe optics and optical engineering, and combine them with the relationship of human and the nature, the development of human society and human health. In this course we introduce different historical periods of light-based science and technologies, the great optical researchers, the typical research methods, advantages, academic discussions and the relationship with human civilization. The relevant cross-fields of learning and Nobel Prize winners are also included. This course provides the students with the typical examples about how academic revolution influences the world development, and also with humanism sight which exceeds the range of science and technologies themselves.

  12. Pavement Condition Survey in Kagawa Prefecture using ROMDAS

    OpenAIRE

    Mohammad, Mamunur Rashid; 角川, 浩二

    2006-01-01

    Highway is one of the most important areas among the various facilities of infrastructure. Therefore, most of the organizations related to the infrastructure management system pay higher attention to the pavement which is the most important facility of highway management. An effective pavement management system (PMS) helps to carry out all the preservation and necessary maintenance operations of the pavement. In order to implement a pavement management system, data collection that indicates e...

  13. AutoPAVER: A software package for automated pavement evaluation

    Science.gov (United States)

    Ginsberg, Mark D.; Shahin, M. Y.; Walther, Jeanette A.

    1990-07-01

    This research developed a method that improves data collection and reduces data entry times for Pavement Condition Index (PCI) surveys for use with PAVER, a pavement maintenance management system. The method, AutoPAVER, is a microcomputer software package used to analyze pictures of pavement surfaces and to forward the resulting analysis to PAVER. The user works interactively with the system to identify and classify pavement distresses. Distress measurement and data entry are done on the computer.

  14. Pavement Condition Survey in Kagawa Prefecture using ROMDAS

    OpenAIRE

    Mohammad Mamunur Rashid; 角川, 浩二

    2005-01-01

    Highway is one of the most important areas among the various facilities of infrastructure. Therefore, most of the organizations related to the infrastructure management system pay higher attention to the pavement which is the most important facility of highway management. An effective pavement management system (PMS) helps to carry out all the preservation and necessary maintenance operations of the pavement. In order to implement a pavement management system, data collection that indicates e...

  15. Design and construction of PCC pavements. Volume 2, design features and practices that influence performance of pavements

    Science.gov (United States)

    1998-10-01

    A study has been conducted to evaluate and analyze Portland cement concrete (PCC) pavements in order to develop recommendations for the design and construction of long-lived concrete pavements. In involved a detailed evaluation and analysis of the PC...

  16. Design and construction of PCC pavements, volume 2 : design features and practices that influence performance of pavements.

    Science.gov (United States)

    1998-10-01

    A study has been conducted to evaluate and analyze portland cement concrete (PCC) pavements in order to : develop recommendations for the design and construction of long-lived concrete pavements. It involved a : detailed evaluation and analysis of th...

  17. Design and construction of PCC pavements. Volume 1, summary of design features and construction practices that influence performance of pavements

    Science.gov (United States)

    1998-04-01

    A study has been conducted to evaluate and analyze Portland cement concrete (PCC) pavements in order to develop recommendations for the design and construction of long-lived concrete pavements. In involved a detailed evaluation and analysis of the PC...

  18. Evaluation of current Louisiana flexible pavement structures using PMS data and new mechanistic-empirical pavement design guide : tech summary.

    Science.gov (United States)

    2012-04-01

    The new Mechanistic-Empirical Pavement Design Guide (MEPDG) developed under the National Cooperative Highway : Research Program (NCHRP) Project 1-37A represents a major change as compared to the 1993 AASHTO Pavement : Design Guide. MEPDG provides a r...

  19. Evaluation of current Louisiana flexible pavement structures using PMS data and new M-E pavement design guide.

    Science.gov (United States)

    2010-10-01

    The proposed study uses the new MEPDG together with data available from LADOTDs Pavement Management System (PMS) and other data sources from LADOTDs main frame to evaluate typical flexible pavement structures currently used and to make changes ...

  20. Accuracy Improvement Capability of Advanced Projectile Based on Course Correction Fuze Concept

    Directory of Open Access Journals (Sweden)

    Ahmed Elsaadany

    2014-01-01

    Full Text Available Improvement in terminal accuracy is an important objective for future artillery projectiles. Generally it is often associated with range extension. Various concepts and modifications are proposed to correct the range and drift of artillery projectile like course correction fuze. The course correction fuze concepts could provide an attractive and cost-effective solution for munitions accuracy improvement. In this paper, the trajectory correction has been obtained using two kinds of course correction modules, one is devoted to range correction (drag ring brake and the second is devoted to drift correction (canard based-correction fuze. The course correction modules have been characterized by aerodynamic computations and flight dynamic investigations in order to analyze the effects on deflection of the projectile aerodynamic parameters. The simulation results show that the impact accuracy of a conventional projectile using these course correction modules can be improved. The drag ring brake is found to be highly capable for range correction. The deploying of the drag brake in early stage of trajectory results in large range correction. The correction occasion time can be predefined depending on required correction of range. On the other hand, the canard based-correction fuze is found to have a higher effect on the projectile drift by modifying its roll rate. In addition, the canard extension induces a high-frequency incidence angle as canards reciprocate at the roll motion.