WorldWideScience

Sample records for bicycle path pavements

  1. 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...

  2. Potential risk and its influencing factors for separated bicycle paths.

    Science.gov (United States)

    Xu, Cheng; Yang, Ying; Jin, Sheng; Qu, Zhaowei; Hou, Lei

    2016-02-01

    In this paper, we propose two potential risk indicators to define and evaluate the safety of bicycle path at the microscopic level. Field bicycle data were collected from three survey sites under different traffic conditions. These two risk indicators based on speed dispersion were proposed and calculated during each 5-min interval. The risk influences of various widths of bicycle path and traffic conditions were analyzed by using one-way ANOVA. We further proposed a generalized linear model (GLM) for modeling and analyzing the relationships between bicycle risks and v/c ratio and percentages of electric bicycles, male cyclists, young cyclists, and loaded cyclists. The stepwise regression models were applied for determination of coefficients. The results show that the influences of gender and age of cyclists on potential risks are not significant. The risks increase with the width of bicycle path and percentage of electric bicycles, while only for wider bicycle path (4-lane case in this study), the risks are associated with whether or not cyclists are loaded. The findings could contribute for analysis and evaluation of the safety for bicycle path. Copyright © 2015 Elsevier Ltd. All rights reserved.

  3. Traffic conflicts on bicycle paths: a systematic observation of behaviour from video

    NARCIS (Netherlands)

    Horst, A.R.A. van der; Goede, M. de; Hair-Buijssen, S.H.H.M. de; Methorst, R.

    2014-01-01

    In The Netherlands, on bicycle paths, single-bicycle accidents, bicycle-bicycle and bicycle-moped accidents constitute a considerable share of all bicyclist injuries. Over three quarters of all hospitalised bicyclist victims in the Netherlands cannot be directly related to a crash with motorised tra

  4. Traffic conflicts on bicycle paths: a systematic observation of behaviour from video.

    Science.gov (United States)

    van der Horst, A Richard A; de Goede, Maartje; de Hair-Buijssen, Stefanie; Methorst, Rob

    2014-01-01

    In The Netherlands, on bicycle paths, single-bicycle accidents, bicycle-bicycle and bicycle-moped accidents constitute a considerable share of all bicyclist injuries. Over three quarters of all hospitalised bicyclist victims in the Netherlands cannot be directly related to a crash with motorised traffic. As the usage of bicycle paths steadily increases, it is to be expected that safety on bicycle paths will become a major issue in the coming years in The Netherlands. A study was conducted into the behaviour of bicyclists and moped riders to improve traffic safety on bicycle paths. By behavioural observations with video, mutual conflicts and bicyclist behaviour on bicycle paths were recorded and analysed, among other things by means of the conflict observation method DOCTOR (Dutch Objective Conflict Technique for Operation and Research). The explorative phase of the study (phase 1), included two research locations, one in the city of Amsterdam and one in Eindhoven. The results gave guidance for a better understanding of the behaviour between different users of separate two-directional bicycle paths. An example includes the relationship between bicyclist-moped rider behaviour and the width of the bicycle path. For a condition with busy bicycle traffic in both directions the width of the bicycle path in Amsterdam (effectively 3.55m) is relatively narrow, whereas the bicycle path width in Eindhoven (>4.94m) appears to be sufficient to accommodate large flows of bicyclists. Because of a large flow of crossing pedestrians resulting in (severe) conflicts with bicyclists in Amsterdam, additional countermeasures to better control these interactions are needed. The DOCTOR conflict observation method from video appears to be applicable for conflicts between intersecting road users and for head-on conflicts on the bicycle path. Conflict situations between bicyclists in the same direction (constituting an important share of injury accidents on bicycle paths) require an

  5. The Effect of Sharrows, Painted Bicycle Lanes and Physically Protected Paths on the Severity of Bicycle Injuries Caused by Motor Vehicles

    Directory of Open Access Journals (Sweden)

    Stephen P. Wall

    2016-12-01

    Full Text Available We conducted individual and ecologic analyses of prospectively collected data from 839 injured bicyclists who collided with motorized vehicles and presented to Bellevue Hospital, an urban Level-1 trauma center in New York City, from December 2008 to August 2014. Variables included demographics, scene information, rider behaviors, bicycle route availability, and whether the collision occurred before the road segment was converted to a bicycle route. We used negative binomial modeling to assess the risk of injury occurrence following bicycle path or lane implementation. We dichotomized U.S. National Trauma Data Bank Injury Severity Scores (ISS into none/mild (0–8 versus moderate, severe, or critical (>8 and used adjusted multivariable logistic regression to model the association of ISS with collision proximity to sharrows (i.e., bicycle lanes designated for sharing with cars, painted bicycle lanes, or physically protected paths. Negative binomial modeling of monthly counts, while adjusting for pedestrian activity, revealed that physically protected paths were associated with 23% fewer injuries. Painted bicycle lanes reduced injury risk by nearly 90% (IDR 0.09, 95% CI 0.02–0.33. Holding all else equal, compared to no bicycle route, a bicycle injury nearby sharrows was nearly twice as likely to be moderate, severe, or critical (adjusted odds ratio 1.94; 95% confidence interval (CI 0.91–4.15. Painted bicycle lanes and physically protected paths were 1.52 (95% CI 0.85–2.71 and 1.66 (95% CI 0.85–3.22 times as likely to be associated with more than mild injury respectively.

  6. Design of an aluminium bicycle path integrated in a steel bridge

    NARCIS (Netherlands)

    Maljaars, J.; Soetens, F.; Burggraaf, H.G.

    2007-01-01

    This paper describes the design of the aluminium structure of a bicycle path which is mounted on an existing steel brige. The benefits of aluminium, being low self weight, freedom in design obtained by extrusion and good corrosion resistance were maximal utilized. One of the main drawbacks of alumin

  7. Bicycle accidents.

    Science.gov (United States)

    Lind, M G; Wollin, S

    1986-01-01

    Information concerning 520 bicycle accidents and their victims was obtained from medical records and the victims' replies to questionnaires. The analyzed aspects included risk of injury, completeness of accident registrations by police and in hospitals, types of injuries and influence of the cyclists' age and sex, alcohol, fatigue, hunger, haste, physical disability, purpose of cycling, wearing of protective helmet and other clothing, type and quality of road surface, site of accident (road junctions, separate cycle paths, etc.) and turning manoeuvres.

  8. Bicycle safety

    Science.gov (United States)

    ... states have bike lanes and laws that protect bicycle riders. But riders are still at risk of ... stop or take evasive action. While riding your bicycle: Watch for opening car doors, potholes, children, and ...

  9. Removable Urban Pavements: An innovative, sustainable technology

    OpenAIRE

    2012-01-01

    Removable Urban Pavements: An innovative, sustainable technology By definition, a Removable Urban Pavement (RUP) can be quickly opened and closed, using lightweight equipment, for easy access to underground networks. While no such pavement appears to have ever been constructed, the premises of the concept can be found in certain military paths or industrial soils. A survey conducted among French municipal authorities has revealed the potential benefit of the RUP concept in decreasing the publ...

  10. Bicycling injuries.

    Science.gov (United States)

    Silberman, Marc R

    2013-01-01

    Bicycling injuries can be classified into bicycle contact, traumatic, and overuse injuries. Despite the popularity of cycling, there are few scientific studies regarding injuries. Epidemiological studies are difficult to compare due to different methodologies and the diverse population of cyclists studied. There are only three studies conducted on top level professionals. Ninety-four percent of professionals in 1 year have experienced at least one overuse injury. Most overuse injuries are mild with limited time off the bike. The most common site of overuse injury is the knee, and the most common site of traumatic injury is the shoulder, with the clavicle having the most common fracture. Many overuse and bicycle contact ailments are relieved with simple bike adjustments.

  11. Bicycle Wheel

    Science.gov (United States)

    1991-01-01

    An aerodynamic bicycle wheel developed by two DuPont engineers and a California company incorporates research into NASA airfoils. Computer modeling was accomplished with MSC/NASTRAN. Each of the three spokes in the wheel is, in effect, an airfoil, maximizing aerodynamic efficiency for racing.

  12. Bicycling for transportation and health: the role of infrastructure.

    Science.gov (United States)

    Dill, Jennifer

    2009-01-01

    This paper aims to provide insight on whether bicycling for everyday travel can help US adults meet the recommended levels of physical activity and what role public infrastructure may play in encouraging this activity. The study collected data on bicycling behavior from 166 regular cyclists in the Portland, Oregon metropolitan area using global positioning system (GPS) devices. Sixty percent of the cyclists rode for more than 150 minutes per week during the study and nearly all of the bicycling was for utilitarian purposes, not exercise. A disproportionate share of the bicycling occurred on streets with bicycle lanes, separate paths, or bicycle boulevards. The data support the need for well-connected neighborhood streets and a network of bicycle-specific infrastructure to encourage more bicycling among adults. This can be accomplished through comprehensive planning, regulation, and funding.

  13. The self-stabilising dynamics of bicycles

    CERN Document Server

    Warner, Mark

    2010-01-01

    We analyse the classical problem of the stability of bicycles when moving quickly and upright. Developing a lean causes the front wheel to turn thereby setting the bicycle instantaneously into circular motion. The centripetal force associated with the lean-dependent turning circle gives a restoring torque which corrects the lean. The force also helps self-steer the front wheel, ensuring the bicycle continues in an essentially straight path. We give the frequency of lean oscillations about the vertical executed during riding. As in the literature, we discuss the neglect of gyroscopic effects, which experiment suggests are negligible.

  14. Concrete Pavement Joint Deterioration

    OpenAIRE

    2016-01-01

    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 INDOT specification, pavement materials, designs and construction practices, and current de-icing materials were examined and related to the durability of concrete at the joints of existing pavements. A survey of concrete pavements across the state ...

  15. Pavement management and rehabilitation of portland cement concrete pavements

    Science.gov (United States)

    Zegeer, C. V.; Agent, K. R.; Rizenbergs, R. L.; Curtayne, P. C.; Scullion, T.; Pedigo, R. D.; Hudson, W. R.; Roberts, F. L.; Karan, M. A.; Haas, R.

    Pavement management and rehabilitation projects and techniques are discussed. The following topics are discussed: economic analyses and dynamic programming in resurfacing project selection; implementation of an urban pavement management system; pavement performance modeling for pavement management; illustration of pavement management: from data inventory to priority analysis; rehabilitation of concrete pavements by using portland cement concrete overlays; pavement management study: Illinois tollway pavement overlays; resurfacing of plain jointed-concrete pavements; design procedure for premium composite pavement; model study of anchored pavement; prestressed concrete overlay at O'Hare International Airport: in-service evaluation; and, bonded portland cement concrete resurfacing.

  16. Lost Kingdom of Bicycles?

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    For most people born in the 1950s and '60s, the bicycle was a faithful companion of their youth, when China was known as a kingdom of bicycles. A bicycle ride was a favorite pastime during a colorful spring day or in the crisp

  17. 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...

  18. Bituminous Pavement Failures

    Directory of Open Access Journals (Sweden)

    Surajo Abubakar Wada

    2016-02-01

    Full Text Available Pavement deterioration is a serious problem for road and traffic sector in almost every country, the most affecting causes of bituminous pavement failures have been studied in this paper. The paper describes the lessons learnt from pavement failures and problems experienced. Failures of bituminous pavements are caused due to many reasons or combination of reasons. Application of correction in the existing surface will enhance the life of maintenance works as well as that of strengthening layer. Along with the maintenance techniques there are various methods for pavement preservation which will help in enhancing the life of pavement and delaying of its failure.This paper discusses the possible causes of pavement failures, and recommendbetter ways to minimize and hopefully eliminate the causes of failures in bituminous pavements.

  19. 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...

  20. Bicycle Braking System

    OpenAIRE

    Brady, Noel

    2001-01-01

    A bicycle braking system for permitting controlled rotation and continuous power to the wheels of a bicycle during braking of the bicycle to enhance control of the bicycle during braking includes a cylindrical brake pad that is spring loaded within angled slots in a casing. The brake pad is positioned proximate the rim of a wheel and a cable assembly is coupled to the brake pad for urging the brake pad towards an end of the angled slots and against the rim of the wheel to slow rotation of the...

  1. Bicycles made to measure

    NARCIS (Netherlands)

    Van Dijk, T.

    2007-01-01

    For almost a century and a half, mathematicians have been racking their brains about the bike. How can a rolling bicycle be so stable of its own accord? Delft researchers now say they have completed the model to end all models. Bicycle manufacturer Batavus intends to use it to make better bikes for

  2. Bicycle Purchaser Training Workshop.

    Science.gov (United States)

    Schwarz, William

    A course was developed to provide data to buyers of new bicycles so they could make an informed decision about their purchases. The instructional systems design process (analysis, design, development, implementation, and evaluation) was used to analyze the need for a training course on buying and fitting a bicycle. Information was collected…

  3. Bicycle Promotion Plan

    Energy Technology Data Exchange (ETDEWEB)

    Simone, G. A.

    1981-03-09

    The objective of this Bicycle Promotion Plan is to outline a set of recommendations and supporting strategies for implementation by the US DOE toward increased use of the bicycle for energy conservation. The recommendations are designed in such a way as to function in concert with: (1) bicycle programs administered by other Federal government agencies; and (2) related programs and activities already sponsored by DOE. The approach to preparation of the Plan involved a review of all current and planned bicycle promotion programs at the Federal level as well as a review of the array of lierature on the subject. The UniWorld project staff also interacted with several DOE program offices, in order to determine the extent to which they might appropriately contribute to the implementation of bicycle promotional efforts. A synthesis of all the information gathered was published in January of 1981 as a part of the project (The Bicycle Program Review). Based upon this information and an examination of the barriers to bicycle use identified by bicycle transportation specialists in the field, UniWorld developed a series of the most potentially effective recommendations and program strategies for implementation by DOE. The recommendations address activities that could be undertaken in conjunction with existing DOE programs, new developments that might be considered to fulfill critical needs in the field, and interagency efforts that DOE could play a role in.

  4. Pavement Testing Facility

    Data.gov (United States)

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

  5. 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...

  6. Electro-optical approach to pavement deflection management

    Science.gov (United States)

    Rish, Jeff W., III; Adcock, Avery D.; Tuan, Christopher Y.; Baker, Samuel L.; Welker, Hugh W., II; Johnson, Roger F.

    1995-07-01

    A prototype continuous deflection device, referred to as a rolling weight deflectometer (RWD), has been developed as a nondestructive evaluation tool for airfield pavements. The system consists of a rigid trailer equipped with specially designed optical triangulation pavement sensors, a high-speed data acquisition system, and a high-pressure tire/load platform assembly. Pavement sensors are mounted on a rigid box beam equipped with an internal sensor system that corrects, in real time, the relative pavement height position measurements for displacements induced in the beam by mechanical vibrations, changes in temperature, or nonuniform dynamic loads at points where the beam attaches to the frame. The device produces continuous deflection profiles that show pavement response to a moving loaded wheel along the path of travel. These deflection profiles, combined with multiple passes along a lane, provide a far more detailed picture of the pavement structural integrity than has ever before been possible, because existing evaluation tools only produce response information at discrete points. Preliminary results show deflections measured by the RWD are in general agreement with the expected pavement response for various loads. A discussion of the device configuration, preliminary data, and potential as a pavement management tool is presented.

  7. Asphalt in Pavement Maintenance.

    Science.gov (United States)

    Asphalt Inst., College Park, MD.

    Maintenance methods that can be used equally well in all regions of the country have been developed for the use of asphalt in pavement maintenance. Specific information covering methods, equipment and terminology that applies to the use of asphalt in the maintenance of all types of pavement structures, including shoulders, is provided. In many…

  8. Concrete Block Pavements

    Science.gov (United States)

    1983-03-01

    1967, Cedergren 1974, Federal Highway .’,U .. V,47 -’":: 37 Administration 1980). Block pavements have essentially the same prob- lems with moisture...Vicksburg, Miss. Cedergren , H. R. 1974. Drainage of Highway and Airfield Pavements, John Wiley and Sons, New VOk. I Cement and Concrete Association

  9. Quantifying bicycle network connectivity.

    Science.gov (United States)

    Lowry, Michael; Loh, Tracy Hadden

    2017-02-01

    The intent of this study was to compare bicycle network connectivity for different types of bicyclists and different neighborhoods. Connectivity was defined as the ability to reach important destinations, such as grocery stores, banks, and elementary schools, via pathways or roads with low vehicle volumes and low speed limits. The analysis was conducted for 28 neighborhoods in Seattle, Washington under existing conditions and for a proposed bicycle master plan, which when complete will provide over 700 new bicycle facilities, including protected bike lanes, neighborhood greenways, and multi-use trails. The results showed different levels of connectivity across neighborhoods and for different types of bicyclists. Certain projects were shown to improve connectivity differently for confident and non-confident bicyclists. The analysis showed a positive correlation between connectivity and observed utilitarian bicycle trips. To improve connectivity for the majority of bicyclists, planners and policy-makers should provide bicycle facilities that allow immediate, low-stress access to the street network, such as neighborhood greenways. The analysis also suggests that policies and programs that build confidence for bicycling could greatly increase connectivity.

  10. On a Bicycle in Beijing

    Institute of Scientific and Technical Information of China (English)

    RON ROSSI

    2010-01-01

    @@ Other expats here in Beijing have all bought bicycles.One friend who was excited about his new bicycle told me he spent about 2,100 yuan($300).Another mentioned he had spent what would be equivalent to $500.

  11. Bicycle safety in bicycle to car accidents

    OpenAIRE

    Rodarius, C.; Mordaka, J.K.; Versmissen, A.C.M.

    2008-01-01

    Much attention is being paid to pedestrian safety by international working groups such as EEVC WG17, in research projects such as APROSYS (www.aprosys.com) and consumer organisations like Euro NCAP (www.euroncap.com). In addition legal requirements are in place, like the EU directive 2003/102/EC. However, it can be seen from the BRON (Bestand geRegistreerde Ongevallen Nederland) accident database that in the Netherlands more people get killed or injured while riding a bicycle than as a pedest...

  12. Bicycle Trailers Increase Mobility

    Science.gov (United States)

    Exceptional Parent, 2006

    2006-01-01

    This article describes the experiences of an exceptional parent who always takes his daughter for rides in a CycleTote special needs bicycle trailer. Dennis Foster, an exceptional parent from Commerce, Oklahoma, found that taking his twenty-eight-year-old daughter Hasha for rides has made her happy. Hasha has been diagnosed with cerebral palsy.

  13. Bicycles and Valentines

    Institute of Scientific and Technical Information of China (English)

    2004-01-01

    Shanghai municipality's announcement late last year that bicycles were to be banned from the city's main thoroughfares was ill received by many residents. The measure was taken to relieve traffic congestion and reflects how traditional modes of transport fail to meet the changing needs of Chinese contemporary life.

  14. The safety of electrically assisted bicycles compared to classic bicycles.

    Science.gov (United States)

    Schepers, J P; Fishman, E; den Hertog, P; Wolt, K Klein; Schwab, A L

    2014-12-01

    Use of electrically assisted bicycles with a maximum speed of 25 km/h is rapidly increasing. This growth has been particularly rapid in the Netherlands, yet very little research has been conducted to assess the road safety implications. This case-control study compares the likelihood of crashes for which treatment at an emergency department is needed and injury consequences for electric bicycles to classic bicycles in the Netherlands among users of 16 years and older. Data were gathered through a survey of victims treated at emergency departments. Additionally, a survey of cyclists without any known crash experience, drawn from a panel of the Dutch population acted as a control sample. Logistic regression analysis is used to compare the risk of crashes with electric and classical bicycles requiring treatment at an emergency department. Among the victims treated at an emergency department we compared those being hospitalized to those being send home after the treatment at the emergency department to compare the injury consequences between electric and classical bicycle victims. The results suggest that, after controlling for age, gender and amount of bicycle use, electric bicycle users are more likely to be involved in a crash that requires treatment at an emergency department due to a crash. Crashes with electric bicycles are about equally severe as crashes with classic bicycles. We advise further research to develop policies to minimize the risk and maximize the health benefits for users of electric bicycles. Copyright © 2014 Elsevier Ltd. All rights reserved.

  15. Pavement Snow Melting

    Energy Technology Data Exchange (ETDEWEB)

    Lund, John W.

    2005-01-01

    The design of pavement snow melting systems is presented based on criteria established by ASHRAE. The heating requirements depends on rate of snow fall, air temperature, relative humidity and wind velocity. Piping materials are either metal or plastic, however, due to corrosion problems, cross-linked polyethylene pipe is now generally used instead of iron. Geothermal energy is supplied to systems through the use of heat pipes, directly from circulating pipes, through a heat exchanger or by allowing water to flow directly over the pavement, by using solar thermal storage. Examples of systems in New Jersey, Wyoming, Virginia, Japan, Argentina, Switzerland and Oregon are presented. Key words: pavement snow melting, geothermal heating, heat pipes, solar storage, Wyoming, Virginia, Japan, Argentina, Klamath Falls.

  16. DRAINAGE AND FLEXIBLE PAVEMENT PERFORMANCE

    Directory of Open Access Journals (Sweden)

    SIDDHARTHA ROKADE

    2012-04-01

    Full Text Available Providing adequate drainage to a pavement system has been considered as an important design consideration to prevent premature failures due to water related problems such as pumping action, loss of support, and rutting, among others. Most water in pavements is due to rainfall infiltration into unsaturated pavement layers, throughjoints, cracks, shoulder edges, and various other defects, especially in older deteriorated pavements. Water also seep upward from a high groundwater table due to capillary suction or vapour movements, or it may flow laterally from the pavement edges and side ditches. Providing adequate drainage to a pavement system has been considered as an important design consideration to ensure satisfactory performance of the pavement, particularly from the perspective of life cycle cost and serviceability. To minimize premature pavement distresses and to enhance the pavement performance, it is imperative to provide adequate drainage to allow infiltrated water to drain out from the base and sub-base, thus avoiding saturation of base and subgrade soils. This paper deals with the analysis of the impact of subsurface drainage on pavement system performance. The requirement ofeffective subsurface drainage for pavement performance is also discussed.

  17. Butchers and Bicycles

    DEFF Research Database (Denmark)

    Kahle, Lynn; Eriksen, Steen Mandsfelt

    2016-01-01

    , maneuverability and styling. With his engineering and design background, Wagener set out to design a new trike; which would meet the needs of the target market, which his research identified as well- educated individuals who were very interested in aesthetics. Furthermore, Wagener was convinced that trikes were......Morten Wagener is a Danish design, and innovator who founded the cargo and personal transportation bicycle company, ”Butchers and Bicycles,”. He identified a business opportunity to improve the future of urban transport. His idea was that most of the trikes) on the market lacked good design...... between order and delivery. From a marketing perspective, one of the differentiating factors of Morten’s product is the quality of the ride (compared to competing products) and so his marketing team coined the slogan “Built-to-Tilt” because even though it’s a trike it feels like riding a two...

  18. Land of Bicycles

    Institute of Scientific and Technical Information of China (English)

    ZhangHua; LuRucai

    2004-01-01

    There are currently more than 500 million cyclists in China,10million of them in Bejing.Despite efficient bus networks,legions of taxis and surging private car ownership,the bicycle remains a firm fixture in Chinese daily life.But it is much more than just a means of transport to cyclists today,who demand a afr greater chioce of design and function than ever before.

  19. Cyclists' attitudes toward policies encouraging bicycle travel: findings from the Taupo Bicycle Study in New Zealand.

    Science.gov (United States)

    Tin Tin, Sandar; Woodward, Alistair; Thornley, Simon; Langley, John; Rodgers, Anthony; Ameratunga, Shanthi

    2010-03-01

    Utility cycling provides substantial health, environmental and economic benefits. Despite a favourable trend in leisure-time cycling, cycling is infrequently used for everyday travel needs in New Zealand. This study investigated cyclists' attitudes toward environmental and policy measures that would encourage them to cycle more, particularly for a trip to work. A cross-sectional analysis was undertaken using baseline data obtained from the Taupo Bicycle Study, a web-based longitudinal study. The study population comprised 2469 cyclists, aged 16 years or over, who had enrolled in the 2006 Wattyl Lake Taupo Cycle Challenge. The majority (88%) reported the provision of bicycle lanes as an important factor that would encourage them to cycle more often, followed by bicycle paths (76%), better bicycle security (64%), reduced motor vehicle speed (55%) and bike friendly public transport (38%). Of those who reported travelling to work at least once a week (N = 2223), varying proportions reported shower facilities at work (61%), fewer difficult intersections (43%), rising fuel costs (41%), fewer car parks (27%), bike designed to commute (26%) and rising cost of car parking (25%) as important factors that would encourage them to cycle to work more often. There were important differences in these perceived influences defined by the participants' socio-demographic characteristics and current cycling habits.

  20. Precast Concrete Pavements

    Science.gov (United States)

    1981-11-01

    Gorsuch 1962, Kruse 1966, Jacoby 1967, and Hargett 1970). The final slab design used in construction is shown in Figure 2. These slabs were 6 ft wide, 24...Experiment Station, CE, Vicksburg, Miss. Gorsuch , R. F. 1962. "Preliminary Investigation of Precast Prestressed Concrete Pavements," MS Thesis, South Dakota

  1. The effects of surface-induced loads on forearm muscle activity during steering a bicycle.

    Science.gov (United States)

    Arpinar-Avsar, Pinar; Birlik, Gülin; Sezgin, Onder C; Soylu, Abdullah R

    2013-01-01

    On the bicycle, the human upper extremity has two essential functions in steering the bicycle and in supporting the body. Through the handlebar, surface- induced loads are transmitted to the hand and arm of the bicycle rider under vibration exposure conditions. Thus, the purpose of the study was to investigate the effect of vibration exposure on forearm muscle activity for different road surfaces (i.e. smooth road, concrete stone pavement, rough road) and for different bicycles. Ten subjects participated in experiments and two types of bicycles, i.e. Road Bike (RB) and Mountain Bike (MTB) are compared. The acceleration magnitudes were dominant along x and z-axes. The r.m.s acceleration values in the z direction at the stem of MTB were at most 2.56, 7.04 and 10.76 m·s(-2) when pedaling respectively on asphalt road, concrete pavement and rough road. In the case of RB the corresponding values were respectively 4.43, 11.75 and 27.31 m·s(-2). The cumulative normalized muscular activity levels during MTB trials on different surfaces had the same tendency as with acceleration amplitudes and have ranked in the same order from lowest to highest value. Although road bike measurements have resulted in a similar trend of increment, the values computed for rough road trials were higher than those in MTB trials. During rough road measurements on MTB, rmsEMG of extensor muscles reached a value corresponding to approximately 50% of MVC (Maximum Voluntary Contraction). During RB trials performed on rough road conditions, rmsEMG (%MVC) values for the forearm flexor muscles reached 45.8% of their maximal. The level of muscular activity of forearm muscles in controlling handlebar movements has been observed to be enhanced by the increase in the level of vibration exposed on the bicycle. Since repeated forceful gripping and pushing forces to a handle of a vibratory tool can create a risk of developing circulatory, neurological, or musculoskeletal disorder, a bicycle rider can be

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

    CSIR Research Space (South Africa)

    Steyn, WJvdM

    2001-07-01

    Full Text Available and AT VISSER* CSIR Transportek, PO Box 395, Pretoria, 0001 *University of Pretoria, Department of Civil Engineering, Pretoria, 0002 ABSTRACT Current mechanistic pavement design and analysis techniques use several simplifications to enable... the process to be practical and cost-effective. These include equivalent vehicle loads, linear elastic analysis and static vehicle load and pavement response analysis. These simplifications allow the process of pavement design and analysis to be applied...

  3. The Bicycle Assembly Line Game

    Science.gov (United States)

    Klotz, Dorothy

    2011-01-01

    "The Bicycle Assembly Line Game" is a team-based, in-class activity that helps students develop a basic understanding of continuously operating processes. Each team of 7-10 students selects one of seven prefigured bicycle assembly lines to operate. The lines are run in real-time, and the team that operates the line that yields the…

  4. The Bicycle Assembly Line Game

    Science.gov (United States)

    Klotz, Dorothy

    2011-01-01

    "The Bicycle Assembly Line Game" is a team-based, in-class activity that helps students develop a basic understanding of continuously operating processes. Each team of 7-10 students selects one of seven prefigured bicycle assembly lines to operate. The lines are run in real-time, and the team that operates the line that yields the…

  5. Predicting Free Flow Speed and Crash Risk of Bicycle Traffic Flow Using Artificial Neural Network Models

    Directory of Open Access Journals (Sweden)

    Cheng Xu

    2015-01-01

    Full Text Available Free flow speed is a fundamental measure of traffic performance and has been found to affect the severity of crash risk. However, the previous studies lack analysis and modelling of impact factors on bicycles’ free flow speed. The main focus of this study is to develop multilayer back propagation artificial neural network (BPANN models for the prediction of free flow speed and crash risk on the separated bicycle path. Four different models with considering different combinations of input variables (e.g., path width, traffic condition, bicycle type, and cyclists’ characteristics were developed. 459 field data samples were collected from eleven bicycle paths in Hangzhou, China, and 70% of total samples were used for training, 15% for validation, and 15% for testing. The results show that considering the input variables of bicycle types and characteristics of cyclists will effectively improve the accuracy of the prediction models. Meanwhile, the parameters of bicycle types have more significant effect on predicting free flow speed of bicycle compared to those of cyclists’ characteristics. The findings could contribute for evaluation, planning, and management of bicycle safety.

  6. [Prevention of bicycle accidents].

    Science.gov (United States)

    Zwipp, H; Barthel, P; Bönninger, J; Bürkle, H; Hagemeister, C; Hannawald, L; Huhn, R; Kühn, M; Liers, H; Maier, R; Otte, D; Prokop, G; Seeck, A; Sturm, J; Unger, T

    2015-04-01

    For a very precise analysis of all injured bicyclists in Germany it would be important to have definitions for "severely injured", "seriously injured" and "critically injured". By this, e.g., two-thirds of surgically treated bicyclists who are not registered by the police could become available for a general analysis. Elderly bicyclists (> 60 years) are a minority (10 %) but represent a majority (50 %) of all fatalities. They profit most by wearing a helmet and would be less injured by using special bicycle bags, switching on their hearing aids and following all traffic rules. E-bikes are used more and more (145 % more in 2012 vs. 2011) with 600,000 at the end of 2011 and are increasingly involved in accidents but still have a lack of legislation. So even for pedelecs 45 with 500 W and a possible speed of 45 km/h there is still no legislative demand for the use of a protecting helmet. 96 % of all injured cyclists in Germany had more than 0.5 ‰ alcohol in their blood, 86 % more than 1.1 ‰ and 59 % more than 1.7 ‰. Fatalities are seen in 24.2 % of cases without any collision partner. Therefore the ADFC calls for a limit of 1.1 ‰. Some virtual studies conclude that integrated sensors in bicycle helmets which would interact with sensors in cars could prevent collisions or reduce the severity of injury by stopping the cars automatically. Integrated sensors in cars with opening angles of 180° enable about 93 % of all bicyclists to be detected leading to a high rate of injury avoidance and/or mitigation. Hanging lamps reduce with 35 % significantly bicycle accidents for children, traffic education for children and special trainings for elderly bicyclists are also recommended as prevention tools. As long as helmet use for bicyclists in Germany rates only 9 % on average and legislative orders for using a helmet will not be in force in the near future, coming up campaigns seem to be necessary to be promoted by the Deutscher

  7. Geotextiles in Flexible Pavement Construction

    Science.gov (United States)

    Alungbe, Gabriel D.

    2004-01-01

    People everywhere in the developed world regularly drive on paved roads. Learning about the construction techniques and materials used in paving benefits technology and construction students. This article discusses the use of geosynthetic textiles in pavement construction. It presents background on pavements and describes geotextiles and drainage…

  8. Pavement roughness and skid properties

    Science.gov (United States)

    Road roughness and roadway safety as it relates to both surface and air transportation are discussed. The role of road roughness in vehicle ride, the measurement of roughness, the evaluation of riding confort, and the effect of grooving pavements are discussed. The effects of differential pavement friction on the response of cars in skidding maneuvers is discussed.

  9. 36 CFR 13.914 - Bicycle use.

    Science.gov (United States)

    2010-07-01

    ... 36 Parks, Forests, and Public Property 1 2010-07-01 2010-07-01 false Bicycle use. 13.914 Section... § 13.914 Bicycle use. The use of a bicycle is prohibited— (a) On the Savage River Loop Trail; the... in public parking areas, or on trails and areas designated for bicycle use by the Superintendent....

  10. 15 CFR 265.22 - Bicycle traffic.

    Science.gov (United States)

    2010-01-01

    ... 15 Commerce and Foreign Trade 1 2010-01-01 2010-01-01 false Bicycle traffic. 265.22 Section 265.22... Bicycle traffic. No person shall ride a bicycle other than in a manner exercising due caution for pedestrian and other traffic. No person shall ride a bicycle on sidewalks or inside any building, nor...

  11. Bicycle Rider Control: Observations, Modeling & Experiments

    NARCIS (Netherlands)

    Kooijman, J.D.G.

    2012-01-01

    Bicycle designers traditionally develop bicycles based on experience and trial and error. Adopting modern engineering tools to model bicycle and rider dynamics and control is another method for developing bicycles. This method has the potential to evaluate the complete design space, and thereby dev

  12. Bicycle traffic in urban areas

    Directory of Open Access Journals (Sweden)

    Anđelković Zorica

    2015-01-01

    Full Text Available Cycling is a term describing the use of bicycles, but also any mean of transport driven solely by human power. Development of bicycle traffic in urban areas involves construction of cycling infrastructure, adapting streets and other traffic infrastructure to a form suitable for cycling and other means of transport (individual motorized traffic, public transport, walking, ensuring the adequate budget and systematic planning and development of sustainable transport in cities. The paper presents basic settings and conditions as input elements to plan bicycle traffic in urban areas, as well as program- design conditions which lead the activities of planners and designers of urban roads in connection with cyclists.

  13. Using data mining techniques to predict the severity of bicycle crashes.

    Science.gov (United States)

    Prati, Gabriele; Pietrantoni, Luca; Fraboni, Federico

    2017-04-01

    To investigate the factors predicting severity of bicycle crashes in Italy, we used an observational study of official statistics. We applied two of the most widely used data mining techniques, CHAID decision tree technique and Bayesian network analysis. We used data provided by the Italian National Institute of Statistics on road crashes that occurred on the Italian road network during the period ranging from 2011 to 2013. In the present study, the dataset contains information about road crashes occurred on the Italian road network during the period ranging from 2011 to 2013. We extracted 49,621 road accidents where at least one cyclist was injured or killed from the original database that comprised a total of 575,093 road accidents. CHAID decision tree technique was employed to establish the relationship between severity of bicycle crashes and factors related to crash characteristics (type of collision and opponent vehicle), infrastructure characteristics (type of carriageway, road type, road signage, pavement type, and type of road segment), cyclists (gender and age), and environmental factors (time of the day, day of the week, month, pavement condition, and weather). CHAID analysis revealed that the most important predictors were, in decreasing order of importance, road type (0.30), crash type (0.24), age of cyclist (0.19), road signage (0.08), gender of cyclist (0.07), type of opponent vehicle (0.05), month (0.04), and type of road segment (0.02). These eight most important predictors of the severity of bicycle crashes were included as predictors of the target (i.e., severity of bicycle crashes) in Bayesian network analysis. Bayesian network analysis identified crash type (0.31), road type (0.19), and type of opponent vehicle (0.18) as the most important predictors of severity of bicycle crashes. Copyright © 2017 Elsevier Ltd. All rights reserved.

  14. Bicycle Use and Cyclist Safety Following Boston’s Bicycle Infrastructure Expansion, 2009–2012

    Science.gov (United States)

    Angriman, Federico; Bellows, Alexandra L.; Taylor, Kathryn

    2016-01-01

    Objectives. To evaluate changes in bicycle use and cyclist safety in Boston, Massachusetts, following the rapid expansion of its bicycle infrastructure between 2007 and 2014. Methods. We measured bicycle lane mileage, a surrogate for bicycle infrastructure expansion, and quantified total estimated number of commuters. In addition, we calculated the number of reported bicycle accidents from 2009 to 2012. Bicycle accident and injury trends over time were assessed via generalized linear models. Multivariable logistic regression was used to examine factors associated with bicycle injuries. Results. Boston increased its total bicycle lane mileage from 0.034 miles in 2007 to 92.2 miles in 2014 (P cyclist safety. PMID:27736203

  15. USE OF RECLAIMED ASPHALT PAVEMENT WITH MILLED ROAD PAVEMENT LAYERS

    OpenAIRE

    Andrzej Plewa; Marta Wasilewska; Władysław Gardziejczyk; Paweł Gierasimiuk

    2015-01-01

    The article presents the results of research on the functional properties of asphalt mixes using RAP obtained from milling asphalt road pavements. Asphalt concrete AC 22P with 0%, 10%, 15% and 20% addition of RAP used for base course of road pavements were designed. It was found that asphalt mixes with RAP characterized by comparable and in some cases better functional properties compared to the asphalt mixes without RAP (0%). One should notice the influence of RAP on the performance and ...

  16. Bicyclic glutamic acid derivatives.

    Science.gov (United States)

    Meyer, Udo; Bisel, Philippe; Weckert, Edgar; Frahm, August Wilhelm

    2006-05-15

    For the second-generation asymmetric synthesis of the trans-tris(homoglutamic) acids via Strecker reaction of chiral ketimines, the cyanide addition as the key stereodifferentiating step produces mixtures of diastereomeric alpha-amino nitrile esters the composition of which is independent of the reaction temperature and the type of the solvent, respectively. The subsequent hydrolysis is exclusively achieved with concentrated H(2)SO(4) yielding diastereomeric mixtures of three secondary alpha-amino alpha-carbamoyl-gamma-esters and two diastereomeric cis-fused angular alpha-carbamoyl gamma-lactams as bicyclic glutamic acid derivatives, gained from in situ stereomer differentiating cyclisation of the secondary cis-alpha-amino alpha-carbamoyl-gamma-esters. Separation was achieved by CC. The pure secondary trans-alpha-amino alpha-carbamoyl-gamma-esters cyclise on heating and treatment with concentrated H(2)SO(4), respectively, to diastereomeric cis-fused angular secondary alpha-amino imides. Their hydrogenolysis led to the enantiomeric cis-fused angular primary alpha-amino imides. The configuration of all compounds was completely established by NMR methods, CD-spectra, and by X-ray analyses of the (alphaR,1R,5R)-1-carbamoyl-2-(1-phenylethyl)-2-azabicyclo[3.3.0]octan-3-one and of the trans-alphaS,1S,2R-2-ethoxycarbonylmethyl-1-(1-phenylethylamino)cyclopentanecarboxamide.

  17. THE EFFECTS OF SURFACE-INDUCED LOADS ON FOREARM MUSCLE ACTIVITY DURING STEERING A BICYCLE

    Directory of Open Access Journals (Sweden)

    Pinar Arpinar-Avsar

    2013-09-01

    Full Text Available On the bicycle, the human upper extremity has two essential functions in steering the bicycle and in supporting the body. Through the handlebar, surface- induced loads are transmitted to the hand and arm of the bicycle rider under vibration exposure conditions. Thus, the purpose of the study was to investigate the effect of vibration exposure on forearm muscle activity for different road surfaces (i.e. smooth road, concrete stone pavement, rough road and for different bicycles. Ten subjects participated in experiments and two types of bicycles, i.e. Road Bike (RB and Mountain Bike (MTB are compared. The acceleration magnitudes were dominant along x and z-axes. The r.m.s acceleration values in the z direction at the stem of MTB were at most 2.56, 7.04 and 10.76 m·s-2 when pedaling respectively on asphalt road, concrete pavement and rough road. In the case of RB the corresponding values were respectively 4.43, 11.75 and 27.31 m·s-2. The cumulative normalized muscular activity levels during MTB trials on different surfaces had the same tendency as with acceleration amplitudes and have ranked in the same order from lowest to highest value. Although road bike measurements have resulted in a similar trend of increment, the values computed for rough road trials were higher than those in MTB trials. During rough road measurements on MTB, rmsEMG of extensor muscles reached a value corresponding to approximately 50% of MVC (Maximum Voluntary Contraction. During RB trials performed on rough road conditions, rmsEMG (%MVC values for the forearm flexor muscles reached 45.8% of their maximal. The level of muscular activity of forearm muscles in controlling handlebar movements has been observed to be enhanced by the increase in the level of vibration exposed on the bicycle. Since repeated forceful gripping and pushing forces to a handle of a vibratory tool can create a risk of developing circulatory, neurological, or musculoskeletal disorder, a bicycle rider

  18. 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 pra

  19. 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...

  20. 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...

  1. The Bicycle Rental Market In Hangzhou

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    On May 1, 2008, Hangzhou, capital of east China’s Zhejiang Province, included bicycle rentals in the public transportation system. Now, bicycles have become the most convenient form of transport for Hangzhou residents. Data from the Hangzhou Bureau of Transportation show that on average each bicycle gets rented five times a day.

  2. "Bicycles May Use Full Lane" Signage Communicates U.S. Roadway Rules and Increases Perception of Safety.

    Science.gov (United States)

    Hess, George; Peterson, M Nils

    2015-01-01

    Many global challenges, including obesity, health care costs, and climate change, could be addressed in part by increasing the use of bicycles for transportation. Concern about the safety of bicycling on roadways is frequently cited as a deterrent to increasing bicycle use in the USA. The use of effective signage along roadways might help alleviate these concerns by increasing knowledge about the rights and duties of bicyclists and motorists, ideally reducing crashes. We administered a web-based survey, using Twitter for recruitment, to examine how well three US traffic control devices communicated the message that bicyclists are permitted in the center of the travel lane and do not have to "get out of the way" to allow motorists to pass without changing lanes: "Bicycles May Use Full Lane" and "Share the Road" signage, and Shared Lane Markings on the pavement. Each was compared to an unsigned roadway. We also asked respondents whether it was safe for a bicyclist to occupy the center of the travel lane. "Bicycles May Use Full Lane" signage was the most consistently comprehended device for communicating the message that bicyclists may occupy the travel lane and also increased perceptions of safety. "Share the Road" signage did not increase comprehension or perceptions of safety. Shared Lane Markings fell somewhere between. "Bicycles May Use Full Lane" signage showed notable increases in comprehension among novice bicyclists and private motor vehicle commuters, critical target audiences for efforts to promote bicycling in the USA. Although limited in scope, our survey results are indicative and suggest that Departments of Transportation consider replacing "Share the Road" with "Bicycles May Use Full Lane" signage, possibly combined with Shared Lane Markings, if the intent is to increase awareness of roadway rights and responsibilities. Further evaluation through virtual reality simulations and on-road experiments is merited.

  3. "Bicycles May Use Full Lane" Signage Communicates U.S. Roadway Rules and Increases Perception of Safety.

    Directory of Open Access Journals (Sweden)

    George Hess

    Full Text Available Many global challenges, including obesity, health care costs, and climate change, could be addressed in part by increasing the use of bicycles for transportation. Concern about the safety of bicycling on roadways is frequently cited as a deterrent to increasing bicycle use in the USA. The use of effective signage along roadways might help alleviate these concerns by increasing knowledge about the rights and duties of bicyclists and motorists, ideally reducing crashes. We administered a web-based survey, using Twitter for recruitment, to examine how well three US traffic control devices communicated the message that bicyclists are permitted in the center of the travel lane and do not have to "get out of the way" to allow motorists to pass without changing lanes: "Bicycles May Use Full Lane" and "Share the Road" signage, and Shared Lane Markings on the pavement. Each was compared to an unsigned roadway. We also asked respondents whether it was safe for a bicyclist to occupy the center of the travel lane. "Bicycles May Use Full Lane" signage was the most consistently comprehended device for communicating the message that bicyclists may occupy the travel lane and also increased perceptions of safety. "Share the Road" signage did not increase comprehension or perceptions of safety. Shared Lane Markings fell somewhere between. "Bicycles May Use Full Lane" signage showed notable increases in comprehension among novice bicyclists and private motor vehicle commuters, critical target audiences for efforts to promote bicycling in the USA. Although limited in scope, our survey results are indicative and suggest that Departments of Transportation consider replacing "Share the Road" with "Bicycles May Use Full Lane" signage, possibly combined with Shared Lane Markings, if the intent is to increase awareness of roadway rights and responsibilities. Further evaluation through virtual reality simulations and on-road experiments is merited.

  4. 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.

  5. 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.

  6. Field Investigation of High Performance Pavements in Virginia

    OpenAIRE

    2005-01-01

    This study evaluated 18 pavement sections located in high-traffic highways in Virginia to find a premium pavement design with a life span of 40 years or more using current and past field experience. The selected pavement sections were thought to perform well. Eight flexible pavements, six composite pavements, two continuously reinforced concrete pavements, and two jointed plain concrete pavements were investigated. Field testing consisted of (1) falling weight deflectometer (FWD) testing to a...

  7. EP BICYCLE POOL - VIGNETTES 2002

    CERN Multimedia

    EP-SMI Help Desk

    2002-01-01

    The vignettes (insurance certificates) for 2002 become obligatory from 1 June. If you have a bicycle from the EP Pool, please bring it to the EP-SMI Help Desk (Building 124) on any working day up to 31 May between 8h.30 - 12h.00 or 13h.30 - 17h.30. EP-SMI Help Desk

  8. Bicycle Safety: Sport Education Style

    Science.gov (United States)

    Sinelnikov, Oleg A.; Hastie, Peter A.; Cole, Amy; Schneulle, Deanna

    2005-01-01

    Although the benefits of regular physical activity are well-documented and very well known, Americans are still becoming more sedentary and obese. As some experts envision the potential of nonmotorized transport in the future, especially in urban settings, it is not surprising that diverse groups view walking and bicycling as a solution to an…

  9. Car Hits Boy on Bicycle

    Science.gov (United States)

    Ruiz, Michael J.

    2005-01-01

    In this article we present the fascinating reconstruction of an accident where a car hit a boy riding his bicycle. The boy dramatically flew several metres through the air after the collision and was injured, but made a swift and complete recovery from the accident with no long-term after-effects. Students are challenged to determine the speed of…

  10. Methods of bicycle users’ survey

    OpenAIRE

    Tokmylenko, Olena

    2015-01-01

    The paper provides a review of data collection methods that can be used for bicycling modeling and planning. The review includes fifteen international studies that use different methods of data collection. The main advantages and disadvantages of each method are listed and the recommendations on when to use particular method are provided.

  11. USE OF RECLAIMED ASPHALT PAVEMENT WITH MILLED ROAD PAVEMENT LAYERS

    Directory of Open Access Journals (Sweden)

    Andrzej Plewa

    2015-07-01

    Full Text Available The article presents the results of research on the functional properties of asphalt mixes using RAP obtained from milling asphalt road pavements. Asphalt concrete AC 22P with 0%, 10%, 15% and 20% addition of RAP used for base course of road pavements were designed. It was found that asphalt mixes with RAP characterized by comparable and in some cases better functional properties compared to the asphalt mixes without RAP (0%. One should notice the influence of RAP on the performance and durability of the asphalt mixtures, as compared to virgin asphalt mixtures (without RAP.

  12. Deflection Control in Rigid Pavements

    Science.gov (United States)

    Varunkrishna, Nulu; Jayasankar, R.

    2017-07-01

    The need for modern transportation systems together with the high demand for perpetual pavements under the drastically increasing applied loads has led to a great deal of research on concrete as a pavement material worldwide. This research indeed instigated many modifications in concrete aiming for improving the concrete properties. Pavement Quality Concrete requires higher flexural strength and fewer deflections in hardened state. Fiber reinforcement and latex modification are two reliable approaches serving the required purposes. The concrete made with these two modifications is called Polymer-modified Fiber-reinforced concrete. The present study deals with the usage of polypropylene as fiber and SBR (Styrene Butadiene Rubber) Latex as polymer. M30 grade concrete was modified by replacing cement with two different percentages of fiber (0.5%, 1.0% of weight of cement) and with three different percentages of SBR latex (10%, 15% & 20% of weight of cement).

  13. Road characteristics and bicycle accidents.

    Science.gov (United States)

    Nyberg, P; Björnstig, U; Bygren, L O

    1996-12-01

    In Umeå, Sweden, defects in the physical road surface contributed to nearly half of the single bicycle accidents. The total social cost of these injuries to people amount to at least SEK 20 million (SEK 60,000 or about USD 8,500 per accident), which corresponds to the estimated loss of "eight life equivalents a year". Improved winter maintenance seems to have the greatest injury prevention potential and would probably reduce the number of injuries considerably, whereas improved road quality and modification of kerbs would reduce the most severe injuries. A local traffic safety program should try to prevent road accidents instead of handling the consequences of them. In accordance with Parliament decisions on traffic we would like to see increased investment in measures favoring bicycle traffic, where cycling is seen as a solution, not as a problem.

  14. 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,

  15. 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…

  16. 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…

  17. Electric-bicycle propulsion power

    Energy Technology Data Exchange (ETDEWEB)

    Oman, H.; Morchin, W.C. [Electro-Bicycle, Inc., Auburn, WA (United States); Jamerson, F.E. [Electric Battery Bicycle Co., Naples, FL (United States)

    1995-12-31

    In a human-powered hybrid electric vehicle (HPHEV) the travel distance available from a single battery charge can be lengthened with power from another source, the cyclist`s leg muscles. In a battery-powered electric bicycle the propulsion power goes mostly into overcoming aerodynamic drag. For example, at 18 km per hour (11 miles per hour) this drag represents 200 watts at the tire-to-road interface for a typical cyclist`s shape and clothing. Today`s typical electrical bicycle is propelled by a high-speed dc motor which is powered from a lead-acid battery. The combined efficiency of the motor and its speed-reducing gears is 50 to 65 percent. In this paper we calculate available travel distances, as a function of speed, grade, and the battery energy-content as measured in watt-hours per kg. We show the effect of battery cost and charge/discharge cycle-life on travel cost in terms of cents per kilometer travelled. Designs used in today`s electric bicycles are illustrated.

  18. SOFIE, a bicycle that supports older cyclists?

    Science.gov (United States)

    Dubbeldam, R; Baten, C; Buurke, J H; Rietman, J S

    2016-10-13

    Older cyclists remain at high risk of sustaining an injury after a fall with their bicycle. A growing awareness for the need and possibilities to support safety of older cyclists has been leading to bicycle design ideas. However, the effectiveness and acceptance of such designs has not been studied yet. This study aims to analyse the effect of 3 support systems: an automatic adjustable saddle height, optimised frame and wheel geometry and drive-off assistance. The support systems are integrated on the SOFIE bicycle, a prototype bicycle designed to support older cyclists during (dis-)mounting and at lower cycling speeds. Nine older cyclists (65-80 years) were asked to cycle on a 'normal' and on the 'SOFIE' bicycle. They cycled on a parking lot to avoid interaction with traffic. The following tasks were analysed: cycling at comfortable and low speed avoiding an obstacle and (dis-)mounting the bicycle. Bicycle and cyclist motions were recorded with 10 Inertial Measurement Units and by 2 video cameras. FUSION software (LABVIEW) was used to assess kinematic parameters. First, a subjective analysis of the different cycling tasks was made, supported by video analysis. Second, differences in cyclist and bicycle kinematic parameters between the normal and SOFIE bicycle were studied for the various cycling tasks. The SOFIE bicycle was experienced as a 'supportive' and comfortable bicycle and objectively performed 'safer' on various cycling tasks. For example: The optimised frame geometry with low step-in enabled a faster (dis-)mounting time and less sternum roll angle and angular acceleration. The adjustable saddle height enabled the participants to keep both feet on the ground till they started cycling with the 'drive-off' support. The latter reduces steering activity: maximum steer angle and angular acceleration. During sudden obstacle avoidance, less upper body and thigh accelerations are recorded. In conclusion, the SOFIE bicycle was able to support older cyclists during

  19. BMX bicycles: accident comparison with other models.

    OpenAIRE

    1985-01-01

    A comparison has been made between BMX bicycle accidents and those occurring when children ride other types of bicycle. The injuries sustained are compared to see if the clinical impressions that BMX are more dangerous, and produce more facial injuries, are correct. This was found not to be true as half the children involved rode BMX bicycles, and the injuries sustained were similar to those occurring to non BMX riders. BMX riders had a lower proportion of serious injuries than riders of raci...

  20. Calibration of full-scale accelerated pavement testing data using long-term pavement performance data

    CSIR Research Space (South Africa)

    VdM Steyn, WJ

    2012-09-01

    Full Text Available Accelerated Pavement Testing (APT) has always been conducted with the objective of improving the understanding of real pavements under real traffic and environmental conditions. While APT provides an accelerated view of some of the major structural...

  1. Use and application of accelerated pavement testing in pavement preservation research

    CSIR Research Space (South Africa)

    Steyn, WJVDM

    2009-09-01

    Full Text Available is that pavement preservation treatments can be evaluated using APT machines. Specific aspects that require careful attention during the process are the preparation of the test section (replication of failure mechanism to be rectified), monitoring of pavement...

  2. Observational study of compliance with Queensland bicycle helmet laws.

    Science.gov (United States)

    Debnath, Ashim Kumar; Haworth, Narelle; Schramm, Amy; Williamson, Amy

    2016-12-01

    Mandatory bicycle helmet laws have been found to increase helmet wearing rates in Australia and internationally. However, much of the research on factors influencing compliance with the Australian helmet laws is dated or focuses on commuters and city areas only. To address this gap, video recordings of bicycle riders were undertaken at 17 sites across Queensland, Australia, representing a mixture of on- and off-road locations, speed limits and regions. Helmet status was able to be determined for 98% of riders observed. The level of compliance with the laws was very high, with 98.3% of the more than 27,000 riders observed wearing helmets. Riders riding on roads were less compliant than those riding on bicycle paths, but no significant differences were observed between the school-holiday and school-term periods. Among the on-road riders, boys were less compliant than girls and overall children were less compliant than adults. Higher compliance levels were found for group riders, road bike riders, lycra-clad riders, during morning hours, and on 50km/h or lower speed limit roads. While the overall level of compliance was very high, certain subgroups were identified as a possible focus for interventions to further improve the compliance level, for example children (particularly boys) riding mountain bikes away from groups during the afternoon hours on 60km/h roads.

  3. Evaluation of Precast Panels for Airfield Pavement Repair. Phase 2: Results of Accelerated Pavement Testing

    Science.gov (United States)

    2013-09-01

    concrete panels for contingency rigid airfield pavement repairs. AFRL Technical Report AFRL-RX- TY-TR-2010-0095. Tyndall AFB, FL: US Air Force...will be used to further refine the design of the precast panel repair system. 15. SUBJECT TERMS Airfield repair Airfield rigid pavements ...ER D C/ G SL T R -1 3 -2 4 Evaluation of Precast Panels for Airfield Pavement Repair Phase II: Results of Accelerated Pavement Testing

  4. Simplified Pavement Design for LPAs: Introduction to PaveXpress

    OpenAIRE

    2015-01-01

    Simplified Pavement Design for LPA's; An introduction to and use of PaveXpress, a simplified, free, web-based pavement design scoping tool for roadway and parking lot pavements. The system was developed by Pavia Systems in partnership with the National Asphalt Pavement Association. PaveXpress creates technical sound pavement structural designs for flexible and rigid pavements based on widely accepted industry standards from the Association of State Highway Officials (AASHTO). The simplified p...

  5. Simplified Pavement Design for LPAs: Introduction to PaveXpress

    OpenAIRE

    Bonte, Dudley

    2015-01-01

    Simplified Pavement Design for LPA's; An introduction to and use of PaveXpress, a simplified, free, web-based pavement design scoping tool for roadway and parking lot pavements. The system was developed by Pavia Systems in partnership with the National Asphalt Pavement Association. PaveXpress creates technical sound pavement structural designs for flexible and rigid pavements based on widely accepted industry standards from the Association of State Highway Officials (AASHTO). The simplified p...

  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. Improving the distribution and reducing the magnitude of pavement damage

    Science.gov (United States)

    Barker, W. R.; Chou, U. T.

    1980-08-01

    In the analysis of flexible pavement, the layered elastic theory was used to compute the pavement response. For the rigid pavement, finite difference, layered elastic theory, and Westergard procedures were used to compute tensile stresses in concrete that formed the basis for predicting allowable stress repetitions. For flexible pavement, the only effective means to reduce pavement damage was to modify the wheel assembly to reduce stress or strain at the critical locations in the pavement systems. The most effective modification would be to increase the spacing between duals. For rigid pavements, the edge effect was critical, thus suggesting that modifications to shift the loading away from the pavement edge would be effective.

  8. Investigation of perpetual pavement using finite element modelling

    Directory of Open Access Journals (Sweden)

    Monireh Zokaei

    2016-06-01

    Full Text Available With considering numerous failures which exist in flexible pavements, a huge amount of money is spending on treatment and reconstructing pavements. Many researches have been performed to with improving pavement quality, increased the performance and pavements life. One type of long lasting pavements is perpetual pavement. In this research ABAQUS software is used to simulate pavement. . Materials are modelled as visco-elastic type and loading wheel is assumed to be moving. After gaining results, the effects of different parameters on pavements function is assessed. Modelling movements of loading wheel is very effective in viscoelastic condition, increase more accuracy of the finite-element model.

  9. Improving Data Quality for Pavement Management System

    OpenAIRE

    2015-01-01

    The Metropolitan Transportation Commission (MTC) has developed a pavement management StreetSaver program with more than 400 users in the United States. MTC uses the program to evaluate street and road condition and perform maintenance needs assessments for the 109 cities and counties in the San Francisco Bay Area. Quality pavement condition survey data is a critical component of a pavement management system. MTC has augmented a new quality acceptance (QA) program as part of its Quality Data M...

  10. Applications of observational techniques in pavement engineering

    CSIR Research Space (South Africa)

    Steyn, WJVDM

    2007-05-01

    Full Text Available includes engineers, site agents, contractors, managers and anybody else that has a specific concern with roads and their functioning) has a daily requirement to record events on roads. These include the whole spectrum of the life of a road, starting... to the travelling public include the following: • Visual evaluation of pavement condition as required for Pavement Management Systems (PMS) and rehabilitation evaluations; • Forensic investigations of failures on pavements; • Construction / as-built records...

  11. Green building handbook: Green pavement

    CSIR Research Space (South Africa)

    Van Wyk, Llewellyn V

    2010-11-01

    Full Text Available (as is often experienced in South African locations). Green storm water runoff management mimics nature using man-made elements such as pervious pavement, soakaways, ponds, and gently sloping channels (swales) to attenuate and treat urban runoff...; Pollution from overflowing latrines, soakaways and sewers, causing faecal pollution and disease; Cross contamination of water supplies; Wet soils leading to ideal conditions for worm infections; Providing habitats for vectors (mosquitoes and snails...

  12. Enhancing pavements for thermal applications

    OpenAIRE

    Keikhaei Dehdezi, Pejman

    2012-01-01

    Renewable energy combined with energy efficiency can offer a viable and influential solution to minimise the harmful consequences of both fossil fuel depletion and increases in the cost of power generation. However, in most cases renewable energy technologies require high initial investments that may deter potential users. Pavement Energy Systems (PES) potentially offer a low-cost solution to sustainable and clean energy generation by utilising the thermo-physical properties and design featur...

  13. Full-Scale Accelerated Pavement Testing of Warm-Mix Asphalt (WMA) for Airfield Pavements

    Science.gov (United States)

    2014-01-01

    ER D C/ G SL T R -1 4 -3 Full-Scale Accelerated Pavement Testing of Warm-Mix Asphalt (WMA) for Airfield Pavements G eo te ch n ic al...2014 Full-Scale Accelerated Pavement Testing of Warm-Mix Asphalt (WMA) for Airfield Pavements Mariely Mejías-Santiago, Jesse D. Doyle, and John F... asphalt (WMA) mixtures designed for airfield pavements. Three WMA mixtures were evaluated and compared to a control hot-mix asphalt (HMA) mixture. Data

  14. Stabilizing a Bicycle: A Modeling Project

    Science.gov (United States)

    Pennings, Timothy J.; Williams, Blair R.

    2010-01-01

    This article is a project that takes students through the process of forming a mathematical model of bicycle dynamics. Beginning with basic ideas from Newtonian mechanics (forces and torques), students use techniques from calculus and differential equations to develop the equations of rotational motion for a bicycle-rider system as it tips from…

  15. Bicycle parking preferences: costs versus walking time

    NARCIS (Netherlands)

    Molin, E.J.E.; Maat, K.

    2014-01-01

    Successful bicycle stimulating policies may increase the need for bicycle parking capacity, especially at main railway stations located in city centers. A potential solution for this problem involves combining paid surveyed indoor parking near the platforms and free open-air parking without surveill

  16. Good Practices Guide for Bicycle Safety Education.

    Science.gov (United States)

    Department of Transportation, Washington, DC.

    The purpose of this guide is to serve as an informational resource for educators and other interested professionals in planning and developing bicycle safety education programs. The guide examines 15 existing bicycle safety education programs in the United States and one from Canada. (Author)

  17. Evaluation electric bicycles; Evaluation velos electriques

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2002-10-01

    Leovelo service is the first measure in favor of the bicycle to control the air pollution and to conserve energy. It provides in the city of Clermont-Ferrand (France) a service of bicycle hiring. This document evaluates the project after two years of operating. It provides a technical evaluation (maintenance, equipment, financing) and also the socio-economic impacts. (A.L.B.)

  18. Survey of options on legalizing bicycling (VB)

    DEFF Research Database (Denmark)

    Zwahlen, Jurg; Sulewski, Sharon; Sacovitch, Stephen

    1999-01-01

    , gender, residency, frequency of use and their utilization of the area (i.e. walking, jogging, bicycling) as compared to the support for bicycling in the area. This was an Interactive Qualifying Project (IQP), that was designed to merge technical and scientific knowledge with society, and stresses...... the importance of this interaction....

  19. Beijing Bicycle - Stories from a Transformative Space

    DEFF Research Database (Denmark)

    Bagger-Petersen, Mai Corlin

    2012-01-01

    of the global. Beijing Bicycle is thematically similar to Vittorio de Sicas neorealist classic Bicycle Thieves (1948) and Akira Kurosawas filmnoir classic Stray Dog (1949). Both films describe a disillusioned post-war society in an impoverished Italy and a humiliated Japan respectively. The stories told become...

  20. A study on electric bicycle energy efficiency

    Directory of Open Access Journals (Sweden)

    Ivan EVTIMOV

    2015-09-01

    Full Text Available The paper presents a construction of an experimental electric bicycle for evaluation of the energy efficiency. The bicycle is equipped with onboard computer which can store the information about motion and energy consumption. The result concerning power, energy consumption, recharging during brake process, etc. are given. Energy consumption for 3 typical city routes is studied.

  1. 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.

  2. STRESS ANALYSIS OF BICYCLE FRAME

    Directory of Open Access Journals (Sweden)

    Mr.M.V.Pazare

    2014-06-01

    Full Text Available This paper deals with the stress analysis of bicycle frame by using Finite Element Method. The analysis is carried out in Ansys, The F.E.A. results are compared with theoretical results. In theoretical analysis the frame is treated as truss like structure and the stresses in various members of frame like top tube, down tube, seat tube, chain stay and seat stay are determined, considering various condition like, static start up, steady state paddling, vertical impact, horizontal impact, rear wheel braking. Also Finite Element Analysis is done considering the above conditions. From the analysis it is found that there is a good agreement between analytical and F.E.A. results. Result of all the cases reveals that maximum stress is found in top tube of the bicycle frame as compared to other frame members and is equal to 24.84 MPa which is less than yield strength in tension (i.e.Syt = 290 MPa for the material (aluminum T 6061 selected.

  3. 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.

  4. 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 condit

  5. 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.

  6. Muscle fatigue based evaluation of bicycle design.

    Science.gov (United States)

    Balasubramanian, V; Jagannath, M; Adalarasu, K

    2014-03-01

    Bicycling posture leads to considerable discomfort and a variety of chronic injuries. This necessitates a proper bicycle design to avoid injuries and thereby enhance rider comfort. The objective of this study was to investigate the muscle activity during cycling on three different bicycle designs, i.e., rigid frame (RF), suspension (SU) and sports (SP) using surface electromyography (sEMG). Twelve male volunteers participated in this study. sEMG signals were acquired bilaterally from extensor carpi radialis (ECR), trapezius medial (TM), latissimus dorsi medial (LDM) and erector spinae (ES), during 30 min of cycling on each bicycle and after cycling. Time domain (RMS) and frequency domain (MPF) parameters were extracted from acquired sEMG signals. From the sEMG study, it was found that the fatigue in right LDM and ES were significantly (p bicycle. This was corroborated by a psychophysical assessment based on RBG pain scale. The study also showed that there was a significantly lesser fatigue with the SU bicycle than the RF and SP bicycles.

  7. Theoretical Development and Engineering Practice of Pavements in China

    Institute of Scientific and Technical Information of China (English)

    QIU Yan-jun

    2008-01-01

    This paper presents a comprehensive review of historical theory development and current construction practice of pavement engineering in China. Mechanical models, design guides, construction techniques, evaluation methods and maintenance standards are elaborated for Portland cement concrete (PCC) pavements and asphalt concrete (AC) pavements. Differences in design methodology among pavements of rural highways, urban roads and airport fields are discussed based on service requirements.Lessons and experiences based on the past 20 years' construction practice and pavement performance are summarized. Current research areas in pavement engineering associated with unconventional geological and/or landscaping in China's highway construction and national strategic plan for pavement engineering are also covered.

  8. Improving rutting resistance of pavement structures using geosynthetics: an overview.

    Science.gov (United States)

    Mirzapour Mounes, Sina; Karim, Mohamed Rehan; Khodaii, Ali; Almasi, Mohammad Hadi

    2014-01-01

    A pavement structure consists of several layers for the primary purpose of transmitting and distributing traffic loads to the subgrade. Rutting is one form of pavement distresses that may influence the performance of road pavements. Geosynthetics is one type of synthetic materials utilized for improving the performance of pavements against rutting. Various studies have been conducted on using different geosynthetic materials in pavement structures by different researchers. One of the practices is a reinforcing material in asphalt pavements. This paper intends to present and discuss the discoveries from some of the studies on utilizing geosynthetics in flexible pavements as reinforcement against permanent deformation (rutting).

  9. Improving Rutting Resistance of Pavement Structures Using Geosynthetics: An Overview

    Directory of Open Access Journals (Sweden)

    Sina Mirzapour Mounes

    2014-01-01

    Full Text Available A pavement structure consists of several layers for the primary purpose of transmitting and distributing traffic loads to the subgrade. Rutting is one form of pavement distresses that may influence the performance of road pavements. Geosynthetics is one type of synthetic materials utilized for improving the performance of pavements against rutting. Various studies have been conducted on using different geosynthetic materials in pavement structures by different researchers. One of the practices is a reinforcing material in asphalt pavements. This paper intends to present and discuss the discoveries from some of the studies on utilizing geosynthetics in flexible pavements as reinforcement against permanent deformation (rutting.

  10. Electric bicycles in The Netherlands: Current developments and future possibilities

    NARCIS (Netherlands)

    Rooijen, T. van

    2010-01-01

    Developments with electric bicycles in the Netherlands are progressing rapidly. The number of electric bicycles sold is rises every year. Cycling is a very popular mode of transport in The Netherlands. In 2008 more than one million bicycles were sold. At the moment one out of ten bicycles sold is al

  11. Electric bicycles in The Netherlands: Current developments and future possibilities

    NARCIS (Netherlands)

    Rooijen, T. van

    2010-01-01

    Developments with electric bicycles in the Netherlands are progressing rapidly. The number of electric bicycles sold is rises every year. Cycling is a very popular mode of transport in The Netherlands. In 2008 more than one million bicycles were sold. At the moment one out of ten bicycles sold is

  12. Survey of options on legalizing bicycling (VB)

    DEFF Research Database (Denmark)

    Zwahlen, Jurg; Sulewski, Sharon; Sacovitch, Stephen;

    1999-01-01

    the opposition against the proposal was.The goal of this project was to identify categories of users that were opposed to bicycling on the Dosseringen of the Østerbro and Nørrebro District lakes in Copenhagen. The identification of the opposition and its strength, rationale and organization was in terms of age......, gender, residency, frequency of use and their utilization of the area (i.e. walking, jogging, bicycling) as compared to the support for bicycling in the area. This was an Interactive Qualifying Project (IQP), that was designed to merge technical and scientific knowledge with society, and stresses...

  13. Policy to promote bicycle use or bicycle to promote politicians? Bicycles in the imagery of urban mobility in Brazil

    Directory of Open Access Journals (Sweden)

    Rafael Milani Medeiros

    2013-01-01

    Full Text Available During the last 15 years an increasing number of presidents, prime ministers, governors and mayors in developed and developing countries have been riding bicycles to promote a more sustainable and friendly form of urban mobility. We believe that these images also reveal and influence the image of contemporary urban mobility – the way in which people see what urban mobility is and how it should be. In this paper we discuss how the image of the bicycle has changed in Brazil and how this may influence an increase in its actual 1% bicycle modal share in big cities. We conclude that the importance of the bicycle in the image of urban mobility has been changing cyclically, and what seems to be a positive trend today might end up as being just an ephemeral positive image, with the risk of having no further practical consequences.

  14. A Sociological Analysis of the Relationship between Attitude towards Bicycle and Using Bicycle in Short Trips in Isfahan

    Directory of Open Access Journals (Sweden)

    Siroos Ahmadi

    2013-07-01

    The main goal of this research is to investigate relationship between attitude toward bicycle and using bicycle among the men in Isfahan. Based on the descriptive research findings, mean using bicycle score is low in Iran. This situation is not satisfactory for a metropolis such as Isfahan that has an increasing population and motor vehicles, and also has many difficulties in urban base facilities and must be changed. In addition to mean attitude toward bicycle is high that is an opportunity for urban planners. Inferential findings show that attitude toward bicycle has a significant impact on using bicycle. In other words, increase attitude toward bicycle means an increase in using bicycle for short trips. This research finding theoretically confirm relation between attitude and behavior. Moreover it is compatible with results of the research that show there is significant relationship between attitude toward bicycle and using bicycle. There is an inverse significant relationship between age and using bicycle and with rising age using bicycle is decreased. This research finding shows that urban infrastructure in Isfahan for using bicycle is not available and consequently with rising age, bicycle risk is increased. There is a direct significant relationship between income rate and using bicycle and with increasing income rate, using bicycle is also increased. This research finding is rooted in social prestige bicycle and higher classes prefer to use motor vehicle for transportation instead of bicycle. There is a significant relationship between marital status and using bicycle and single men use bicycle more than married men but there is no significant relationship between education level and using bicycle. This research findings show that with rising education level in spite of rising income, using bicycle is not decreased. And finally there is no significant relationship between employed and unemployed persons in using bicycle. On the basis of the evidences such

  15. Effective flow resistivity of highway pavements.

    Science.gov (United States)

    Rochat, Judith L; Read, David R

    2013-12-01

    In the case of highway traffic noise, propagating sound is influenced by the ground over which it travels, whether it is the pavement itself or the ground between the highway and nearby communities. Properly accounting for ground type in modeling can increase accuracy in noise impact determinations and noise abatement design. Pavement-specific effective flow resistivity values are being investigated for inclusion in the Federal Highway Administration Traffic Noise Model, which uses these values in the sound propagation algorithms and currently applies a single effective flow resistivity value to all pavement. Pavement-specific effective flow resistivity values were obtained by applying a modified version of the American National Standards Institute S1.18 standard. The data analysis process was tailored to allow for increased sensitivity and extraction of effective flow resistivity values for a broad range of pavements (sound absorptive to reflective). For porous pavements (sound absorptive), it was determined that examination of the measured data can reveal influence from an underlying structure. Use of such techniques can aid in the design of quieter pavements.

  16. Synthesis of Caged Bicyclic Phosphate Derivatives

    Institute of Scientific and Technical Information of China (English)

    FANG Xiao-min; OU Yu-xiang; LUO Rui-bin; WANG Yong; LIAN Dan-jun; LI Xin

    2008-01-01

    Seven caged bicyclic phosphate compounds were synthesized by using 1-oxo-4-hydroxymethy1-2,6,7-trioxa-1-pho-sphabicyclo[2.2.2] octane (PEPA) as starting material. Within them were three PEPA derivatives containing single caged bicyclic phosphate structure(1a,2a,3a), another three PEPA deviratives containing two caged bicyclic phosphate structures(1b,2b,3b) and one devirative(1c) containing three caged bicyclic phosphate structures. Structures of the products were characterized by FTIR, 1H NMR, elemental analysis and TG analysis. The reaction conditions were also discussed. Thermal analysis showed they had high thermal stability and excellent char-forming ability. Besides, these compounds had pentaerythritol bone and flame retardant elements of phosphorus, bromine or nitrogen simultaneously in their molecules, endowed them with good fire retardancy, and made them can be used as intumescent flame retardant.

  17. 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 the technology can be found in the petroleum industry (locating sources of crude oil inside rock masses), geotechnical engineering (quantification of rock and soil (Wightman et al, 2003)) and pavement engineering (evaluating pavement layer properties...., Yuan, D., Tandon, V. & Arellano, M. 2002. Quality management of flexible pavement layers with seismic methods. Research Project 0-1735, Texas Department of Transportation, Centre for Highway Materials Research, University of Texas at El Paso, El Paso...

  18. Risky riding: Naturalistic methods comparing safety behavior from conventional bicycle riders and electric bike riders.

    Science.gov (United States)

    Langford, Brian Casey; Chen, Jiaoli; Cherry, Christopher R

    2015-09-01

    As electric bicycles (e-bikes) have emerged as a new transportation mode, their role in transportation systems and their impact on users have become important issues for policy makers and engineers. Little safety-related research has been conducted in North America or Europe because of their relatively small numbers. This work describes the results of a naturalistic GPS-based safety study between regular bicycle (i.e., standard bicycle) and e-bike riders in the context of a unique bikesharing system that allows comparisons between instrumented bike technologies. We focus on rider safety behavior under four situations: (1) riding in the correct direction on directional roadway segments, (2) speed on on-road and shared use paths, (3) stopping behavior at stop-controlled intersections, and (4) stopping behavior at signalized intersections. We find that, with few exceptions, riders of e-bike behave very similarly to riders of bicycles. Violation rates were very high for both vehicles. Riders of regular bicycles and e-bikes both ride wrong-way on 45% and 44% of segments, respectively. We find that average on-road speeds of e-bike riders (13.3kph) were higher than regular bicyclists (10.4kph) but shared use path (greenway) speeds of e-bike riders (11.0kph) were lower than regular bicyclists (12.6kph); both significantly different at >95% confidence. At stop control intersections, both bicycle and e-bike riders violate the stop signs at the similar rate with bicycles violating stop signs at a slightly higher rate at low speed thresholds (∼80% violations at 6kph, 40% violations at 11kph). Bicycles and e-bikes violate traffic signals at similar rates (70% violation rate). These findings suggest that, among the same population of users, e-bike riders exhibit nearly identical safety behavior as regular bike riders and should be regulated in similar ways. Users of both technologies have very high violation rates of traffic control devices and interventions should occur to

  19. A Geographical Analysis of Bicycle Sharing Systems

    OpenAIRE

    Médard De Chardon, Cyrille

    2016-01-01

    This thesis evaluates the performance of bicycle sharing systems (BSS), autonomous systems of accessible bicycles that can be easily used for one way trips, and determines whether they are successful at achieving promoted social and environmental outcomes through quantitative and qualitative methods. Such systems are typically surrounded by positive narratives of success, health, environmental and social benefits. This work challenges these notions. This thesis begins with the formalisation o...

  20. Open-Graded Bases for Airfield Pavements.

    Science.gov (United States)

    1987-07-01

    pressure. 7. The rapid drainage of the bases is particularly important for rigid pavement to prevent pumping at the joints. Cedergren (1974) was a particu...filter cloth, collector trenches or perforated collector pipe, pipe outlets, and outlet markers. 11. From the studies by Cedergren , Rollings, and...paper No. 2516, American Society of Civil Engineers, New York. Cedergren , H. R. 1974a. Drainage of Highway and Airfield Pavements, John Wiley and Sons

  1. Pavement Performance Index for Indian rural roads

    Directory of Open Access Journals (Sweden)

    Abhay Tawalare

    2016-09-01

    Full Text Available The performance of a road is evaluated from time to time so as to improve its quality and helps in planning maintenance of roads. For this purpose various pavement deteriorating models as a decision tool are available. But they are not easy to use for field engineers due to either huge past data requirement or complicated calculations. Therefore, this paper presents a Pavement Performance Index for rural roads by using simple methodology. The distress parameters of rural roads were identified through literature review. Similarly rating criteria for each distress parameters were identified through literature. For final selection of distress parameters in context of Indian rural road, opinions of five highly experienced industrial experts were taken. After that the weightage for severity of each parameter causing distress of pavement is calculated by using data of questionnaire survey in which 117 professionals working in Pradhan Mantri Gram Sadak Yojana across the country were participated. The paper suggests a formula to decide Pavement Performance Index that depends on rating criterion and severity weightage of distress parameters of pavement performance. The study concluded that suggested Pavement Performance Index makes calculations easy for field engineers and will be useful to decide priority list of rural roads for repair and maintenance schedule.

  2. Fracture of highway and airport pavements

    Science.gov (United States)

    Ramsamooj, D. V.

    1993-03-01

    Existing solutions for the stresses in a cracked slab containing a crack and supported by an elastic foundation are extended to obtain the stress intensity factor (SIF) for a crack in a pavement subjected to moving vehicular loads. In the existing solutions the stresses can be obtained only for a uniform bending stress (before the crack occurs) along the crack surface. For pavements subjected to moving vehicular loads, the stress distribution along the crack surface is not uniform and the approximation of a uniform stress is often unsatisfactory. The present work extends the above solutions to cover more realistic loading of highway and airport pavements. This facilitates the application of the principles of fracture mechanics to the fatigue crack propagation and fracture of pavements. Beginning with a part-through semi-elliptical starter crack, the crack is assumed to grow under load and the SIF is presented at various stages of crack growth, from the starter crack into a short through-crack that eventually becomes a very long through-crack. Some examples of the fracture of typical rigid and flexible highway and airport pavements are presented to show the need to consider fracture in the design of pavements.

  3. 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.

  4. Improving a pavement-watering method on the basis of pavement surface temperature measurements

    CERN Document Server

    Hendel, Martin; Diab, Youssef; Royon, Laurent

    2014-01-01

    Pavement-watering has been studied since the 1990's and is currently considered a promising tool for urban heat island reduction and climate change adaptation. However, possible future water resource availability problems require that water consumption be optimized. Although pavement heat flux can be studied to improve pavement-watering methods (frequency and water consumption), these measurements are costly and require invasive construction work to install appropriate sensors in a dense urban environment. Therefore, we analyzed measurements of pavement surface temperatures in search of alternative information relevant to this goal. It was found that high frequency surface temperature measurements (more than every 5 minutes) made by an infrared camera can provide enough information to optimize the watering frequency. Furthermore, if the water retaining capacity of the studied pavement is known, optimization of total water consumption is possible on the sole basis of surface temperature measurements.

  5. Flying blind: designing and maintaining jointed concrete pavement without monitoring pavement pressure generation

    Science.gov (United States)

    Burke, Martin P., Jr.

    2001-08-01

    The generation of longitudinal pavement pressures or growth of jointed-rigid pavement have been recognized by many engineers for at least a century. The manifestations of this pressure/growth phenomenon, in the form of progressive pavement and bridge damage, are vivid examples of its destructive potential. Yet, only a few researchers have attempted to measure the pressures generated by this phenomenon. None, to the author's knowledge, have attempted to periodically monitor pressure generation for the purpose of either determining and describing pressure generation characteristics or predicting the probability of its abrupt final and destructive manifestations. Because the pavement/growth phenomenon occurs over such a long period of time (a decade or more), it is generally unrecognized, or if recognized, it is poorly understood. Consequently, design and maintenance of jointed rigid pavement continues to be guided more by intuition and personal judgement rather than be replicated research and professional consensus. This paper provides a speculative description of the pavement pressure/growth phenomenon. It also contains an appeal to research professionals to develop instrumentation suitable to monitor generating pavement pressures. The results of such research should finally enable the transportation profession to establish suitable background so that future pavement design and maintenance will be guided so that pressure generation will be minimized and pavement and bridge function and durability will be improved. Otherwise, transportation systems will continue to experience progressive and substantial pavement and bridge damage, commensurate repair costs, and the traveling public will continue to be exposed to occasional but abrupt manifestations of its destructive potential.

  6. School based bicycle safety education and bicycle injuries in children: a case-control study.

    Science.gov (United States)

    Carlin, J B; Taylor, P; Nolan, T

    1998-03-01

    To evaluate possible benefits of a school based bicycle safety education program ("Bike Ed") on the risk of bicycle injury in children. A population based case-control study was undertaken in a region of Melbourne, Australia. Cases were children presenting at hospital emergency departments with injuries received while riding bicycles. Controls were recruited by calling randomly selected telephone numbers. Data were collected by personal interview. Analysis, based on 148 cases and 130 controls aged 9 to 14 years, showed no evidence of a protective effect and suggested a possible harmful effect of exposure to the bicycle safety course (odds ratio (OR) 1.64, 95% confidence interval (CI) 0.98 to 2.75). This association was not substantially altered by adjustment for sex, age, socioeconomic status, and exposure, measured as time or distance travelled. Subgroup analysis indicated that the association was strongest in boys (OR 2.0, 95% CI 1.1 to 3.8), younger children, children from families with lower parental education levels, and children lacking other family members who bicycle. It is concluded that this educational intervention does not reduce the risk of bicycle injury in children and may possibly produce harmful effects in some children, perhaps due to inadvertent encouragement of risk taking or of bicycling with inadequate supervision.

  7. Bicycling to school improves the cardiometabolic risk factor profile

    DEFF Research Database (Denmark)

    Ostergaard, Lars; Børrestad, Line A B; Tarp, Jakob;

    2012-01-01

    To investigate whether bicycling to school improves cardiometabolic risk factor profile and cardiorespiratory fitness among children.......To investigate whether bicycling to school improves cardiometabolic risk factor profile and cardiorespiratory fitness among children....

  8. Methods to assess the stability of a bicycle rider system

    NARCIS (Netherlands)

    Cooke, A.G.; Bulsink, Vera Elisabeth; Beusenberg, Mark; Dubbeldam, Rosemary; Bonnema, Gerrit Maarten; Poelman, Wim; Koopman, Hubertus F.J.M.

    2012-01-01

    The SOFIE (Intelligent Assisted Bicycles) project wishes to create performance and design guidelines for mechatronic appliances which improve the stability of electric bicycles, so-called intelligent stability assist devices (IAD). To achieve this goal, a stability hypothesis, an advanced

  9. 40 CFR 52.1162 - Regulation for bicycle use.

    Science.gov (United States)

    2010-07-01

    ...: (i) For present bicycle riders, the origin, destination, frequency, travel time, distance and purpose... Section 52.1162 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS..., regional and local planning staffs, state, regional and local agencies, bicycle organizations and...

  10. Wireless controller and smartphone based interaction system for electric bicycles

    National Research Council Canada - National Science Library

    Jorge REVUELTA HERRERO; Gabriel VILLARRUBIA; Alberto L. BARRIUSO; Daniel HERNÁNDEZ; Álvaro LOZANO; Marco Antonio DE LA SERNA GONZÁLEZ

    2016-01-01

    .... This paper proposes a brand-new solution in the automotive field, consisting of a new product family which aims to transform the traditional bicycle to an electric bicycle using an architecture...

  11. 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...

  12. Methods to assess the stability of a bicycle rider system

    OpenAIRE

    Cooke, A.G.; Bulsink, Vera Elisabeth; Beusenberg, Mark; Dubbeldam, Rosemary; Bonnema, Gerrit Maarten; Poelman, Wim; Koopman, Hubertus F.J.M.

    2012-01-01

    The SOFIE (Intelligent Assisted Bicycles) project wishes to create performance and design guidelines for mechatronic appliances which improve the stability of electric bicycles, so-called intelligent stability assist devices (IAD). To achieve this goal, a stability hypothesis, an advanced rider/bicycle model and bicycle stability test bench, will be created. This paper describes the development of these components and its goal is to present the project design. The stability hypothesis is base...

  13. Porous Flame-retarded Asphalt Pavement for Highway Tunnel

    Institute of Scientific and Technical Information of China (English)

    HU Shuguang; HUANG Shaolong; Ding Qingjun

    2008-01-01

    A new way to improve the tunnel fire protection by using flame-retarded porous asphalt pavement containing ATH powders was introduced. Based on the miniature burning test designed and conducted, the burning time and temperature of porous asphalt (PA) and flame-retarded porous asphalt (FRPA) were studied comparing with cement concrete pavement, dense-graded HMA and S MA. Results of burning test and pavement performance test indicate that FRPA is appropriate and suitable as the pavement material of highway tunnel.

  14. Discrete element modelling of permanent pavement deformation in granular materials

    OpenAIRE

    Cai, Wei

    2015-01-01

    The permanent deformation of a pavement due to vehicle load is one of the important factors affecting the design life as well as the maintenance cost of a pavement. For the purpose of obtaining a cost-effective design, it is advisable to predict the traffic-loadinduced permanent pavement deformation. The permanent deformation in pavements (i.e. rutting) can be classified into three categories, including the wearing of the asphalt layers, compaction, and shear deformations. In the present stud...

  15. A Bicycle Safety Education Program for Parents of Young Children

    Science.gov (United States)

    Lohse, Julie L.

    2003-01-01

    This study examined parental perceptions of the benefits and barriers to bicycle helmet use and their level of knowledge about bicycle safety issues. A school-based bicycle safety education program was taught to first- and second-grade students in a rural/suburban school district by a graduate nursing student. Pender's Health Promotion Model was…

  16. Associations between a walkability index and bicycle use in Denmark

    DEFF Research Database (Denmark)

    Madsen, T.; Christiansen, L.; Nielsen, Thomas Alexander Sick;

    2012-01-01

    associations between measures of walkability and bicycle use for transport and the present study focuses on exploring whether these findings can be applied to a Danish setting where cycling culture differs and bicycle share is much higher (17% of all trips are by bicycle)...

  17. On the Stability of a Bicycle on Rollers

    Science.gov (United States)

    Cleary, Patricia A.; Mohazzabi, Pirooz

    2011-01-01

    Riding a bicycle on the newest form of indoor training, rollers, presents a unique experiment on bicycle stability. The stability factors eliminated by riding on rollers are discussed in terms of refined handling and control of the centre of mass on a bicycle. This paper is intended for undergraduate physics majors as well as any other general…

  18. An Analysis of Florida Physical Educators' Knowledge of Bicycle Laws

    Science.gov (United States)

    Connaughton, Daniel P.; Egberts, John B.; Spengler, J. O.; Zhang, James J.; Jin, Liyan

    2012-01-01

    Bicycling among youth is a popular activity, but like all modes of travel it is not without risk. Florida has a particularly high rate of bicycle-related fatalities and injuries. To reduce such risks, the Florida Department of Transportation and Florida Department of Education have developed a youth bicycle safety educational program (Florida…

  19. Knowledge Discovery and Pavement Performance: Intelligent Data Mining

    NARCIS (Netherlands)

    Miradi, M.

    2009-01-01

    The main goal of the study was to discover knowledge from data about asphalt road pavement problems to achieve a better understanding of the behavior of them and via this understanding improve pavement quality and enhance its lifespan. Four pavement problems were chosen to be investigated; raveling

  20. Understanding the Effects of Climate on Airfield Pavement Deterioration Rates

    Science.gov (United States)

    2013-03-01

    34   Table 2. Moisture Related Distress in rigid (PCC) pavements ......................................... 35   Table 3...labor intensive and took as long as 8 hours to complete, including time for repairs. Plate bearing tests were performed on rigid pavements and...DCP index is then correlated to CBR. The final structural evaluation that is conducted is core drills of rigid and flexible pavements . The core

  1. Evaluation of Procedures for Backcalculation of Airfield Pavement Moduli

    Science.gov (United States)

    2015-08-01

    99  Table 28. Metha approach rigid pavements results...materials. For the subgrade material, only the flag “Manual” is allowed. For rigid pavements , the flags associated with the layer corresponding to the...backcalculating the moduli of pavement layers in flexible, rigid , or composite systems. Recommendations from this table are compared to current backcalculation

  2. Pavement Sealcoat, PAHs, and the Environment

    Science.gov (United States)

    Van Metre, P. C.; Mahler, B. J.

    2011-12-01

    Recent research by the USGS has identified coal-tar-based pavement sealants as a major source of polycyclic aromatic hydrocarbons (PAHs) to the environment. Coal-tar-based sealcoat is commonly used to coat parking lots and driveways and is typically is 20-35 percent coal tar pitch, a known human carcinogen. Several PAHs are suspected mutagens, carcinogens, and (or) teratogens. In the central and eastern U.S. where the coal-tar-based sealants dominate use, sum-PAH concentration in dust particles from sealcoated pavement is about 1,000 times higher than in the western U.S. where the asphalt-based formulation is prevalent. Source apportionment modeling indicates that particles from sealcoated pavement are contributing the majority of the PAHs to recent lake sediment in 35 U.S. urban lakes and are the primary cause of upward trends in PAHs in many of these lakes. Mobile particles from parking lots with coal-tar-based sealcoat are tracked indoors, resulting in elevated PAH concentrations in house dust. In a recently completed study, volatilization fluxes of PAHs from sealcoated pavement were estimated to be about 60 times fluxes from unsealed pavement. Using a wide variety of methods, the author and colleagues have shown that coal-tar-based sealcoat is a major source of PAHs to the urban environment and might pose risks to aquatic life and human health.

  3. Spills on Flat Inclined Pavements

    Energy Technology Data Exchange (ETDEWEB)

    Simmons, Carver S.; Keller, Jason M.; Hylden, Jeff L.

    2004-03-01

    This report describes the general spill phenomenology for liquid spills occurring on relatively impermeable surfaces such as concrete or asphalt pavement and the development and application of a model to describe the time evolution of such spills. The discussion assumes evaporation and degradation are negligible and a homogeneous surface. In such an instance, the inherent interfacial properties determine the spatial extent of liquid spreading with the initial flow being controlled by the release rate of the spill and by the liquids resistance to flow as characterized by its viscosity. A variety of spill scenarios were simulated and successful implementation of the model was achieved. A linear relationship between spill area and spill volume was confirmed. The simulations showed spill rate had little effect on the final spill area. Slope had an insignificant effect on the final spill area, but did modify spill shape considerably. However, a fluid sink on the edge of the simulation domain, representing a storm drain, resulted in a substantial decrease in spill area. A bona fide effort to determine the accuracy of the model and its calculations remain, but comparison against observations from a simple experiment showed the model to correctly determine the spill area and general shape under the conditions considered. Further model verification in the form of comparison against small scale spill experiments are needed to confirm the models validity.

  4. Heat transfer variations of bicycle helmets.

    Science.gov (United States)

    Brühwiler, P A; Buyan, M; Huber, R; Bogerd, C P; Sznitman, J; Graf, S F; Rösgen, T

    2006-09-01

    Bicycle helmets exhibit complex structures so as to combine impact protection with ventilation. A quantitative experimental measure of the state of the art and variations therein is a first step towards establishing principles of bicycle helmet ventilation. A thermal headform mounted in a climate-regulated wind tunnel was used to study the ventilation efficiency of 24 bicycle helmets at two wind speeds. Flow visualization in a water tunnel with a second headform demonstrated the flow patterns involved. The influence of design details such as channel length and vent placement was studied, as well as the impact of hair. Differences in heat transfer among the helmets of up to 30% (scalp) and 10% (face) were observed, with the nude headform showing the highest values. On occasion, a negative role of some vents for forced convection was demonstrated. A weak correlation was found between the projected vent cross-section and heat transfer variations when changing the head tilt angle. A simple analytical model is introduced that facilitates the understanding of forced convection phenomena. A weak correlation between exposed scalp area and heat transfer was deduced. Adding a wig reduces the heat transfer by approximately a factor of 8 in the scalp region and up to one-third for the rest of the head for a selection of the best ventilated helmets. The results suggest that there is significant optimization potential within the basic helmet structure represented in modern bicycle helmets.

  5. Bicyclic semigroups of left I-quotients

    CERN Document Server

    Ghroda, Nassraddin

    2011-01-01

    In this article we study left I-orders in the bicyclic monoid $\\mathcal{B}$. We give necessary and sufficient conditions for a subsemigroup of $\\mathcal{B}$ to be a left I-oreder in $\\mathcal{B}$. We then prove that any left I-order in $\\mathcal{B}$ is straight.

  6. What do we know about bicycle helmets?

    NARCIS (Netherlands)

    Bogerd, C.P. Halldin, P. Houtenbos, M. Otte, D. Rossi, R.M. Walker, L. Willinger, R. & Shinar, D.

    2012-01-01

    Cycling is an excellent sustainable alternative to driving for many journeys. But cyclists have fewer safety options than car-users, with a helmet being the main safety device that is available. However, there are indications that increasing bicycle helmet usage through legislation causes confoundin

  7. Revitalization of Cycling in a Former Bicycle Kingdom: Beijing

    DEFF Research Database (Denmark)

    Zhao, Chunli; Carstensen, Trine Agervig; Olafsson, Anton Stahl;

    This paper scrutinizes and analyses the relevant historical policy documents chronologically - from the 1960s to the present - in order to figure out the potentials of revitalizing the bicycle mode share in Beijing. Firstly, we targeted two top-drawer conflicts of the bicycle use, which are travel......- or commuting distance and motorised vehicle-oriented urban development. Secondly, we analysed how the various related policies resulted in the changing landscape of the bicycle mode share, including increasing in the bicycle mode share, created the conflicts and declined the bicycle mode share. The results...

  8. Safety effects of permanent running lights for bicycles

    DEFF Research Database (Denmark)

    Madsen, Jens Chr. Overgaard; Andersen, T.; Lahrmann, Harry

    2013-01-01

    3845 cyclists was carried out in Odense, Denmark in order to examine, if permanent running lights mounted to bicycles would improve traffic safety for cyclists. The permanent running lights were mounted to 1845 bicycles and the accident rate was recorded through 12 months for this treatment group...... and 2000 other bicyclists, the latter serving as a control group without bicycle running lights. The safety effect of the running lights is analysed by comparing incidence rates – number of bicycle accidents recorded per man-month – for the treatment group and the control group. The incidence rate......, including all recorded bicycle accidents with personal injury to the participating cyclist, is 19% lower for cyclists with permanent running lights mounted; indicating that the permanent bicycle running light significantly improves traffic safety for cyclists. The study shows that use of permanent bicycle...

  9. Structural Design of Pavement Overlays Based on Functional Parameters

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    This paper reports a practical pavement overlay design methodbased on PCI (Pavement Condition Index). Current pavement investigation method (JTJ 073-96) is compared to the ASTM D 5340, which is the standard test method for airport pavement condition evaluation initially developed for US Air Force. The deficiency in the calculation of PCI based on field data in JTJ 073 is discussed. The proposed design method is compared to AASHTO overlay design method with good agreement. The paper concludes with an example illustrating how the existing pavement structural capacity is related to pavement distress survey results. The presented design method can be used in the design for overlay rehabilitation of pavements of highways, urban streets and airports.

  10. Porous pavement. Phase 1: Design and operational criteria

    Science.gov (United States)

    Diniz, E. V.

    1980-08-01

    Utilization concepts, benefits and disadvantages, as well as other characteristics of porous pavements are presented with emphasis on porous asphalt pavements, but the criteria and design approach are applicable to all other porous pavement types. Design considerations include siting problems, load bearing design and hydrologic design. The history of porous pavement development and previous experience with porous pavement by several designers, contractors and operators are described. A computer model for hydrologic performance evaluation of existing or proposed porous pavement systems is also examined. Load bearing design criteria are based on previous work conducted for porous asphalt pavements. Appendices include a sample set of specifications for porous asphalt construction and a list of soils and their permeability classes as prepared by the U.S. Soil Conservation Service.

  11. Environmental Determinants of Bicycling Injuries in Alberta, Canada

    Directory of Open Access Journals (Sweden)

    Nicole T. R. Romanow

    2012-01-01

    Full Text Available This study examined environmental risk factors for bicycling injuries, by combining data on bicyclist injuries collected by interviews in the emergency department (ED with street-level environmental audits of injury locations, capturing path, roadway, safety, land use, and aesthetic characteristics. Cases were bicyclists struck by a motor vehicle (MV or with severe injuries (hospitalized. Controls were bicyclists who were not hit by a car or those seen and discharged from the ED, matched on time and day of injury. Logistic regression odds ratios (ORs adjusted for age, sex, peak time, and bicyclist speed with 95% confidence intervals (CIs were estimated to relate injury risk to environmental characteristics. Factors contributing to MV events included greater traffic volume (OR 5.13; 95% CI [1.44, 18.27], intersections (OR 6.89; 95% CI [1.48, 32.14], retail establishments (OR 5.56; 95% CI [1.72, 17.98], and path obstructions (OR 3.83; 95% CI [1.03, 14.25]. Locations where the road was in good condition (OR 0.25; 95% CI [0.07, 0.96] and where there was high surveillance from surrounding buildings (OR 0.32; 95% CI [0.13, 0.82] were associated with less severe injuries. These findings could be used by bicyclists and transportation planners to improve safety.

  12. Environmental Determinants of Bicycling Injuries in Alberta, Canada

    Science.gov (United States)

    Romanow, Nicole T. R.; Couperthwaite, Amy B.; McCormack, Gavin R.; Nettel-Aguirre, Alberto; Rowe, Brian H.; Hagel, Brent E.

    2012-01-01

    This study examined environmental risk factors for bicycling injuries, by combining data on bicyclist injuries collected by interviews in the emergency department (ED) with street-level environmental audits of injury locations, capturing path, roadway, safety, land use, and aesthetic characteristics. Cases were bicyclists struck by a motor vehicle (MV) or with severe injuries (hospitalized). Controls were bicyclists who were not hit by a car or those seen and discharged from the ED, matched on time and day of injury. Logistic regression odds ratios (ORs) adjusted for age, sex, peak time, and bicyclist speed with 95% confidence intervals (CIs) were estimated to relate injury risk to environmental characteristics. Factors contributing to MV events included greater traffic volume (OR 5.13; 95% CI [1.44, 18.27]), intersections (OR 6.89; 95% CI [1.48, 32.14]), retail establishments (OR 5.56; 95% CI [1.72, 17.98]), and path obstructions (OR 3.83; 95% CI [1.03, 14.25]). Locations where the road was in good condition (OR 0.25; 95% CI [0.07, 0.96]) and where there was high surveillance from surrounding buildings (OR 0.32; 95% CI [0.13, 0.82]) were associated with less severe injuries. These findings could be used by bicyclists and transportation planners to improve safety. PMID:23251192

  13. Interim revision of the South African Mechanistic-Empirical pavement design method for flexible pavements

    CSIR Research Space (South Africa)

    Theyse, HL

    2011-09-01

    Full Text Available an interim revision of the SAMDM recommending increased contact stress values at the tyre-pavement interface; updated unbound material characterisation parameters; effective stress analysis for unbound material; and revised damage models for estimating...

  14. Which environmental factors most strongly influence a street's appeal for bicycle transport among adults? A conjoint study using manipulated photographs.

    Science.gov (United States)

    Mertens, Lieze; Van Dyck, Delfien; Ghekiere, Ariane; De Bourdeaudhuij, Ilse; Deforche, Benedicte; Van de Weghe, Nico; Van Cauwenberg, Jelle

    2016-09-01

    Micro-environmental factors (specific features within a streetscape), instead of macro-environmental factors (urban planning features), are more feasible to modify in existing neighborhoods and thus more practical to target for environmental interventions. Because it is often not possible to change the whole micro-environment at once, the current study aims to determine which micro-environmental factors should get the priority to target in physical environmental interventions increasing bicycle transport. Additionally, interaction effects among micro-environmental factors on the street's appeal for bicycle transport will be determined. In total, 1950 middle-aged adults completed a web-based questionnaire consisting of a set of 12 randomly assigned choice tasks with manipulated photographs. Seven micro-environmental factors (type of cycle path, speed limit, speed bump, vegetation, evenness of the cycle path surface, general upkeep and traffic density) were manipulated in each photograph. Conjoint analysis was used to analyze the data. Providing streets with a cycle path separated from motorized traffic seems to be the best strategy to increase the street's appeal for adults' bicycle transport. If this adjustment is not practically feasible, micro-environmental factors related to safety (i.e. speed limit, traffic density) may be more effective in promoting bicycle transport than micro-environmental factors related to comfort (i.e. evenness of the cycle path surface) or aesthetic (i.e. vegetation, general upkeep). On the other hand, when a more separated cycle path is already provided, micro-environmental factors related to comfort or aesthetic appeared to become more prominent. Findings obtained from this research could provide advice to physical environmental interventions about which environmental factors should get priority to modify in different environmental situations. The study was approved by the Ethics Committee of the Ghent University Hospital. B

  15. The Effect of an All-Ages Bicycle Helmet Law on Bicycle-Related Trauma.

    Science.gov (United States)

    Kett, Paula; Rivara, Frederick; Gomez, Anthony; Kirk, Annie Phare; Yantsides, Christina

    2016-12-01

    In 2003, Seattle implemented an all-ages bicycle helmet law; King County outside of Seattle had implemented a similar law since 1994. For the period 2000-2010, the effect of the helmet legislation on helmet use, helmet-preventable injuries, and bicycle-related fatalities was examined, comparing Seattle to the rest of King County. Data was retrieved from the Washington State Trauma Registry and the King County Medical Examiner. Results comparing the proportions of bicycle related head injuries before (2000-2002) and after (2004-2010) the law show no significant change in the proportion of bicyclists admitted to the hospital and treated for head injuries in either Seattle (37.9 vs 40.2 % p = 0.75) nor in the rest of King County (30.7 vs 31.4 %, p = 0.84) with the extension of the helmet law to Seattle in 2003. However, bicycle-related major head trauma as a proportion of all bicycle-related head trauma did decrease significantly in Seattle (83.9 vs 64.9 %, p = 0.04), while there was no significant change in King County (64.4 vs 57.6 %, p = 0.41). While the results do not show an overall decrease in head injuries, they do reveal a decrease in the severity of head injuries, as well as bicycle-related fatalities, suggesting that the helmet legislation was effective in reducing severe disability and death, contributing to injury prevention in Seattle and King County. The promotion of helmet use through an all ages helmet law is a vital preventative strategy for reducing major bicycle-related head trauma.

  16. Adaptive Road Crack Detection System by Pavement Classification

    Directory of Open Access Journals (Sweden)

    Alejandro Amírola

    2011-10-01

    Full Text Available This paper presents a road distress detection system involving the phases needed to properly deal with fully automatic road distress assessment. A vehicle equipped with line scan cameras, laser illumination and acquisition HW-SW is used to storage the digital images that will be further processed to identify road cracks. Pre-processing is firstly carried out to both smooth the texture and enhance the linear features. Non-crack features detection is then applied to mask areas of the images with joints, sealed cracks and white painting, that usually generate false positive cracking. A seed-based approach is proposed to deal with road crack detection, combining Multiple Directional Non-Minimum Suppression (MDNMS with a symmetry check. Seeds are linked by computing the paths with the lowest cost that meet the symmetry restrictions. The whole detection process involves the use of several parameters. A correct setting becomes essential to get optimal results without manual intervention. A fully automatic approach by means of a linear SVM-based classifier ensemble able to distinguish between up to 10 different types of pavement that appear in the Spanish roads is proposed. The optimal feature vector includes different texture-based features. The parameters are then tuned depending on the output provided by the classifier. Regarding non-crack features detection, results show that the introduction of such module reduces the impact of false positives due to non-crack features up to a factor of 2. In addition, the observed performance of the crack detection system is significantly boosted by adapting the parameters to the type of pavement.

  17. Adaptive Road Crack Detection System by Pavement Classification

    Science.gov (United States)

    Gavilán, Miguel; Balcones, David; Marcos, Oscar; Llorca, David F.; Sotelo, Miguel A.; Parra, Ignacio; Ocaña, Manuel; Aliseda, Pedro; Yarza, Pedro; Amírola, Alejandro

    2011-01-01

    This paper presents a road distress detection system involving the phases needed to properly deal with fully automatic road distress assessment. A vehicle equipped with line scan cameras, laser illumination and acquisition HW-SW is used to storage the digital images that will be further processed to identify road cracks. Pre-processing is firstly carried out to both smooth the texture and enhance the linear features. Non-crack features detection is then applied to mask areas of the images with joints, sealed cracks and white painting, that usually generate false positive cracking. A seed-based approach is proposed to deal with road crack detection, combining Multiple Directional Non-Minimum Suppression (MDNMS) with a symmetry check. Seeds are linked by computing the paths with the lowest cost that meet the symmetry restrictions. The whole detection process involves the use of several parameters. A correct setting becomes essential to get optimal results without manual intervention. A fully automatic approach by means of a linear SVM-based classifier ensemble able to distinguish between up to 10 different types of pavement that appear in the Spanish roads is proposed. The optimal feature vector includes different texture-based features. The parameters are then tuned depending on the output provided by the classifier. Regarding non-crack features detection, results show that the introduction of such module reduces the impact of false positives due to non-crack features up to a factor of 2. In addition, the observed performance of the crack detection system is significantly boosted by adapting the parameters to the type of pavement. PMID:22163717

  18. Asphalt for draining pavement; Haisuisei hosoyo asphalt

    Energy Technology Data Exchange (ETDEWEB)

    Yamamori, H.; Nakamura, Y. [Mitsubishi Oil Co. Ltd., Tokyo (Japan)

    1994-12-28

    The effect and functions of draining pavement with a superb performance as a paved road were introduced. In the draining pavement, a porous asphalt mixture was used for the surface and base layers of the road and the remaining layers are not in water penetration property. It is necessary that void continues to prevent water film from being generated when rain falls and resistance against water flow is small but durability has problems when the void rate is large. According to the balance, the void rate ranges from 20 to 23 % for execution, thus preventing water splash on a rainy day, hydroplaning, and dazzlement, etc. due to reflection of light. The noise during driving due to the tire of an automobile is reduced by 5 to 6 dB owing to draining pavement. Also, engine noise is reduced to 40 - 60 % since the surface is porous. In the draining pavement, a high-viscosity asphalt is used for a binder and the void rate is large, thus preventing temperature to rise easily due to heat release and achieving an improved flow behavior. 6 refs., 11 figs., 14 tabs.

  19. Viscoelastic Pavement Modeling with a Spreadsheet

    DEFF Research Database (Denmark)

    Levenberg, Eyal

    2016-01-01

    The aim herein was to equip civil engineers and students with an advanced pavement modeling tool that is both easy to use and highly adaptive. To achieve this, a mathematical solution for a layered viscoelastic half-space subjected to a moving load was developed and subsequently implemented...

  20. Pavement behaviour under the super single tyre

    CSIR Research Space (South Africa)

    Viljoen, AW

    1982-06-01

    Full Text Available Pavement behaviour under the super single tyre (SST) was investigated and compared with that under a conventional dual tyre (CDT). Contact areas and contact pressures over a range of loading conditions were measured and compared. Two approaches were...

  1. "Full-Scale Testing of Pavement Response"

    DEFF Research Database (Denmark)

    Ullidtz, Per; Ekdahl, Peter

    1998-01-01

    Three pavement sections in southern Sweden were instrumented in late 1991. Each section have instruments for measuring the strain at the bottom of the asphalt layer, vertical stress and strains in the subgrade and temperatures at different depths. The purpose was to evaluate different theoretical...

  2. Cracking of open traffic rigid pavement

    Directory of Open Access Journals (Sweden)

    Niken Chatarina

    2017-01-01

    Full Text Available 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 shrinkage mechanism was studied in concrete micro structure. Open traffic make hydration process occur under vibration; therefore, fresh concrete was compressed and tensioned alternately since beginning. High temperature together with compression, cement dissociation, the growth of Ca2+ at very early age leads abnormal swelling. No prevention from outside water movement leads hydration process occur with limited water which caused spreads fine cracks. Limited water improves shrinkage and plastic phase becomes shorter; therefore, rigid pavement can’t accommodate the abnormal swelling and shrinking alternately and creates the spread of cracks. Discontinuing casting the concrete makes both mix under different condition, the first is shrink and the second is swell and creates weak line on the border; so, the cracks appear as cracks across the road.

  3. Path Dependency

    OpenAIRE

    Mark Setterfield

    2015-01-01

    Path dependency is defined, and three different specific concepts of path dependency – cumulative causation, lock in, and hysteresis – are analyzed. The relationships between path dependency and equilibrium, and path dependency and fundamental uncertainty are also discussed. Finally, a typology of dynamical systems is developed to clarify these relationships.

  4. Pavement management and weigh-in-motion. Transportation research record

    Energy Technology Data Exchange (ETDEWEB)

    Cation, K.A.; Shahin, M.Y.; Scullion, T.; Lytton, R.L.; Butt, A.A.

    1987-01-01

    The 15 papers in the report deal with the following areas: development of a preventive maintenance algorithm for use in pavement-management systems; pavement-performance prediction model using the Markov Process; roadway modeling and data conversion for a transportation-facilities information system; development of a methodology to estimate pavement maintenance and repair costs for different ranges of pavement-condition index; new techniques for modeling pavement deterioration; pavement management at the local government level; a comprehensive ranking system for local-agency pavement management; expert system as a part of pavement management; MAPCON: a pavement-evaluation data-analysis computer system; a microcomputer procedure to analyze axle load limits and pavement damage responsibility; selected results from the first three years of the Oregon automatic monitoring demonstration project; automated acquisition of truck-tire pressure data; calibration and accuracy testing of weigh-in-motion systems; accuracy and tolerances of weigh-in-motion systems; on-site calibration of weigh-in-motion systems.

  5. System identification of the brompton bicycle

    Science.gov (United States)

    Hladun, Monique Victoria Teresa

    The Brompton (a European folding design) bicycle was instrumented with a variety of sensors including acceleration, angular rate, speed, and steering sensors. A bicycle state estimator was designed to obtain additional information from this data including heading, turn rate, lean angle, steer rate, and positions of the wheels during a trajectory. The first part of the thesis describes the model setup for system identification including the Steer-to-Lean dynamics and Lean-to-Steer dynamics reduced models. CIFER software was used in the system identification process of these models. The second part describes the validation of the Empirical model by using the Rider Control model ([1]) and the Complete Rider/Vehicle model ([1]) to determine the feedback gains. The Theoretical model feedback gains were also determined by using the Rider Control model ([1]) and the Complete Rider/Vehicle model ([1]).

  6. Maximum Estrada Index of Bicyclic Graphs

    CERN Document Server

    Wang, Long; Wang, Yi

    2012-01-01

    Let $G$ be a simple graph of order $n$, let $\\lambda_1(G),\\lambda_2(G),...,\\lambda_n(G)$ be the eigenvalues of the adjacency matrix of $G$. The Esrada index of $G$ is defined as $EE(G)=\\sum_{i=1}^{n}e^{\\lambda_i(G)}$. In this paper we determine the unique graph with maximum Estrada index among bicyclic graphs with fixed order.

  7. Free Use of Bicycles at CERN

    CERN Multimedia

    2000-01-01

    Imagine you have just arrived at CERN. You are from Russia or Japan and have no car but you do need to get around and do not like depending on public transport. What do you do? You go to the EP Service Point (Building 124) and meet Boris Cabaud to get a CERN bicycle. Use of the bicycle is free but you have to fill in an application form which needs to be signed by your Group or Division Secretary. Then the application is filled in, you are put on the waiting list and it might take you from one to four weeks to get your bike depending on the season. “Normally the bikes are only for Users in the EP division as they are paid for by the EP budget,” says Boris, “but some other divisions have made arrangements to cover the costs.” Boris takes care of 350 bicycles at present. Each bike can be lent for maximum one year. During the winter the bikes can be stored in building 301 as it is difficult to ride them in the snow. If a bike is broken or lost all costs will be billed to the group or team account of the bo...

  8. Bicycling and walking are associated with different cortical oscillatory dynamics

    Directory of Open Access Journals (Sweden)

    Lena eStorzer

    2016-02-01

    Full Text Available Although bicycling and walking involve similar complex coordinated movements, surprisingly Parkinson’s patients with freezing of gait typically remain able to bicycle despite severe difficulties walking. This observation suggests functional differences in the motor networks subserving bicycling and walking. However, a direct comparison of brain activity related to bicycling and walking has never been performed, neither in healthy participants nor in patients. Such a comparison could potentially help elucidating the cortical involvement in motor control and the mechanisms through which bicycling ability may be preserved in patients with freezing of gait. The aim of this study was to contrast the cortical oscillatory dynamics involved in bicycling and walking in healthy participants.To this end, EEG and EMG data of 14 healthy participants were analyzed, who cycled on a stationary bicycle at a slow cadence of 40 revolutions per minute (rpm and walked at 40 strides per minute (spm, respectively.Relative to walking, bicycling was associated with a stronger power decrease in the high beta band (23-35 Hz during movement initiation and execution, followed by a stronger beta power increase after movement termination. Walking, on the other hand, was characterized by a stronger and persisting alpha power (8-12 Hz decrease. Both bicycling and walking exhibited movement cycle-dependent power modulation in the 24-40 Hz range that was correlated with EMG activity. This modulation was significantly stronger in walking.The present findings reveal differential cortical oscillatory dynamics in motor control for two types of complex coordinated motor behavior, i.e., bicycling and walking. Bicycling was associated with a stronger sustained cortical activation as indicated by the stronger high beta power decrease during movement execution and less cortical motor control within the movement cycle. We speculate this to be due to the more continuous nature of

  9. Estimating Bicycle and Pedestrian Demand in San Diego

    OpenAIRE

    Jones, Michael; Buckland, Lauren

    2008-01-01

    This paper introduces the concepts behind estimating bicycle and pedestrian demand and provides an example of the development of a sketch-plan method for estimating bicycle and pedestrian demand from land use in San Diego County. The paper describes the methodology involved in collecting counts for the currently ongoing Seamless Travel project. The Seamless Travel project intends to develop a model for estimating bicycle and pedestrian demand within San Diego County. The project methodology i...

  10. Technical analysis and market study of electric bicycles

    OpenAIRE

    Matasyan, Artur

    2015-01-01

    This thesis project was done in collaboration with a Prismattery LLC, which is based in Tallinn, Estonia and is interested in entering the market of electric bicycles. For that reason in this report a detailed study concerning the market of electrical bicycles, its current situation and trends were performed and a promising target market was indicated. The market study showed that although in different countries the specifications and preferred types of electric bicycles may vary,...

  11. Factors of the safety in bicycle traffic in the City of Zagreb and its surrounding

    Directory of Open Access Journals (Sweden)

    Sindik Joško

    2014-01-01

    Full Text Available The aim of this study was to determine the differences in underlying factors of Zagreb cycling, compared to the "types of cyclists" (driving style, i.e. different ways of using bicycles as a means of transport. The study included over 3,000 frequent participants in urban traffic cycling, sample of members of the association Cyclist Union (N = 1259 and snowball sample of "typical" of cyclists, i.e. people who are using the bike, but are not the members of the Cyclist Union (N = 1831, using the conveniently assembled questionnaire. Study participants who bike used in various applications prefer the safest driving style (only on sidewalks and bike paths / lines. Barriers of the weather conditions are ubiquitous in the safest driving style. Daily, weekly and yearly riding a bicycle are more often found in those who prefer the safest driving style. Cyclists who drive with medium secure style (roads with less traffic and lower speeds, more often ride a bike, as compared with those who prefer the safest driving style. Having a better bike line / track and other infrastructure is the most often considered at those with the highest risk driving style. The results provide the guidance for local authorities and for the cyclists to improve the conditions for a safer and more often by bicycle circulation in the City of Zagreb and its surroundings.

  12. A solid solution to a conjecture on the maximal energy of bipartite bicyclic graphs

    CERN Document Server

    Huo, Bofeng; Li, Xueliang; Shi, Yongtang

    2011-01-01

    The energy of a simple graph $G$, denoted by $E(G)$, is defined as the sum of the absolute values of all eigenvalues of its adjacency matrix. Let $C_n$ denote the cycle of order $n$ and $P^{6,6}_n$ the graph obtained from joining two cycles $C_6$ by a path $P_{n-12}$ with its two leaves. Let $\\mathscr{B}_n$ denote the class of all bipartite bicyclic graphs but not the graph $R_{a,b}$, which is obtained from joining two cycles $C_a$ and $C_b$ ($a, b\\geq 10$ and $a \\equiv b\\equiv 2\\, (\\,\\textmd{mod}\\, 4)$) by an edge. In [I. Gutman, D. Vidovi\\'{c}, Quest for molecular graphs with maximal energy: a computer experiment, {\\it J. Chem. Inf. Sci.} {\\bf41}(2001), 1002--1005], Gutman and Vidovi\\'{c} conjectured that the bicyclic graph with maximal energy is $P^{6,6}_n$, for $n=14$ and $n\\geq 16$. In [X. Li, J. Zhang, On bicyclic graphs with maximal energy, {\\it Linear Algebra Appl.} {\\bf427}(2007), 87--98], Li and Zhang showed that the conjecture is true for graphs in the class $\\mathscr{B}_n$. However, they could not...

  13. A Geo-Aware and VRP-Based Public Bicycle Redistribution System

    Directory of Open Access Journals (Sweden)

    J. H. Lin

    2012-01-01

    Full Text Available Public Bicycle System (PBS has been developed for short-distance transportation as a part of the mass transportation system. The supply and demand of bikes in PBS is usually unbalanced at different stations and needs to be continuously and widely monitored and redistributed. The bicycle redistribution is a part of the vehicle routing problem (VRP. We can apply solutions to the VRP to redistribute bicycle efficiently. However, most solutions to the VRP use the Euclidean distance as the condition factor, which does not take road conditions, traffic regulations, and geographical factors into account, resulting in unnecessary waste of delivery time and human resources. In this work, we propose an actual path distance optimization method for the VRP to adapt the several additional constraints of road problems. We also implement a system that integrates real-time station information, Web GIS, the urban road network, and heuristics algorithms for PBS. The system includes a simulator inside that can assist PBS managers to do the route planning efficiently and find the best scheduling strategy to achieve hotspot analysis and the adjustment of station deployment strategies to reduce PBS operation cost.

  14. Incorporating moving dynamic tyre loads in pavement design and analysis

    CSIR Research Space (South Africa)

    Steyn, WJvdM

    2000-07-01

    Full Text Available and AT VISSER* CSIR Transportek, PO Box 395, Pretoria, 00011 *Department of Civil Engineering, University of Pretoria, Pretoria INTRODUCTION Current mechanistic pavement design and analysis techniques use several simplifications to enable... the process to be practical and cost-effective. These include equivalent vehicle loads, linear elastic analysis and static vehicle load and pavement response analysis. These simplifications allow the process of pavement design and analysis to be applied...

  15. Permeability testing of drilling core sample from pavement

    Institute of Scientific and Technical Information of China (English)

    Suda WANG; Zhengguang TANG; Xiaojun NING; Peiguan WU; Pingyi XING

    2008-01-01

    The permeability coefficient of pavement material is a very important parameter in designing the drainage of pavement structures and is also used to evalu-ate the quality of road construction. New equipment is used to measure the permeability coefficient of the pave-ment drilling core sample and relevant testing methods are introduced. Testing drilling core samples from a certain highway of Yunnan province has been proven to be feas-ible. The test results are also analyzed.

  16. Truck fleet model for design and assessment of flexible pavements

    OpenAIRE

    Belay, Abraham; O'Brien, Eugene J.; Kroese, Dirk P.

    2008-01-01

    The mechanistic empirical method of flexible pavement design/assessment uses a large number of numerical truck model runs to predict a history of dynamic load. The pattern of dynamic load distribution along the pavement is a key factor in the design/ assessment of flexible pavement. While this can be measured in particular cases, there are no reliable methods of predicting the mean pattern for typical traffic conditions. A simple linear quarter car model is developed here which aims to reprod...

  17. Evaluation of Nontraditional Airfield Pavement Surfaces for Contingency Operations

    Science.gov (United States)

    2014-01-01

    to predict the performance of nontraditional pavements , although it was designed for traditional PCC ( rigid ), HMA (flexible), and unsurfaced...including a combination of rigid and flexible pavement analyses and, if possible, these criteria should be followed as detailed in ETL 08-14 (AFCESA...ER D C/ G SL T R -1 4 -2 Evaluation of Nontraditional Airfield Pavement Surfaces for Contingency Operations G eo te ch n ic al a n d

  18. Stochastic finite element applications in rigid pavement performance

    Science.gov (United States)

    Attoh-Okine, Nii O.

    1999-05-01

    Rigid pavement structures have uncertainties and variability in their structural layers and components. These variations and uncertainties are seldomly included in performance assessment and evaluation in pavement systems. This paper proposes to use Stochastic Finite Element Method (SFEM) in rigid pavement faulting and load transfer efficiency. The SFEM uses random parameters, as stochastic process namely random fields. These random fields are characterized, quantitatively by spatial functions of statistical moment like the mean, variance and covariance.

  19. A simulator-based analysis of engineering treatments for right-hook bicycle crashes at signalized intersections.

    Science.gov (United States)

    Warner, Jennifer; Hurwitz, David S; Monsere, Christopher M; Fleskes, Kayla

    2017-07-01

    A right-hook crash is a crash between a right-turning motor vehicle and an adjacent through-moving bicycle. At signalized intersections, these crashes can occur during any portion of the green interval when conflicting bicycles and vehicles are moving concurrently. The objective of this research was to evaluate the effectiveness of four types of engineering countermeasures - regulatory signage, intersection pavement marking, smaller curb radius, and protected intersection design - at modifying driver behaviors that are known contributing factors in these crashes. This research focused on right-hook crashes that occur during the latter stage of the circular green indication at signalized intersections with a shared right-turn and through lane. Changes in driver performance in response to treatments were measured in a high-fidelity driving simulator. Twenty-eight participants each completed 22 right-turn maneuvers. A partially counterbalanced experimental design exposed drivers to critical scenarios, which had been determined in a previous experiment. For each turn, driver performance measures, including visual attention, crash avoidance, and potential crash severity, were collected. A total of 75 incidents (47 near-collisions and 28 collisions) were observed during the 616 right turns. All treatments had some positive effect on measured driver performance with respect to the right-turn vehicle conflicts. Further work is required to map the magnitude of these changes in driver performance to crash-based outcomes. Copyright © 2017 Elsevier Ltd. All rights reserved.

  20. Environmentally friendly pavements: Results from noise measurements 2005-2008

    OpenAIRE

    Berge, Truls Svenn; Haukland, Frode; Ustad, Asbjørn

    2009-01-01

    CPX-measurements (tyre A) have been performed on a wide range of ordinary dense Norwegian road pavements and special test pavements, as part of the R&D project “Environmental friendly pavements” initiated by the Norwegian Public Roads Administration. The following conclusions can be made from the investigation:- New dense asphalt concrete pavements can give a tyre/road noise level (CPX) of 4-8 dB(A) lower noise level, compared to a chosen reference level for a pavement of type AC 0/11 and SMA...

  1. Hybrid green permeable pave with hexagonal modular pavement systems

    Science.gov (United States)

    Rashid, M. A.; Abustan, I.; Hamzah, M. O.

    2013-06-01

    Modular permeable pavements are alternatives to the traditional impervious asphalt and concrete pavements. Pervious pore spaces in the surface allow for water to infiltrate into the pavement during rainfall events. As of their ability to allow water to quickly infiltrate through the surface, modular permeable pavements allow for reductions in runoff quantity and peak runoff rates. Even in areas where the underlying soil is not ideal for modular permeable pavements, the installation of under drains has still been shown to reflect these reductions. Modular permeable pavements have been regarded as an effective tool in helping with stormwater control. It also affects the water quality of stormwater runoff. Places using modular permeable pavement has been shown to cause a significant decrease in several heavy metal concentrations as well as suspended solids. Removal rates are dependent upon the material used for the pavers and sub-base material, as well as the surface void space. Most heavy metals are captured in the top layers of the void space fill media. Permeable pavements are now considered an effective BMP for reducing stormwater runoff volume and peak flow. This study examines the extent to which such combined pavement systems are capable of handling load from the vehicles. Experimental investigation were undertaken to quantify the compressive characteristics of the modular. Results shows impressive results of achieving high safety factor for daily life vehicles.

  2. A novel micromechanics based approach in modeling pavement response

    Science.gov (United States)

    Bhattacharya, Arun

    For maintaining a smooth flow of traffic in the nation's highway system, sections of pavements that are damaged need to be serviced frequently. Among the various types of damage, those caused by heavy trucks are a major concern. Based on a detailed and broad literature survey, it is apparent that no analytical model exists which could closely predict dynamic pavement response and progressive damage, even qualitatively, due to truck loading. It is such a model that is developed in this work. In order to predict pavement response and damage analytically, a model will have to be based on a theory that captures the essential features of the pavement material. The state-of-the-art Microplane Theory, which has never been applied before to pavement, is chosen to model the material behavior in this research. The theory is implemented in a finite element code to predict tri-axial pavement response. The pavement material damage due to traffic loading is also presented qualitatively. Furthermore, using Taguchi Methods, the critical parameters in a pavement design are determined. Finally, the response of pavement to various joint designs parameters is evaluated.

  3. Dynamic Modeling of Pavements with Application to Deflection Measurements

    DEFF Research Database (Denmark)

    Madsen, Stine Skov

    Pavement surface deflection measurements are the primary means of evaluating the bearing capacity of a pavement. The most common type of device used for measuring pavement surface deflections is the Falling Weight Deflectometer (FWD). However, increasing attention has been given to the Rolling Wheel...... Deflectometer (RWD) type of device due to its ability to measure deflections continuously while driving at traffic speed. To be able to properly interpret deflection measurements from an RWD device, more knowledge about the structural behavior of a pavement when subjected to transient dynamic loads moving...

  4. 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.

  5. The impact of transportation infrastructure on bicycling injuries and crashes: a review of the literature

    Directory of Open Access Journals (Sweden)

    Cripton Peter A

    2009-10-01

    Full Text Available Abstract Background Bicycling has the potential to improve fitness, diminish obesity, and reduce noise, air pollution, and greenhouse gases associated with travel. However, bicyclists incur a higher risk of injuries requiring hospitalization than motor vehicle occupants. Therefore, understanding ways of making bicycling safer and increasing rates of bicycling are important to improving population health. There is a growing body of research examining transportation infrastructure and the risk of injury to bicyclists. Methods We reviewed studies of the impact of transportation infrastructure on bicyclist safety. The results were tabulated within two categories of infrastructure, namely that at intersections (e.g. roundabouts, traffic lights or between intersections on "straightaways" (e.g. bike lanes or paths. To assess safety, studies examining the following outcomes were included: injuries; injury severity; and crashes (collisions and/or falls. Results The literature to date on transportation infrastructure and cyclist safety is limited by the incomplete range of facilities studied and difficulties in controlling for exposure to risk. However, evidence from the 23 papers reviewed (eight that examined intersections and 15 that examined straightaways suggests that infrastructure influences injury and crash risk. Intersection studies focused mainly on roundabouts. They found that multi-lane roundabouts can significantly increase risk to bicyclists unless a separated cycle track is included in the design. Studies of straightaways grouped facilities into few categories, such that facilities with potentially different risks may have been classified within a single category. Results to date suggest that sidewalks and multi-use trails pose the highest risk, major roads are more hazardous than minor roads, and the presence of bicycle facilities (e.g. on-road bike routes, on-road marked bike lanes, and off-road bike paths was associated with the lowest

  6. An international view of pavement engineering

    CSIR Research Space (South Africa)

    Rust, FC

    1998-01-01

    Full Text Available .9 2.0 0.0 0.0 Lithuania 55.0 1.0 44.0 0.0 0.0 Poland 100 .0 0.0 0.0 0.0 0.0 Romania 90.0 10.0 0.0 0.0 0.0 Russia 87.0 8.0 0.0 0.0 5.0 Ukraine 55.0 1.5 13.0 9.5 21.0 Estonia 17.4 0.0 ? ? 27.9 46.7 8.0 28 Table 9 : Rigid Pavement and D esign... - 1,000 390 - 725 20 -8 Ukraine 600 - 1,400 100 - 950 24 -2 Washington State Seattle 0 - 200 10 - 50 17 5 Spokane 700 - 900 370 - 600 18 -3 27 Table 8 : Pavement Types for Various C entral, Eastern European, and Baltic Countries...

  7. Design of Road Pavement Using Recycled Aggregate

    Science.gov (United States)

    Remišová, Eva; Decký, Martin; Mikolaš, Milan; Hájek, Matej; Kovalčík, Luboš; Mečár, Martin

    2016-10-01

    The presented article gives special attention to codified clauses of the road construction law, the relevant clauses of the standards and technical regulations to design and control the quality of recycled aggregate constructions. The article also presents the authors’ suggestions to design of earth constructions and pavements of roads according to the Slovak technical standards, technical regulations and objectively determined results of research and development of road infrastructure. The article presents a comparison of the mechanical characteristics measurements of the structural layers of road pavements built from the recycled and natural aggregate. It also presents correlation functions of results obtained from in situ and in laboratory CBR (Californian Bearing Ratio) measuring, representing the world's most widely used control method of bearing capacity of mentioned construction layers.

  8. Expedient Repair Materials for Roadway Pavements

    Science.gov (United States)

    2005-03-01

    cores used for the adhesion test was thin-cut with a concrete saw to expose an aggregate face on which the oven-aged mixture was compacted (Figure 4...asphalt cement with various antistrip and high- adhesion additives. An open-graded, high-quality, locally available aggregate is required for blending...www.qprcoldpatch.com 3. Description: QPR is a cold-mix patch material for asphalt and concrete pavements. The binder is a proprietary modified bitumen . The aggregate

  9. Effectiveness of transverse grooves in rigid pavement

    Science.gov (United States)

    Gurney, G. F.; Bryden, J. E.

    1982-10-01

    Transverse grooves were installed at 11 intersection approaches on worn rigid pavement to reduce a high rate of wet road accidents. In most cases, accident reductions were experienced only at intersections with multiple negative operational characteristics, including higher approach speeds, limited sight distances, and frequent vehicle stopping for turns or stop signs. Intersections with no more than one negative characteristic generally did not benefit from grooving.

  10. On Wiener polarity index of bicyclic networks

    Science.gov (United States)

    Ma, Jing; Shi, Yongtang; Wang, Zhen; Yue, Jun

    2016-01-01

    Complex networks are ubiquitous in biological, physical and social sciences. Network robustness research aims at finding a measure to quantify network robustness. A number of Wiener type indices have recently been incorporated as distance-based descriptors of complex networks. Wiener type indices are known to depend both on the network’s number of nodes and topology. The Wiener polarity index is also related to the cluster coefficient of networks. In this paper, based on some graph transformations, we determine the sharp upper bound of the Wiener polarity index among all bicyclic networks. These bounds help to understand the underlying quantitative graph measures in depth.

  11. Solar Electric Bicycle Body Modeling and Simulation

    Directory of Open Access Journals (Sweden)

    Zhikun Wang

    2013-10-01

    Full Text Available A new solar electric bicycle design and study were carried out on in this paper. Application of CAD technology to establish three-dimension geometric model, using the kinetic analysis on the frame and other parts for numerical simulation and static strength analysis for the vehicle model design, virtual assembly, complete frame dynamics analysis and vibration analysis, with considering other factors, first on the frame structure improvement, second on security of design calculation analysis and comparison, finally get the ideal body design.

  12. 77 FR 39927 - Vehicles and Traffic Safety-Bicycles

    Science.gov (United States)

    2012-07-06

    ... bicycle trails for beautiful scenery, exercise, and adventure. People bicycle alone, with friends, or with... through a written determination, remain in effect, and the new rule does not require that they be reissued..., and Wyoming). Studies show that helmet use while riding decreases the risk of head and brain injury...

  13. Bicycle facilities on road segments and intersections of distributor roads.

    NARCIS (Netherlands)

    2008-01-01

    A sustainably safe road environment requires bicycle facilities that separate motorized traffic from relatively vulnerable road users like cyclists. Research indicates that on distributor roads the road sections with adjoining or separate bicycle tracks are safer than the road sections without any b

  14. On Sum--Connectivity Index of Bicyclic Graphs

    CERN Document Server

    Du, Zhibin

    2009-01-01

    We determine the minimum sum--connectivity index of bicyclic graphs with $n$ vertices and matching number $m$, where $2\\le m\\le \\lfloor\\frac{n}{2}\\rfloor$, the minimum and the second minimum, as well as the maximum and the second maximum sum--connectivity indices of bicyclic graphs with $n\\ge 5$ vertices. The extremal graphs are characterized.

  15. Bicycle Freewheeling with Air Drag as a Physics Experiment

    Science.gov (United States)

    Janssen, Paul; Janssens, Ewald

    2015-01-01

    To familiarize first-year students with the important ingredients of a physics experiment, we offer them a project close to their daily life: measuring the effect of air resistance on a bicycle. Experiments are done with a bicycle freewheeling on a downhill slope. The data are compared with equations of motions corresponding to different models…

  16. Factors of the physical environment associated with walking and bicycling

    NARCIS (Netherlands)

    Wendel-Vos, G.C.W.; Schuit, A.J.; Niet, de R.; Boshuizen, H.C.; Saris, W.H.M.; Kromhout, D.

    2004-01-01

    PURPOSE: The purpose of this study was to identify factors of the physical environment that may influence time spent on walking and bicycling. METHODS: Demographic factors and time spent on walking and bicycling (during leisure time and for commuting purposes) were assessed with a self-administered

  17. Bicycle facilities on road segments and intersections of distributor roads.

    NARCIS (Netherlands)

    2008-01-01

    A sustainably safe road environment requires bicycle facilities that separate motorized traffic from relatively vulnerable road users like cyclists. Research indicates that on distributor roads the road sections with adjoining or separate bicycle tracks are safer than the road sections without any b

  18. Methods to assess the stability of a bicycle rider system

    NARCIS (Netherlands)

    Cooke, A.G.; Bulsink, V.E.; Beusenberg, C.M.; Dubbeldam, R.; Bonnema, G.M.; Poelman, W.A.; Koopman, H.F.J.M.

    2012-01-01

    The SOFIE (Intelligent Assisted Bicycles) project wishes to create performance and design guidelines for mechatronic appliances which improve the stability of electric bicycles, so-called intelligent stability assist devices (IAD). To achieve this goal, a stability hypothesis, an advanced rider/bicy

  19. Bicycle-related maxillofacial injuries : a double-center study

    NARCIS (Netherlands)

    Boffano, Paolo; Roccia, Fabio; Gallesio, Cesare; Karagozoglu, K. Hakki; Forouzanfar, Tymour

    2013-01-01

    Objective. Bicycle-related injuries account for an important proportion of road injuries all over the world. As only few reports have focused on the characteristics of maxillofacial fractures sustained in bicycle accidents, the purpose of this study was to present and compare epidemiological data ab

  20. Bicycle-related maxillofacial injuries: a double-center study

    NARCIS (Netherlands)

    Boffano, P.; Roccia, F.; Gallesio, C.; Karagozoglu, K.H.; Forouzanfar, T.

    2013-01-01

    Objective Bicycle-related injuries account for an important proportion of road injuries all over the world. As only few reports have focused on the characteristics of maxillofacial fractures sustained in bicycle accidents, the purpose of this study was to present and compare epidemiological data abo

  1. Modeling of speed distribution for mixed bicycle traffic flow

    Directory of Open Access Journals (Sweden)

    Cheng Xu

    2015-11-01

    Full Text Available Speed is a fundamental measure of traffic performance for highway systems. There were lots of results for the speed characteristics of motorized vehicles. In this article, we studied the speed distribution for mixed bicycle traffic which was ignored in the past. Field speed data were collected from Hangzhou, China, under different survey sites, traffic conditions, and percentages of electric bicycle. The statistics results of field data show that the total mean speed of electric bicycles is 17.09 km/h, 3.63 km/h faster and 27.0% higher than that of regular bicycles. Normal, log-normal, gamma, and Weibull distribution models were used for testing speed data. The results of goodness-of-fit hypothesis tests imply that the log-normal and Weibull model can fit the field data very well. Then, the relationships between mean speed and electric bicycle proportions were proposed using linear regression models, and the mean speed for purely electric bicycles or regular bicycles can be obtained. The findings of this article will provide effective help for the safety and traffic management of mixed bicycle traffic.

  2. A mixed methods investigation of bicycle exposure in crash rates.

    Science.gov (United States)

    Fournier, Nicholas; Christofa, Eleni; Knodler, Michael A

    2017-03-01

    Crash rates are an essential tool enabling researchers and practitioners to assess whether a location is truly more dangerous, or simply serves a higher volume of vehicles. Unfortunately, this simple crash rate is far more difficult to calculate for bicycles due to data challenges and the fact that they are uniquely exposed to both bicycle and automobile volumes on shared roadways. Bicycle count data, though increasingly more available, still represents a fraction of the available count data for automobiles. Further compounding on this, bicycle demand estimation methods often require more data than automobiles to account for the high variability that bicycle demand is subject to. This paper uses a combination of mixed methods to overcome these challenges and to perform an investigation of crash rates and exposure to different traffic volumes.

  3. Bicyclic Peptide Inhibitor of Urokinase-Type Plasminogen Activator

    DEFF Research Database (Denmark)

    Roodbeen, Renée; Paaske, Berit; Jiang, Longguang;

    2013-01-01

    The development of protease inhibitors for pharmacological intervention has taken a new turn with the use of peptidebased inhibitors. Here, we report the rational design of bicyclic peptide inhibitors of the serine protease urokinase-type plasminogen activator (uPA), based on the established...... monocyclic peptide, upain-2. It was successfully converted to a bicyclic peptide, without loss of inhibitory properties. The aim was to produce a peptide cyclised by an amide bond with an additional stabilising across-the-ring covalent bond. We expected this bicyclic peptide to exhibit a lower entropic...... burden upon binding. Two bicyclic peptides were synthesised with affinities similar to that of upain-2, and their binding energetics were evaluated by isothermal titration calorimetry. Indeed, compared to upain-2, the bicyclic peptides showed reduced loss of entropy upon binding to uPA. We also...

  4. Predicting bicycle setup for children based on anthropometrics and comfort.

    Science.gov (United States)

    Grainger, Karl; Dodson, Zoe; Korff, Thomas

    2017-03-01

    Bicycling is a popular activity for children. In order for children to enjoy cycling and to minimize injury, it is important that they are positioned appropriately on the bicycle. The purpose of this study was therefore to identify a suitable bicycle setup for children aged between 7 and 16 years which accommodates developmental differences in anthropometrics, flexibility and perceptions of comfort. Using an adjustable bicycle fitting rig, we found the most comfortable position of 142 children aged 7 to 16. In addition, a number of anthropometric measures were recorded. Seat height and the horizontal distance between seat and handlebars were strongly predictable (R(2) > 0.999, p bicycle manufacturers.

  5. In-depth analysis of bicycle hydraulic disc brakes

    Science.gov (United States)

    Maier, Oliver; Györfi, Benedikt; Wrede, Jürgen; Arnold, Timo; Moia, Alessandro

    2017-10-01

    Hydraulic Disc Brakes (HDBs) represent the most recent and innovative bicycle braking system. Especially Electric Bicycles (EBs), which are becoming more and more popular, are equipped with this powerful, unaffected by environmental influences, and low-wear type of brakes. As a consequence of the high braking performance, typical bicycle braking errors lead to more serious accidents. This is the starting point for the development of a Braking Dynamics Assistance system (BDA) to prevent front wheel lockup and nose-over (falling over the handlebars). One of the essential prerequisites for the system design is a better understanding of bicycle HDBs' characteristics. A physical simulation model and a test bench have been built for this purpose. The results of the virtual and real experiments conducted show a high correlation and allow valuable insights into HDBs on bicycles, which have not been studied scientifically in any depth so far.

  6. Infiuence of Bicycle Traffic on Capacity of Typical Signalized Intersection

    Institute of Scientific and Technical Information of China (English)

    CHEN Xiaoming; SHAO Chunfu; YUE Hao

    2007-01-01

    Bicycle traffic has a significant effect on the capacity of signalized intersections. This paper divides the influence of bicyclists on vehicular flow into four types with the time durations estimated based on probability, shock wave, and gap acceptance theory. Vehicular saturation flow rate is predicted for various conditions on the basis of the speed-flow curve for the capacity of typical intersections influenced by bicycle traffic.The model overcomes the limitations of the Highway Capacity Manual (HCM, 2000) method for left-turns due to data collection, and takes into account the effect of trapped bicycles on the through vehicular traffic.The numerical results show that the left-turn and through capacities predicted by the model are lower than those of the HCM method. The right-turn capacity is close to that of the HCM method at Iow bicycle volumes and higher than that of the HCM method at high bicycle volumes.

  7. Safe bicycling – Problems and solutions

    Directory of Open Access Journals (Sweden)

    Grecka M.

    2014-01-01

    Full Text Available Herewith a popularity of bicycling, various safety problems of cyclists are researched. Studies are connected with infrastructure, riding culture, choice of cyclist's suit and riding equipment. Overall, 382 respondents (159 cyclists, 119 drivers, 104 pedestrians were involved in the survey. The road participants' mutual communication problems in the traffic and opportunities of solving them were clarified. Most of cyclists wear comfortable daily or sporty clothing with reflective elements, and in their opinion, clothing with light emissive elements must be like daily clothing. The drivers could better notice cyclists, if they wear brightly colored suit with light emissive and reflective elements, but pedestrians – if cyclists use warning sound signals. The opinions of road participants about the placement of light emissive and reflective elements in cyclist's clothing were clarified. The prototype of cycling belt (Fig. 1e has been drawn up with LED stop signals, which are activated by the accelerometer placed in the central back pocket. The results of approbation have shown that the sensor does not provide the proper functioning of signals, due to a high level of riding movements. Using Motion Capture technology and bicycle exercise equipment, the research of oscillation of anthropometric points on the back has been carried out. The accelerometer should be placed between scapulae to design the cycling jacket.

  8. The Design of Sport Bicycle Speed Odometer

    Directory of Open Access Journals (Sweden)

    Dongbing Liu

    2013-04-01

    Full Text Available As bicycle sport equipment, a sport bike needs a speed and distance measuring device, due to the characteristic of road cycling, thereby mastering the state of motion. According to external conditions such as temperature, wind speed, the bike can make the appropriate adjustment to achieve the best movement effect. The bicycle speed odometer is a major accessibility tool that satisfies with needs of the people with fast development. This study elaborated a bike speed odometer design based on Hall element, taking AT89C52 single chip as the core, measuring speed with A44E Hall sensor, to finish the bike mileage/speed measurement and statistics by displaying bike mileage and speed in real time. By using the Hall elements, the hardware of speed odometer input the number of pulse of per circle into the single-chip computer system. Then the signal processed by the single-chip computer displays. The software is programmed with assembly language and modular design idea. The design of the hardware circuit is simple and the subroutine has universal property, which fully meet the design requirements and possess a wide range of application and dissemination value.

  9. Dynamic Study of Bicycle Frame Structure

    Science.gov (United States)

    Sani, M. S. M.; Nazri, N. A.; Zahari, S. N.; Abdullah, N. A. Z.; Priyandoko, G.

    2016-11-01

    Bicycle frames have to bear variety of loads and it is needed to ensure the frame can withstand dynamic loads to move. This paper focusing on dynamic study for bicycle frame structure with a purpose to avoid the problem regarding loads on the structure and to ensure the structure is safe when multiple loads are applied on it. The main objectives of dynamic study are to find the modal properties using two method; finite element analysis (FEA) and experimental modal analysis (EMA). The correlation between two studies will be obtained using percentage error. Firstly, 3D model of mountain bike frame structure has been draw using computer-aided design (CAD) software and normal mode analysis using MSC Nastran Patran was executed for numerical method meanwhile modal testing using impact hammer was performed for experimental counterpart. From the correlation result, it show that percentage error between FEA and EMA were below 10% due to noise, imperfect experiment setup during perform EMA and imperfect modeling of mountain bike frame structure in CAD software. Small percentage error differences makes both of the method can be applied to obtain the dynamic characteristic of structure. It is essential to determine whether the structure is safe or not. In conclusion, model updating method is required to reduce more percentage error between two results.

  10. Full-Depth Asphalt Pavements for Parking Lots and Driveways.

    Science.gov (United States)

    Asphalt Inst., College Park, MD.

    The latest information for designing full-depth asphalt pavements for parking lots and driveways is covered in relationship to the continued increase in vehicle registration. It is based on The Asphalt Institute's Thickness Design Manual, Series No. 1 (MS-1), Seventh Edition, which covers all aspects of asphalt pavement thickness design in detail,…

  11. 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 Perfo...

  12. sensitivity analysis on flexible road pavement life cycle cost model

    African Journals Online (AJOL)

    user

    methods of assessing and managing the risk and uncertainties ... cost studies in flexible pavement delivery, it is important ... developed for the road pavement in the study area as .... vehicle counts per day of 400 of a single carriageway ..... from the Intermodal Terminal” in Sweden, which had ... Company, Malabar, Florida.

  13. Effect of induced deformation on NDT pavement evaluation

    Science.gov (United States)

    Tawfiq, Kamal S.; Sobanjo, John O.; Ruiz, R.

    1999-02-01

    Three nondestructive testing techniques were used in this study to evaluate pavement layer properties. These techniques included deflection and seismic methods. In the deflection methods, measurable surface deformations were induced using falling weight deflectometer and Dynaflect tests. These two tests utilized different schemes of dynamic loading applications to produce deflection basins from which the pavement layer properties were back calculated. Pavement properties from seismic methods were obtained from the analysis of surface waves due to transient load applications. In this study the seismic pavement analyzer (SPA) was used to determine pavement moduli values. Although the same assumptions for linear elastic behavior of pavement properties are usually assumed in all the three methods, obtained moduli values from these techniques did not conform to each other. Commonly, pavement deflection from SPA is not considered when analyzing layer properties. To narrow the gap between the obtained results, however, time-history records and frequency response functions were used to determine surface deflections from the three methods. Deflection measurements correlated with the obtained moduli values. Using these correlations, moduli values at any pavement deflection levels could be evaluated, especially at levels produced by traffic loads.

  14. Research on pavement crack recognition methods based on image processing

    Science.gov (United States)

    Cai, Yingchun; Zhang, Yamin

    2011-06-01

    In order to overview and analysis briefly pavement crack recognition methods , then find the current existing problems in pavement crack image processing, the popular methods of crack image processing such as neural network method, morphology method, fuzzy logic method and traditional image processing .etc. are discussed, and some effective solutions to those problems are presented.

  15. 3D Tyre/Road pavement contact stress measurements

    CSIR Research Space (South Africa)

    De Beer, Morris

    2010-10-01

    Full Text Available The CSIR’s proprietary Stress-in-Motion (SIM) measurements provide rational descriptions of 1D, 2D and 3D tyre/road pavement stresses for: Road pavement design testing and evaluation, as well as tyre design, testing and evaluation....

  16. Importance of dowels in transversal joints in concrete pavements

    Science.gov (United States)

    Grosek, Jiri; Chupik, Vladimir; Stryk, Josef; Brezina, Ilja

    2017-09-01

    Concrete pavements are designed for heavy loaded road structures. Their usage brings a number of specific issues. It is necessary to solve them all to ensure that concrete pavements will fulfil their function along the whole design period. One of these issues concerns dowels, which are located in transversal joints. Modelling of load, caused by heavy vehicles, with the use of the finite element method, provides valuable information about the stress condition of concrete pavement. The results of modelling can be verified by measurements or experiments in practice. Dowels and tie bars in jointed unreinforced concrete pavements and the importance of their correct placement, dimensions and material quality on pavement behaviour and lifespan were studied as a part of R&D projects of Technology Agency of the Czech Republic Nos. TA02031195 and TE01020168. The paper presents the experience from the modelling and performed experiments and makes conclusions which are important for the use in practice.

  17. Towards Understanding Tyre-Pavement Contact in APT Research on Flexible Pavements

    CSIR Research Space (South Africa)

    De Beer, Morris

    2016-09-01

    Full Text Available An important element of Accelerated Pavement Testing (APT) is the selection of appropriate test tyre(s) to be used for APT testing. By far the majority of full scale (or scaled) APT devices uses pneumatic rubber tyres. Tyres differ not only in size...

  18. Reconsideration of tyre-pavement input parameters for the structural design of flexible pavements

    CSIR Research Space (South Africa)

    De Beer, Morris

    2006-08-01

    Full Text Available which have higher inflation pressures and hence higher contact stresses than was previously the case. The aim of this paper is to highlight the variabilities associated with actual measured three-dimensional tyre-pavement contact loading/stress regimes...

  19. Utilization of Advanced Diagnostic Methods for Texture and Rut Depth Analysis on a Testing Pavement Section

    Science.gov (United States)

    Slabej, Martin; Grinč, Michal; Kotek, Peter; Kováč, Matúš; Decký, Martin

    2015-05-01

    Qualitative characteristics of pavement in wide range reflects the pavement serviceability, which is a summary of the characteristics of the pavement, providing a fast, smooth, economical and especially safe driving of motor-vehicles. The target factor of pavement serviceability and safety of roads represents the quality of their surface properties. In the framework of research activities performed in the Research Centre founded under the auspices of University of Žilina, individual parameters of pavement serviceability were monitored by pavement surface scanning. This paper describes the creation of a 3D - road surface model and its analysis and evaluation from the viewpoint of two pavement serviceability parameters - the rut depth and texture. Measurements were performed on an experimental pavement section used contemporary in an Accelerated Pavement Testing experiment. The long-term goal is to ascertain functions predicting degradation of these two pavement serviceability parameters.

  20. Utilization of Advanced Diagnostic Methods for Texture and Rut Depth Analysis on a Testing Pavement Section

    Directory of Open Access Journals (Sweden)

    Slabej Martin

    2015-05-01

    Full Text Available Qualitative characteristics of pavement in wide range reflects the pavement serviceability, which is a summary of the characteristics of the pavement, providing a fast, smooth, economical and especially safe driving of motor-vehicles. The target factor of pavement serviceability and safety of roads represents the quality of their surface properties. In the framework of research activities performed in the Research Centre founded under the auspices of University of Žilina, individual parameters of pavement serviceability were monitored by pavement surface scanning. This paper describes the creation of a 3D - road surface model and its analysis and evaluation from the viewpoint of two pavement serviceability parameters - the rut depth and texture. Measurements were performed on an experimental pavement section used contemporary in an Accelerated Pavement Testing experiment. The long-term goal is to ascertain functions predicting degradation of these two pavement serviceability parameters.

  1. 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.

  2. Rates of bicycle helmet use in an affluent Michigan County.

    Science.gov (United States)

    Jacques, L B

    1994-01-01

    Bicycle helmet use in the United States has remained low despite clear demonstration of its beneficial effect on reducing the incidence of serious head injury. Several interventions have been reported, with variable results and costs. Much of the recent literature has focused on child cyclists and on demographic factors associated with helmet use. This paper reports on helmet use by children and adults in a sample of 652 riders in an affluent southeast Michigan region, chosen to minimize the effect of previously recognized socioeconomic negative predictors that are not readily changed by intervention. Subjects were classified by age, sex, location, riding surface, type of bicycle, child bicycle seat use, child bicycle trailer use, and helmet use by companions. Overall helmet use was 24 percent; infants and toddlers had the highest rate of helmet use at 61 percent, followed by adults at 26 percent and school-aged children at 17 percent. The strongest predictor of helmet use in all age categories was the presence of a helmeted companion. Adult helmet use was also positively predicted by riding in the street and by riding a racing-type bicycle. The use of a city-type bicycle negatively predicted helmet use. For non-adults, female sex and the use of a child seat or trailer were positive predictors. Fostering peer pressure to increase helmet use may be an effective yet relatively inexpensive way to achieve the goal of widespread use of bicycle helmets.

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

    OpenAIRE

    Guo, Zhongyin; Sultan, Saud A.

    2017-01-01

    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 man...

  4. Wavelet-aided pavement distress image processing

    Science.gov (United States)

    Zhou, Jian; Huang, Peisen S.; Chiang, Fu-Pen

    2003-11-01

    A wavelet-based pavement distress detection and evaluation method is proposed. This method consists of two main parts, real-time processing for distress detection and offline processing for distress evaluation. The real-time processing part includes wavelet transform, distress detection and isolation, and image compression and noise reduction. When a pavement image is decomposed into different frequency subbands by wavelet transform, the distresses, which are usually irregular in shape, appear as high-amplitude wavelet coefficients in the high-frequency details subbands, while the background appears in the low-frequency approximation subband. Two statistical parameters, high-amplitude wavelet coefficient percentage (HAWCP) and high-frequency energy percentage (HFEP), are established and used as criteria for real-time distress detection and distress image isolation. For compression of isolated distress images, a modified EZW (Embedded Zerotrees of Wavelet coding) is developed, which can simultaneously compress the images and reduce the noise. The compressed data are saved to the hard drive for further analysis and evaluation. The offline processing includes distress classification, distress quantification, and reconstruction of the original image for distress segmentation, distress mapping, and maintenance decision-making. The compressed data are first loaded and decoded to obtain wavelet coefficients. Then Radon transform is then applied and the parameters related to the peaks in the Radon domain are used for distress classification. For distress quantification, a norm is defined that can be used as an index for evaluating the severity and extent of the distress. Compared to visual or manual inspection, the proposed method has the advantages of being objective, high-speed, safe, automated, and applicable to different types of pavements and distresses.

  5. Tire Footprint Affects Hydroplaning On Wet Pavement

    Science.gov (United States)

    Yager, Thomas J.

    1989-01-01

    Recent investigations of tire hydroplaning at highway speeds reveal, in addition to inflation pressure, tire-footprint aspect ratio (FAR), defined as width divided by length of tire surface in contact with pavement, significantly influences speed at which dynamic hydroplaning begins. Tire speeds and forces developed during tests of up to 65 mi/h (105 km/h) were monitored on flooded test surface to identify development of hydroplaning. Study focused on automotive tires because FAR's of automotive tires vary more than those of aircraft tires.

  6. The frequency of single-bicycle crashes (SBCs) in countries with varying bicycle mode shares

    DEFF Research Database (Denmark)

    Schepers, Paul; Agerholm, Niels; Amoros, Emmanuelle;

    In  order  to  encourage  cycling,  we  need  to  reduce  the  hazards  that  cyclists  face. Single-bicycle crashes or ‘bicycle-only crashes’ are falls and obstacle collisions in which only one cyclist is involved. Between 60 and 95% of cyclists admitted to hospital or treated at an emergency...... department are victims of single-bicycle crashes. As proportion of the total number of traffic casualties  the  share  exceeds  20%  in  most  countries  with  medium  to  high  levels  of cycling.  This paper  discusses  the  prevalence  of  the  problem  and  describes  measures  that  may  both reduce...

  7. Bicyclic graphs with maximal revised Szeged index

    CERN Document Server

    Li, Xueliang

    2011-01-01

    The revised Szeged index $Sz^*(G)$ is defined as $Sz^*(G)=\\sum_{e=uv \\in E}(n_u(e)+ n_0(e)/2)(n_v(e)+ n_0(e)/2),$ where $n_u(e)$ and $n_v(e)$ are, respectively, the number of vertices of $G$ lying closer to vertex $u$ than to vertex $v$ and the number of vertices of $G$ lying closer to vertex $v$ than to vertex $u$, and $n_0(e)$ is the number of vertices equidistant to $u$ and $v$. Hansen used the AutoGraphiX and made the following conjecture about the revised Szeged index for a connected bicyclic graph $G$ of order $n \\geq 6$:

  8. Bamboo Bicycle – Past or Future?

    Directory of Open Access Journals (Sweden)

    Suzana Jakovljević

    2016-01-01

    Full Text Available In this article the experiment was carried out to establish tensile strength values of two different bamboo species, which are obtained by the static tensile test. The tensile strength results of two tested species Tonkin Cane and Ku Zhu bamboo are presented and compared with traditional materials used for bicycle frame to determine their suitability for designing a frame. Physiology and other properties of bamboo were elaborated as well. The purpose of this study was to gain more knowledge on bamboo and prove his suitability in use as an alternative for ecologically unacceptable materials. Therefore, application of the natural materials is essential for the sustainable development. The fact that they have unlimited resources the use of bamboo has great potential and this article explains why.

  9. Beijing Bicycle - Stories from a Transformative Space

    DEFF Research Database (Denmark)

    Bagger-Petersen, Mai Corlin

    2012-01-01

    Ideas, words, images and stories travel from west to east – and from east to west. Stories are chosen and retold in different settings and images are reproduced and appropriated into new contexts – and in new times. Cinema, in this case the mainland Chinese, becomes both a space of production...... and a production of space that reveals how transnational and translocal mechanisms affect the cinematic language, transforming the images and stories chosen for the cinematic representation. Wang Xiaoshuai’s Beijing Bicycle (Shiqi Sui de Danche) (2001) is a result of transnational currents weaving the carpet...... relevant in a new context – that of the Chinese mainland society in the 21st century. Doreen Massey (2005: 9) defines space as “a simultaneity of stories-so-far”, a space that is constantly exploding and imploding with the influx of new and old stories. Within this theoretical framework Wang Xiaoshuai...

  10. Bicycle helmet ventilation and comfort angle dependence.

    Science.gov (United States)

    Brühwiler, Paul A; Ducas, Charline; Huber, Roman; Bishop, Phillip A

    2004-09-01

    Five modern bicycle helmets were studied to elucidate some of the variations in ventilation performance, using both a heated manikin headform and human subjects (n = 7). Wind speed and head angle were varied to test their influence on the measured steady-state heat exchange (cooling power) in the skull section of the headform. The cooling power transmitted by the helmets varied from about 60% to over 90% of that of the nude headform, illustrating the range of present manufacturer designs. Angling the head forward by 30 degrees was found to provide better cooling power to the skull (up to 25%) for three of the helmets and almost equal cooling power in the remaining two cases. Comparisons of skull ventilation at these angles with human subjects strongly supported the headform results.

  11. Survival Analysis of Fatigue and Rutting Failures in Asphalt Pavements

    Directory of Open Access Journals (Sweden)

    Pabitra Rajbongshi

    2016-01-01

    Full Text Available Fatigue and rutting are two primary failure mechanisms in asphalt pavements. The evaluations of fatigue and rutting performances are significantly uncertain due to large uncertainties involved with the traffic and pavement life parameters. Therefore, deterministically it is inadequate to predict when an in-service pavement would fail. Thus, the deterministic failure time which is known as design life (yr of pavement becomes random in nature. Reliability analysis of such time (t dependent random variable is the survival analysis of the structure. This paper presents the survival analysis of fatigue and rutting failures in asphalt pavement structures. It is observed that the survival of pavements with time can be obtained using the bathtub concept that contains a constant failure rate period and an increasing failure rate period. The survival function (S(t, probability density function (pdf, and probability distribution function (PDF of failure time parameter are derived using bathtub analysis. It is seen that the distribution of failure time follows three parametric Weibull distributions. This paper also works out to find the most reliable life (YrR of pavement sections corresponding to any reliability level of survivability.

  12. Variability of pavement noise benefit by vehicle type

    Science.gov (United States)

    Rochat, Judith L.; Read, David R.

    2005-09-01

    The Volpe Center Acoustics Facility, in support of the California Department of Transportation (Caltrans), is participating in a long-term study to assess several types of pavement for the purpose of noise abatement. On a four-mile stretch of a two-lane highway in Southern California, several asphalt pavement overlays are being examined. Acoustical, meteorological, and traffic data are collected in each pavement overlay section, where microphones are deployed at multiple distances and heights. Single vehicle pass-by events are recorded primarily for three vehicle types: automobiles, medium trucks, and heavy trucks. Data are analyzed to determine the noise benefit of each pavement as compared to the reference dense-graded asphaltic concrete (DGAC); this includes a modified Statistical Pass-By Index as well as average Lmax values for each vehicle type. In addition, 1/3-octave band data are examined. Automobiles and heavy trucks are the focus of this paper, where benefits due to pavement will be presented for three pavement types: open-graded asphaltic concrete (OGAC) of 75 mm thickness, open-graded asphaltic concrete (OGAC) of 30 mm thickness, and rubberized asphaltic concrete, Type O (open) (RAC) of 30 mm thickness. Average Lmax values and spectral data show that noise benefits due to pavement can vary by vehicle type.

  13. An Innovative Strategy for Maintenance of Highway Pavement

    Directory of Open Access Journals (Sweden)

    Sandeep Choudhary, Dr. P. K. Agarwal

    2013-05-01

    Full Text Available Highway pavement are deteriorating fast due to lack of timely maintenance, leading to higher vehicle operating costs, increasing number of accidents etc. Thus, timely maintenance of the highway pavement is essential. Because, once pavements start to deteriorate; they deteriorate rapidly beyond the point where maintenance is effective. Thus, there is an urgent need to develop a strategy for maintenance of pavement in a huge highway network. In this study, an innovative strategy for maintenance of highway pavement is proposed. A two stage maintenance strategy is proposed. In stage I, it is proposed to determine priority of highway sections. In Stage II, priority of various maintenance activities to be carried out on various sections will be determined. Maintenance priority of the pavement is based on importance of the road sections, present road conditions, and future road conditions. The methodology proposed in this study is illustrated with the help of example of some hypothetical highway network consisting of 4 sections. Analysis results indicated that the proposed strategy is considered to be more rational, innovative & logical. Some strategies for maintenance of urban roads are also presented in this study. Therefore, it is expected that this study will be useful for maintenance of huge highway network in India and thus will be useful for preserving huge asset of pavement infrastructure.

  14. Evaluation of accelerated deterioration in NAPTF flexible test pavements

    Institute of Scientific and Technical Information of China (English)

    Kasthurirangan GOPALAKRISHNAN

    2008-01-01

    Previous research studies have successfully demonstrated the use of artificial neural network(ANN)models for predicting critical structural responses and layer moduli of highway flexible pavements.The primary objective of this study was to develop an ANN-based approach for backcalculation of pavement moduli based on heavy weight deflectometer(HWD)test data,especially in the analysis of airport flexible pavements subjected to new generation aircraft(NGA).Two medium-strength subgrade flexible test sections,at the National Airport Pavement Test Facility(NAPTF),were modeled using a finite element(FE) based pavement analysis program,which can consider the non-linear stress-dependent behavior of pavement geomaterials.A multi-layer,feed-forward network which uses an error-backpropagation algorithm was trained to approximate the HWD backcalculation function using the FE program generated synthetic database.At the NAPTF,test sections were subjected to Boeing 777 (B777)trafficking on one lane and Boeing 747(B747)trafficking on the other lane using a test machine.To monitor the effect of traffic and climatic variations on pavement structural responses.HWD tests were conducted on the traffieked lanes and on the untraffieked centerline of test sections as trafficking progressed.The trained ANN models were successfully applied on the actual HWD test data acquired at the NAPTF to predict the asphalt concrete moduli and non-1inear subgrade moduli of the medium-strength subgrade flexible test sections.

  15. 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.

  16. Application of Conductive Materials to Asphalt Pavement

    Directory of Open Access Journals (Sweden)

    Hai Viet Vo

    2017-01-01

    Full Text Available Snow-melting pavement technique is an advanced preservation method, which can prevent the forming of snow or ice on the pavement surface by increasing the temperature using an embedded heating system. The main scope of this study is to evaluate the impact of conductive additives on the heating efficiency. The electrical resistivity and thermal conductivity were considered to investigate effects of conductive additives, graphite, and carbon fibers on the snow-melting ability of asphalt mixtures. Also, the distribution of the conductive additives within the asphalt concrete body was investigated by microstructural imaging. An actual test was applied to simulate realistic heating for an asphalt concrete mixture. Thermal testing indicated that graphite and carbon fibers improve the snow-melting ability of asphalt mixes and their combination is more effective than when used alone. As observed in the microstructural image, carbon fibers show a long-range connecting effect among graphite conductive clusters and gather in bundles when added excessively. According to the actual test, adding the conductive additives helps improve snow-melting efficiency by shortening processing time and raising the surface temperature.

  17. Research on Alkaline Filler Flame-Retarded Asphalt Pavement

    Institute of Scientific and Technical Information of China (English)

    HU Shuguang; ZHANG Houji; WANG Jiaolan

    2006-01-01

    Used as flame retardant of tunnel asphalt pavement, organic bromides produce a large amount of poisons and smoke in construction and flame retardation stage. The alkaline filler was found to replace mineral filler, and the flame-retarded asphalt mixtures were produced. Experimental results show that these asphalt mixtures are smoke restrained; the performances and construction technology of asphalt pavement are not influenced; also the alkaline filler is of low-price. So this kind of flame-retarded asphalt mixtures is suitable for tunnel pavement.

  18. 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...

  19. Morphological Algorithms For The Analysis Of Pavement Structure

    Science.gov (United States)

    Grivas, Dimitri A.; Skolnick, Michael M.

    1989-11-01

    The applicability of morphological image processing techniques for the description of condition and analysis of pavement surfaces is examined. Morphological techniques can be used in the measurement of pavement media consisting of grain (aggregates) and binding substances (bituminous or Portland cement mixtures). Measurements of size and size distributions on surface features related to texture and distresses can be obtained via morphological opening and closing transformations and distributions. When correlated with actual physical measurements of such quantities, the presented morphological measures of size and size distributions may prove to be useful in characterizing the surface condition of both asphalt and concrete pavement structures.

  20. Culminating paths

    Directory of Open Access Journals (Sweden)

    Mireille Bousquet-Mélou

    2008-04-01

    Full Text Available Let a and b be two positive integers. A culminating path is a path of ℤ 2 that starts from (0,0, consists of steps (1,a and (1,-b, stays above the x-axis and ends at the highest ordinate it ever reaches. These paths were first encountered in bioinformatics, in the analysis of similarity search algorithms. They are also related to certain models of Lorentzian gravity in theoretical physics. We first show that the language on a two letter alphabet that naturally encodes culminating paths is not context-free. Then, we focus on the enumeration of culminating paths. A step by step approach, combined with the kernel method, provides a closed form expression for the generating function of culminating paths ending at a (generic height k. In the case a = b, we derive from this expression the asymptotic behaviour of the number of culminating paths of length n. When a > b, we obtain the asymptotic behaviour by a simpler argument. When a < b, we only determine the exponential growth of the number of culminating paths. Finally, we study the uniform random generation of culminating paths via various methods. The rejection approach, coupled with a symmetry argument, gives an algorithm that is linear when a ≥ b, with no precomputation stage nor non-linear storage required. The choice of the best algorithm is not as clear when a < b. An elementary recursive approach yields a linear algorithm after a precomputation stage involving O (n 3 arithmetic operations, but we also present some alternatives that may be more efficient in practice.

  1. Pavement-Transportation Computer Assisted Structural Engineering (PCASE) Implementation of the Modified Berggren (ModBerg) Equation for Computing the Frost Penetration Depth within Pavement Structures

    Science.gov (United States)

    2012-04-01

    effects of soil freezing and thawing cycles when designing any structure, in particular pavement structures. Pavements , either rigid or flexible...ER D C/ G SL T R -1 2 -1 5 Pavement -Transportation Computer Assisted Structural Engineering (PCASE) Implementation of the Modified...Berggren (ModBerg) Equation for Computing the Frost Penetration Depth within Pavement Structures G eo te ch n ic al a n d S tr u ct u re s La b or at

  2. Associations between bicycling and carotid arterial stiffness in adolescents

    DEFF Research Database (Denmark)

    Ried-Larsen, M; Grøntved, A; Østergaard, Lars;

    2015-01-01

    The aim of the study was to investigate the associations between bicycling and carotid arterial stiffness, independent of objectively measured moderate-and-vigorous physical activity. This cross-sectional study included 375 adolescents (age 15.7 ± 0.4 years) from the Danish site of the European...... Youth Heart Study. Total frequency of bicycle usage was assessed by self-report, and carotid arterial stiffness was assessed using B-mode ultrasound. After adjusting for pubertal status, body height, and objectively measured physical activity and other personal lifestyle and demographic factors, boys...... modulus [standard beta -0.48 (95% CI -0.91 to -0.06)]. Similar trends were observed when investigating the association between commuter bicycling and carotid arterial stiffness. These associations were not observed in girls. Our observations suggest that increasing bicycling in adolescence may...

  3. On the Skill of Balancing While Riding a Bicycle.

    Science.gov (United States)

    Cain, Stephen M; Ashton-Miller, James A; Perkins, Noel C

    2016-01-01

    Humans have ridden bicycles for over 200 years, yet there are no continuous measures of how skill differs between novice and expert. To address this knowledge gap, we measured the dynamics of human bicycle riding in 14 subjects, half of whom were skilled and half were novice. Each subject rode an instrumented bicycle on training rollers at speeds ranging from 1 to 7 m/s. Steer angle and rate, steer torque, bicycle speed, and bicycle roll angle and rate were measured and steering power calculated. A force platform beneath the roller assembly measured the net force and moment that the bicycle, rider and rollers exerted on the floor, enabling calculations of the lateral positions of the system centers of mass and pressure. Balance performance was quantified by cross-correlating the lateral positions of the centers of mass and pressure. The results show that all riders exhibited similar balance performance at the slowest speed. However at higher speeds, the skilled riders achieved superior balance performance by employing more rider lean control (quantified by cross-correlating rider lean angle and bicycle roll angle) and less steer control (quantified by cross-correlating steer rate and bicycle roll rate) than did novice riders. Skilled riders also used smaller steering control input with less variation (measured by average positive steering power and standard deviations of steer angle and rate) and less rider lean angle variation (measured by the standard deviation of the rider lean angle) independent of speed. We conclude that the reduction in balance control input by skilled riders is not due to reduced balance demands but rather to more effective use of lean control to guide the center of mass via center of pressure movements.

  4. On the Skill of Balancing While Riding a Bicycle.

    Directory of Open Access Journals (Sweden)

    Stephen M Cain

    Full Text Available Humans have ridden bicycles for over 200 years, yet there are no continuous measures of how skill differs between novice and expert. To address this knowledge gap, we measured the dynamics of human bicycle riding in 14 subjects, half of whom were skilled and half were novice. Each subject rode an instrumented bicycle on training rollers at speeds ranging from 1 to 7 m/s. Steer angle and rate, steer torque, bicycle speed, and bicycle roll angle and rate were measured and steering power calculated. A force platform beneath the roller assembly measured the net force and moment that the bicycle, rider and rollers exerted on the floor, enabling calculations of the lateral positions of the system centers of mass and pressure. Balance performance was quantified by cross-correlating the lateral positions of the centers of mass and pressure. The results show that all riders exhibited similar balance performance at the slowest speed. However at higher speeds, the skilled riders achieved superior balance performance by employing more rider lean control (quantified by cross-correlating rider lean angle and bicycle roll angle and less steer control (quantified by cross-correlating steer rate and bicycle roll rate than did novice riders. Skilled riders also used smaller steering control input with less variation (measured by average positive steering power and standard deviations of steer angle and rate and less rider lean angle variation (measured by the standard deviation of the rider lean angle independent of speed. We conclude that the reduction in balance control input by skilled riders is not due to reduced balance demands but rather to more effective use of lean control to guide the center of mass via center of pressure movements.

  5. Cost-Effective Pavement Performance Management of Indiana's Enhanced National Highway System through Strategic Modification of the Pavement Rehabilitation Treatment Trigger Values

    OpenAIRE

    Noureldin, Menna; Fricker, Jon D.; Sinha, Kumares C.

    2015-01-01

    Cost-Effective Pavement Performance Management of Indiana's Enhanced National Highway System through Strategic Modification of the Pavement Rehabilitation Treatment Trigger Values Presented during Session 3: Policy and Funding, moderated by Magdy Mikhail, at the 9th International Conference on Managing Pavement Assets (ICMPA9) in Alexandria, VA. Includes conference paper and PowerPoint slides.

  6. 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.

  7. Applying the health action process approach to bicycle helmet use and evaluating a social marketing campaign.

    Science.gov (United States)

    Karl, Florian M; Smith, Jennifer; Piedt, Shannon; Turcotte, Kate; Pike, Ian

    2017-08-05

    Bicycle injuries are of concern in Canada. Since helmet use was mandated in 1996 in the province of British Columbia, Canada, use has increased and head injuries have decreased. Despite the law, many cyclists do not wear a helmet. Health action process approach (HAPA) model explains intention and behaviour with self-efficacy, risk perception, outcome expectancies and planning constructs. The present study examines the impact of a social marketing campaign on HAPA constructs in the context of bicycle helmet use. A questionnaire was administered to identify factors determining helmet use. Intention to obey the law, and perceived risk of being caught if not obeying the law were included as additional constructs. Path analysis was used to extract the strongest influences on intention and behaviour. The social marketing campaign was evaluated through t-test comparisons after propensity score matching and generalised linear modelling (GLM) were applied to adjust for the same covariates. 400 cyclists aged 25-54 years completed the questionnaire. Self-efficacy and Intention were most predictive of intention to wear a helmet, which, moderated by planning, strongly predicted behaviour. Perceived risk and outcome expectancies had no significant impact on intention. GLM showed that exposure to the campaign was significantly associated with higher values in self-efficacy, intention and bicycle helmet use. Self-efficacy and planning are important points of action for promoting helmet use. Social marketing campaigns that remind people of appropriate preventive action have an impact on behaviour. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

  8. Path Sensitization

    Institute of Scientific and Technical Information of China (English)

    赵著行; 闵应骅; 等

    1997-01-01

    For different delay models,the concept of sensitization can be very different.Traditonal concepts of sensitization cannot precisely describe circuit behavior when the input vectors change very fast.Using Boolean process aporoach,this paper presents a new definition of sensitization for arbitrary input waveforms.By this new concept it is found that if the inputs of a combinational circuit can change at any time,and each gate's delay varies within an interval (bounded gate delay model),then every path,which is not necessarily a single topological path,is sensitizable.From the experimental results it can be seen that,all nonsensitizable paths for traditional concepts actually can propagate transitions along them for some input waveforms.However,specified time between input transitions(STBIT) and minimum permissible pulse width(ε)are two major factors to make some paths non-sensitizable.

  9. [Bicycle spoke-related injuries in children: emphasise prevention].

    Science.gov (United States)

    Kramer, William L M; Haaring, Gert-Jan

    2011-01-01

    Three children, a 6-year-old boy and two girls aged 5 and 4 years, were seen at an emergency department due to distal lower-leg injuries sustained from the spokes of bicycle wheels. All three patients had been passengers on rear carrying seats of moving bicycles. Only the third bicyclist had used a special child safety seat. The second girl had drawn her foot up from underneath a strap and suffered a tibial fracture later treated with an osteosynthetic plate. The other two patients recovered after conservative casting treatment. Bicycle spoke-related injuries are sustained when the foot or lower limb makes contact with the spokes of a bicycle wheel and usually by children who are bicycle passengers. In the Netherlands, approximately 4600 children are seen at emergency departments with such injuries each year. Bicycle spoke-related accidents can cause severe damage that can result in lengthy recovery periods. Not only physical complications but also psychological ones can occur. The latter are often overlooked but do deserve proper treatment. The physician treating a spoke-related injury is in a good position to advice parents as to preventive measures, particularly on the use of special child safety seats.

  10. Test Verification and Design of the Bicycle Frame Parameters

    Institute of Scientific and Technical Information of China (English)

    ZHANG Long; XIANG Zhongxia; LUO Huan; TIAN Guan

    2015-01-01

    Research on design of bicycles is concentrated on mechanism and auto appearance design, however few on matches between the bike and the rider. Since unreasonable human-bike relationship leads to both riders’ worn-out joints and muscle injuries, the design of bicycles should focus on the matching. In order to find the best position of human-bike system, simulation experiments on riding comfort under different riding postures are done with the lifemode software employed to facilitate the cycling process as well as to obtain the best position and the size function of it. With BP neural network and GA, analyzing simulation data, conducting regression analysis of parameters on different heights and bike frames, the equation of best position of human-bike system is gained at last. In addition, after selecting testers, customized bikes based on testers’ height dimensions are produced according to the size function. By analyzing and comparing the experimental data that are collected from testers when riding common bicycles and customized bicycles, it is concluded that customized bicycles are four times even six times as comfortable as common ones. The equation of best position of human-bike system is applied to improve bikes’ function, and the new direction on future design of bicycle frame parameters is presented.

  11. Orthopedic injury in electric bicycle-related collisions.

    Science.gov (United States)

    Li, Xiaoxuan; Yun, Zhe; Li, Xiaoxiang; Wang, Yucai; Yang, Tongtao; Zheng, Lianhe; Qian, Jixian

    2017-05-19

    Although electric bicycle-related injuries have become the most common reason for hospitalization due to a road crash in China, no study has comprehensively investigated electric bicycle collisions and their impact on orthopedic injuries; such a study may provide evidence to support a new road safety policy. A retrospective review of orthopedic injuries from electric bicycle collisions was performed in an urban trauma center. We collected variables including age, gender, location of fracture, presence of open or closed fractures, concomitant vascular, and neurologic injuries. A total of 2,044 cases were involved in electric bicycle collisions. The orthopedic injury victims were predominantly male and middle aged. The most common orthopedic injury was a femur fracture. Open fractures frequently involved the forearm and tibia/fibula. Male patients were more likely to suffer from multiple fractures and associated injuries than female patients. Fewer patients age 60 years old or older wore helmets at the time of the accident compared to those in other age groups. Orthopedic injuries from electric bicycle-related accidents cause patients substantial suffering that could lead to serious social consequences. Helmet use and protective clothing or similar safety gear, especially for electric bicycle users, should be required to provide greater protection.

  12. Bicycle helmet use and non-use - recently published research.

    Science.gov (United States)

    Uibel, Stefanie; Müller, Daniel; Klingelhoefer, Doris; Groneberg, David A

    2012-05-25

    Bicycle traumata are very common and especially neurologic complications lead to disability and death in all stages of the life. This review assembles the most recent findings concerning research in the field of bicycle traumata combined with the factor of bicycle helmet use. The area of bicycle trauma research is by nature multidisciplinary and relevant not only for physicians but also for experts with educational, engineering, judicial, rehabilitative or public health functions. Due to this plurality of global publications and special subjects, short time reviews help to detect recent research directions and provide also information from neighbour disciplines for researchers. It can be stated that to date, that although a huge amount of research has been conducted in this area more studies are needed to evaluate and improve special conditions and needs in different regions, ages, nationalities and to create successful prevention programs of severe head and face injuries while cycling.Focus was explicit the bicycle helmet use, wherefore sledding, ski and snowboard studies were excluded and only one study concerning electric bicycles remained due to similar motion structures within this review. The considered studies were all published between January 2010 and August 2011 and were identified via the online databases Medline PubMed and ISI Web of Science.

  13. Comparative life cycle assessment of ghana-made bamboo-frame bicycle and conventional bicycles assembled and used in the Netherlands

    NARCIS (Netherlands)

    Agyekum, E.O.; Fortuin, K.P.J.; Harst, van der E.J.M.

    2014-01-01

    In order to assess the sustainability of bamboo-framed bicycles produced in Ghana, an environmental and social life cycle assessments (LCA) were performed. For the environmental LCA, a bamboo-frame bicycle was compared with aluminium- and steel-frame bicycles, focussing on processes related to the

  14. Comparative life cycle assessment of ghana-made bamboo-frame bicycle and conventional bicycles assembled and used in the Netherlands

    NARCIS (Netherlands)

    Agyekum, E.O.; Fortuin, K.P.J.; Harst, van der E.J.M.

    2014-01-01

    In order to assess the sustainability of bamboo-framed bicycles produced in Ghana, an environmental and social life cycle assessments (LCA) were performed. For the environmental LCA, a bamboo-frame bicycle was compared with aluminium- and steel-frame bicycles, focussing on processes related to the f

  15. An international review of the frequency of single-bicycle crashes (SBCs) and their relation to bicycle modal share

    DEFF Research Database (Denmark)

    Schepers, Paul; Agerholm, Niels; Amoros, Emmanuelle;

    2015-01-01

    Objectives To study cyclists’ share of transport modes (modal share) and single-bicycle crashes (SBCs) in different countries in order to investigate if the proportion of cyclist injuries resulting from SBCs is affected by variation in modal share. Methods A literature search identified figures...... (largely from western countries) on SBC casualties who are fatally injured, hospitalised or treated at an emergency department. Correlation and regression analyses were used to investigate how bicycle modal share is related to SBCs. Results On average, 17% of fatal injuries to cyclists are caused by SBCs...... of SBC casualties among the total number of road crash casualties increases proportionally less than the increase in bicycle modal share. Conclusions While most fatal injuries among cyclists are due to motor vehicle–bicycle crashes, most hospital admissions and emergency department attendances result...

  16. 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.

  17. Ultra thin continuously reinforced concrete pavement research in south Africa

    CSIR Research Space (South Africa)

    Perrie, BD

    2007-08-01

    Full Text Available Ultra thin continuously reinforced concrete pavements (UTCRCP), in literature also referred to as Ultra Thin Reinforced High Performance Concrete (UTHRHPC), have been used in Europe successfully as a rehabilitation measure on steel bridge decks...

  18. Rehabilitation design of flexible pavements in South Africa.

    CSIR Research Space (South Africa)

    De Beer, Morris

    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...

  19. Fracture in high performance fibre reinforced concrete pavement materials

    CSIR Research Space (South Africa)

    Denneman, E

    2011-05-01

    Full Text Available reliable predictions of the flexural capacity of full size pavement structures, 2.In contrast to the MOR parameter, the fracture mechanics damage models developed as part of this study do provide reliable predictions of the flexural behaviour...

  20. Effect of training algorithms on neural networks aided pavement ...

    African Journals Online (AJOL)

    user

    Department of Civil, Construction, and Environmental Engineering, 354 Town ... Routine pavement maintenance necessitates present structural diagnosis and ... assessment is routinely carried out by engineers from public works, road ...

  1. Forensic analysis of asphaltic pavement failures in Ghana: case histories

    CSIR Research Space (South Africa)

    Ampadu, SIK

    2015-08-01

    Full Text Available Many newly constructed asphaltic pavements in Ghana have suffered premature failures shortly after opening to traffic. In all cases, available records from the road agencies appeared to show that the roads were constructed in accordance...

  2. Overview of the South African mechanistic pavement design analysis method

    CSIR Research Space (South Africa)

    Theyse, HL

    1996-01-01

    Full Text Available cemented material, and deformation of selected and subgrade material. The critical parameters and transfer functions for these material types and modes of failure are discussed and included in the pavement life prediction process....

  3. Long-Term Field Performance of Pervious Concrete Pavement

    Directory of Open Access Journals (Sweden)

    Aleksandra Radlińska

    2012-01-01

    Full Text Available The work described in this paper provides an evaluation of an aged pervious concrete pavement in the Northeastern United States to provide a better understanding of the long-lasting effects of placement techniques as well as the long-term field performance of porous pavement, specifically in areas susceptible to freezing and thawing. Multiple samples were taken from the existing pavement and were examined in terms of porosity and unit weight, compressive and splitting tensile strength, and the depth and degree of clogging. It was concluded that improper placement and curing led to uneven pavement thickness, irregular pore distribution within the pervious concrete, and highly variable strength values across the site, as well as sealed surfaces that prevented infiltration.

  4. Development of probabilistic rigid pavement design methodologies for military airfields

    Science.gov (United States)

    Witczak, M. W.; Uzan, J.; Johnson, M.

    1983-12-01

    The current Corps of Engineers design procedures for rigid airfield pavements is based on the Westergaard free edge stress slab theory, and a proposed procedure is based on the multilayer elastic theory. These two design procedures have been expanded to airfield pavement designs expressed in probabilistic and reliability terms. Further developments were required in these procedures to make the analysis more practicable. Two major investigations were conducted: (1) Evaluation and use of the composite modulus of elasticity for layers beneath the rigid pavement, and (2) Evaluation of the maximum tensile stress at the bottom of the slab for different aircraft types. Derivations obtained from the investigation of the composite modulus and maximum tensile stress are reported and are included in computer programs for probabilistic/reliability analysis of rigid pavements. The approximate closed form (Taylor series expansion) is utilized. Example runs of the computer program are presented.

  5. Striated clast pavements: Products of deforming subglacial sediment?

    Science.gov (United States)

    Clark, Peter U.

    1991-05-01

    Studies of modern glaciers have recently drawn attention to the importance of subglacial sediment deformation to glacier dynamics and processes. Inferences regarding the probable shear strength of this sediment imply that large clasts may in some cases sink to underlying rigid sediment, where abrasion by overlying deforming sediment could occur. This scenario provides a formative mechanism for striated clast pavements commonly described from the base of fine-grained massive diamictons associated with the late Pleistocene Laurentide ice sheet. Such a mechanism indicates that, at the time of formation of clast pavements, overlying diamictons associated with pavements had a low yield strength (≤0.5 kPa) and were deforming mechanically like a debris flow. Clast pavements may therefore be an important criterion for recognition of sediments deposited by subglacial deformation transport.

  6. Nondestructive evaluation of load transfer at rigid airport pavement joints

    Science.gov (United States)

    Hammons, Michael I.

    1995-07-01

    Current design criteria for rigid pavements for commercial and military airfields assume that 25% of the load applied to an edge of a slab is transferred through the joint to an adjacent unloaded slab. A nondestructive testing technique using a falling weight deflectometer (FWD) was used to conduct field testing at a number of sites. A transfer function, developed from an analytical study, was used to estimate load transfer from the measured joint efficiency as a function of the loaded area and the radius of relative stiffness of the pavement. This procedure, although analytically sound, lacks actual field verification at an instrumented pavement site. This procedure was used to estimate load transfer at a number of commercial and military airfields for a variety of joint types, climate conditions, and pavement structures. The results of these tests indicate that the assumption of load transfer as a constant value of 25% appears to be unconservative, especially during the winter months.

  7. Effect of Pavement Conditions on Rolling Resistance

    Directory of Open Access Journals (Sweden)

    Mr.Dipanjan Mukherjee

    2014-07-01

    Full Text Available Rolling resistance is the force acting on a vehicle over a full journey. It is generated by the hysteresis of tyre and pavement. Rolling resistance, sometimes called rolling friction or rolling drag, is the force resisting the motion when a body (such as a ball, tire, or wheel rolls on a surface. It is mainly caused by non-elastic effects; that is, not all the energy needed for deformation (or movement of the wheel, roadbed, etc. is recovered when the pressure is removed. A hysteresis phenomenon can be observed when viscoelastic materials undergo a load-then-unload process. A typical hysteresis curve of viscoelastic material can be found. The shadow area enclosed by the hysteresis loop represents energy loss. A characteristic of a deformable material such that the energy of deformation is greater than the energy of recovery. The rubber compound in a tire exhibits hysteresis. As the tire rotates under the weight of the vehicle, it experiences repeated cycles of deformation and recovery, and it dissipates the hysteresis energy loss as heat. Hysteresis is the main cause of energy loss associated with rolling resistance and is attributed to the viscoelastic characteristics of the rubber. Materials that have a large hysteresis effect, such as rubber, which bounce back slowly, exhibit more rolling resistance than materials with a small hysteresis effect that bounce back more quickly and more completely, such as steel or silica. Low rolling resistance tires typically incorporate silica in place of carbon black in their tread compounds to reduce low-frequency hysteresis without compromising traction. Note that railroads also have hysteresis in the roadbed structure. Like the fuel consumption, rolling resistance also has a significant relationship with velocity. experiment has shown that, for a 32-tonn goods vehicle, rolling resistance contributes about 70% of total drag when driven at 50km/h and about 37% at 100km/h. An important issue which should not

  8. Low temperature influence in the predicted of pavement overlay

    OpenAIRE

    Minhoto, Manuel; Pais, Jorge; Pereira, Paulo; Picado-Santos, Luís

    2003-01-01

    This paper describes a study of the influence of temperature variation in the pavement overlay life, using finite-element methodology that considers the most predominant type of overlay distress observed in the field: the reflective cracking. The temperature variation has a significant influence on thermally induced stresses that, in turn, affects the overlay predictive service life. This paper presents a three-dimensional (3D) finite element analysis used to predict the pavement overlay life...

  9. 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.

  10. Ground Penetrating Radar Assessment of Flexible Road Pavement Degradation

    OpenAIRE

    Sandro Colagrande; Danilo Ranalli; Marco Tallini

    2011-01-01

    GPR investigations were used to study degraded road pavements built in cutting sections. Road integrity was assessed via quantitative analysis of power curves. 1600 MHz and 600 MHz radar sections were collected in 40 damaged and undamaged road pavement sites. The collected data were processed as follows: (i) linearisation with regression analysis of power curves; (ii) assessment of absorption angle α′ which is directly proportional to absorption coefficient α (this was obtained by setting t...

  11. Field environmental evaluation plan for sulfur use in pavements

    Science.gov (United States)

    Saylak, D.; Deuel, L. E.; Izatt, J. O.; Jacobs, C.; Zahray, R.; Ham, S.

    1982-07-01

    The use of sulfur in highway paving mixtures is discussed. The evaluation procedures deal with the safety and environmental aspects of storage and handling, formulation, construction, operation and maintenance of highway pavements containing sulfur, including the possible generation of noxious and abnoxious fumes, dust and gases. Methods and equipment for monitoring potential emissions and pollutants are recommended and safety practices for the handling of sulfur and sulfur-modified asphalt mixtures and pavements are discussed.

  12. Advanced Construction Material for Airfield Pavements and Rapid Runway Repair

    Science.gov (United States)

    1990-12-01

    AIRFIELD PAVEMENTS AND RAPID RUNWAY REPAIR by Vincent Maurice Saroni, B.S.C.E. and David W. Fowler, Ph.D., P.E. T. U. Taylor Professor in...to my family, Betsy and Mark. ADVANCED CONSTRUCTION MATERIAL FOR AIRFIELD PAVEMENTS AND RAPID RUNWAY REPAIR Vincent Maurice Saroni, B.S.C.E. THESIS...85 C.4 Calculation Results of Modulus of Rupture, Density and Percent Voids for Uncompacted Siliceous G ravel

  13. Research of cost aspects of cement pavements construction

    Science.gov (United States)

    Bezuglyi, Artem; Illiash, Sergii; Tymoshchuk, Oleksandr

    2017-09-01

    The tendency to increasing traffic volume on public roads and to increased axle loads of vehicles makes the road scientists to develop scientifically justified methods for preserving the existing and developing the new transport network of Ukraine. One of the options for solving such issues is the construction of roads with rigid (cement concrete) pavement. However, any solution must be justified considering technical and economic components. This paper presents the results of the research of cost aspects of cement pavements construction.

  14. Bicycle, city and education: search moves

    Directory of Open Access Journals (Sweden)

    Sheila Hempkemeyer

    2016-07-01

    Full Text Available This study comes from a Master’s degree in Education research, which investigates narratives of “pedaling beings” starting from the relationship bicycle-city. The theoretical assumptions lean on the Cultural Studies and concepts about education, culture, everyday life, experience and narratives. Researching with narratives closes everyday life and promotes co-authorship to the subjects in the paper. The article puts in discussion some forms of contemporary subjectivity, resistance techniques and expression. A study that builds narratives and reflections about the experiences of theses hybrid subjects and their everyday life, questioning their way of life in the city. Thinking in this urban medley is connect the environment and the dynamic of these pedaling bodies, emerging other ways of education and interaction with the medium, weaving multiple affectations in aesthetics, poetry, politics, opening breaches to reflect in the everyday happenings. The article also discusses the movements in research and the effects in those who research and are researched.

  15. Bicycle infrastructure: can good design encourage cycling?

    Directory of Open Access Journals (Sweden)

    Angela Hull

    2014-01-01

    Full Text Available This research posits the question that good design of the bicycle infrastructure in a city will encourage more people to cycle. Research is carried out to compare the cycle infrastructure in selected European cities against an adapted Level of Service concept using accompanied ride-alongs. The literature review on the factors that encourage/dissuade cycle use suggests that it is the potential rider’s perceptions on the safety of cycling in their neighbourhood that is the deciding feature. Moreover, the literature review showed that contextual factors such as whether the actual infrastructure meets the needs of different cyclists are relatively under-researched. Six case study cities were selected (Edinburgh, Cambridge, Amsterdam, Rotterdam, The Hague, Utrecht and compared on a range of factors by the riders including the coherence, directness, attractiveness, safety and comfort of the network. A cycle infrastructure scoring system was derived from the cycling research literature and the research was carried out by the researcher, an experienced cyclist, accompanied by an inexperienced cyclist. Using this research, the article makes several recommendations for improving and enhancing existing cycle infrastructure provision.

  16. Analysis of EMG measurements during bicycle pedalling.

    Science.gov (United States)

    Jorge, M; Hull, M L

    1986-01-01

    Activity of eight leg muscles has been monitored for six test subjects while pedalling a bicycle on rollers in the laboratory. Each electromyogram (EMG) data channel was digitized at a sampling rate of 2 kHz by a minicomputer. Data analysis entailed generating plots of both EMG activity regions and integrated EMG (IEMG). For each test subject, data were recorded for five cases of pedalling conditions. The different pedalling conditions were defined to explore a variety of research hypotheses. This exploration has led to the following conclusions: Muscular activity levels of the quadriceps are influenced by the type of shoes worn and activity levels increase with soft sole shoes as opposed to cycling shoes with cleats and toeclips. EMG activity patterns are not strongly related to pedalling conditions (i.e. load, seat height and shoe type). The level of muscle activity, however, is significantly affected by pedalling conditions. Muscular activity bears a complex relationship with seat height and quadriceps activity level decreases with greater seat height. Agonist (i.e. hamstrings) and antagonist (i.e. quadriceps) muscles of the hip/knee are active simultaneously during leg extension. Regions of peak activity levels, however, do not overlap. The lack of significant cocontraction of agonist/antagonist muscles enables muscle forces during pedalling action to be computed by solving a series of equilibrium problems over different regions of the crank cycle. Regions are defined and a solution procedure is outlined.

  17. Pavement Response to Variable Tyre Pressure of Heavy Vehicles

    Directory of Open Access Journals (Sweden)

    Arshad Ahmad Kamil

    2016-01-01

    Full Text Available In recent years, the effect of overinflated tyre pressure and increased heavy vehicles’ axle load on flexible pavements has become a subject of great concern because of the higher stress levels induced and damage caused to road pavements. This paper aims to evaluate the effect of variable tyre inflation pressures (using actual tyre contact/footprint area to determine the responses of flexible pavement. A full scale experiment was conducted on a heavy vehicle with 1:1:2 axle configuration, 10 R 20 tyre size and attached trailer with constant axle load. Measurements were made for actual tyre-pavement contact area. KENPAVE linear elastic program was then used to analyse the effects of the measured actual tyre-pavement contact area and the results was compared using conventional circular tyre contact area. A comparative analysis was then made between the actual contact area and the conventional circular tyre contact area. It was found that high tyre inflation pressure produce smaller contact area, giving more detrimental effect on the flexible pavement. It was also found that the temperature of tyres when the heavy vehicles are operational give less significant impact on tyre inflation pressure for the Malaysian climate.

  18. Numerical Analysis of Asphalt Pavements under Moving Wheel Loads

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    The responses of the pavement in service are the basis for the design of the semi-rigid base course asphalt pavement.Due to the dynamic characteristics of wheel loads and the temperature loads,the dynamic response analysis is very significant.In this article, the dynamic analysis of asphalt pavement under moving wheel loads is carried out using finite element method coupled with non-reflective boundary method.The influences of the base modulus, thickness, the vehicle velocity, the tire pressure, and the contact condition at the interface are studied using parametric analysis.The results of numerical analysis show that it is not appropriate to simply increase the base modulus or thickness in the design.It would be beneficial if the base design is optimized synthetically.The increase of damping is also beneficial to the pavements because of the surface deflection and the stresses declination.Furthermore, the good contact condition at the interface results in good performance because it combines every layer of the pavement to work together.As overload aggravates the working condition of the pavement, it is not allowed.

  19. Development of New Bituminous Pavement Design Method

    DEFF Research Database (Denmark)

    Ullidtz, Per

    The report and work of COST Action 333 sets in place the foundation for a coherent, cost-effective and harmonised European pavement design method. In order to do this, the work programme focused on information gathering, identification of requirements and the selection of the necessary design...... elements for such a European design method. During the course of the Action, 20 countries signed the Memorandum of Understanding and participated in the work, thus showing a very high level of interest in the work programme and results.The document contains a very thorough review of the position in Europe...... at the present time and identifies the basic framework for a design method. It then clearly shows the necessary steps to be taken in the future in order to arrive at a method based on current best practice in the shorter term, and then to move to improved versions....

  20. Latex improvement of recycled asphalt pavement

    Science.gov (United States)

    Drennon, C.

    1982-08-01

    The performance of a single unmodified milled recycled asphalt concrete was compared to milled asphalt concrete modified by addition of three types of rubber latex. Latex was added at 2, 3, 5, and 8 percent latex by weight of asphalt in the asphalt concrete. Lattices used were a styrene butadiene (SBR), a natural rubber (NR), an acrylonitrile butadiene (NBR), and four varieties of out of specification SBR lattices. Marshall tests, while indecisive, showed a modest improvement in properties of SBR and NR added material at 3 and 5 percent latex. Addition of NBR latex caused deterioration in Marshall stability and flow over that of control. Repeated load tests were run using the indirect tensile test, analyzed by the VESYS program, which computes life of pavements. Repeated load tests showed improvement in asphalt concrete life when 3 and 5 percent SBR was added. Improvement was also shown by the out of specification SBR.

  1. Design and Analysis of a Novel Speed-Changing Wheel Hub with an Integrated Electric Motor for Electric Bicycles

    Directory of Open Access Journals (Sweden)

    Yi-Chang Wu

    2013-01-01

    Full Text Available The aim of this paper is to present an innovative electromechanical device which integrates a brushless DC (BLDC hub motor with a speed-changing wheel hub stored on the rear wheel of an electric bicycle. It combines a power source and a speed-changing mechanism to simultaneously provide functions of power generation and transmission for electric bicycles. As part of the proposed integrated device, the wheel hub consists of a basic planetary gear train providing three forward speeds including a low-speed gear, a direct drive, and a high-speed gear. Each gear is manually controlled by the shift control sleeve to selectively engage or disengage four pawl-and-ratchet clutches based on its clutching sequence table. The number of gear teeth of each gear element of the wheel hub is synthesized. The BLDC hub motor is an exterior-rotor-type permanent-magnet synchronous motor. Two-dimensional finite-element analysis (FEA software is employed to facilitate the motor design and performance analysis. An analysis of the power transmission path at each gear is provided to verify the validity of the proposed design. The results of this work are beneficial to the embodiment, design, and development of novel electromechanical devices for the power and transmission systems of electric bicycles.

  2. Grout Impregnation of Pre-Placed Recycled Concrete Pavement (RCP) for Rapid Repair of Deteriorated Portland Cement Concrete Airfield Pavement

    Science.gov (United States)

    2007-04-01

    Hammitt (1985) also reports a high failure rate when using cold mix asphalt for crater repairs and recommended that it be abandoned as a technique...cement-treated base, embankment base material, and aggregate for asphalt paving mixtures . RCP has been used successfully for all of these types of...that recycled asphalt pavement ( RAP ) and RCP have a substantial history of usage in pavement construction. He reports that cost savings of 20 to

  3. Reviving a ghost in the history of technology: the social construction of the recumbent bicycle.

    Science.gov (United States)

    Ahmed, Hassaan; Qureshi, Omer Masood; Khan, Abid Ali

    2015-02-01

    Recumbent bicycles have never truly been associated with international cycling. Conventional safety (upright) bicycles have long been at the center of the cycling world, for both sport and transportation. This is despite the fact that recumbent bicycles are faster, more comfortable, and more efficient than the upright bicycles. The aim of this article is to explain the historical and social perspectives that led to the rejection of the recumbent bicycle by utilizing the theory of Social Construction of Technology (SCOT) and Bijker's two power theory, providing a contrast with the adoption of the safety bicycle.

  4. Built environment influences on healthy transportation choices: bicycling versus driving.

    Science.gov (United States)

    Winters, Meghan; Brauer, Michael; Setton, Eleanor M; Teschke, Kay

    2010-12-01

    A growing body of evidence links the built environment to physical activity levels, health outcomes, and transportation behaviors. However, little of this research has focused on cycling, a sustainable transportation option with great potential for growth in North America. This study examines associations between decisions to bicycle (versus drive) and the built environment, with explicit consideration of three different spatial zones that may be relevant in travel behavior: trip origins, trip destinations, and along the route between. We analyzed 3,280 utilitarian bicycle and car trips in Metro Vancouver, Canada made by 1,902 adults, including both current and potential cyclists. Objective measures were developed for built environment characteristics related to the physical environment, land use patterns, the road network, and bicycle-specific facilities. Multilevel logistic regression was used to model the likelihood that a trip was made by bicycle, adjusting for trip distance and personal demographics. Separate models were constructed for each spatial zone, and a global model examined the relative influence of the three zones. In total, 31% (1,023 out of 3,280) of trips were made by bicycle. Increased odds of bicycling were associated with less hilliness; higher intersection density; less highways and arterials; presence of bicycle signage, traffic calming, and cyclist-activated traffic lights; more neighborhood commercial, educational, and industrial land uses; greater land use mix; and higher population density. Different factors were important within each spatial zone. Overall, the characteristics of routes were more influential than origin or destination characteristics. These findings indicate that the built environment has a significant influence on healthy travel decisions, and spatial context is important. Future research should explicitly consider relevant spatial zones when investigating the relationship between physical activity and urban form.

  5. 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.

  6. Path Dependence

    DEFF Research Database (Denmark)

    Madsen, Mogens Ove

    Begrebet Path Dependence blev oprindelig udviklet inden for New Institutionel Economics af bl.a. David, Arthur og North. Begrebet har spredt sig vidt i samfundsvidenskaberne og undergået en udvikling. Dette paper propagerer for at der er sket så en så omfattende udvikling af begrebet, at man nu kan...... tale om 1. og 2. generation af Path Dependence begrebet. Den nyeste udvikling af begrebet har relevans for metodologi-diskusionerne i relation til Keynes...

  7. Private and public modes of bicycle commuting: a perspective on attitude and perception.

    Science.gov (United States)

    Curto, A; de Nazelle, A; Donaire-Gonzalez, D; Cole-Hunter, T; Garcia-Aymerich, J; Martínez, D; Anaya, E; Rodríguez, D; Jerrett, M; Nieuwenhuijsen, M J

    2016-08-01

    Public bicycle-sharing initiatives can act as health enhancement strategies among urban populations. The aim of the study was to determine which attitudes and perceptions of behavioural control toward cycling and a bicycle-sharing system distinguish commuters with a different adherence to bicycle commuting.  The recruitment process was conducted in 40 random points in Barcelona from 2011 to 2012. Subjects completed a telephone-based questionnaire including 27 attitude and perception statements. Based on their most common one-way commute trip and willingness to commute by bicycle, subjects were classified into Private Bicycle (PB), public bicycle or Bicing Bicycle (BB), Willing Non-bicycle (WN) and Non-willing Non-bicycle (NN) commuters. After reducing the survey statements through principal component analysis, a multinomial logistic regression model was obtained to evaluate associations between attitudinal and commuter sub-groups.  We included 814 adults in the analysis [51.6% female, mean (SD): age 36.6 (10.3) years]. BB commuters were 2.0 times [95% confidence interval (CI) = 1.1-3.7] less likely to perceive bicycle as a quick, flexible and enjoyable mode compared to PB. BB, WN and NN were 2.5 (95% CI = 1.46-4.24), 2.6 (95% CI = 1.53-4.41) and 2.3 times (95% CI = 1.30-4.10) more likely to perceive benefits of using public bicycles (bicycle maintenance and parking avoidance, low cost and no worries about theft and vandalism) than did PB.  Willing non-bicycle and public-bicycle commuters had more favourable perception toward public-shared bicycles compared to private cyclists. Hence, public bicycles may be the impetus for those willing to start bicycle commuting, thereby increasing physical activity levels. © The Author 2016. Published by Oxford University Press on behalf of the European Public Health Association. All rights reserved.

  8. [E-bikers are more often seriously injured in bicycle accidents: results from the Groningen bicycle accident database].

    Science.gov (United States)

    Poos, H P A M; Lefarth, T L; Harbers, J S; Wendt, K W; El Moumni, M; Reininga, I H F

    2017-01-01

    Analysing injury types, injury severity and mortality in victims of accidents with electric bicycles in comparison with conventional bicycles. Prospective cohort study. Data of patients treated at the Accident & Emergency Department of the University Medical Center Groningen after a bicycle accident are being entered in a database since 2014. We have analysed this database for accidents with electric bicycles (e-bikes) and conventional bicycles occurring among adult patients for the period of July 2014 to May 2016. 'Propensity score matching' was used to match e-bikers to conventional cyclists, based on age, gender and the presence of comorbidities. 107 of the 475 included victims were riding an e-bike. Average age of e-bikers and conventional cyclists was 65 years and 39 years respectively. Comorbidity was more common in e-bikers. E-bikers were injured significantly more severely than conventional cyclists. They had more severe injuries of the head and face, and upper and lower extremities. E-bikers were also admitted to the hospital more often, and for longer periods, and they underwent surgery more often. Mortality was the same. Propensity score matching revealed that e-bikers had multiple severe injuries (ISS > 15) twice as often as conventional cyclists, that they had more severe head injuries and were admitted for longer periods than conventional cyclists. E-bikers who had a bicycle accident had more severe injuries, more frequently had multiple injuries and had more severe head injuries than conventional cyclists. This resulted in a greater need for care. Preventive measures such as riding lessons and helmet use should be encouraged. Care providers should pay extra attention to the possibility of severe injuries when a patient had a bicycle accident with an e-bike.

  9. How similar are two-unit bicycle and motorcycle crashes?

    Science.gov (United States)

    Haworth, Narelle; Debnath, Ashim Kumar

    2013-09-01

    This paper explores the similarities and differences between bicycle and motorcycle crashes with other motor vehicles. If similar treatments can be effective for both bicycle and motorcycle crashes, then greater benefits in terms of crash costs saved may be possible for the same investment in treatments. To reduce the biases associated with under-reporting of these crashes to police, property damage and minor injury crashes were excluded. The most common crash type for both bicycles (31.1%) and motorcycles (24.5%) was intersection from adjacent approaches. Drivers of other vehicles were coded most at fault in the majority of two-unit bicycle (57.0%) and motorcycle crashes (62.7%). The crash types, patterns of fault and factors affecting fault were generally similar for bicycle and motorcycle crashes. This confirms the need to combat the factors contributing to failure of other drivers to yield right of way to two-wheelers, and suggest that some of these actions should prove beneficial to the safety of both motorized and non-motorized two-wheelers. In contrast, child bicyclists were more often at fault, particularly in crashes involving a vehicle leaving the driveway or footpath. The greater reporting of violations by riders and drivers in motorcycle crashes also deserves further investigation.

  10. Update to Permeable Pavement Research at the Edison Environmental Center - proceedings

    Science.gov (United States)

    The EPA’s Urban Watershed Management Branch (UWMB) has been monitoring the permeable pavement demonstration site at the Edison Environmental Center, NJ since 2010. This site has three different types of permeable pavements including interlocking concrete permeable pavers, p...

  11. STUDY ON FLOOD CONTROL PROPERTIES OF PERMEABLE PAVEMENT USING SATURATED-UNSATURATED SEEPAGE ANALYSIS

    Science.gov (United States)

    Yano, Takao; Nishiyama, Satoshi; Ohnishi, Yuzo; Nakashima, Shinichiro; Moriishi, Kazushi; Wada, Minoru

    The rainfall storage and infiltration facility of permeable pavement have been attracted attention as a control measure of flood and an environmental improvement measure in urban areas. However, rainfall infiltration of permeable pavement is unsteady flow and strongly dependent on the behavior of unsaturated zones in the pavement. Moreover, the wet condition of subbase course also has a great influence on the rainfall infiltration of the pavement. That's why previous studies have not made clear the precise the facility of permeable pavement as a flood control. In this paper, experimental studies and simulated analyses were performed to measure the overflow from the pavement under various conditions of rainfall intensities and estimate the rainfall infiltration of the pavement using the measurement data and unsaturated infiltration characteristics of porous asphalt materials. It is clear that this study shows the methods to have a quantitative estimation of the rainfall storage and infiltration facility of permeable pavement.

  12. Top-down cracking of rigid pavements constructed with fast setting hydraulic cement concrete

    CSIR Research Space (South Africa)

    Heath, AC

    2009-01-29

    Full Text Available Jointed plain concrete pavement (JPCP) test sections were constructed using fast setting hydrualic cement concrete (FSHCC) as part of the California accelerated pavement testing program (CAL/APT). Many of the longer slabs cracked under environmental...

  13. Influence of Cracks on the Lifetime of Semi-Rigid Pavements

    Science.gov (United States)

    Kazimierowicz-Frankowska, Krystyna

    2016-12-01

    This paper focuses on a better understanding of the process of reflective cracking propagation through the pavement structure. A series of finite element numerical simulations were conducted to investigate the initial stress and strain states in typical semi-rigid pavements with and without reflective cracks under traffic loading. It was assumed that reflective-cracks propagate from the base layer to the pavement surface. The influence of selected parameters, such as the load position, overlay thickness, and subgrade quality on stress and strain concentrations was investigated. The behaviour of the pavement structure under repeated traffic loading was analyzed in terms of ground compaction. The original theoretical model proposed by Prof. Andrzej Sawicki was used to predict the deformation of a pavement subgrade subjected to traffic loading. The damaging effect of cracks appearing in the pavement structure was investigated. It was found that even a single crack in the pavement structure may significantly reduce the pavement lifetime.

  14. Sound Absorption and Friction Properties of Nano-Lotus Leaf Coated Concrete for Rigid Pavement

    National Research Council Canada - National Science Library

    GONZALEZ, Marcelo; SAFIUDDIN, Md; CAO, Jingwen; TIGHE, Susan

    2016-01-01

    ... for application in rigid pavements. The study involved an evaluation of nanomaterials at the laboratory scale to analyze the effects of microtexture modification on the friction and sound absorption of concrete pavement...

  15. 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.

  16. Moisture Influence on Structural Behaviour of Pavements : Field and Laboratory Investigations

    OpenAIRE

    Salour, Farhad

    2015-01-01

    The structural behaviour of pavements in cold regions can considerably be affected by seasonal variation in environmental factors such as temperature and moisture content. Along with the destructive effect of heavy traffic loads, climatic and environmental factors can considerably contribute to pavement deterioration. These factors can influence the structural and functional capacity of the pavement structures which, as a result, can trigger and accelerate pavement deterioration mechanisms. S...

  17. Implementation of the AASHTO pavement design procedures into MULTI-PAVE.

    OpenAIRE

    Bekele, Abiy

    2011-01-01

    This thesis implements the empirical pavement design procedures for flexible as well as rigid pavement by American Association of State Highways and Transportation Officials (AASHTO) into two MATLAB modules of MULTI-PAVE. MULTI-PAVE was developed as a teaching tool that performs pavement thickness design for multiple design procedures using a common input file and a common output format. The AASHTO components were developed in accordance with the 1993 AASHTO Pavement Design Guide, and verifie...

  18. Some advances/results in monitoring road cracks from 2D pavement images within the scope of the collaborative FP7 TRIMM project

    Science.gov (United States)

    Baltazart, Vincent; Moliard, Jean-Marc; Amhaz, Rabih; Wright, Dean; Jethwa, Manish

    2015-04-01

    Monitoring road surface conditions is an important issue in many countries. Several projects have looked into this issue in recent years, including TRIMM 2011-2014. The objective of such projects has been to detect surface distresses, like cracking, raveling and water ponding, in order to plan effective road maintenance and to afford a better sustainability of the pavement. The monitoring of cracking conventionally focuses on open cracks on the surface of the pavement, as opposed to reflexive cracks embedded in the pavement materials. For monitoring surface condition, in situ human visual inspection has been gradually replaced by automatic image data collection at traffic speed. Off-line image processing techniques have been developed for monitoring surface condition in support of human visual control. Full automation of crack monitoring has been approached with caution, and depends on a proper manual assessment of the performance. This work firstly presents some aspects of the current state of monitoring that have been reported so far in the literature and in previous projects: imaging technology and image processing techniques. Then, the work presents the two image processing techniques that have been developed within the scope of the TRIMM project to automatically detect pavement cracking from images. The first technique is a heuristic approach (HA) based on the search for gradient within the image. It was originally developed to process pavement images from the French imaging device, Aigle-RN. The second technique, the Minimal Path Selection (MPS) method, has been developed within an ongoing PhD work at IFSTTAR. The proposed new technique provides a fine and accurate segmentation of the crack pattern along with the estimation of the crack width. HA has been assessed against the field data collection provided by Yotta and TRL with the imaging device Tempest 2. The performance assessment has been threefold: first it was performed against the reference data set

  19. Index of /data/knapsack-bicycle [Life Science Database Archive metadata

    Lifescience Database Archive (English)

    Full Text Available Index of /data/knapsack-bicycle Name Last modified Size Description Parent Director...y - 20140516/ 16-May-2014 10:03 - LATEST/ 16-May-2014 10:03 - Index of /data/knapsack-bicycle ...

  20. Electric-bicycle-related injury: a rising traffic injury burden in China.

    Science.gov (United States)

    Feng, Zhiying; Raghuwanshi, Rakesh P; Xu, Zigang; Huang, Dayong; Zhang, Chong; Jin, Tao

    2010-12-01

    To examine the rising casualty rate related to electric bicycle usage. Analysis of the Hangzhou Police Bureau's data on electric-bicycle-related injuries and deaths. Hangzhou, China, 2004-2008. PATIENTS OR SUBJECTS: Electric-bicycle riders. Electric-bicycle-related casualty rates in Hangzhou from 2004 to 2008. There was a significant average annual increase in electric-bicycle-related casualty rates of 2.7 per 100,000 population (95% CI 1.5 to 3.9, p=0.005). At the same time, overall road traffic and manual-bicycle-related deaths and injuries decreased. As it is difficult to ban the use of electric bicycles in China, laws, rules and regulations need to be reinforced and strengthened. New regulations should be created for the safety of electric bicycle riders and others on the road, and mandatory helmet use should be considered.

  1. Interventions in Bicycle Infrastructure, Lessons from Dutch and Danish Cases

    DEFF Research Database (Denmark)

    van Goeverden, K.; Nielsen, Thomas Alexander Sick; Harder, Henrik

    2015-01-01

    Today the interest in cycling is increasing worldwide and in many countries authorities are faced with the question how cycling can be promoted efficiently. In the Netherlands and Denmark, this question came up already in the 1970s when the downsides of the rapidly increasing motorisation became...... evident. At the time, in both countries large scale interventions in bicycle infrastructure were introduced and evaluated extensively in order to create knowledge on efficient promoting of cycling in urban areas. The interventions included the construction of new bicycle routes on urban arterials in some...... to be still generally valid. In addition to studies that traditionally focus on dedicated bicycle infrastructure, two cases of shared space are discussed, a rather new type of intervention that assumes mixed use of infrastructure. One case is from Denmark, the other from the Netherlands. The paper will so...

  2. Use and activity levels on newly built bicycle playgrounds

    DEFF Research Database (Denmark)

    Schipperijn, Jasper; Hansen, Christine Kier; Rask, Simon

    2015-01-01

    Increasing the use of urban green space (UGS) as well as increasing cycling could potentially help address the growing inactivity problem. Three bicycle playgrounds were designed based on a participatory process and afterwards constructed in the UGS along a cycle-route on the historic outer defence...... circle around the City of Copenhagen, the Copenhagen Fortifications. The concept of a bicycle playground is new, and to examine how the three areas were used, and explore how users experience the areas, this study was designed as a combination of systematic observations, using the System for Observing...... Play and Recreation in Communities (SOPARC), and short on-site interviews with ‘typical users’. Based on the structural observations and 12 short interviews it became clear that 63% of the users were active during their use. The bicycle playgrounds main users were teenagers and children, especially...

  3. Bicycling to Work and Primordial Prevention of Cardiovascular Risk

    DEFF Research Database (Denmark)

    Grøntved, Anders; Koivula, Robert W; Johansson, Ingegerd

    2016-01-01

    BACKGROUND: Bicycling to work may be a viable approach for achieving physical activity that provides cardiovascular health benefits. In this study we investigated the relationship of bicycling to work with incidence of obesity, hypertension, hypertriglyceridemia, and impaired glucose tolerance...... across a decade of follow-up in middle-aged men and women. METHODS AND RESULTS: We followed 23 732 Swedish men and women with a mean age of 43.5 years at baseline who attended a health examination twice during a 10-year period (1990-2011). In multivariable adjusted models we calculated the odds......% CI 0.74-0.91) compared with participants not cycling to work at both times points or who switched from cycling to other modes of transport during follow-up. CONCLUSIONS: These data suggest that commuting by bicycle to work is an important strategy for primordial prevention of clinical cardiovascular...

  4. Predicting Public Bicycle Adoption Using the Technology Acceptance Model

    Directory of Open Access Journals (Sweden)

    Benjamin T. Hazen

    2015-10-01

    Full Text Available Bicycle sharing programs provide a sustainable mode of urban transportation. Although cities across the globe have developed these systems for their citizens and visitors, usage rates are not as high as anticipated. This research uses the technology acceptance model as the basis to understand one’s intention to adopt bicycle sharing programs. Using survey data derived from 421 participants in Beijing, China, the proposed covariance-based structural equation model consisting of perceived quality, perceived convenience, and perceived value is found to predict 50.5% of the variance in adoption intention. The findings of this research contribute to theory and practice in the burgeoning literature on public bicycle systems and sustainable urban transportation by offering a theoretical lens through which to consider system adoption, and providing information to practitioners as to what factors might contribute most to adoption.

  5. Towards using tire-road contact stresses in pavement design and analysis

    CSIR Research Space (South Africa)

    De Beer, Morris

    2011-09-01

    Full Text Available pavement design. Four different tire models were used to represent a single tire type in order to demonstrate its effect on road pavement response of a typical South African pavement structure. Only applied vertical stress was used for the analyses...

  6. Effects of moving dynamic tyre loads on tyre-pavement contact stresses

    CSIR Research Space (South Africa)

    Steyn, WJvdM

    2002-01-01

    Full Text Available The purpose of this paper is to indicate the effect that moving dynamic tyre loads has on the tyre-pavement contact stresses used in pavement analysis. Traditionally tyre loads (in pavement analysis) are modelled as constant loads applied through...

  7. Development of ground-penetrating radar equipment for detecting pavement condition for preventive maintenance

    Science.gov (United States)

    Smith, S. S.; Scuillion, T.

    1993-10-01

    The report documents the development of a ground penetrating radar (GPR) system for locating potential maintenance problems in highway pavements. The report illustrates how GPR has the potential to detect four defects in pavements: stripping in an asphalt layer; moisture in base layer; voids or loss of support under rigid pavements; and overlay delamination.

  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.

  9. Bicycle cycles and mobility patterns - Exploring and characterizing data from a community bicycle program

    CERN Document Server

    Kaltenbrunner, Andreas; Grivolla, Jens; Codina, Joan; Banchs, Rafael

    2008-01-01

    This paper provides an analysis of human mobility data in an urban area using the amount of available bikes in the stations of the community bicycle program Bicing in Barcelona. The data was obtained by periodic mining of a KML-file accessible through the Bicing website. Although in principle very noisy, after some preprocessing and filtering steps the data allows to detect temporal patterns in mobility as well as identify residential, university, business and leisure areas of the city. The results lead to a proposal for an improvement of the bicing website, including a prediction of the number of available bikes in a certain station within the next minutes/hours. Furthermore a model for identifying the most probable routes between stations is briefly sketched.

  10. Path Creation

    DEFF Research Database (Denmark)

    Karnøe, Peter; Garud, Raghu

    2012-01-01

    This paper employs path creation as a lens to follow the emergence of the Danish wind turbine cluster. Supplier competencies, regulations, user preferences and a market for wind power did not pre-exist; all had to emerge in a tranformative manner involving multiple actors and artefacts. Competenc......This paper employs path creation as a lens to follow the emergence of the Danish wind turbine cluster. Supplier competencies, regulations, user preferences and a market for wind power did not pre-exist; all had to emerge in a tranformative manner involving multiple actors and artefacts....... Competencies emerged through processes and mechanisms such as co-creation that implicated multiple learning processes. The process was not an orderly linear one as emergent contingencies influenced the learning processes. An implication is that public policy to catalyse clusters cannot be based...

  11. Mechanical Response of Typical Cement Concrete Pavements under Impact Loading

    Directory of Open Access Journals (Sweden)

    Ding Fei

    2017-01-01

    Full Text Available In order to study the mechanical response of cement concrete pavements under impact loading, four types of typical cement concrete pavement structures are investigated experimentally and numerically under an impact load. Full-scale three-dimensional pavement slots are tested under an impact load and are monitored for the mechanical characteristics including the deflection of the pavement surface layer, the strain distribution at the bottom of the slab, and the plastic damage and cracking under the dynamic impact load. Numerical analysis is performed by developing a three-dimensional finite element model and by utilizing a cement concrete damage model. The results show that the calculation results based on the cement concrete damage model are in reasonable agreement with the experimental results based on the three-dimensional test slot experiment. The peak values of stress and strain as monitored by the sensors are analyzed and compared with the numerical results, indicating that the errors of numerical results from the proposed model are mostly within 10%. The rationality of the finite element model is verified, and the model is expected to be a suitable reference for the analysis and design of cement concrete pavements.

  12. Efficiency of choice set generation methods for bicycle routes

    DEFF Research Database (Denmark)

    Halldórsdóttir, Katrín; Rieser-Schussler, Nadine; Axhausen, Kay W.

    2014-01-01

    The current study analyses the efficiency of choice set generation methods for bicycle routes and proposes the extension of cost functions to bicycle-oriented factors not limited to distance and time. Three choice set generation methods for route choice were examined in their ability to generate...... relevant and heterogeneous routes: doubly stochastic generation function, breadth first search on link elimination, and branch & bound algorithm. Efficiency of the methods was evaluated for a high-resolution network by comparing the performances with four multi-attribute cost functions accounting...... generated realistic routes, while the former outperformed in computation cost and the latter produced more heterogeneous routes....

  13. Wireless controller and smartphone based interaction system for electric bicycles.

    Directory of Open Access Journals (Sweden)

    Jorge REVUELTA HERRERO

    2016-07-01

    Full Text Available Throughout the last years, great improvements have been made in the automotive industry, a sector with a high impact in both economics and social environments. Many development efforts have targeted on satisfying the need of providing smart environments to the end user in vehicles, such as cars. This paper proposes a brand-new solution in the automotive field, consisting of a new product family which aims to transform the traditional bicycle to an electric bicycle using an architecture that provides an adaptive environment to the user, improving the driving experience enabling value-added services.

  14. The effect of a yellow bicycle jacket on cyclist accidents

    DEFF Research Database (Denmark)

    Lahrmann, Harry; Madsen, Tanja Kidholm Osmann; Olesen, Anne Vingaard

    2017-01-01

    Highlights •A randomised controlled trial with 6793 cyclists shows a reduced accident risk due to a yellow bicycle jacket. •The test group had 47% fewer multiparty accidents with personal injury. •The test group had 55% fewer multiparty accidents against motorised vehicles.......Highlights •A randomised controlled trial with 6793 cyclists shows a reduced accident risk due to a yellow bicycle jacket. •The test group had 47% fewer multiparty accidents with personal injury. •The test group had 55% fewer multiparty accidents against motorised vehicles....

  15. Head injuries and bicycle helmet laws.

    Science.gov (United States)

    Robinson, D L

    1996-07-01

    The first year of the mandatory bicycle helmet laws in Australia saw increased helmet wearing from 31% to 75% of cyclists in Victoria and from 31% of children and 26% of adults in New South Wales (NSW) to 76% and 85%. However, the two major surveys using matched before and after samples in Melbourne (Finch et al. 1993; Report No. 45, Monash Univ. Accident Research Centre) and throughout NSW (Smith and Milthorpe 1993; Roads and Traffic Authority) observed reductions in numbers of child cyclists 15 and 2.2 times greater than the increase in numbers of children wearing helmets. This suggests the greatest effect of the helmet law was not to encourage cyclists to wear helmets, but to discourage cycling. In contrast, despite increases to at least 75% helmet wearing, the proportion of head injuries in cyclists admitted or treated at hospital declined by an average of only 13%. The percentage of cyclists with head injuries after collisions with motor vehicles in Victoria declined by more, but the proportion of head injured pedestrians also declined; the two followed a very similar trend. These trends may have been caused by major road safety initiatives introduced at the same time as the helmet law and directed at both speeding and drink-driving. The initiatives seem to have been remarkably effective in reducing road trauma for all road users, perhaps affecting the proportions of victims suffering head injuries as well as total injuries. The benefits of cycling, even without a helmet, have been estimated to outweigh the hazards by a factor of 20 to 1 (Hillman 1993. Cycle helmets-the case for and against. Policy Studies Institute, London). Consequently, a helmet law, whose most notable effect was to reduce cycling, may have generated a net loss of health benefits to the nation. Despite the risk of dying from head injury per hour being similar for unhelmeted cyclists and motor vehicle occupants, cyclists alone have been required to wear head protection. Helmets for motor

  16. Orthopaedic injuries among electric bicycle users.

    Science.gov (United States)

    Tenenbaum, Shay; Weltsch, Daniel; Bariteau, Jason T; Givon, Adi; Peleg, Kobi; Thein, Ran

    2017-08-11

    The use of electric bicycles (E-bike) has dramatically increased. E-bikes offer convenient, environmental-friendly, and less expensive alternative to other forms of transport. However, E-bikes provide a new public health challenge in terms of safety and injury prevention. This study is the first to specifically investigate the E-bike related orthopaedic injuries, based on a national trauma registry. Data from a National Trauma Registry were reviewed for patients hospitalized following E-bike related injuries. Between Jan 2014 to Dec 2015, a total of 549 patients were reviewed. Data were analyzed according to demography, type of orthopaedic injury, associated injuries and severity, injury mechanism and treatment in the operating room. A total of 360 (65%) patients sustained orthopaedic injuries, out of them 230 (63.8%) sustained limb/pelvis/spine fractures. Lower extremity fractures were more prevalent than upper extremity fractures (p<0.001). The tibia was the most fractured bone (19.2%). Patients over the age of 50 years were at the highest risk for spine (20. 5%, p=0.0001), pelvis (15.9%, p=0.0001) and femoral neck (15.9%, p=0.0172) fractures relative to other age groups. Approximately 42% of patients sustained associated injuries, with head/neck/face injuries being the most prevalent (30.3%). followed by chest (11.9%) and abdominal injury (13.3%). A collision between E-bike and a motorized vehicle was the mechanism of injury in 35% of cases. In this mechanism of injury, patients had 1.7 times the risk for associated injuries (p<0.0001) and the risk for major trauma (ISS score ≥16) was more than the double (p=0.03). One third of patients with orthopaedic injuries required treatment in the operating room. Treatment varied depending on the type of fracture. This study provides unique information on epidemiological characteristics of orthpaedic injuries caused be E-bikes, pertinent both to medical care providers, as well as to health policy-makers allocating

  17. 16 CFR Figure 8 to Part 1512 - Reflectorized Bicycle Wheel Rim Abrasion Test Device

    Science.gov (United States)

    2010-01-01

    ... 16 Commercial Practices 2 2010-01-01 2010-01-01 false Reflectorized Bicycle Wheel Rim Abrasion... HAZARDOUS SUBSTANCES ACT REGULATIONS REQUIREMENTS FOR BICYCLES Pt. 1512, Fig. 8 Figure 8 to Part 1512—Reflectorized Bicycle Wheel Rim Abrasion Test Device EC03OC91.074...

  18. 16 CFR Figure 1 to Part 1512 - Bicycle Front Fork Cantilever Bending Test Rig

    Science.gov (United States)

    2010-01-01

    ... 16 Commercial Practices 2 2010-01-01 2010-01-01 false Bicycle Front Fork Cantilever Bending Test Rig 1 Figure 1 to Part 1512 Commercial Practices CONSUMER PRODUCT SAFETY COMMISSION FEDERAL HAZARDOUS SUBSTANCES ACT REGULATIONS REQUIREMENTS FOR BICYCLES Pt. 1512, Fig. 1 Figure 1 to Part 1512—Bicycle...

  19. Bicycle Training for Youth with Down Syndrome and Autism Spectrum Disorders

    Science.gov (United States)

    MacDonald, Megan; Esposito, Phil; Hauck, Janet; Jeong, Irully; Hornyak, Joseph; Argento, Angela; Ulrich, Dale A.

    2012-01-01

    Children with Down syndrome (DS) and autism spectrum disorders (ASD) frequently have difficulty riding a two-wheel bicycle. The purpose of this study was to investigate an intervention using an adapted bicycle and individualized instruction to teach 71 youth to ride a standard two-wheel bicycle. Youth with DS (n = 30) and ASD (n = 41) between the…

  20. Rapid Inspection of Pavement Markings Using Mobile LIDAR Point Clouds

    Science.gov (United States)

    Zhang, Haocheng; Li, Jonathan; Cheng, Ming; Wang, Cheng

    2016-06-01

    This study aims at building a robust semi-automated pavement marking extraction workflow based on the use of mobile LiDAR point clouds. The proposed workflow consists of three components: preprocessing, extraction, and classification. In preprocessing, the mobile LiDAR point clouds are converted into the radiometrically corrected intensity imagery of the road surface. Then the pavement markings are automatically extracted with the intensity using a set of algorithms, including Otsu's thresholding, neighbor-counting filtering, and region growing. Finally, the extracted pavement markings are classified with the geometric parameters using a manually defined decision tree. Case studies are conducted using the mobile LiDAR dataset acquired in Xiamen (Fujian, China) with different road environments by the RIEGL VMX-450 system. The results demonstrated that the proposed workflow and our software tool can achieve 93% in completeness, 95% in correctness, and 94% in F-score when using Xiamen dataset.

  1. Application of Artificial Intelligence for Optimization in Pavement Management

    Directory of Open Access Journals (Sweden)

    Reus Salini

    2015-07-01

    Full Text Available Artificial intelligence (AI is a group of techniques that have quite a potential to be applied to pavement engineering and management. In this study, we developed a practical, flexible and out of the box approach to apply genetic algorithms to optimizing the budget allocation and the road maintenance strategy selection for a road network. The aim is to provide an alternative to existing software and better fit the requirements of an important number of pavement managers. To meet the objectives, a new indicator, named Road Global Value Index (RGVI, was created to contemplate the pavement condition, the traffic and the economic and political importance for each and every road section. This paper describes the approach and its components by an example confirming that genetic algorithms are very effective for the intended purpose.

  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. RAPID INSPECTION OF PAVEMENT MARKINGS USING MOBILE LIDAR POINT CLOUDS

    Directory of Open Access Journals (Sweden)

    H. Zhang

    2016-06-01

    Full Text Available This study aims at building a robust semi-automated pavement marking extraction workflow based on the use of mobile LiDAR point clouds. The proposed workflow consists of three components: preprocessing, extraction, and classification. In preprocessing, the mobile LiDAR point clouds are converted into the radiometrically corrected intensity imagery of the road surface. Then the pavement markings are automatically extracted with the intensity using a set of algorithms, including Otsu’s thresholding, neighbor-counting filtering, and region growing. Finally, the extracted pavement markings are classified with the geometric parameters using a manually defined decision tree. Case studies are conducted using the mobile LiDAR dataset acquired in Xiamen (Fujian, China with different road environments by the RIEGL VMX-450 system. The results demonstrated that the proposed workflow and our software tool can achieve 93% in completeness, 95% in correctness, and 94% in F-score when using Xiamen dataset.

  4. Acoustical estimation of parameters of porous road pavement

    Science.gov (United States)

    Valyaev, V. Yu.; Shanin, A. V.

    2012-11-01

    In the simplest case, porous road pavement of a known thickness is described by such parameters as porosity, tortuosity, and flow resistance. The problem of estimating these parameters is investigated in this paper. An acoustic signal reflected by the pavement is used for this. It is shown that this problem can be solved by an experiment conducted in the time domain (i.e., the pulse response of the media is recorded). The incident sound wave is thrown at a grazing angle to the surface between the pavement and the air to improve penetration into the porous medium. The procedure of computing of the pulse response using the Morse-Ingard model is described in detail.

  5. 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.

  6. Geo synthetic-reinforced Pavement systems; Sistemas de pavimentos reforzados con geosinteticos

    Energy Technology Data Exchange (ETDEWEB)

    Zornberg, J. G.

    2014-02-01

    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)

  7. Airfield Rigid Pavement Structural Design—A Review of Main Aspects and Methods of Analysis

    Science.gov (United States)

    Tiago Bonucci, Pereira

    2010-05-01

    Airfield pavements present a number of characteristics that make their design considerably different from that of road pavements. Apart from load magnitude and it's frequency, maintenance issues and pavement strength classification reporting are aspects that must be considered in the design phase. In the present paper, these aspects are analysed in the light of traditional and new methods of airfield pavement analysis. Parametric studies are performed in order to study the effects of different factors, such as pavement structure, layer thickness, material strength, effects of temperature, load transfer across joints and traffic characteristics.

  8. Evaluation of Common Maintenance Methods for Flexible Pavements

    Directory of Open Access Journals (Sweden)

    Asma T. Ibraheem

    2011-01-01

    Full Text Available Problem statement: With the increasing use and awareness of pavement management systems and the growing emphasis on asset management of pavement infrastructure, it is important to strengthen the maintenance components of these systems and particularly the preventive maintenance component. Iraqi Roads don’t receive an effective and proper maintenance during their service life until they reach the state of major failure that requires rehabilitation. Roads in Iraq are being lost. Approach: In this study, a study of the status of maintenance methods for road pavements in Iraq with special reference to flexible pavements is presented. For this purpose, open and closed questionnaires were executed in Baghdad to investigate the status of road pavement maintenance in Iraq. Road maintenance offices as (Ministry of construction and Housing, State Corporation for Roads and Bridges, Amanat Baghdad, Project office, were included in the questionnaire to arrive at the level of maintenance and techniques followed to maintain paved road in Iraq. Results: The interviews carried out reveal that maintenance in Iraq has secondary importance, apparently with no special budget allocated for such important works. In addition the maintenance methods and techniques followed do not comply the developments and modern techniques. Conclusion/Recommendations: Poor and miss-management of maintenance works and activities leading to delays and accumulation of failure in the highway network that require unusual expenditures to repair and maintain the accumulated damages. Also shortages in resources allocated for maintenance works and this leads to the diversion of significant portion of the allocated fund for maintenance works toward purchasing of new, or additional equipment to be used for the construction of new roads. It is strongly recommended to design a planning system for management pavement maintenance of road network in Iraq and develop a particular failure criterion

  9. Evaluation of multilayered pavement structures from measurements of surface waves

    Science.gov (United States)

    Ryden, N.; Lowe, M.J.S.; Cawley, P.; Park, C.B.

    2006-01-01

    A method is presented for evaluating the thickness and stiffness of multilayered pavement structures from guided waves measured at the surface. Data is collected with a light hammer as the source and an accelerometer as receiver, generating a synthetic receiver array. The top layer properties are evaluated with a Lamb wave analysis. Multiple layers are evaluated by matching a theoretical phase velocity spectrum to the measured spectrum. So far the method has been applied to the testing of pavements, but it may also be applicable in other fields such as ultrasonic testing of coated materials. ?? 2006 American Institute of Physics.

  10. Cold Region Pavements%寒区路面

    Institute of Scientific and Technical Information of China (English)

    GuyDore

    2002-01-01

    The article mainly discusses several essential problems of cold region pavement, including thermal cracking of asphalt concrete, cracking deterioration and heaving, frost heave, seasonal and long term roughness induced by different frost heave, frost heave cracking, bearing capacity loss during spring thaw. The reason for these problems is that cold region pavements are subjected to intense solicitation by climatic and environmental factors. The author offers several models corresponding to the solicitation. Furthermore in conclusion of the article the author indicates future research for cold region.

  11. Thin, applied surfacing for improving skid resistance of concrete pavements

    Science.gov (United States)

    Scholer, C. F.

    1980-12-01

    The use of select aggregate in a thin wearing surface of portland cement mortar to prolone or restore a concrete pavement's ability to develop high friction was accomplished. Two fine aggregates, blast furnace slag and lightweight expanded shale were found to exhibit skid resistance greater than the other aggregates evaluated. The British polishing wheel was used in the laboratory evaluation of aggregate to simulate wear. The need for a method of restoring friction to a worn, but otherwise sound concrete pavement led to a field evaluation of several different techniques for placing a very thin overlay. The successful method was a broomed, very thin layer of mortar, 3 mm thick.

  12. "Walking" Along a Free Rotating Bicycle Wheel (Round and Round)

    CERN Document Server

    Guemez, Julio

    2016-01-01

    We describe the kinematics, dynamics and also some energetic issues related to the Marta mouse motion when she walks on top of a horizontal bicycle wheel, which is free to rotate like a merry-to-go round, as presented recently by Paul Hewitt in the Figuring Physics section of this magazine.

  13. "Walking" Along a Free Rotating Bicycle Wheel (Round and Round)

    Science.gov (United States)

    Güémez, J.; Fiolhais, M.

    2015-01-01

    We describe the kinematics, dynamics, and also some energy issues related to Marta mouse's motion when she walks on top of a horizontal bicycle wheel, which is free to rotate like a merry-go-round, as presented recently by Paul Hewitt in the "Figuring Physics" section of this journal. The situation is represented in Fig. 1, which was…

  14. Bicyclic graphs with exactly two main signless Laplacian eigenvalues

    CERN Document Server

    Huang, He

    2012-01-01

    A signless Laplacian eigenvalue of a graph $G$ is called a main signless Laplacian eigenvalue if it has an eigenvector the sum of whose entries is not equal to zero. In this paper, all connected bicyclic graphs with exactly two main eigenvalues are determined.

  15. Embedding the bicyclic semigroup into countably compact topological semigroups

    CERN Document Server

    Banakh, Taras; Gutik, Oleg

    2008-01-01

    We study algebraic and topological properties of topological semigroups containing a copy of the bicyclic semigroup $C(p,q)$. We prove that each topological semigroup $S$ with pseudocompact square contains no dense copy of $C(p,q)$. On the other hand, we construct a consistent example of a Tychonov countably compact semigroup containing a copy of $C(p,q)$.

  16. Utilizing the Bicycle for Non-Traditional Activities

    Science.gov (United States)

    Maina, Michael P.; Maina, Julie Schlegel; Sebek, Ludek; Hoffmanova, Jana; Kane, Jennifer Jackson

    2012-01-01

    This article examines the bicycle as not simply a means of transportation or as an exercise device, but rather as a vehicle for teambuilding and problem solving activities within a physical education curriculum. The activities described in this article focus on bike-centered initiatives that foster creative problem solving. They have universal…

  17. Consequences of Underestimating Impalement Bicycle Handlebar Injuries in Children.

    Science.gov (United States)

    Ramos-Irizarry, Carmen T; Swain, Shakeva; Troncoso-Munoz, Samantha; Duncan, Malvina

    Impalement bicycle handlebar trauma injuries are rare; however, on initial assessment, they have the potential of being underestimated. We reviewed our prospective trauma database of 3,894 patients for all bicycle injuries from January 2010 to May 2015. Isolated pedal bike injuries were reported in 2.6% (N = 101) of the patients who were admitted to the trauma service. Fifteen patients suffered direct handlebar trauma. Patients were grouped into blunt trauma (n = 12) and impalement trauma (n = 3). We examined gender, age, injury severity score (ISS), Glasgow Coma Scale score, use of protective devices, need for surgical intervention, need for intensive care (ICU), and hospital length of stay. Mean age was 9.6 years. All children with penetrating injuries were males. Mean ISS was less than 9 in both groups. None of the children were wearing bicycle helmets. Three patients who sustained blunt injuries required ICU care due to associated injuries. All of the children with impalement injuries required several surgical interventions. These injuries included a traumatic direct inguinal hernia, a medial groin and thigh laceration with resultant femoral hernia, and a lateral deep thigh laceration. Impalement bicycle handlebar injuries must be thoroughly evaluated, with a similar importance given to blunt injuries. A high index of suspicion must be maintained when examining children with handlebar impalement injuries, as they are at risk for missed or underestimation of their injuries.

  18. How Fast Can You Go on a Bicycle?

    Science.gov (United States)

    Dunning, R. B.

    2009-01-01

    The bicycle provides a context-rich problem accessible to students in a first-year physics course, encircling several core physics principles such as conservation of total energy and angular momentum, dissipative forces, and vectors. In this article, I develop a simple numerical model that can be used by any first-year physics student to…

  19. Experimental and mathematical car-bicycle collision simulations.

    NARCIS (Netherlands)

    Huybers, J.J.W. & Janssen, E.G.

    1988-01-01

    The results of 35 mathematical simulations will be used to get a better insight in car-bicycle collisions. This information will be used later on to formulate hypotheses to be tested in an accident investigation project. In this paper special attention is given to the influence of the shape of the

  20. A Formal Synthesis of ( + )-Cassiol Exploiting Meyers' Bicyclic Lactam Methodology

    Institute of Scientific and Technical Information of China (English)

    SHEN,Xin(沈鑫); WU,Yi-Kang(伍贻康); ZHANG,Fan(张帆)

    2002-01-01

    A formal synthesis of ( + )-cassiol using (1S,2S)-2-amino-1-(4- nitrophenyl)-1,3-propanediol as chiral auxiliary is reported.The quaternary chiral center in the molecule was constructed by sequential alkylation of a bicyclic lactam (prepared from the aforementioned auxiliary and 5-oxo-heptanlic acid) with methyl iodide and benzyloxymethyl chloride.

  1. Nonfatal bicycle accident risk after an evening of alcohol consumption

    NARCIS (Netherlands)

    Verster, J.C.; van Herwijnen, J.; Volkerts, E.R.; Olivier, B.

    2009-01-01

    Introduction: After an evening of alcohol consumption, blood alcohol concentration (BAC) may reach intoxication levels above legal limits for operating a car or bicycle. In the Netherlands, legal limits for participating in traffic are 0.05% for experienced drivers and 0.02% for novice drivers. The

  2. Synthesis and anticonvulsant activity of novel bicyclic acidic amino acids

    DEFF Research Database (Denmark)

    Conti, Paola; De Amici, Marco; Joppolo Di Ventimiglia, Samuele

    2003-01-01

    Bicyclic acidic amino acids (+/-)-6 and (+/-)-7, which are conformationally constrained homologues of glutamic acid, were prepared via a strategy based on a 1,3-dipolar cycloaddition. The new amino acids were tested toward ionotropic and metabotropic glutamate receptor subtypes; both of them...

  3. Barriers and facilitators to bicycle commuting amoung college students

    Directory of Open Access Journals (Sweden)

    Nikolas Olekszechen

    2016-06-01

    Full Text Available Confronted with the current challenge of urban mobility, the bicycle has been presented as an alternative to individual transportation. Studies on this topic have mainly identified the individual factors involved in the choosing of this mean of transportation, sometimes putting the environmental factors in second plan, and neglecting the person-environment implications of the bicycle use a mean of transportation. This article aimed to identify, through environmental psychology, the barrier and facilitators in the use of the bicycle among college students in the city of Florianópolis-SC. Eighteen college students (twelve men and eight woman answered a semistructured interview. The data was organized into two categories of four subcategories each, based on the categorical-content analysis. The results indicated as barriers the Environment factors, social conjuncture, and political and personal factors. Among the facilitators, the time, practicality, motorized system, and personal factors were indicated as main characteristics. The results show a need to comprehend the use of bicycles as a mean of transportation in a contextualized way and as part of a public policy in effect. Furthermore, this study emphasizes the existence of an interpersonal dimension of traffic, which requires from its participants a sharing posture, rather than a competitive one.

  4. Nonfatal bicycle accident risk after an evening of alcohol consumption

    NARCIS (Netherlands)

    Verster, J.C.; van Herwijnen, J.; Volkerts, E.R.; Olivier, B.

    2009-01-01

    Introduction: After an evening of alcohol consumption, blood alcohol concentration (BAC) may reach intoxication levels above legal limits for operating a car or bicycle. In the Netherlands, legal limits for participating in traffic are 0.05% for experienced drivers and 0.02% for novice drivers. The

  5. Expedition Paris-Beijing by Bicycle 2008 Launched

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    <正>From March 15 to17, at the invitation of the Euro-Chinese Friendship Association (ECFA) of France, a CPAFFC representative attended the launching ceremony of the Expedition Paris-Beijing by Bicycle 2008 in Paris, during which he met with officials of the National Commission on Decentralized Cooperation (Commission Nationale de la Cooperation Decentralisee-CNCD) of France.

  6. Will a bicycle friendly policy make passenger travel more sustainably?

    DEFF Research Database (Denmark)

    Christensen, Linda; Jensen, Thomas Christian

    and bicycling. The study shows that instruments that improve the cyclists’ speed and increase the car drivers’ time consumption and costs will influence the competition conditions significantly. The total transfer potential will be between 12 and 16 % of the car trips in case of short tours, equivalent to 1...

  7. Experimental and mathematical car-bicycle collision simulations.

    NARCIS (Netherlands)

    Huybers, J.J.W. & Janssen, E.G.

    1988-01-01

    The results of 35 mathematical simulations will be used to get a better insight in car-bicycle collisions. This information will be used later on to formulate hypotheses to be tested in an accident investigation project. In this paper special attention is given to the influence of the shape of the

  8. Functionality Enhancement of Industrialized Optical Fiber Sensors and System Developed for Full-Scale Pavement Monitoring

    Directory of Open Access Journals (Sweden)

    Huaping Wang

    2014-05-01

    Full Text Available Pavements always play a predominant role in transportation. Health monitoring of pavements is becoming more and more significant, as frequently suffering from cracks, rutting, and slippage renders them prematurely out of service. Effective and reliable sensing elements are thus in high demand to make prognosis on the mechanical properties and occurrence of damage to pavements. Therefore, in this paper, various types of functionality enhancement of industrialized optical fiber sensors for pavement monitoring are developed, with the corresponding operational principles clarified in theory and the performance double checked by basic experiments. Furthermore, a self-healing optical fiber sensing network system is adopted to accomplish full-scale monitoring of pavements. The application of optical fiber sensors assembly and self-healing network system in pavement has been carried out to validate the feasibility. It has been proved that the research in this article provides a valuable method and meaningful guidance for the integrity monitoring of civil structures, especially pavements.

  9. Bearing capacity evaluation of rubblized concrete pavements

    Directory of Open Access Journals (Sweden)

    González, M.

    2009-03-01

    Full Text Available The paper presents the findings of a research work performed on a real scale concrete pavement project where Rubblizing technology was used for its structural rehabilitation. Rubblizing may be defined as a fracture technique in which a concrete pavement slab is transformed in a granular base with a very high Modulus. This technique, fractures the concrete slab in angular pieces by using a concentrated dynamic load of low amplitude and high frequency. The research work was based on field study on the rehabilitation of 5 km motorway. The structural evaluations where made, before, during and after one year construction. Measurements and site evaluation where made by using DCP, Light Weight Deflectometer and FWD (on top of asphalt layer and excavating inside pits. The structural capacity of the Rubblized layer was evaluated through theoretical analysis. Because of the anisotropic properties of the Rubblized layer the results are presented using AASHTO structural layer coefficient. The structural layer coefficients recommended are between the range of 0.25 and 0.30 for concrete slabs with thickness grater than 220 mm.El trabajo presenta los resultados de un estudio a escala real de la capacidad estructural de un firme de hormigón rehabilitado utilizando la técnica de Rubblizing. La técnica de Rubblizing ha sido traducida como el pulverizado del firme de hormigón pero, es más bien un efecto combinado de trituración y fracturación de la losa de hormigón en todo su espesor para convertir esta en una base granular de alto módulo. Esta tecnica fractura la losa de hormigón en trozos angulares y entrelazados empleando una carga dinámica concentrada, de baja amplitud y alta frecuencia. La investigación se basó en el estudio de la rehabilitación de 5 km de autopista. Los estudios de la capacidad estructural fueron realizados durante, al término y un año después de la construcción. Para las mediciones y evaluaciones de terreno se utilizó, el

  10. Bicycle Conversion Factor Calibration at Two-Phase Intersections in Mixed Traffic Flows

    Institute of Scientific and Technical Information of China (English)

    WANG Dianhai; LIANG Chunyan; JING Chunguang; WANG Guohua

    2007-01-01

    Chinese traffic is typically composed of bicycles and motor vehicles on the same road. The efficiency of bicycle traffic in time and space at intersections was investigated for eight typical intersections in the cities of Tianjin, Shenyang, and Changchun, all in China, by means of video recording. Models were developed to calculate the through bicycle traffic and the left-turn bicycle traffic conversion factors in intersections where bicycles and motor vehicles share the same road. The results indicate that the through bicycle conversion factor is 0.28 and the left-turn bicycle conversion factor is 0.33. This conclusion differs from the current value used in China. More research on the conversion factor is necessary to evaluate the impact of intersections.

  11. Power assist control of electric bicycle taking environment and rider's condition into account

    Science.gov (United States)

    Niki, Hiroshi; Miyata, Junichi; Murakami, Toshiyuki

    2005-12-01

    Recently, bicycles are widely used as a convenient transportation tool. But from a viewpoint of wide use for the future aging society, it is problem to pedal on rider's own. As well known, power assistance bicycle has already been used. The power assistance bicycle helps the elderly people or the people who has weak legs to expand their field. However, existing power assistance bicycle doesn't take running environment and rider's condition into account. The new control algorithm for power assistance bicycle is proposed in this paper. Human input and running friction are estimated as a disturbance torque with a disturbance observer. By using high pass filter (HPF), human input is separated from running friction. This method realizes power assistance bicycle without torque sensor. Disturbance observer compensates running friction. Compliance control is applied to make the bicycle have desired compliance. The effectiveness of this control algorithm is verified by numerical and experimental results.

  12. Does the Effect of Micro-Environmental Factors on a Street's Appeal for Adults' Bicycle Transport Vary across Different Macro-Environments? An Experimental Study.

    Science.gov (United States)

    Mertens, Lieze; Van Cauwenberg, Jelle; Ghekiere, Ariane; Van Holle, Veerle; De Bourdeaudhuij, Ilse; Deforche, Benedicte; Nasar, Jack; Van de Weghe, Nico; Van Dyck, Delfien

    2015-01-01

    Characteristics of the physical environment can be classified into two broad categories: macro- ("raw" urban planning features influenced on a regional level) and micro- (features specifically within a streetscape influenced on a neighborhood level) environmental factors. In urban planning applications, it is more feasible to modify conditions at the neighborhood level than at the regional level. Yet for the promotion of bicycle transport we need to know whether relationships between micro-environmental factors and bicycle transport depend on different types of macro-environments. This study aimed to identify whether the effect of three micro-environmental factors (i.e., evenness of the cycle path surface, speed limits and type of separation between cycle path and motorized traffic) on the street's appeal for adults' bicycle transport varied across three different macro-environments (i.e., low, medium and high residential density street). In total, 389 middle-aged adults completed a web-based questionnaire consisting of socio-demographic characteristics and a series of choice tasks with manipulated photographs, depicting two possible routes to cycle along. Conjoint analysis was used to analyze the data. Although the magnitude of the overall effects differed, in each macro-environment (i.e., low, medium and high residential density), middle-aged adults preferred a speed limit of 30 km/h, an even cycle path surface and a hedge as separation between motorized traffic and the cycle path compared to a speed limit of 50 or 70 km/h, a slightly uneven or uneven cycle path surface and a curb as separation or no separation between motorized traffic and the cycle path. Our results suggest that irrespective of the macro-environment, the same micro-environmental factors are preferred in middle-aged adults concerning the street's appeal for bicycle transport. The controlled environment simulations in the experimental choice task have the potential to inform real life

  13. Does the Effect of Micro-Environmental Factors on a Street’s Appeal for Adults’ Bicycle Transport Vary across Different Macro-Environments? An Experimental Study

    Science.gov (United States)

    Mertens, Lieze; Van Cauwenberg, Jelle; Ghekiere, Ariane; Van Holle, Veerle; De Bourdeaudhuij, Ilse; Deforche, Benedicte; Nasar, Jack; Van de Weghe, Nico; Van Dyck, Delfien

    2015-01-01

    Background Characteristics of the physical environment can be classified into two broad categories: macro- (“raw” urban planning features influenced on a regional level) and micro- (features specifically within a streetscape influenced on a neighborhood level) environmental factors. In urban planning applications, it is more feasible to modify conditions at the neighborhood level than at the regional level. Yet for the promotion of bicycle transport we need to know whether relationships between micro-environmental factors and bicycle transport depend on different types of macro-environments. This study aimed to identify whether the effect of three micro-environmental factors (i.e., evenness of the cycle path surface, speed limits and type of separation between cycle path and motorized traffic) on the street’s appeal for adults’ bicycle transport varied across three different macro-environments (i.e., low, medium and high residential density street). Methods In total, 389 middle-aged adults completed a web-based questionnaire consisting of socio-demographic characteristics and a series of choice tasks with manipulated photographs, depicting two possible routes to cycle along. Conjoint analysis was used to analyze the data. Results Although the magnitude of the overall effects differed, in each macro-environment (i.e., low, medium and high residential density), middle-aged adults preferred a speed limit of 30 km/h, an even cycle path surface and a hedge as separation between motorized traffic and the cycle path compared to a speed limit of 50 or 70 km/h, a slightly uneven or uneven cycle path surface and a curb as separation or no separation between motorized traffic and the cycle path. Conclusions Our results suggest that irrespective of the macro-environment, the same micro-environmental factors are preferred in middle-aged adults concerning the street’s appeal for bicycle transport. The controlled environment simulations in the experimental choice task

  14. Path Control Experiment of Mobile Robot Based on Supervised Learning

    Directory of Open Access Journals (Sweden)

    Gao Chi

    2013-07-01

    Full Text Available To solve the weak capacity and low control accuracy of the robots which adapt to the complex working conditions, proposed that a path control method based on the driving experience and supervised learning. According to the slope road geometry characteristics, established the modeling study due to ramp pavement path control method and the control structure based on monitoring and self-learning. Made use of the Global Navigation Satellite System did the experiment. The test data illustrates that when the running speed is not greater than 5 m / s, the straight-line trajectory path transverse vertical deviation within 士20cm ,which proved that the control method has a high feasibility. 

  15. An Approach for Nonlinear Fatigue Damage Evaluation in Asphalt Pavements

    Science.gov (United States)

    Rajbongshi, Pabitra; Thongram, Sonika

    2016-09-01

    Fatigue due to vehicular loads is one of the primary distress mechanisms in asphalt pavements. It happens primarily due to deterioration in asphalt material with load repetitions. Degradation of asphalt material may be evaluated using different parameters. In view of degradation, the incremental damage in a given pavement section would be different for different repetitions, even with same loadings. Therefore, the damage progression becomes nonlinear with repetitions. Accounting such nonlinearity in damage accumulation, and based on different damage evaluation parameters, this paper presents an equivalent approach for fatigue damage evaluation in asphalt pavements. Traditional fatigue equation adopted in mechanistic-empirical pavement design has been used in the present work. Four different criteria, namely number of load repetitions, asphalt stiffness reduction, strain enhancement and fatigue life reduction with repetitions are considered for damage estimation. The proposed approach could estimate same value of nonlinear damage, irrespective of the criteria used. The simplest form of criterion i.e. the number of load repetitions can be used for fatigue performance evaluation. Probabilistically, the damage propagation is also correlated and assessed with the failure probability.

  16. Representative volume element of asphalt pavement for electromagnetic measurements

    Directory of Open Access Journals (Sweden)

    Terhi Pellinen

    2015-02-01

    Full Text Available The motivation for this study was to investigate the representative volume element (RVE needed to correlate the nondestructive electromagnetic (EM measurements with the conventional destructive asphalt pavement quality control measurements. A large pavement rehabilitation contract was used as the test site for the experiment. Pavement cores were drilled from the same locations where the stationary and continuous Ground Penetrating Radar (GPR measurements were obtained. Laboratory measurements included testing the bulk density of cores using two methods, the surface-saturated dry method and determining bulk density by dimensions. Also, Vector Network Analyzer (VNA and the through specimen transmission configuration were employed at microwave frequencies to measure the reference dielectric constant of cores using two different footprint areas and therefore volume elements. The RVE for EM measurements turns out to be frequency dependent; therefore in addition to being dependent on asphalt mixture type and method of obtaining bulk density, it is dependent on the resolution of the EM method used. Then, although the average bulk property results agreed with theoretical formulations of higher core air void content giving a lower dielectric constant, for the individual cores there was no correlation for the VNA measurements because the volume element seizes deviated. Similarly, GPR technique was unable to capture the spatial variation of pavement air voids measured from the 150-mm drill cores. More research is needed to determine the usable RVE for asphalt.

  17. A Detailed Study of Cbr Method for Flexible Pavement Design

    Directory of Open Access Journals (Sweden)

    Er. Devendra Kumar Choudhary

    2014-06-01

    Full Text Available As per IRC recommendation, California Bearing Ratio (CBR value of subgrade is used for design of flexible pavements. California Bearing Ratio (CBR value is an important soil parameter for design of flexible pavements and runway of air fields. It can also be used for determination of sub grade reaction of soil by using correlation. It is one of the most important engineering properties of soil for design of sub grade of roads. CBR value of soil may depends on many factors like maximum dry density (MDD, optimum moisture content (OMC, liquid limit (LL, plastic limit (PL, plasticity index (PI, type of soil, permeability of soil etc. Besides, soaked or unsoaked condition of soil also affects the value. These tests can easily be performed in the laboratory. the estimation of the CBR could be done on the basis of these tests which are quick to perform, less time consuming and cheap, then it will be easy to get the information about the strength of subgrade over the length of roads, By considering this aspect, a number of investigators in the past made their investigations in this field and designed different pavements by determining the CBR value on the basis of results of low cost, less time consuming and easy to perform tests. In this study, attempts have been made to seek the values of CBR of different soil samples and correlate their CBR values for the design purpose of flexible pavement as per guidelines of IRC: SP: 37-2001.

  18. Time series trends of the safety effects of pavement resurfacing.

    Science.gov (United States)

    Park, Juneyoung; Abdel-Aty, Mohamed; Wang, Jung-Han

    2017-04-01

    This study evaluated the safety performance of pavement resurfacing projects on urban arterials in Florida using the observational before and after approaches. The safety effects of pavement resurfacing were quantified in the crash modification factors (CMFs) and estimated based on different ranges of heavy vehicle traffic volume and time changes for different severity levels. In order to evaluate the variation of CMFs over time, crash modification functions (CMFunctions) were developed using nonlinear regression and time series models. The results showed that pavement resurfacing projects decrease crash frequency and are found to be more safety effective to reduce severe crashes in general. Moreover, the results of the general relationship between the safety effects and time changes indicated that the CMFs increase over time after the resurfacing treatment. It was also found that pavement resurfacing projects for the urban roadways with higher heavy vehicle volume rate are more safety effective than the roadways with lower heavy vehicle volume rate. Based on the exploration and comparison of the developed CMFucntions, the seasonal autoregressive integrated moving average (SARIMA) and exponential functional form of the nonlinear regression models can be utilized to identify the trend of CMFs over time. Copyright © 2017 Elsevier Ltd. All rights reserved.

  19. Evaluating Pavement Cracks with Bidimensional Empirical Mode Decomposition

    Directory of Open Access Journals (Sweden)

    Nii Attoh-Okine

    2008-05-01

    Full Text Available Crack evaluation is essential for effective classification of pavement cracks. Digital images of pavement cracks have been analyzed using techniques such as fuzzy set theory and neural networks. Bidimensional empirical mode decomposition (BEMD, a new image analysis method recently developed, can potentially be used for pavement crack evaluation. BEMD is an extension of the empirical mode decomposition (EMD, which can decompose nonlinear and nonstationary signals into basis functions called intrinsic mode functions (IMFs. IMFs are monocomponent functions that have well-defined instantaneous frequencies. EMD is a sifting process that is nonparametric and data driven; it does not depend on an a priori basis set. It is able to remove noise from signals without complicated convolution processes. BEMD decomposes an image into two-dimensional IMFs. The present paper explores pavement crack detection using BEMD together with the Sobel edge detector. A number of images are filtered with BEMD to remove noise, and the residual image analyzed with the Sobel edge detector for crack detection. The results are compared with results from the Canny edge detector, which uses a Gaussian filter for image smoothing before performing edge detection. The objective is to qualitatively explore how well BEMD is able to smooth an image for more effective edge detection with the Sobel method.

  20. Initial investigation into development of accelerated pavement evaluation (APE) vehicle

    CSIR Research Space (South Africa)

    Steyn, WJvdM

    2002-08-01

    Full Text Available CSIR Transportek has for many years been at the forefront of Accelerating Pavement Testing (APT) technology. The use of the HVS for research purpose has attracted much attention. One aspect of the HVS's capabilities has not been used that often...

  1. Optimisation of the Crack Pattern in Continuously Reinforced Concrete Pavements

    NARCIS (Netherlands)

    Ren, D.

    2015-01-01

    Recent field investigations on several new Continuously Reinforced Concrete Pavements (CRCP) in Belgium indicate that its crack pattern is characterized by low mean crack spacing along with a high percentage of clusters of closely spaced cracks. Field surveys also indicate that it is difficult to si

  2. 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.

  3. Development of traffic induced permanent strain in concrete block pavements

    NARCIS (Netherlands)

    Huurman, M.

    1996-01-01

    Concrete block pavements (c.b.p.) commonly consist of concrete blocks placed over a granular substructure. As a result of wheel load passages permanent strains will slowly develop in the substructure and cause rutting. This paper is about the prediction of the permanent strain development in the sub

  4. Resilient behavior characterization of geomaterials for pavement design

    CSIR Research Space (South Africa)

    Anochie-Boateng, Joseph

    2010-08-01

    Full Text Available pavements analysis. However, there is a major difference between the two tests in terms of materials properties. Whereas CBR test evaluates the potential strength of geomaterials, resilient modulus is a stiffness property obtained under repeated/cyclic load...

  5. Optimisation of the Crack Pattern in Continuously Reinforced Concrete Pavements

    NARCIS (Netherlands)

    Ren, D.

    2015-01-01

    Recent field investigations on several new Continuously Reinforced Concrete Pavements (CRCP) in Belgium indicate that its crack pattern is characterized by low mean crack spacing along with a high percentage of clusters of closely spaced cracks. Field surveys also indicate that it is difficult to si

  6. Road Materials and Pavement Design, 30 May 2017

    CSIR Research Space (South Africa)

    De Beer, Morris

    2017-01-01

    Full Text Available and Pavement Design Vol. 18, Issue 1 2017 http://www.tandfonline.com/toc/trmp20/18/1?nav=tocList Editorial board EDITORS-IN-CHIEF Hervé Di Benedetto - University of Lyon / ENTPE, Vaulx-en-Velin, France Andrew Charles Collop - De Montfort University...

  7. Ground Penetrating Radar Assessment of Flexible Road Pavement Degradation

    Directory of Open Access Journals (Sweden)

    Sandro Colagrande

    2011-01-01

    Full Text Available GPR investigations were used to study degraded road pavements built in cutting sections. Road integrity was assessed via quantitative analysis of power curves. 1600 MHz and 600 MHz radar sections were collected in 40 damaged and undamaged road pavement sites. The collected data were processed as follows: (i linearisation with regression analysis of power curves; (ii assessment of absorption angle α′ which is directly proportional to absorption coefficient α (this was obtained by setting the e.m. propagation velocity to 10 cm/ns; (iii comparison of absorption coefficients in both damaged and undamaged zones with respect to road pavement degradation. If the absorption coefficients of damaged and undamaged road sections have nearly the same value, then the likely cause of degradation is the fatigue or the thermal shrinkage; if they are not, then road degradation is due to the different compactness of the soil caused by vehicular traffic load. In a considerable number of sites, the statistical comparison of damaged and undamaged zones through the absorption coefficient analysis shows that surface observations of road pavements are quite consistent with power curve analyses.

  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. Nitrogen Transformations in Three Types of Permeable Pavement

    Science.gov (United States)

    In 2009, USEPA constructed a 0.4-ha (1-ac) parking lot at the Edison Environmental Center in Edison, NJ, that incorporated three different permeable pavement types - permeable interlocking concrete pavers (PICP), pervious concrete (PC), and porous asphalt (PA). The driving lanes...

  10. Modeling Recycling Asphalt Pavement Processing Technologies in Asphalt Mixing Plants

    OpenAIRE

    Simonas Tamaliūnas; Henrikas Sivilevičius

    2011-01-01

    The article presents reclaimed asphalt pavement (RAP) processing technologies and equipment models used in the asphalt mixing plant (AMP). The schematic model indicating all possible ways to process RAP in AMP is shown. The model calculating the needed temperature of mineral materials used for heating RAP is given and an example of such calculation is provided.Article in Lithuanian

  11. Modeling Recycling Asphalt Pavement Processing Technologies in Asphalt Mixing Plants

    Directory of Open Access Journals (Sweden)

    Simonas Tamaliūnas

    2011-04-01

    Full Text Available The article presents reclaimed asphalt pavement (RAP processing technologies and equipment models used in the asphalt mixing plant (AMP. The schematic model indicating all possible ways to process RAP in AMP is shown. The model calculating the needed temperature of mineral materials used for heating RAP is given and an example of such calculation is provided.Article in Lithuanian

  12. Optimisation of the Crack Pattern in Continuously Reinforced Concrete Pavements

    NARCIS (Netherlands)

    Ren, D.

    2015-01-01

    Recent field investigations on several new Continuously Reinforced Concrete Pavements (CRCP) in Belgium indicate that its crack pattern is characterized by low mean crack spacing along with a high percentage of clusters of closely spaced cracks. Field surveys also indicate that it is difficult to

  13. 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

  14. 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

  15. Bicycle Trains, Cycling, and Physical Activity: A Pilot Cluster RCT.

    Science.gov (United States)

    Mendoza, Jason A; Haaland, Wren; Jacobs, Maya; Abbey-Lambertz, Mark; Miller, Josh; Salls, Deb; Todd, Winifred; Madding, Rachel; Ellis, Katherine; Kerr, Jacqueline

    2017-10-01

    Increasing children's cycling to school and physical activity are national health goals. The objective was to conduct an RCT of a bicycle train program to assess impact on students' school travel mode and moderate-to-vigorous physical activity (MVPA). Pilot cluster RCT with randomization at the school level and N=54 participants. Fourth-fifth graders from four public schools serving low-income families in Seattle, WA in 2014 with analyses in 2015-2016. All participants were provided and fitted with bicycles, safety equipment (helmets, locks, and lights), and a 2- to 3-hour bicycle safety course. The intervention was a bicycle train offered daily (i.e., students volunteered to cycle with study staff to and from school). Time 1 assessments occurred prior to randomization. Time 2 assessments occurred after 3-5 weeks of the intervention (i.e., during Weeks 4-6 of the intervention period). The primary outcome was the percentage of daily commutes to school by cycling measured by validated survey. MVPA, measured by accelerometry and GPS units and processed by machine learning algorithms, was a secondary outcome. For two separate adjusted repeated measures linear mixed effects models in which students (N=54) were nested within schools (N=4), intervention participants had: (1) an absolute increase in mean percentage of daily commutes by cycling of 44.9%, (95% CI=26.8, 63.0) and (2) an increase in mean MVPA of 21.6 minutes/day, (95% CI=8.7, 34.6) from Time 1 to Time 2 compared with controls. A pilot bicycle train intervention increased cycling to school and daily MVPA in the short term among diverse, inner-city elementary school students. The bicycle train intervention appears promising and warrants further experimental trials among large, diverse samples with longer follow-up. This study is registered at www.clinicaltrials.gov NCT02006186. Copyright © 2017 American Journal of Preventive Medicine. Published by Elsevier Inc. All rights reserved.

  16. Chest Traumas due to Bicycle accident in Childhood

    Directory of Open Access Journals (Sweden)

    Ufuk Cobanoglu

    2011-09-01

    Full Text Available Aim:Childhood injuries are the leading cause of death in children and result in significant healthcare utilization. Trauma is the second most common cause of mortality in children aged 1-4 years and leading cause of death in children older than 4 years. Thoracic injury is the second most leading cause of death in traumatized children. Multisystemic injury is found in more than 50% of children with thoracic injuries most of which are secondary to blunt traumas. We planned this study to evaluate thorax trauma cases secondary to bicycle driving in childhood and to draw attention to the importance of the regulation of traffic rules, the education of bicycle drivers.Material and Methods:  A retrospective evaluation was performed in 17 pediatric patients admitted to the Department of Thoracic Surgery during 2006-2010 with a diagnosis of chest trauma due to bicycle driving. For every patient, a pediatric trauma score (PTS was calculated. Descriptive statistics were performed for PTS. Results; Eleven (64.70% cases were injured due to the tricycle accidents and six cases 6 (35.29% were injured due to the two-wheeled bicycle accidents. The most frequent thoracic pathologies included pulmonary contusion (41.2% and chest wall contusion (29.41%. Extrathoracic injuries were seen in 35.29%, the extremities (17.64% and abdomino pelvic (11.76% being the most commonly involved. Treatment consisted of symptomatic treatment in 12 patients (70.58%, tube thoracostomy in 2 patients (11.76%, and thoracotomy in 1 patient (5.9%. The morbidity was seen in 3 patients (17.64%. The mortality rate was 5.9% (n:1. The mean PTS of the cases who had additional system injuries were significantly worse than the cases who had isolated chest traumas Conclusions: The pediatric thorax has a greater cartilage content and incomplete ossification of the ribs. Due to the pliability of the pediatric rib cage and mediastinal mobility, significant intrathoracic injury may exist in the

  17. Physical activity when riding an electric assisted bicycle.

    Science.gov (United States)

    Berntsen, Sveinung; Malnes, Lena; Langåker, Aleksander; Bere, Elling

    2017-04-26

    The objectives of the present study were to compare time spent cycling, exercise intensity, and time spent in moderate- (MPA) and vigorous intensity physical activity (VPA) when cycling on an E-bike and a conventional bicycle on two "cycling-to-work" routes with differences in topography, defined as a hilly and a flat route. Eight adults (23-54 years, two women) cycled outdoors on a conventional bicycle and an E-bike, on a flat (8.2 km) and a hilly (7.1 km) route, resulting in 32 journeys. Duration, elevation, and oxygen consumption were recorded using a portable oxygen analyser with GPS. A maximal cardiorespiratory fitness test was performed on a cycle ergometer. Resting metabolic rate was obtained by indirect calorimetry with a canopy hood. The participants spent less time (median (IQR)) cycling on the E-bike compared with the conventional bicycle, on both the hilly (18.8 (4.9) vs. 26.3 (6.4) minutes) and the flat (20.0 (2.9) vs. 23.8 (1.8) minutes) routes. Lower exercise intensity was observed with the E-bike compared with the conventional bicycle, both on the hilly (50 (18) vs. 60 (22) % of maximal oxygen uptake) and the flat (52 (19) vs. 55 (12) % of maximal oxygen uptake) routes. In both cycling modes, most time was spent in MVPA (92-99%). However, fewer minutes were spent in MVPA with the E-bike than the conventional bicycle, for both the hilly (26% lower) and the flat (17% lower) routes. Cycling on the E-bike also resulted in 35 and 15% fewer minutes in vigorous intensity, respectively on the hilly and flat routes. Cycling on the E-bike resulted in lower trip duration and exercise intensity, compared with the conventional bicycle. However, most of the time was spent in MVPA. This suggests that changing the commuting mode from car to E-bike will significantly increase levels of physical activity while commuting.

  18. Effect Analysis of Vehicle System Parameters on Dynamic Response of Pavement

    Directory of Open Access Journals (Sweden)

    Rong-xia Xia

    2015-01-01

    Full Text Available In order to study the damage of a semirigid pavement under vehicle loads with varied parameters, the random dynamic loads applied on the pavement by a running vehicle were computed with two degrees of freedom, quarter-vehicle model, and then a three-dimensional finite element analysis model of semirigid asphalt pavement was established. With the peak stress index of each pavement layer, the effect of varied vehicle parameters on pavement response was studied. The results indicated that the stress wave frequency of each pavement layer was similar to that of the dynamic random load, and, with increased pavement depth, the wave effect decreased. The pavement response increased with increased suspension stiffness and tire stiffness and decreased with increased suspension damping and tire damping. Furthermore, compared to the stiffness, the response variation induced by the damping was orders of magnitude lower. Compared with the traditional time response analysis method, the peak response analysis of the pavement structure was more scientific, rational, and intuitive, which could be useful for the study of vehicle-pavement interaction and road damage.

  19. 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.

  20. Predicting physical clogging of porous and permeable pavements

    Science.gov (United States)

    Yong, C. F.; McCarthy, D. T.; Deletic, A.

    2013-02-01

    SummaryPorous pavements are easily retrofitted, and effective in improving water quality and hydrology, but prone to clogging. Despite being a major determinant in the lifespan of porous pavements, there is limited information on the physical clogging processes through these systems. The aim of this study was to understand the main physical processes that govern physical clogging and develop a simple black-box model that predicts physical clogging. The key variables that were hypothesised to influence clogging were pavement design and climate characteristics. Two compressed time scale laboratory experiments were conducted over 3 years on three common porous pavement types; monolithic porous asphalt, modular Hydrapave and monolithic Permapave. Pavement design was found to be an important role in clogging. Permapave did not clog even after 26 years of operation in simulated sub-tropical Brisbane (Australia) climate while porous asphalt and Hydrapave clogged after just 12 years, from surface clogging and geotextile clogging, respectively. Each system was tested using two different dosing patterns: (1) continual wetting with no dry periods and (2) variable inflow rates with drying periods (i.e. representing more natural conditions). The latter dosing method approximately doubled the lifespan of all systems suggesting the influence of climate conditions on clogging. Clogging was found to be highly correlated with cumulative volume and flow rate. A simple black-box regression model that predicts physical clogging was developed as a function of cumulative volume and Brisbane climatic conditions. However it is very likely that the shape of this regression is general, and that it could be calibrated for different climates in the future.

  1. Recent rubber crumb asphalt pavement projects in Alberta

    Energy Technology Data Exchange (ETDEWEB)

    Soleyman, H.R. [Alberta Univ., Edmonton, AB (Canada). Dept. of Civil and Environmental Engineering; Pulles, B.C.M.; Treleaven, L.B. [EBA Engineering Consultants Ltd., Edmonton, AB (Canada)

    2003-07-01

    Several countries around the world have been using rubber crumb (RC) for pavement applications for more than 20 years. The performance of asphalt pavements is enhanced by the use of recycled tires, which has the added advantage of solving the problem of tire disposal. In 2002, the Tire Recycling Management Association of Alberta (TRMA) and Alberta Transportation (AT) evaluated the feasibility and performance of an overlay using asphalt rubber (AR) pavement in Alberta. A partnership in the project was formed by AT, the City of Calgary, the City of Edmonton, and Strathcona County, where each one paved one section of a road with AR in conjunction with a section using conventional or other asphalt mixture types. The roads selected were: (1) 112 Avenue North West in Calgary, (2) 17 Street and Baseline Road in Strathcona County, (3) 137 Avenue in Edmonton, and (4) highway 630 in the vicinity of North Cooking Lake (Alberta Transportation). Two different AR pavement thicknesses were used to study the effects of overlay thicknesses on the performance of the overlay. The structural and functional factors were monitored before, during and after the construction of all sections. The preliminary evaluation of the application of AR in Alberta was presented, along with a summary of test results and performances of AR pavement sections. A full freeze-thaw cycle is required (Spring 2003) before the results of the analysis of the testing are known. The reduced thickness AR sections performed in a similar manner to those with full thickness AC sections. 10 refs., 5 tabs., 3 figs.

  2. EFFECTIVE REMOVAL METHOD OF ILLEGAL PARKING BICYCLES BASED ON THE QUANTITATIVE CHANGE AFTER REMOVAL

    Science.gov (United States)

    Toi, Satoshi; Kajita, Yoshitaka; Nishikawa, Shuichirou

    This study aims to find an effective removal method of illegal parking bicycles based on the analysis on the numerical change of illegal bicycles. And then, we built the time and space quantitative distribution model of illegal parking bicycles after removal, considering the logistic increase of illegal parking bicycles, several behaviors concerning of direct return or indirect return to the original parking place and avoidance of the original parking place, based on the investigation of real condition of illegal bicycle parking at TENJIN area in FUKUOKA city. Moreover, we built the simulation model including above-mentioned model, and calculated the number of illegal parking bicycles when we change the removal frequency and the number of removal at one time. The next interesting four results were obtained. (1) Recovery speed from removal the illegal parking bicycles differs by each zone. (2) Thorough removal is effective to keep the number of illegal parking bicycles lower level. (3) Removal at one zone causes the increase of bicycles at other zones where the level of illegal parking is lower. (4) The relationship between effects and costs of removing the illegal parking bicycles was clarified.

  3. Personal and behavioral factors associated with bicycling in adults from Curitiba, Parana State, Brazil

    Directory of Open Access Journals (Sweden)

    Marilson Kienteka

    2014-01-01

    Full Text Available Bicycling is an important form of physical activity that can promote health benefits. The objective of this study was to analyze the association between personal and behavioral aspects in transportation bicycling and leisure time bicycling in adults. Data was drawn from a household survey involving 677 adults (53.1% female in Curitiba, Paraná State, Brazil. The prevalence of bicycling was 11.2% for transportation and 16.7% for leisure. The frequency of leisure time bicycling was higher among men (PR = 2.08; p < 0.001, young people < 30 and adults aged between 30 and 39.9, bicycle owners (PR = 8.76; p < 0.001 and among the physically active. Transportation bicycling occurred more frequently among men (PR = 3.63; p < 0.001, individuals aged 30 to 39.9, those with a low socioeconomic status (PR = 5.00; p = 0.006, bicycle owners (PR = 10.2; p < 0.001 and individuals with a negative perception of their quality of life. The prevalence of bicycling is low in Curitiba considering its potential as a means of physical activity. Personal and behavioral factors were associated with each form of bicycling.

  4. The fastest bicycle in the world; how a team of Delft students is building a bicycle to break the world speed record

    NARCIS (Netherlands)

    Annega, G.

    2011-01-01

    The Netherlands is a country known for its extensive use of bicycles as a means of everyday transport. However, while it has existed for about two centuries, todays bicycles only differ from those of the 19th century in relatively small details. Human Power Team Delft is building a whole new type of

  5. Simultaneous optimization of transit network and public bicycle station network

    Institute of Scientific and Technical Information of China (English)

    刘洋; 朱宁; 马寿峰

    2015-01-01

    The traditional manner to design public transportation system is to sequentially design the transit network and public bicycle network. A new public transportation system design problem that simultaneously considers both bus network design and public bicycle network design is proposed. The chemical reaction optimization (CRO) is designed to solve the problem. A shortcoming of CRO is that, when the two-molecule collisions take place, the molecules are randomly picked from the container. Hence, we improve CRO by employing different mating strategies. The computational results confirm the benefits of the mating strategies. Numerical experiments are conducted on the Sioux-Falls network. A comparison with the traditional sequential modeling framework indicates that the proposed approach has a better performance and is more robust. The practical applicability of the approach is proved by employing a real size network.

  6. BUGS at work : a bicycle user group guide

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2002-07-01

    This guide provides practical advice to cyclists on how start a Bicycle User Group (BUG) at their workplace. It offers tools to encourage employers to be proactive in improving facilities in support of cycle commuting. Several BUGs across Canada have worked towards getting better bicycle parking, lockers and shower facilities at their workplace. Other incentives include policies such as flexible work hours for cyclist commuters; casual dress on Friday; reimbursement for the subsidized cost of free parking provided by employers; and, use of a company car if needed for company business during the work day. The advantages to employers include: reduced health care costs because cyclists are physically fit; decreased absenteeism; increased productivity; reduced parking costs; lower company transportation bills; and, a greener corporate image. BUGs provide cycling information ranging from cycling maps to pamphlets and they raise cycle awareness. This guide includes cycling survey samples and examples of successful BUG activities across Canada. refs., tabs., figs.

  7. MIT-Skywalker: Evaluating comfort of bicycle/saddle seat.

    Science.gov (United States)

    Goncalves, Rogerio S; Hamilton, Taya; Daher, Ali R; Hirai, Hiroaki; Krebs, Hermano I

    2017-07-01

    The MIT-Skywalker is a robotic device developed for the rehabilitation of gait and balance after a neurological injury. This device has been designed based on the concept of a passive walker and provides three distinct training modes: discrete movement, rhythmic movement, and balance training. In this paper, we present our efforts to evaluate the comfort of a bicycle/saddle seat design for the system's novel actuated body weight support device. We employed different bicycle and saddle seats and evaluated comfort using objective and subjective measures. Here we will summarize the results obtained from a study of fifteen healthy subjects and one stroke patient that led to the selection of a saddle seat design for the MIT-Skywalker.

  8. Optimal Design of Mountain Bicycle Based on Biomechanics

    Institute of Scientific and Technical Information of China (English)

    卜研; 黄田; 项忠霞; 吴小凡; 陈春

    2010-01-01

    To achieve better cycling performance and vibration comfort of mountain bicycle, the optimization of frame structural parameters and rear suspension scale parameters is investigated based on biomechanics.Firstly, the quadratic sum of rider lower limb muscles stresses is presented as the evaluation criterion of muscle fatigue.By taking the criterion as the objective function, the relative positions of three pivot points of frame are optimized to ensure that the frame structural parameters match the stature o...

  9. Rates of bicycle helmet use in an affluent Michigan County.

    OpenAIRE

    Jacques, L B

    1994-01-01

    Bicycle helmet use in the United States has remained low despite clear demonstration of its beneficial effect on reducing the incidence of serious head injury. Several interventions have been reported, with variable results and costs. Much of the recent literature has focused on child cyclists and on demographic factors associated with helmet use. This paper reports on helmet use by children and adults in a sample of 652 riders in an affluent southeast Michigan region, chosen to minimize the ...

  10. [Mortality due to bicycle accidents in Pernambuco, Brazil].

    Science.gov (United States)

    Galvão, Pauliana Valéria Machado; Pestana, Luciana Pinto; Pestana, Valter Mário; Spíndola, Michelline Oliveira Pedrosa; Campello, Reginaldo Inojosa Carneiro; de Souza, Eliane Helena Alvim

    2013-05-01

    The scope of this paper was to conduct a quantitative analysis of deaths resulting from bicycle accidents in the state of Pernambuco by studying secondary data between 2001 and 2010. The sample consisted of all the Deaths recorded in the Mortality Information System of the Unified Health System Database that reported bicycle accidents between 2001 and 2010. Descriptive measures were determined for all variables. Socio-demographic variables were paired with the basic cause of death in order to find a statistical correlation. In Pernambuco, the aforementioned information system recorded 517 deaths resulting from bicycle accidents, with greater frequency in men between 25 and 59 years of age, Afro-Brazilians, single and of unknown schooling. The mean age was 36.82 years (SD = 17.026), and the minimum and maximum age of 4 and 86 years old, respectively. The findings highlight the need for the creation of adequate infrastructure and effective legal measures to prevent traffic accidents involving this type of vehicle, relying on the evidence of distribution of cases in most Pernambuco municipalities.

  11. Harvesting energy from the counterbalancing (weaving) movement in bicycle riding.

    Science.gov (United States)

    Yang, Yoonseok; Yeo, Jeongjin; Priya, Shashank

    2012-01-01

    Bicycles are known to be rich source of kinetic energy, some of which is available for harvesting during speedy and balanced maneuvers by the user. A conventional dynamo attached to the rim can generate a large amount of output power at an expense of extra energy input from the user. However, when applying energy conversion technology to human powered equipments, it is important to minimize the increase in extra muscular activity and to maximize the efficiency of human movements. This study proposes a novel energy harvesting methodology that utilizes lateral oscillation of bicycle frame (weaving) caused by user weight shifting movements in order to increase the pedaling force in uphill riding or during quick speed-up. Based on the 3D motion analysis, we designed and implemented the prototype of an electro-dynamic energy harvester that can be mounted on the bicycle's handlebar to collect energy from the side-to-side movement. The harvester was found to generate substantial electric output power of 6.6 mW from normal road riding. It was able to generate power even during uphill riding which has never been shown with other approaches. Moreover, harvesting of energy from weaving motion seems to increase the economy of cycling by helping efficient usage of human power.

  12. Electric motor assisted bicycle as an aerobic exercise machine.

    Science.gov (United States)

    Nagata, T; Okada, S; Makikawa, M

    2012-01-01

    The goal of this study is to maintain a continuous level of exercise intensity around the aerobic threshold (AT) during riding on an electric motor assisted bicycle using a new control system of electrical motor assistance which uses the efficient pedaling rate of popular bicycles. Five male subjects participated in the experiment, and the oxygen uptake was measured during cycling exercise using this new pedaling rate control system of electrical motor assistance, which could maintain the pedaling rate within a specific range, similar to that in previous type of electrically assisted bicycles. Results showed that this new pedaling rate control system at 65 rpm ensured continuous aerobic exercise intensity around the AT in two subjects, and this intensity level was higher than that observed in previous type. However, certain subjects were unable to maintain the expected exercise intensity because of their particular cycling preferences such as the pedaling rate. It is necessary to adjust the specific pedaling rate range of the electrical motor assist control according to the preferred pedaling rate, so that this system becomes applicable to anyone who want continuous aerobic exercise.

  13. Design Analysis And Applications Of A Regenerative Bicycle Ergometer

    Directory of Open Access Journals (Sweden)

    Chukwuneke J. L.

    2015-08-01

    Full Text Available Man needs to do some form of physical work in other to remain healthy this work is similar to the work done by any machine or equipment and thus should be channeled to give useful output but rather it is usually dissipated into the environment in form of heat. The regenerative bicycle ergometer takes advantage of the greater power generated by the limbs and arms thus conserves converts and stores the energy dissipated by the rider with an ideal mechanical advantage of 7.6 it strategically uses simple mechanisms to magnify its work and then converts this mechanical energy into electrical energy by the use of a dynamo with a speed ratio of 108.5 and a transmission efficiency of 89 the rider pedals 27rpm to obtain the dynamos rated input of 2600rpm giving an output of 12.6volts. The regenerative bicycle ergometer is designed and constructed to perform all the core functions of a bicycle ergometer having an allowable load of 116.5kg and a maximum resistance of 65.33N which is equivalent to a mass of 6.66kg. The energy converted is stored in a 12volts battery making its use flexible clean and meeting the energy demands of man.

  14. Long-term stormwater quantity and quality performance of permeable pavement systems.

    Science.gov (United States)

    Brattebo, Benjamin O; Booth, Derek B

    2003-11-01

    This study examined the long-term effectiveness of permeable pavement as an alternative to traditional impervious asphalt pavement in a parking area. Four commercially available permeable pavement systems were evaluated after 6 years of daily parking usage for structural durability, ability to infiltrate precipitation, and impacts on infiltrate water quality. All four permeable pavement systems showed no major signs of wear. Virtually all rainwater infiltrated through the permeable pavements, with almost no surface runoff. The infiltrated water had significantly lower levels of copper and zinc than the direct surface runoff from the asphalt area. Motor oil was detected in 89% of samples from the asphalt runoff but not in any water sample infiltrated through the permeable pavement. Neither lead nor diesel fuel were detected in any sample. Infiltrate measured 5 years earlier displayed significantly higher concentrations of zinc and significantly lower concentrations of copper and lead.

  15. 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.

  16. The airport pavements reinforced with Mineral-Asphalt Mixtures’ (MAM layers

    Directory of Open Access Journals (Sweden)

    Jan Marszałek

    2016-09-01

    Full Text Available The article presents original solutions, methodology, and procedure for determining the thickness of bituminous overlays for renovation and modernization of the existing airfield pavements.Using the Westergaard method, the algorithm and nomograms were developed in order to determine the edge stress and the loading force. The nomograms are a state of the art solutions that have never been presented in a similar form. After derivation of aforementioned dependencies, the practical way to use the nomograms, depending on the existing bituminous airport pavement, was demonstrated.The plots were developed on the basis of calculations using the derived equations. They will definitely facilitate the procedure of selecting the thickness of the flexible overlay to the airport pavements which require repair or modernization.[b]Keywords[/b]: airport rigid pavements, airport vulnerable pavements, strengthening the pavement

  17. It's not just about speed: Reviewing the recumbent bicycle once more.

    Science.gov (United States)

    Wieser, Bernhard

    2016-12-01

    Why did the recumbent bicycle never become a dominant design, despite the fact that it was faster than the safety bicycle on the racetrack? Hassaan Ahmed et al. argue in their recently published paper that the main reason for the marginalization of the recumbent bicycle was semiotic power deployed by the Union Cycliste Internationale (UCI). Here, I demonstrate that the authors drew their conclusions from an incomplete application of the Social Construction of Technology (SCOT) framework. Understanding the diffusion of alternative bicycle designs requires considering more than speed, and more than the UCI as a powerful actor. The recumbent bicycle was fast, but rather tricky to ride, and was not really feasible for the transport needs of the working classes, which constituted the most relevant social group of bicycle users during the 1930s.

  18. Sensitivity analysis of longitudinal cracking on asphalt pavement using MEPDG in permafrost region

    OpenAIRE

    Chen Zhang; Hainian Wang; Zhanping You; Biao Ma

    2015-01-01

    Longitudinal cracking is one of the most important distresses of asphalt pavement in permafrost regions. The sensitivity analysis of design parameters for asphalt pavement can be used to study the influence of every parameter on longitudinal cracking, which can help optimizing the design of the pavement structure. In this study, 20 test sections of Qinghai–Tibet Highway were selected to conduct the sensitivity analysis of longitudinal cracking on material parameter based on Mechanistic-Empiri...

  19. Integrating Pavement Crack Detection and Analysis Using Autonomous Unmanned Aerial Vehicle Imagery

    Science.gov (United States)

    2015-03-27

    the- art status in pavement health classification, UAV technology, and computer vision. Pavement Health Pavement repair has been a concern since... photography is uses an f-number. Each time the f- number is doubled, twice the rate of light is allowed onto the image sensor. A camera with a higher... photography in support of this research. Table 2 lists these airframes tested and applicable attributes examined in the selection process. Table 2

  20. Pre-Cast Concrete Panels for Contingency Rigid Airfield Pavement Damage Repairs

    Science.gov (United States)

    2010-06-01

    transfer mechanism in rigid pavements . Load transfer is essentially a design parameter that characterizes the reduction in the stresses and strains in the...the PCC slabs at the joints. Therefore, pavement responses such as stresses and strains are significantly lower compared to situations where no load...presented in Appendix C. Another method to calculate the load transfer efficiency in rigid pavements is based on the stresses under the PCC slabs at

  1. Use of Reclaimed Asphalt Pavement in Conjunction with Ground Improvement: A Case History

    OpenAIRE

    Foye, Kevin C.

    2011-01-01

    The use of Reclaimed Asphalt Pavement (RAP) in lieu of virgin crushed stone aggregate is becoming a widely accepted practice for a number of construction applications, particularly pavement base courses. A number of laboratory RAP studies have considered the mechanical properties of RAP bases in order to support pavement designs incorporating RAP. These studies have revealed a number of interesting relationships between RAP moisture content, compaction, and stiffness. This paper discusses the...

  2. Minimum Thickness of Concrete Pavement for the F-15 and C-17 Aircraft

    Science.gov (United States)

    2013-07-01

    for the design of military rigid airfield pavements contained in the Unified Facilities Criteria 3-260-02 gives the minimum thickness of airfield...Documentation Page ERDC/GSL TR-13-34 v Figures and Tables Figures Figure 1. Layout of the rigid pavement test section...necessary. The study herein provides data to justify the recommended changes in the minimum thickness values of rigid airfield pavements . Personnel of the

  3. Evaluation of Precast Panels for Airfield Pavement Repair. Phase 1: System Optimization and Test Section Construction

    Science.gov (United States)

    2013-06-01

    panel repair system for repair of rigid airfield pavements in contingency situations. Design criteria were provided by AFCEC to assist with the...dimensions limit repair versatility, since they do not align with typical rigid airfield pavement slab sizes. The Air Force prototype system design consists...at the joint. The original Air Force panel design used 0.75-in.-wide joints that were backfilled with a rapid-setting rigid pavement repair material

  4. Conversion Of An Ordinary N Bicycle Into An Electric Bike And Related Research

    OpenAIRE

    2014-01-01

    An electric bicycle as a transport and leisure vehicle is expected to have a promising future. Currently, he market offers a great choice of factory electric bicycles and conversion kits to remake an ordinary bicycle into an electric bike. Also, the increasing number of electric vehicles is determined by the reduction in costs for manufacturing of batteries and an evolution in battery technology. This article presents the implementation of an electric bike by selecting the “Golden Motor Techn...

  5. Modeling cyclist acceleration process for bicycle traffic simulation using naturalistic data

    OpenAIRE

    Ma, Xiaoliang; Luo, Ding

    2016-01-01

    Cycling is a healthy and sustainable form of transportation. The recent increase of daily cyclists in Sweden has triggered broad interest in finding how policies and measures may facilitate the planning of bicycle traffic in the urban area. However, in comparison to car traffic, bicycle traffic is still far from well understood. This study is part of the research effort to investigate microscopic cyclist behavior, model bicycle traffic and finally build a simulation tool for applications in t...

  6. Bicycle-related injuries: a survey in a pediatric emergency department.

    OpenAIRE

    Cushman, R; Down, J; MacMillan, N; Waclawik, H

    1990-01-01

    The number of bicycle-related injuries has risen significantly with the increased popularity of bicycle riding in Canada. The risk of injury is highest among children. To assess the magnitude of the problem and to identify the contributing factors we used a questionnaire, injury reports and patient charts to survey bicycle-related injuries among children brought to the emergency department of the Children's Hospital of Eastern Ontario, Ottawa, between May 1 and Sept. 30, 1988. The questionnai...

  7. Improvement of Freezing of Gait in Patients with Parkinson's Disease by Imagining Bicycling

    Directory of Open Access Journals (Sweden)

    Akio Kikuchi

    2014-03-01

    Full Text Available Freezing of gait (FOG is one of the factors that reduce the quality of life in patients with Parkinson's disease (PD. Imagining bicycling before gait start provided improvement in FOG in 2 PD patients. Imagining and mimicking bicycling after the initiation of gait allowed the rhythmic gait to continue without interruption. We suggest that imagining and mimicking bicycling, which are nonexternal cues, could serve as a helpful therapeutic approach for the intractable freezing and interruption of gait of PD patients.

  8. Bicyclic graphs with maximum sum of the two largest Laplacian eigenvalues

    Directory of Open Access Journals (Sweden)

    Yirong Zheng

    2016-11-01

    Full Text Available Abstract Let G be a simple connected graph and S 2 ( G $S_{2}(G$ be the sum of the two largest Laplacian eigenvalues of G. In this paper, we determine the bicyclic graph with maximum S 2 ( G $S_{2}(G$ among all bicyclic graphs of order n, which confirms the conjecture of Guan et al. (J. Inequal. Appl. 2014:242, 2014 for the case of bicyclic graphs.

  9. Performance of pervious pavement parking bays storing rainwater in the north of Spain.

    Science.gov (United States)

    Gomez-Ullate, E; Bayon, J R; Coupe, S; Castro-Fresno, D

    2010-01-01

    Pervious pavements are drainage techniques that improve urban water management in a sustainable manner. An experimental pervious pavement parking area has been constructed in the north of Spain (Santander), with the aim of harvesting good quality rainwater. Forty-five pervious pavement structures have been designed and constructed to measure stored water quantity and quality simultaneously. Ten of these structures are specifically constructed with different geotextile layers for improving water storage within the pavements. Following the confirmation in previous laboratory experiments that the geotextile influenced on water storage, two different geosynthetics (Inbitex and a One Way evaporation control membrane) and control pervious pavements with no geotextile layers were tested in the field. Weather conditions were monitored in order to find correlations with the water storage within the pervious pavement models tested. During one year of monitoring the three different pervious pavement types tested remained at their maximum storage capacity. The heavy rain events which occurred during the experimental period caused evaporation rates within the pervious pavements to be not significant, but allowed the researchers to observe certain trends in the water storage. Temperature was the most closely correlated weather factor with the level of the water stored within the pervious pavements tested.

  10. Compositions comprising a polypeptide having cellulolytic enhancing activity and a bicycle compound and uses thereof

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Feng; Sweeney, Matthew; Quinlan, Jason

    2015-06-16

    The present invention relates to compositions comprising: a polypeptide having cellulolytic enhancing activity and a bicyclic compound. The present invention also relates to methods of using the compositions.

  11. Compositions comprising a polypeptide having cellulolytic enhancing activity and a bicyclic compound and uses thereof

    Energy Technology Data Exchange (ETDEWEB)

    Quinlan, Jason; Xu, Feng; Sweeney, Matthew

    2016-10-04

    The present invention relates to compositions comprising: a polypeptide having cellulolytic enhancing activity and a bicyclic compound. The present invention also relates to methods of using the compositions.

  12. Mechanical Properties of Asphalt Pavement Structure in Highway Tunnel

    Institute of Scientific and Technical Information of China (English)

    SHI Chun-xiang; GUO Zhong-yin

    2008-01-01

    A linear full 3D finite element method (FEM) was performed in order to present the key design parameters of highway tunnel asphalt pavement under double-wheel load on rectangular loaded area considering horizontal contact stress induced by the acceleration/deceleration of vehicles. The key design parameters are the maximum horizontal tensile stresses at the surface of the asphalt layer, the maximum horizontal tensile stresses at the bottom of the asphalt layer and the maximum vertical shear stresses at the surface of the as- phalt layer were calculated. The influencing factors such as double-wheel weight; asphalt layer thickness; base course stiffness modulus and thickness; and the contact conditions among the structure layers on these key design parameters were also examined separately to propose construction procedures of highway tunnel asphalt pavement.

  13. Application of infrared camera to bituminous concrete pavements: measuring vehicle

    Science.gov (United States)

    Janků, Michal; Stryk, Josef

    2017-09-01

    Infrared thermography (IR) has been used for decades in certain fields. However, the technological level of advancement of measuring devices has not been sufficient for some applications. Over the recent years, good quality thermal cameras with high resolution and very high thermal sensitivity have started to appear on the market. The development in the field of measuring technologies allowed the use of infrared thermography in new fields and for larger number of users. This article describes the research in progress in Transport Research Centre with a focus on the use of infrared thermography for diagnostics of bituminous road pavements. A measuring vehicle, equipped with a thermal camera, digital camera and GPS sensor, was designed for the diagnostics of pavements. New, highly sensitive, thermal cameras allow to measure very small temperature differences from the moving vehicle. This study shows the potential of a high-speed inspection without lane closures while using IR thermography.

  14. Variation Of Characteristics Of Vibropressed Concrete Pavement Blocks

    Directory of Open Access Journals (Sweden)

    Skripkiūnas Gintautas

    2014-10-01

    Full Text Available Concrete pavement blocks were formed and the following properties were investigated after 7 days of curing: density, tensile splitting strength, freezing-thawing resistance, using de-icing salts in one-sided way, and abrasion resistance. The scattering of the values of density and tensile splitting strength of the concrete pavement blocks in the pallet during the process of manufacture was examined. It was determined that the values of density and splitting tensile strength were similar in the diagonals of the pallet. Bigger changes were seen on the edges of the tray. The variation coefficients of the examined properties ranged from 0.5 % to 15.6 %. The biggest scattering of research results was noted in strength.

  15. Use of Recycled Aggregate and Fly Ash in Concrete Pavement

    Directory of Open Access Journals (Sweden)

    Myle N. James

    2011-01-01

    Full Text Available Problem statement: Recycled materials aggregate from the demolished concrete structures and fly ash from burning coal shows the possible application as structural and non structural components in concrete structures. This research aims to evaluate the feasibility of using concrete containing recycled concrete aggregate and fly ash in concrete pavement. Approach: Two water cement ratio (0.45 and 0.55 the compressive strength, modulus of electricity and flexural strength for concrete with recycled aggregate and fly ash with 0, 25% replacing cement in mass were considered. Results: The material properties of recycled aggregate concrete with fly ash indicate comparable results with that of concrete with natural aggregate and without fly ash. Conclusion/Recommendations: The recycled materials could be used in concrete pavement and it will promote the sustainability of concrete.

  16. 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.

  17. Investigations of the dynamics of road pavement reflectance

    Institute of Scientific and Technical Information of China (English)

    Kang Jiang; Kai Yu; Yongchao Zhao

    2012-01-01

    Road pavement reflectance is usually assumed to be invariant in short periods of time in some quantitative remote sensing applications. To examine its variability,reflectance sequences of concrete and asphalt pavement are measured in field for half a day in visible and near-infarecd (VNIR) spectral range using dual-beam method.As much as 20.7% and 3.52% of relative changes are found in asphalt and concrete reflectance data at 550 nm,and all VNIR bands demonstrate similar variations found to correlate with both illumination geometry and the relative portion of diffuse irradiance.In this letter,this effect is interpreted from a mathematic view.Further studies are needed to model the dynamics of reflectance physically.

  18. Modeling the surface stored thermal energy in asphalt concrete pavements

    Directory of Open Access Journals (Sweden)

    Matić Bojan J.

    2016-01-01

    Full Text Available Regression analysis is used to develop models for minimal daily pavement surface temperature, using minimal daily air temperature, day of the year, wind speed and solar radiation as predictors, based on data from Awbari, Lybia,. Results were compared with existing SHRP and LTPP models. This paper also presents the models to predict surface pavement temperature depending on the days of the year using neural networks. Four annual periods are defined and new models are formulated for each period. Models using neural networks are formed on the basis of data gathered on the territory of the Republic of Serbia and are valid for that territory. [Projekat Ministarstva nauke Republike Srbije, br. TR 36017

  19. The Application of FAHP in Decisions of Pavement Maintenance

    Science.gov (United States)

    Wu, Zhaorong

    2017-04-01

    In this paper, a method of building the fuzzy complementary judgement matrix and checking consistency is introduced based on the knowledge of the basic theory of FAHP and the procedure to establish the mathematical model corresponded. The scope and the advantages in the problems of multi-objective decisions have also been discussed. The availability of its use in the management system in pavement maintenance is demonstrated by analyzing the optimization for maintenance. Meanwhile, the faulty is also pointed out.

  20. Assessment of Asphalt Concrete Reinforcement Grid in Flexible Pavements

    Science.gov (United States)

    2016-05-01

    NHDOT) PO Box 483, 5 Hazen Drive Concord, NH 03302-0483 Final Report Approved for public release; distribution is unlimited. Prepared for New...construction of a maintenance overlay and has been subjected to trafficking for several years. Our structural evaluation included a geotechnical...Flexible Pavements.” The technical monitor was Glenn Roberts, NHDOT. This report was prepared by Lynette Barna (Force Projection and Sustain- ment Branch

  1. Pavement wear and airborne dust pollution in Norway

    OpenAIRE

    Snilsberg, Brynhild

    2008-01-01

    In several large cities in Norway the traffic volume is high. The use of studded tires and other friction enhancing measures during winter leads to significant pavement wear, which in turn leads to an increase in the amount of airborne particulate matter, often exceeding the limits set in the ambient air regulation. This represents a nuisance or health risk for people being exposed to the pollution. According to regulations set by the European Union particulate matter is measured and regulate...

  2. Kinect, a Novel Cutting Edge Tool in Pavement Data Collection

    Science.gov (United States)

    Mahmoudzadeh, A.; Firoozi Yeganeh, S.; Golroo, A.

    2015-12-01

    Pavement roughness and surface distress detection is of interest of decision makers due to vehicle safety, user satisfaction, and cost saving. Data collection, as a core of pavement management systems, is required for these detections. There are two major types of data collection: traditional/manual data collection and automated/semi-automated data collection. This paper study different non-destructive tools in detecting cracks and potholes. For this purpose, automated data collection tools, which have been utilized recently are discussed and their applications are criticized. The main issue is the significant amount of money as a capital investment needed to buy the vehicle. The main scope of this paper is to study the approach and related tools that not only are cost-effective but also precise and accurate. The new sensor called Kinect has all of these specifications. It can capture both RGB images and depth which are of significant use in measuring cracks and potholes. This sensor is able to take image of surfaces with adequate resolution to detect cracks along with measurement of distance between sensor and obstacles in front of it which results in depth of defects. This technology has been very recently studied by few researchers in different fields of studies such as project management, biomedical engineering, etc. Pavement management has not paid enough attention to use of Kinect in monitoring and detecting distresses. This paper is aimed at providing a thorough literature review on usage of Kinect in pavement management and finally proposing the best approach which is cost-effective and precise.

  3. DYNAMIC JOINT LOAD TRANSFER EFFICIENCY OF RIGID PAVEMENT

    Directory of Open Access Journals (Sweden)

    YU Xinhua

    2011-02-01

    Full Text Available the mechanistic analysis presented in this paper is only the beginning of new approach for understanding the real joint load transfer capability on airport and highway concrete pavements. It gives up the two major assumptions those have been popularly adopted by hundreds of published papers: the load is transferred under a wheel with zero speed and with fixed position. The real load transfer in field is always under wheels with non-zero speed and with varied position at any moment. The objective of this study focuses on quantifying the dynamic effects of a moving wheel while it is crossing a joint on a pavement. The analysis is conducted using a model of two-slab system on Kelvin foundation under a moving wheel with variable speed v, different pavement damping Cs, foundation reaction modulus k and foundation damping Ck. The dynamic joint load transfer efficiency is temporarily and empirically defined by the peak strain ratio LTE(S on the two sides of a joint. The primary findings include: (1 The higher speed of a moving wheel leads to the higher LTE(S;(2 The larger the pavement damping Cs leads to the higher LTE(S;(3 The numerical ratio c(=LTE(Sdynamic/ LTE(Sstatic varies in the range 1 to 2 mainly depending on speed v and damping Cs;(4 The LTE(Sdynamic is not sensitive to foundation reaction modulus k and foundation damping Ck. Further researches are needed for appropriate applications of the new model in practice.

  4. Guidelines for Design, Construction, and Evaluation of Airport Pavement Drainage

    Science.gov (United States)

    1990-10-01

    Cedergren et. al. (11) have indicated that subsurface drainage may not be needed in pavement systems where the average annual precipitation is less...contributes water flow to each crack or joint (2). These are several ways in which the surface infiltration rate can be determined. Cedergren (3,4) has...Calculation Modules The program performs the following calculations: 5.5.7.1 Water Sources Surface infiltration (user selectable) Ridgeway procedure Cedergren

  5. The improvement of pavement performance using asphalt rubber hot mixes

    OpenAIRE

    Pais, Jorge C.; Pereira, Paulo A. A.

    2007-01-01

    The need of a better pavement performance has led researchers to develop new road materials, mainly for the asphalt layers, where the modification of the asphalt is the main example. This modification usually forces the use of polymers and fibers and, more recently, the use of crumb rubber from ground tires, where the modified asphalt is known as asphalt rubber. This asphalt rubber used in asphalt mixtures produces a superior performance if compared to the asphalt mixtures with...

  6. Structural Design of Asphalt Pavement for Low Cost Rural Roads

    Institute of Scientific and Technical Information of China (English)

    Yuan Goulin; Chen Rongshen

    2006-01-01

    On the basis of the equivalent axle load action frequency, the traffic classifications of rural roads as well as their corresponding types are classified. The asphalt pavement structure, road surface types and thickness of the rural roads are suggested for the various action frequency of the equivalent axle load. Furthermore, the roadbase thickness graphs are provided according to different equivalent axle load action frequency with different roadbed modulus and road surface modulus taken into account.

  7. The Research on the Cracks of the Asphalt Pavement

    Directory of Open Access Journals (Sweden)

    OuYangZiqiang

    2015-07-01

    Full Text Available The cracking is one of the common diseases of the asphalt pavement. According to the shape and the forming reasons, the cracks can be divided into two categories. Each categories can be divided into several types. Through the comparison and the analysis of the causes of different cracks, the prevention and the treatments are proposed in the respects of the structural design, material design and construction

  8. Marginal Aggregates in Flexible Pavements: Background Survey and Experimental Plan

    Science.gov (United States)

    1994-08-01

    cement, bitumen , and water has been marketed in France under the trade name Stabicol 71 , but it is not yet available in the U.S. This composite...in a pavement base course. Geotextile reinforcement and a new portland cement- bitumen emulsion have considerable potential to upgrade substandard...modifiers with SBS , polyethylene. 30 b) Hard Asphalt Cement - AC 40 asphalt cement. c) Large Stone Asphalt Mixtures - Increase maximum aggregate size. e

  9. Influential Factors on Deicing Performance of Electrically Conductive Concrete Pavement

    Institute of Scientific and Technical Information of China (English)

    TANG Zuquan; QIAN Jueshi; LI Zhuoqiu; WU Chuanming

    2006-01-01

    The deicing experiment of carbon fiber reinforced electrically conductive concrete (CFRC) slab was conducted in laboratory at first, then the deicing process of CFRC pavement was analyzed by means of finite element method (FEM). At last, based on the energy conservation law and the computing results of finite element method, the influential factors including the setting of electric heating layer, environmental temperature, the thickness of ice, material parameters, and deicing power on deicing performance and energy consumption were discussed.

  10. 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.

  11. Study the Relationship between Pavement Surface Distress and Roughness Data

    Directory of Open Access Journals (Sweden)

    Mubaraki Muhammad

    2016-01-01

    Full Text Available In this paper, pavement sections from the highway connected Jeddah to Jazan were selected and analyzed to investigate the relationship between International Roughness Index (IRI and pavement damage including; cracking, rutting, and raveling. The Ministry of Transport (MOT of Saudi Arabia has been collecting pavement condition data using the Road Surface Tester (RST vehicle. The MOT measures Roughness, Rutting (RUT, Cracking (CRA, raveling (RAV. Roughness measurements are calculated in terms of the International Roughness Index (IRI. The IRI is calculated over equally spaced intervals along the road profile. Roughness measurements are performed at speed between at 80 kilometers per hour. Thus RST vehicle has been used to evaluate highways across the country. The paper shows three relationships including; cracking (CRA verses roughness (IRI, rutting (RUT verses IRI, and raveling (RAV verses IRI. Also, the paper developed two models namely; model relates IRI to the three distress under study, and model relates IRI to ride quality. The results of the analysis claim at 95% confidence that a significant relationship exist between IRI and cracking, and raveling. It’s also shown that rutting did not show significant relationship to IRI values. That’s leads to conclude that the distresses types: cracking and raveling may possibly be described as ride quality distresses at different level of significant. Rutting distress described as non-ride quality type’s distresses.

  12. Laboratory Measurements of Particulate Matter Concentrations from Asphalt Pavement Abrasion

    Science.gov (United States)

    Fullová, Daša; Đurčanská, Daniela

    2016-12-01

    The issue of emissions from road traffic is compounded by the fact that the number of vehicles and driven kilometres increase each year. Road traffic is one of the main sources of particulate matter and traffic volume is still increasing and has unpleasant impact on longevity of the pavements and the environment. Vehicle motions cause mechanical wearing of the asphalt pavement surface - wearing course by vehicle tyres. The contribution deals with abrasion of bituminous wearing courses of pavements. The asphalt mixtures of wearing courses are compared in terms of mechanically separated particulate matter. The samples of asphalt mixtures were rutted in wheel tracking machine. The particulate matter measurements were performed in laboratory conditions. The experimental laboratory measurements make it possible to sample particulates without contamination from exhaust emissions, abraded particles from vehicles, resuspension of road dust and climate affects. The contribution offers partial results of measurements on six trial samples of asphalt mixtures with different composition. It presents particulate matter morphology and the comparison of rutted asphalt samples in terms of PM mass concentrations and chemical composition.

  13. 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.

  14. EVALUATION OF TIRE RUBBER DISPOSAL IN CONCRETE FOR PAVEMENTS

    Directory of Open Access Journals (Sweden)

    Rosa Cristina Cecche Lintz

    2009-12-01

    Full Text Available The production of waste by the tire industry has been a growing problem, indicating the need for its reuse. More than thirty million tires are discharged per year in Brazil, where regulation for the environment states that for each four new tires, five unusable ones must be adequately disposed by manufacturers and importers. Paving consumes an extremely large quantity of materials, which can be the source of rational application of waste and rejected materials. Research shows that tire rubber can be added to asphalt, which increases its durability and improves pavement quality and safety conditions by absorbing the rubber elastic properties, and also be used for architectural applications, among others. This study deals with the addition of rubber fibers from tire crushing in concrete for roadway pavements in order to provide proper indication about the alternative material disposal through an evaluation of the mechanical behavior of the modified concrete. Different concrete mixes were produced, within which, part of fine aggregates were substituted by tire rubber and mechanical experiment tests were performed, which show that, due to great resistance losses, the disposal of this alternative material in concrete should be considered for light traffic pavements, with the addition of rubber ranging up to 10% in mass.

  15. EVALUATION OF TIRE RUBBER DISPOSAL IN CONCRETE FOR PAVEMENTS

    Directory of Open Access Journals (Sweden)

    Rosa Cristina Cecche Lintz

    2009-01-01

    Full Text Available The production of waste by the tire industry has been a growing problem, indicating the need for its reuse. More than thirty million tires are discharged per year in Brazil, where regulation for the environment states that for each four new tires, five unusable ones must be adequately disposed by manufacturers and importers. Paving consumes an extremely large quantity of materials, which can be the source of rational application of waste and rejected materials. Research shows that tire rubber can be added to asphalt, which increases its durability and improves pavement quality and safety conditions by absorbing the rubber elastic properties, and also be used for architectural applications, among others. This study deals with the addition of rubber fibers from tire crushing in concrete for roadway pavements in order to provide proper indication about the alternative material disposal through an evaluation of the mechanical behavior of the modified concrete. Different concrete mixes were produced, within which, part of fine aggregates were substituted by tire rubber and mechanical experiment tests were performed, which show that, due to great resistance losses, the disposal of this alternative material in concrete should be considered for light traffic pavements, with the addition of rubber ranging up to 10% in mass.

  16. Neuromodulation of Nestmate Recognition Decisions by Pavement Ants.

    Science.gov (United States)

    Bubak, Andrew N; Yaeger, Jazmine D W; Renner, Kenneth J; Swallow, John G; Greene, Michael J

    2016-01-01

    Ant colonies are distributed systems that are regulated in a non-hierarchical manner. Without a central authority, individuals inform their decisions by comparing information in local cues to a set of inherent behavioral rules. Individual behavioral decisions collectively change colony behavior and lead to self-organization capable of solving complex problems such as the decision to engage in aggressive societal conflicts with neighbors. Despite the relevance to colony fitness, the mechanisms that drive individual decisions leading to cooperative behavior are not well understood. Here we show how sensory information, both tactile and chemical, and social context-isolation, nestmate interaction, or fighting non-nestmates-affects brain monoamine levels in pavement ants (Tetramorium caespitum). Our results provide evidence that changes in octopamine and serotonin in the brains of individuals are sufficient to alter the decision by pavement ants to be aggressive towards non-nestmate ants whereas increased brain levels of dopamine correlate to physical fighting. We propose a model in which the changes in brain states of many workers collectively lead to the self-organization of societal aggression between neighboring colonies of pavement ants.

  17. Performance of Recycled Asphalt Pavement as Coarse Aggregate in Concrete

    Directory of Open Access Journals (Sweden)

    Fidelis O. OKAFOR

    2010-12-01

    Full Text Available Recycled asphalt pavement (RAP is the reclaimed and reprocessed pavement material containing asphalt and aggregate. Most RAP is recycled back into pavements, and as a result there is a general lack of data pertaining to the mechanical properties for RAP in other possible applications such as Portland cement concrete. In the present study, some mechanical properties of Portland cement concrete containing RAP as coarse aggregate were investigated in the laboratory. Six concrete mixes of widely differing water/cement ratios and mix proportions were made using RAP as coarse aggregate. The properties tested include the physical properties of the RAP aggregate, the compressive and flexural strengths of the concrete. These properties were compared with those of similar concretes made with natural gravel aggregate. Results of the tests suggest that the strength of concrete made from RAP is dependent on the bond strength of the “asphalt-mortar” (asphalt binder-sand-filler matrix coatings on the aggregates and may not produce concrete with compressive strength above 25 MPa. However, for middle and low strength concrete, the material was found to compare favorably with natural gravel aggregate.

  18. Numerical Simulation of Moving Load on Concrete Pavements

    Directory of Open Access Journals (Sweden)

    Lajčáková Gabriela

    2015-06-01

    Full Text Available The knowledge of the development with time of the strain and stress states in pavement structures is needed in the solution of various engineering tasks as the design fatigue lifetime reliability maintenance and structure development. The space computing model of the truck TATRA 815 is introduced. The pavement computing model is created in the sense of Kirchhof theory of the thin slab on elastic foundation. The goal of the calculation is to obtain the vertical deflection in the middle of the slab and the time courses of vertical tire forces. The equations of motion are derived in the form of differential equations. The assumption about the shape of the slab deflection area is adopted. The equations of the motion are solved numerically in the environment of program system MATLAB. The dependences following the influence of various parameters (speed of vehicle motion, stiffness of subgrade, slab thickness, road profile on the pavement vertical deflections and the vertical tire forces are introduced. The results obtained from the plate computing model are compared with the results obtained by the FEM analysis. The outputs of the numerical solution in the time domain can be transformed into a frequency domain and subsequently used to solve various engineering tasks.

  19. Laboratory Measurements of Particulate Matter Concentrations from Asphalt Pavement Abrasion

    Directory of Open Access Journals (Sweden)

    Fullová Daša

    2016-12-01

    Full Text Available The issue of emissions from road traffic is compounded by the fact that the number of vehicles and driven kilometres increase each year. Road traffic is one of the main sources of particulate matter and traffic volume is still increasing and has unpleasant impact on longevity of the pavements and the environment. Vehicle motions cause mechanical wearing of the asphalt pavement surface - wearing course by vehicle tyres. The contribution deals with abrasion of bituminous wearing courses of pavements. The asphalt mixtures of wearing courses are compared in terms of mechanically separated particulate matter. The samples of asphalt mixtures were rutted in wheel tracking machine. The particulate matter measurements were performed in laboratory conditions. The experimental laboratory measurements make it possible to sample particulates without contamination from exhaust emissions, abraded particles from vehicles, resuspension of road dust and climate affects. The contribution offers partial results of measurements on six trial samples of asphalt mixtures with different composition. It presents particulate matter morphology and the comparison of rutted asphalt samples in terms of PM mass concentrations and chemical composition.

  20. Configurations Of Tire Pressure On The Pavement For Commercial Vehicles: Calculation Of The ‘N’ Number And The Consequences On Pavement Performance

    Directory of Open Access Journals (Sweden)

    Paulo Boulos Filho

    2016-07-01

    Full Text Available Road traffic has a high variety of types of vehicles and cargo transported. One of the main difficulties in pavement design is forecasting the changes in traffic over time and evaluating the comparative deterioration power of the various loads with axle and tire settings and different levels of repetition. The road environment in Brazil, as we know, is the main means of the country's cargo transportation. Throughout the 1990s and 2000s the road modal accounted for over 60% of the total cargo transported in the country leaving the unbalanced Brazilian transport matrix with almost exclusive investments in such means of transportation. According to CNT 2012, which conducted a survey in approximately 45% of the paved network, evaluating the pavement functional conditions, traffic signs and geometry, 46% of the country’s road network has some type of deficiency in the pavement. The goal of this work is to contribute to a better understanding of the complex influence of traffic in the design and service life of the pavement. The load pressure of commercial vehicle tires over the pavement has increased in recent decades. A more apparent effect of this increase in tire pressure would be the change in the pavement- tire contact area which in turn may result in an increase in the contact load between tire and pavement and other harmful effects on the structure. This study aims to determine the effect on the calculation of the N number, or the number of solicitations of the standard axle on the road pavement, measuring the overload as a percentage of the legal load indicated by a scale. In short, we calculate how an increase in the overload percentage in comparison with the allowable load will influence the decrease of the calculated durability of the pavement designed for the highway.

  1. Investigation of mechanical properties of pavement through electromagnetic techniques

    Science.gov (United States)

    Benedetto, Andrea; Tosti, Fabio; D'Amico, Fabrizio

    2014-05-01

    Ground-penetrating radar (GPR) is considered as one of the most flexible geophysical tools that can be effectively and efficiently used in many different applications. In the field of pavement engineering, GPR can cover a wide range of uses, spanning from physical to geometrical inspections of pavements. Traditionally, such inferred information are integrated with mechanical measurements from other traditional (e.g. plate bearing test) or non-destructive (e.g. falling weight deflectometer) techniques, thereby resulting, respectively, in time-consuming and low-significant measurements, or in a high use of technological resources. In this regard, the new challenge of retrieving mechanical properties of road pavements and materials from electromagnetic measurements could represent a further step towards a greater saving of economic resources. As far as concerns unpaved and bound layers it is well-known that strength and deformation properties are mostly affected, respectively, by inter-particle friction and cohesion of soil particles and aggregates, and by bitumen adhesion, whose variability is expressed by the Young modulus of elasticity. In that respect, by assuming a relationship between electromagnetic response (e.g. signal amplitudes) and bulk density of materials, a reasonable correlation between mechanical and electric properties of substructure is therefore expected. In such framework, a pulse GPR system with ground-coupled antennae, 600 MHz and 1600 MHz centre frequencies was used over a 4-m×30-m test site composed by a flexible pavement structure. The horizontal sampling resolution amounted to 2.4×10-2 m. A square regular grid mesh of 836 nodes with a 0.40-m spacing between the GPR acquisition tracks was surveyed. Accordingly, a light falling weight deflectometer (LFWD) was used for measuring the elastic modulus of pavement at each node. The setup of such instrument consisted of a 10-kg falling mass and a 100-mm loading plate so that the influence domain

  2. Thermoregulation during prolonged actual and laboratory-simulated bicycling.

    Science.gov (United States)

    Brown, S L; Banister, E W

    1985-01-01

    Thermoregulatory and cardiorespiratory responses to bicycling 55 km (mean speed 9.7 m X s-1) outdoors (15 degrees C DB) were compared to equivalent cycle ergometry (90 min at 65% VO2max) in the laboratory (20-23 degrees C DB, 50% RH) in 7 trained cyclists. Outdoor environmental conditions were simulated with fans and lamps, and were contrasted with standard no-wind, no-sun laboratory conditions. Sweating rate was similar during outdoor and laboratory simulated outdoor cycling (0.90 and 0.87 to 0.94 1 X h-1 respectively). During outdoor bicycling, mean heart rate (161 bt X min-1) was 7-13% higher (p less than .05) than under laboratory conditions, suggesting a greater strain for a similar external work rate. The increase in rectal temperature (0.8 degrees C) was 33-50% less (p less than 0.05) at the cooler outdoor ambient temperature than in the laboratory. Thermoregulatory stress was greater under the no-fan, no-lamp laboratory condition than during simulated outdoor conditions (36-38% greater (p less than 0.05) sweating rate, 15-18% greater (p less than 0.01) mean skin temperature, 6.4 to 7.8 fold greater (p less than 0.01) amount of clothing-retrained sweat). The cooling wind encountered in actual road bicycling apparently reduces thermoregulatory and circulatory demands compared with stationary cycle ergometry indoors. Failure to account for this enhanced cooling may result in overestimation of the physiological stress of actual road cycling.(ABSTRACT TRUNCATED AT 250 WORDS)

  3. Efficiency of the bicycle operation under various tactical variants

    Directory of Open Access Journals (Sweden)

    A.N. Kolumbet

    2017-10-01

    Full Text Available Aim: to determine the efficiency of the cyclist in various tactical options. Material: In the experiments participated athletes (n = 6 of high qualification (mean age - 19.8 ± 1.3 years, mean weight - 71.4 ± 3.5 kg. As a model of the individual pursuit race at 4 km, a five-minute pedaling on the bicycle ergometer was used. Series of loads was set on the modernized mechanical bicycle ergometer “Monark” . The five-minute bicycle ergometer test is similar to the individual pursuit race at 4 km: according to the time of the exercise; on the frequency of pedaling (110-120 rpm; on the frequency of heartbeats. Results: Tactical variants in the pursuit race at 4 km are considered. The total work in a free test was on average 106.38 ± 3.57 kJ. The operating energy consumption is on average for 379.0±16.1 kJ. The operating efficiency (economy of the exercise attained on average for 28.0 ± 0.75%. This corresponds to the effectiveness of aerobic work of moderate power. The ratio of aerobic and anaerobic contributions to the provision of work was 77.3 and 22.7%. The smallest work was done in a test with step-increasing power. The athletes performed the closest work to the given job in the test with a variable (±15% operating mode. The shortfall in it was on average for 0.46%. The absence of reliable differences in the economics of the work did not allow us to identify a rational variant of power distribution for an exercise lasting 5 minutes. Conclusions: Tactical options in the pursuit race for 4 km depend on the features of the power systems of the rider. When optimizing tactics, it is necessary to select an individually optimal variant of the distribution of forces at a distance.

  4. Consumers’ preferences for “bicycle poultry” in Benin

    DEFF Research Database (Denmark)

    Sodjinou, Epiphane; Henningsen, Arne; Koudande, Delphin O.;

    2015-01-01

    Village poultry, also termed "bicycle poultry," is produced in scavenging farming systems and is a chewy meat with a low fat content, and constitutes an important source of meat in many African countries. This study investigates consumers’ preferences regarding the physical traits of these birds...... (notably chickens, ducks and guinea fowl) in the Republic of Benin. For this purpose, we applied the hedonic price method on field data collected from retailers in four urban and five rural markets. We found that meatier drake and meatier guinea fowl with white plumage are preferred by consumers who...

  5. Consumers’ preferences for “bicycle poultry” in Benin

    DEFF Research Database (Denmark)

    Sodjinou, Epiphane; Henningsen, Arne; Koudande, Delphin O.;

    Village poultry, also termed "bicycle poultry," is produced in scavenging farming systems and is a chewy meat with a low fat content, and constitutes an important source of meat in many African countries. This study investigates consumers’ preferences regarding the physical traits of these birds...... (notably chickens, ducks and guinea fowl) in the Republic of Benin. For this purpose, we applied the hedonic price method on field data collected from retailers in four urban and five rural markets. We found that meatier drake and meatier guinea fowl with white plumage are preferred by consumers who...

  6. Exploring the Chemistry of Bicyclic Isoxazolidines for the Multicomponent Synthesis of Glycomimetic Building Blocks

    NARCIS (Netherlands)

    Hoogenboom, Jorin; Lutz, Martin; Zuilhof, Han; Wennekes, Tom

    2016-01-01

    Starting from a chiral furanone, the nitrone-olefin [3 + 2] cycloaddition can be used to obtain bicyclic isoxazolidines for which we report a set of reactions to selectively modify each functional position. These synthetically versatile bicyclic isoxazolidines allowed us to obtain complex glycomi

  7. Bicyclic isoureas derived from 1-deoxynojirimycin are potent inhibitors of β-glucocerebrosidase

    NARCIS (Netherlands)

    Sevšek, Alen; Čelan, Maša; Erjavec, Bibi; Quarles van Ufford, Linda; Sastre Toraño, Javier; Moret, Ed E; Pieters, Roland J; Martin, Nathaniel I

    2016-01-01

    A series of bicyclic isourea derivatives were prepared from 1-deoxynojirimycin using a concise synthetic protocol proceeding via a guanidino intermediate. Inhibition assays with a panel of glycosidases revealed that these deoxynojirimycin-derived bicyclic isoureas display very potent inhibition agai

  8. The Bicycle Helmet Attitudes Scale: Using the Health Belief Model to Predict Helmet Use among Undergraduates

    Science.gov (United States)

    Ross, Thomas P.; Ross, Lisa Thomson; Rahman, Annalise; Cataldo, Shayla

    2010-01-01

    Objective: This study examined bicycle helmet attitudes and practices of college undergraduates and developed the Bicycle Helmet Attitudes Scale, which was guided by the Health Belief Model (HBM; Rosenstock, 1974, in Becker MH, ed. "The Health Belief Model and Personal Health Behavior". Thorofare, NJ: Charles B. Slack; 1974:328-335) to predict…

  9. Getting Bicycles on Trains - Inter-modal Transport Developments in Denmark

    DEFF Research Database (Denmark)

    Jørgensen, Ulrik; Pedersen, Bjørn Brix

    2001-01-01

    The combined use of bicycles and trains has been favored in contemporary public transport policies in Denmark. Although bicycling has played a major role in Danish personal transportation in more than hundred years, the attitude from public transport authorities towards supporting bicyclists has...

  10. The Dutch Reference Study: Cases of interventions in bicycle infrastructure reviewed in the framework of Bikeability

    NARCIS (Netherlands)

    Van Goeverden, C.D.; Godefrooij, T.

    2011-01-01

    The Netherlands have a tradition of high bicycle usage and a long history of research on effective policies for promoting cycling. Findings in Dutch studies can be useful in the Danish Bikeability-project that has the objective to increase the level of knowledge in relation to bicycle based transpor

  11. Envisioning Competence: Learning, Problem Solving, and Children at Work in the Exploratory Bicycle Shop

    Science.gov (United States)

    Hammond, Charles Florian

    2010-01-01

    This study examines the conceptual learning and cognitive development processes of schoolchildren engaged in problem solving activities in a non-school, workplace setting known as the exploratory bicycle shop. The exploratory bike shop is a commercial bicycle shop: a) that has been adapted for combined retail and educational purposes and b) where…

  12. The unexpected stable market share of the bicycle in The Netherlands

    NARCIS (Netherlands)

    Van Goeverden, C.D.; Van Arem, B.; Godefrooij, T.

    2013-01-01

    In the Netherlands, the share of the bicycle as the main mode in all person trips has been highly constant in the past three decades (about 27%). A constant share is remarkable because a number of developments in this period were unfavourable for bicycle use, like ageing of the population, growing n

  13. Does pedalling on a recumbent bicycle influence the cyclist’s steering behaviour?

    NARCIS (Netherlands)

    Boon, K.M.; Klap, P.; Van Lanen, J.A.; Letsoin, G.J.; Jansen, A.J.

    2014-01-01

    The paper presents the answer to the question how pedalling on a specific recumbent bicycle, such as the VeloX3, influences a cyclist’s ability to steer the bicycle. The research aims to find the correlation between pedalling and the undesired steering movements it creates. To test this assumption a

  14. Radical Technological Innovation: Case Study of the P1.18 Bicycle Transmission by Pinion

    OpenAIRE

    Wohlfeil, Florian

    2015-01-01

    To shed some light on the concrete factors that determine success of radical technological innovations a concrete case of such an innovation will be studied. In 2008, two engineers founded the Pinion GmbH to develop and exploit a new bicycle transmission concept as competitive shifting system for bicycles to overcome the existent disadvantages of traditional derailleur systems and internal gear hubs.

  15. Exploring the Chemistry of Bicyclic Isoxazolidines for the Multicomponent Synthesis of Glycomimetic Building Blocks

    NARCIS (Netherlands)

    Hoogenboom, Jorin; Lutz, Martin; Zuilhof, Han; Wennekes, Tom

    2016-01-01

    Starting from a chiral furanone, the nitrone-olefin [3 + 2] cycloaddition can be used to obtain bicyclic isoxazolidines for which we report a set of reactions to selectively modify each functional position. These synthetically versatile bicyclic isoxazolidines allowed us to obtain complex

  16. The Bicycle Helmet Attitudes Scale: Using the Health Belief Model to Predict Helmet Use among Undergraduates

    Science.gov (United States)

    Ross, Thomas P.; Ross, Lisa Thomson; Rahman, Annalise; Cataldo, Shayla

    2010-01-01

    Objective: This study examined bicycle helmet attitudes and practices of college undergraduates and developed the Bicycle Helmet Attitudes Scale, which was guided by the Health Belief Model (HBM; Rosenstock, 1974, in Becker MH, ed. "The Health Belief Model and Personal Health Behavior". Thorofare, NJ: Charles B. Slack; 1974:328-335) to predict…

  17. Bicycle Design: A different approach to improving on the world human powered speed records

    NARCIS (Netherlands)

    Epema, H.K.; Van den Brand, S.; Gregoor, W.; Kooijman, J.D.G.; Pereboom, H.P.; Wielemaker, D.C.; Van der Zweep, C.J.

    2012-01-01

    The current International Human Powered Vehicle Association world records for faired bicycles stand at 133.284km/h for the 200m flying start speed record and 91.562 km for the hour record. Traditionally the recumbent bicycles that have been developed for breaking one of either of these records have

  18. The unexpected stable market share of the bicycle in The Netherlands

    NARCIS (Netherlands)

    Van Goeverden, C.D.; Van Arem, B.; Godefrooij, T.

    2013-01-01

    In the Netherlands, the share of the bicycle as the main mode in all person trips has been highly constant in the past three decades (about 27%). A constant share is remarkable because a number of developments in this period were unfavourable for bicycle use, like ageing of the population, growing n

  19. Advocating Green Transport and Promoting Healthy Urban Development: Strategies for Bicycle Transport Development in Jinan

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    <正>As a green transport means,the bicycle has a history of over two hundred years.Since the 1970s,due to the inf luence of energy crisis and the consciousness of environment protection,the bicycle has regained its popularity in the public for its

  20. Asphalt Pavement Aging and Temperature Dependent Properties Using Functionally Graded Viscoelastic Model

    Science.gov (United States)

    Dave, Eshan V.

    2009-01-01

    Asphalt concrete pavements are inherently graded viscoelastic structures. Oxidative aging of asphalt binder and temperature cycling due to climatic conditions being the major cause of non-homogeneity. Current pavement analysis and simulation procedures dwell on the use of layered approach to account for these non-homogeneities. The conventional…

  1. RoADS: a road pavement monitoring system for anomaly detection using smart phones

    NARCIS (Netherlands)

    Seraj, Fatjon; Zwaag, van der Berend Jan; Dilo, Arta; Luarasi, Tamara; Havinga, Paul; Atzmueller, Martin; Chin, Alvin; Janssen, Frederik; Schweizer, Immanuel; Trattner, Christoph

    2016-01-01

    Monitoring the road pavement is a challenging task. Authorities spend time and finances to monitor the state and quality of the road pavement. This paper investigate road surface monitoring with smartphones equipped with GPS and inertial sensors: accelerometer and gyroscope. In this study we descri

  2. RoADS: a road pavement monitoring system for anomaly detection using smart phones

    NARCIS (Netherlands)

    Seraj, Fatjon; Zwaag, van der Berend Jan; Dilo, Arta; Luarasi, Tamara; Havinga, Paul

    2014-01-01

    Monitoring the road pavement is a challenging task. Authorities spend time and finances to monitor the state and quality of the road pavement. This paper investigate road surface monitoring with smartphones equipped with GPS and inertial sensors: accelerometer and gyroscope. In this study we describ

  3. Modelling tyre-road contact stresses in pavement design and analysis

    CSIR Research Space (South Africa)

    Maina, JW

    2013-07-01

    Full Text Available to optimize road pavement design, especially close to the surface of the pavement requiring accurate modelling of tyre-road contact stresses. The aim of this paper is to demonstrate modern ways to idealise tyre-road interaction based on Stress-In-Motion (SIM...

  4. Geomaterial characterizations of full scale pavement test sections for mechanistic analysis and design

    CSIR Research Space (South Africa)

    Kwon, J

    2007-02-01

    Full Text Available Resilient modulus is a key input property of pavement foundation geomaterials, i.e., subgrade soil and base/subbase unbound aggregate, for the mechanistic-empirical design of flexible pavements. Recent research at the University of Illinois has...

  5. 23 CFR 973.208 - Indian lands pavement management system (PMS).

    Science.gov (United States)

    2010-04-01

    ... 23 Highways 1 2010-04-01 2010-04-01 false Indian lands pavement management system (PMS). 973.208... HIGHWAYS MANAGEMENT SYSTEMS PERTAINING TO THE BUREAU OF INDIAN AFFAIRS AND THE INDIAN RESERVATION ROADS PROGRAM Bureau of Indian Affairs Management Systems § 973.208 Indian lands pavement management system...

  6. Evaluation of Surface and Subsurface Processes in Permeable Pavement Infiltration Trenches

    Science.gov (United States)

    The hydrologic performance of permeable pavement systems can be affected by clogging of the pavement surface and/or clogging at the interface where the subsurface storage layer meets the underlying soil. As infiltration and exfiltration are the primary functional mechanisms for ...

  7. Creep recovery behaviour of bituminous binders - relevance to permanent deformation of asphalt pavements

    CSIR Research Space (South Africa)

    Mturi, GAJ

    2012-05-01

    Full Text Available different modifiers has expanded the range of PMBs to select from when designing pavements in order to avoid pavement deformation. The new binder selection criterion using the Multiple Stress Creep and Recovery (MSCR) protocol as per ASTM D7405 is meant...

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

    Science.gov (United States)

    2017-06-01

    The inclusion of geosynthetics in pavement structures has been utilized as a means of reducing costs and/or extending pavement service life. These... labor and equipment requirements. As new geosynthetic products are developed, full-scale performance data are needed to provide quantifiable benefits to

  9. 76 FR 67018 - Notice to Manufacturers of Airport In-Pavement Stationary Runway Weather Information Systems

    Science.gov (United States)

    2011-10-28

    ... Information Systems AGENCY: Federal Aviation Administration (FAA), U.S. DOT. ACTION: Notice to Manufacturers of In-Pavement Stationary Runway Weather Information Systems. SUMMARY: Projects funded under the... Active or Passive In- Pavement Stationary Runway Weather Information Systems that meet the...

  10. Intertidal boulder pavements in the northeastern Gulf of Alaska and their geological significance

    Science.gov (United States)

    Eyles, C. H.

    1994-01-01

    Striated boulder pavements, consisting of planar concentrations of clasts having striated upper surfaces, are a common feature of glacigenic deposits but their origin is not well understood. Laterally extensive pavements are currently forming in the intertidal zone west of Icy Bay in the Gulf of Alaska. Pavements comprise "armoured" layers of interlocking boulders, one clast thick, that have been eroded from underlying outcrops of Late Cenozoic glaciomarine diamictites; they originate essentially as lag surfaces along a high energy, storm-dominated, mesotidal shoreline. Boulder pavements are either flat or show a "nucleated" plan form where successively smaller boulders have been accreted around a large core boulder. Nucleation imparts a hummocky surface topography to the pavements and suggests that some form of size sorting of clasts has occurred. Packing is promoted by repeated tamping of the clast lag by floating masses of glacier ice which become grounded across the intertidal zone at low tide. Repeated abrasion of the pavement surface by debris contained within ice blocks produces smooth, flattened clast upper surfaces and short, randomly oriented striations. Data from Icy Bay can be used to constrain the origin of laterally extensive boulder pavements exposed in Late Cenozoic glaciomarine sediments on Middleton Island. The significance of such pavements in the geologic record is that they form along erosional unconformities and may identify sequence boundaries.

  11. Unified Methodology for Airport Pavement Analysis and Design. Volume 1. State of the Art

    Science.gov (United States)

    1991-06-01

    pavements with saturated bases and subgrades to well- drained pavements. The damage factors ranged from 10 to 70,000. Cedergren also demonstrated that...34Modulus of Asphalt Mixtures - An Unresolved Dilemma," Transportation Research Board, Research Record 1171, p. 193, Washington, DC 13. Cedergren , H.R

  12. Quantifying Evaporation and Evaluating Runoff Estimation Methods in a Permeable Pavement System

    Science.gov (United States)

    The U.S. Environmental Protection Agency constructed a 0.4-ha parking lot in Edison, New Jersey, that incorporated permeable pavement in the parking lanes which were designed to receive run-on from the impervious hot-mix asphalt driving lanes. Twelve lined permeable pavement sec...

  13. Effects of reclaimed asphalt pavement on indirect tensile strength test of conditioned foamed asphalt mix

    Science.gov (United States)

    Yati Katman, Herda; Rasdan Ibrahim, Mohd; Yazip Matori, Mohd; Norhisham, Shuhairy; Ismail, Norlela

    2013-06-01

    This paper presents the results of Indirect Tensile Strength (ITS) Test for samples prepared with reclaimed asphalt pavement (RAP). Samples were conditioned in water at 25°C for 24 hours prior to testing. Results show that recycled aggregate from reclaimed asphalt pavement performs as well as virgin aggregate.

  14. Design of Rigid and Flexible Pavements by Various Methods & Their Cost Analysis of Each Method

    Directory of Open Access Journals (Sweden)

    Saurabh Jain

    2013-09-01

    Full Text Available Highway and pavement design plays an important role in the DPR projects. The satisfactory performance of the pavement will result in higher savings in terms of vehicle operating costs and travel time, which has a bearing on the overall economic feasibility of the project. This paper discusses about the design methods that are traditionally being followed and examines the “Design of rigid and flexible pavements by various methods & their cost analysis by each method”. Flexible pavement are preferred over cement concrete roads as they have a great advantage that these can be strengthened and improved in stages with the growth of traffic and also their surfaces can be milled and recycled for rehabilitation. The flexible pavements are less expensive also with regard to initial investment and maintenance. Although Rigid pavement is expensive but have less maintenance and having good design period. The economic part are carried out for the design pavement of a section by using the result obtain by design method and their corresponding component layer thickness. It can be done by drawing comparisons with the standard way and practical way. This total work includes collection of data analysis various flexible and rigid pavement designs and their estimation procedure are very much useful to engineer who deals with highways.

  15. 78 FR 26847 - Including Specific Pavement Types in Federal-aid Highway Traffic Noise Analyses

    Science.gov (United States)

    2013-05-08

    ... Federal Highway Administration Including Specific Pavement Types in Federal-aid Highway Traffic Noise... types used in Federal-aid highway traffic noise analyses. Current highway traffic noise analyses rely on... suggestions on whether and how to include additional pavement types in Federal-aid highway traffic...

  16. Active zone impact on deformation state of non-rigid pavement

    Science.gov (United States)

    Mandula, Ján

    2014-06-01

    The paper deals with the design of non-rigid pavement, with emphasis on the effect of active zone on its deformation state. The concepts of determination of active zone are described. The results of numerical modelling of pavement laying on elastic subgrade are presented in the paper

  17. Active zone impact on deformation state of non-rigid pavement

    Directory of Open Access Journals (Sweden)

    Mandula Ján

    2014-06-01

    Full Text Available The paper deals with the design of non-rigid pavement, with emphasis on the effect of active zone on its deformation state. The concepts of determination of active zone are described. The results of numerical modelling of pavement laying on elastic subgrade are presented in the paper

  18. Can You Ride a Bicycle? The Ability to Ride a Bicycle Prevents Reduced Social Function in Older Adults With Mobility Limitation

    Directory of Open Access Journals (Sweden)

    Ryota Sakura

    2016-06-01

    Full Text Available Background: The health benefits of bicycling in older adults with mobility limitation (ML are unclear. We investigated ML and functional capacity of older cyclists by evaluating their instrumental activities of daily living (IADL, intellectual activity, and social function. Methods: On the basis of interviews, 614 community-dwelling older adults (after excluding 63 participants who never cycled were classified as cyclists with ML, cyclists without ML, non-cyclists with ML (who ceased bicycling due to physical difficulties, or non-cyclists without ML (who ceased bicycling for other reasons. A cyclist was defined as a person who cycled at least a few times per month, and ML was defined as difficulty walking 1 km or climbing stairs without using a handrail. Functional capacity and physical ability were evaluated by standardized tests. Results: Regular cycling was documented in 399 participants, and 74 of them (18.5% had ML; among non-cyclists, 49 had ML, and 166 did not. Logistic regression analysis for evaluating the relationship between bicycling and functional capacity revealed that non-cyclists with ML were more likely to have reduced IADL and social function compared to cyclists with ML. However, logistic regression analysis also revealed that the risk of bicycle-related falls was significantly associated with ML among older cyclists. Conclusions: The ability and opportunity to bicycle may prevent reduced IADL and social function in older adults with ML, although older adults with ML have a higher risk of falls during bicycling. It is important to develop a safe environment for bicycling for older adults.

  19. 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

  20. Contemporary biogenic formation of clay pavements by eucalypts: further support for the phytotarium concept

    Science.gov (United States)

    Pate, John S.; Verboom, William H.

    2009-01-01

    Background and Aims Clayey (sodosolic) pavements were studied in lateral root catchments of eucalypts where mixed myrtaceous:proteaceous vegetation was colonizing a dune of quartzitic sand blown out from a playa lake during late Pleistocene times. The site at Chillinup in south-west Western Australia provided an opportunity to examine these signature pavements in an unequivocally recent setting, and to assess their effects on competing non-eucalypt vegetation. Methods Pavements were located, and their extents and depths assessed by probing with steel rods, followed by corings and pit excavations using an air spade. Listings of plant species, growth forms and root morphologies were assembled for different vegetation zones in a representative transect across the dune. A deep cutting through the dune provided details on pavement morphology and modifications to the sand deposit bioengineered by eucalypt and heath vegetation. Key Results Clay pavements comprised closely spaced, round-topped columns whose mean diameters and depths varied between eucalypt species. Incipient pavement formation was characterized by clumps of clay deposited around fine root material. Pavements appeared to have been synthesized in situ from locally accessed and imported constituents. Understoreys on superficial pavements of a tree eucalypt were considerably less dense and biodiverse than on the deeper pavements of two mallee species, whilst most profuse vegetation cover was encountered in heath on unmodified (non-pavemented) sand. Certain species were restricted to superficially located pavements, whilst other ‘generalist’ species occurred widely across the dune. Relict pavements formed by earlier generations of eucalypts were present in certain areas of the transect and in soil profiles of the cutting. Some relict pavements colonized by proteaceous shrubs were overprinted with ferricrete. Conclusions Clay pavements formed by eucalypts have pronounced effects on understorey vegetation and

  1. Environmental Risk Factors influencing Bicycle Theft: A Spatial Analysis in London, UK

    Science.gov (United States)

    Helbich, Marco

    2016-01-01

    Urban authorities are continuously drawing up policies to promote cycling among commuters. However, these initiatives are counterproductive for the targeted objectives because they increase opportunities for bicycle theft. This paper explores Inner London as a case study to address place-specific risk factors for bicycle theft at the street-segment level while controlling for seasonal variation. The presence of certain public amenities (e.g., bicycle stands, railway stations, pawnshops) was evaluated against locations of bicycle theft between 2013 and 2016 and risk effects were estimated using negative binomial regression models. Results showed that a greater level of risk stemmed from land-use facilities than from area-based socioeconomic status. The presence of facilities such as train stations, vacant houses, pawnbrokers and payday lenders increased bicycle theft, but no evidence was found that linked police stations with crime levels. The findings have significant implications for urban crime prevention with respect to non-residential land use. PMID:27643788

  2. Vision-Based Bicycle Detection Using Multiscale Block Local Binary Pattern

    Directory of Open Access Journals (Sweden)

    Hongyu Hu

    2014-01-01

    Full Text Available Bicycle traffic has heavy proportion among all travel modes in some developing countries, which is crucial for urban traffic control and management as well as facility design. This paper proposes a real-time multiple bicycle detection algorithm based on video. At first, an effective feature called multiscale block local binary pattern (MBLBP is extracted for representing the moving object, which is a well-classified feature to distinguish between bicycles and nonbicycles; then, a cascaded bicycle classifier trained by AdaBoost algorithm is proposed, which has a good computation efficiency. Finally, the method is tested with video sequence captured from the real-world traffic scenario. The bicycles in the test scenario are successfully detected.

  3. The spatio-temporal Development of Copenhagen's bicycle infrastructure 1912-2013

    DEFF Research Database (Denmark)

    Carstensen, Trine Agervig; Olafsson, Anton Stahl; Bech, Nynne Marie

    2015-01-01

    , including periods when the city suffered from spatial, economic and demographic decline, and dominance of car traffic. By discussing reasons and demands for constructing bicycle infrastructure, the study identifies four distinct periods in which bicycle infrastructure was constructed to enhance comfort......Cycling plays an important role in low-carbon transitions. Around the globe, cities are constructing bicycle infrastructure. The city of Copenhagen has a bicycle-friendly infrastructure celebrated for its fine-meshed network. This study documents the spatio-temporal development of Copenhagen....... In search for identifying drivers, the study analyses the city’s spatial growth pattern, migration pattern, development of road network and changes in the transport culture. Analyses reveal that the bicycle infrastructure expanded at a relatively constant pace during distinct periods of urban transformation...

  4. Adult headform impact tests of three Japanese child bicycle helmets into a vehicle.

    Science.gov (United States)

    Mizuno, Koji; Ito, Daisuke; Yoshida, Ryoichi; Masuda, Hiroyuki; Okada, Hiroshi; Nomura, Mitsunori; Fujii, Chikayo

    2014-12-01

    The head is the body region that most frequently incurs fatal and serious injuries of cyclists in collisions against vehicles. Many research studies investigated helmet effectiveness in preventing head injuries using accident data. In this study, the impact attenuation characteristics of three Japanese child bicycle helmets were examined experimentally in impact tests into a concrete surface and a vehicle. A pedestrian adult headform with and without a Japanese child bicycle helmet was dropped onto a concrete surface and then propelled into a vehicle at 35 km/h in various locations such as the bonnet, roof header, windshield and A-pillar. Accelerations were measured and head injury criterion (HIC) calculated. In the drop tests using the adult headform onto a concrete surface from the height of 1.5m, the HIC for a headform without a child helmet was 6325, and was reduced by around 80% when a child helmet was fitted to the headform. In the impact tests, where the headform was fired into the vehicle at 35 km/h at various locations on a car, the computed acceleration based HIC varied depending on the vehicle impact locations. The HIC was reduced by 10-38% for impacts headforms with a child helmet when the impact was onto a bonnet-top and roof header although the HIC was already less than 1000 in impacts with the headform without a child helmet. Similarly, for impacts into the windshield (where a cyclist's head is most frequently impacted), the HIC using the adult headform without a child helmet was 122; whereas when the adult headform was used with a child helmet, a higher HIC value of more than 850 was recorded. But again, the HIC values are below 1000. In impacts into the A-pillar, the HIC was 4816 for a headform without a child helmet and was reduced by 18-38% for a headform with a child helmet depending on the type of Japanese child helmet used. The tests demonstrated that Japanese child helmets are effective in reducing accelerations and HIC in a drop test using

  5. 76 FR 61266 - Special Regulations; Areas of the National Park System, Grand Teton National Park, Bicycle Routes...

    Science.gov (United States)

    2011-10-04

    ..., Grand Teton National Park, Bicycle Routes, Fishing and Vessels AGENCY: National Park Service, Interior... (Park) as routes for bicycle use. National Park Service (NPS) regulations require issuance of a special regulation to designate bicycle routes that are located off park roads and outside developed areas. The...

  6. A multi-modal network approach to model public transport accessibility impacts of bicycle-train integration policies

    NARCIS (Netherlands)

    Geurs, Karst Teunis; La Paix Puello, Lissy Cesarina; van Weperen, Sander

    2016-01-01

    Introduction In the Netherlands, the bicycle plays an important in station access and, to a lesser extent, in station egress. There is however fairly little knowledge in the potential effects of bicycle-train integration policies. The aim of this paper is to examine the impacts of bicycle-train

  7. Road Edge of Pavement, Edge of Pavement - polygon digitized by Furgro Earthdata, Published in 2008, 1:2400 (1in=200ft) scale, Effingham County Board Of Commissioners.

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — This Road Edge of Pavement dataset, published at 1:2400 (1in=200ft) scale, was produced all or in part from Orthoimagery information as of 2008. It is described as...

  8. Numerical analysis of frictional heat generation in bicycle disc brake

    Science.gov (United States)

    Tahmid, Shadman; Alam, Saima

    2017-06-01

    Precise braking operations are pivotal to ensure safety in modern day vehicle designs. Brakes are mechanical devices for increasing the frictional resistance that obstructs the turning motion of vehicle wheels by absorbing either kinetic, potential energy or both while in action. This absorbed energy appears in the form of heat. Stress, distribution of friction on surface, frictional heat generation, material and geometry are the major controlling factors for efficiency of braking operations. Frictional heat generation and its effective dissipation is one of the most predominant of these factors and hence it is the focus of this study. The purpose of this study is to analyze the thermal behavior of a full bicycle disc brake using finite element method. Sequential thermal structured method based on Ansys 14.5 is used to carry out the numerical simulation for evaluating the variation of total heat flux and temperature profiles with respect to time. The analysis model was studied experimentally and results obtained by numerical analysis were within 3% of the experimental result for maximum temperature. The model is thus adequately validated to be followed for a similar analysis on bicycle brakes.

  9. Harvesting Energy from the Counterbalancing (Weaving Movement in Bicycle Riding

    Directory of Open Access Journals (Sweden)

    Shashank Priya

    2012-07-01

    Full Text Available Bicycles are known to be rich source of kinetic energy, some of which is available for harvesting during speedy and balanced maneuvers by the user. A conventional dynamo attached to the rim can generate a large amount of output power at an expense of extra energy input from the user. However, when applying energy conversion technology to human powered equipments, it is important to minimize the increase in extra muscular activity and to maximize the efficiency of human movements. This study proposes a novel energy harvesting methodology that utilizes lateral oscillation of bicycle frame (weaving caused by user weight shifting movements in order to increase the pedaling force in uphill riding or during quick speed-up. Based on the 3D motion analysis, we designed and implemented the prototype of an electro-dynamic energy harvester that can be mounted on the bicycle’s handlebar to collect energy from the side-to-side movement. The harvester was found to generate substantial electric output power of 6.6 mW from normal road riding. It was able to generate power even during uphill riding which has never been shown with other approaches. Moreover, harvesting of energy from weaving motion seems to increase the economy of cycling by helping efficient usage of human power.

  10. Analysis of Load Stress for Asphalt Pavement of Lean Concrete Base

    Science.gov (United States)

    Lijun, Suo; Xinwu, Wang

    The study revealed that whether it is early distresses in asphalt pavement or not depends largely on working performance of base. In the field of asphalt pavement, it is widely accepted that lean concrete base, compared with the general semi-rigid base, has better working performance, such as high strength and good eroding resistance. Problem of early distresses in asphalt pavement, which caused by more traffic loadings, can be settled effectively when lean concrete is used in asphalt pavement. Traffic loading is important parameter used in the analysis of the new pavement design. However, few studies have done extensive and intensive research on the load stress for asphalt pavement of lean concrete base. Because of that, it is necessary to study the load stress for the asphalt pavement. In the paper, first of all, three-dimension finite element model of the asphalt pavement is created for the aim of doing mechanical analysis for the asphalt pavement. And then, the two main objectives of this study are investigated. One is analysis for load stress of lean concrete base, and the other is analysis for load stress of asphalt surface. The results show that load stress of lean concrete base decreases, decrease and increase with increase of base's thickness, surface's thickness and ratio of base's modulus to foundation's modulus respectively. So far as the asphalt surface is concerned, maximum shearing stress, which is caused by load, is evident in asphalt surface which is located in transverse contraction joint of lean concrete base of asphalt pavement. Maximum shearing stress decrease, decrease, decrease and increase respectively with increase of the surface's modulus, the surface's thickness, base's thickness and ratio of base's modulus to foundation's modulus.

  11. Application of matter-element analysis based on entropy right to evaluate the pavement condition in permafrost region

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Evaluation of pavement performance is one of the most important issues in a pavement-management system.By employing the concept of entropy,the matter-element model for evaluating pavement is established,and the weights of the evaluation indices are obtained from surveying data.By calculating the degree of dependence of the matter-element model,the pavement performance evaluation can be obtained by this method.The results show that the matter-element model based on entropy right has good performance for evaluating the pavement condition in permafrost region.

  12. Assessment of porous asphalt pavement performance: hydraulics and water quality

    Science.gov (United States)

    Briggs, J. F.; Ballestero, T. P.; Roseen, R. M.; Houle, J. J.

    2005-05-01

    The objective of this study is to focus on the water quality treatment and hydraulic performance of a porous asphalt pavement parking lot in Durham, New Hampshire. The site was constructed in October 2004 to assess the suitability of porous asphalt pavement for stormwater management in cold climates. The facility consists of a 4-inch asphalt open-graded friction course layer overlying a high porosity sand and gravel base. This base serves as a storage reservoir in-between storms that can slowly infiltrate groundwater. Details on the design, construction, and cost of the facility will be presented. The porous asphalt pavements is qualitatively monitored for signs of distress, especially those due to cold climate stresses like plowing, sanding, salting, and freeze-thaw cycles. Life cycle predictions are discussed. Surface infiltration rates are measured with a constant head device built specifically to test high infiltration capacity pavements. The test measures infiltration rates in a single 4-inch diameter column temporarily sealed to the pavement at its base. A surface inundation test, as described by Bean, is also conducted as a basis for comparison of results (Bean, 2004). These tests assess infiltration rates soon after installation, throughout the winter, during snowmelt, after a winter of salting, sanding, and plowing, and after vacuuming in the spring. Frost penetration into the subsurface reservoir is monitored with a frost gauge. Hydrologic effects of the system are evaluated. Water levels are monitored in the facility and in surrounding wells with continuously logging pressure transducers. The 6-inch underdrain pipe that conveys excess water in the subsurface reservoir to a riprap pad is also continuously monitored for flow. Since porous asphalt pavement systems infiltrate surface water into the subsurface, it is important to assess whether water quality treatment performance in the subsurface reservoir is adequate. The assumed influent water quality is

  13. Numerical modeling of inelastic structures at loading of steady state rolling. Thermo-mechanical asphalt pavement computation

    Science.gov (United States)

    Wollny, Ines; Hartung, Felix; Kaliske, Michael

    2016-05-01

    In order to gain a deeper knowledge of the interactions in the coupled tire-pavement-system, e.g. for the future design of durable pavement structures, the paper presents recent results of research in the field of theoretical-numerical asphalt pavement modeling at material and structural level, whereby the focus is on a realistic and numerically efficient computation of pavements under rolling tire load by using the finite element method based on an Arbitrary Lagrangian Eulerian (ALE) formulation. Inelastic material descriptions are included into the ALE frame efficiently by a recently developed unsplit history update procedure. New is also the implementation of a viscoelastic cohesive zone model into the ALE pavement formulation to describe the interaction of the single pavement layers. The viscoelastic cohesive zone model is further extended to account for the normal pressure dependent shear behavior of the bonding layer. Another novelty is that thermo-mechanical effects are taken into account by a coupling of the mechanical ALE pavement computation to a transient thermal computation of the pavement cross-section to obtain the varying temperature distributions of the pavement due to climatic impact. Then, each ALE pavement simulation considers the temperature dependent asphalt material model that includes elastic, viscous and plastic behavior at finite strains and the temperature dependent viscoelastic cohesive zone formulation. The temperature dependent material parameters of the asphalt layers and the interfacial layers are fitted to experimental data. Results of coupled tire-pavement computations are presented to demonstrate potential fields of application.

  14. 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.

  15. Development of traffic induced permanent strain in concrete block pavements

    OpenAIRE

    1996-01-01

    Concrete block pavements (c.b.p.) commonly consist of concrete blocks placed over a granular substructure. As a result of wheel load passages permanent strains will slowly develop in the substructure and cause rutting. This paper is about the prediction of the permanent strain development in the substructure and the associated rutting on the basis of the results of repeated load triaxial tests and analytical models. By discussing the behaviour of three c.b.p.'s it is shown that insight into c...

  16. Design Basis for Fibre Reinforced Concrete (FRC) Pavements

    DEFF Research Database (Denmark)

    Bendixen, Søren; Stang, Henrik

    1996-01-01

    -crack opening relationship can beused to descibe the properties of fibre reinforced concrete (FRC) intension and how the stress-crack opening relationship can beapplied in a simple design scheme for pavements. The projectincludes development of design tools, experiments to determine thestress-crack opening......The paper summarises a Ph.D. project on development of a new design basis for fibre reinforced concrete ground slabs. The stress-crack openingrelationship is a well know basic material property of theso-called fictitious crack model for concrete. In the presentstudy it is shown how the stress...

  17. Crushing damage estimation for pavement with lightly cementitious bases

    CSIR Research Space (South Africa)

    De Beer, Morris

    2014-07-01

    Full Text Available , Pretoria, South Africa. De Beer, M. 2013. Revision of the South African Pavement Design Method. Project Focus Area: Bound Materials: Damage Laws. Cementitious Materials: Expanded/Revised Damage Laws for Crushing Failure. Contract Report SANRAL/SAPDM-D3... stream_source_info De Beer_2014.pdf.txt stream_content_type text/plain stream_size 25820 Content-Encoding UTF-8 stream_name De Beer_2014.pdf.txt Content-Type text/plain; charset=UTF-8 CRUSHING DAMAGE ESTIMATION...

  18. An improved multi-value cellular automata model for heterogeneous bicycle traffic flow

    Energy Technology Data Exchange (ETDEWEB)

    Jin, Sheng [College of Civil Engineering and Architecture, Zhejiang University, Hangzhou, 310058 China (China); Qu, Xiaobo [Griffith School of Engineering, Griffith University, Gold Coast, 4222 Australia (Australia); Xu, Cheng [Department of Transportation Management Engineering, Zhejiang Police College, Hangzhou, 310053 China (China); College of Transportation, Jilin University, Changchun, 130022 China (China); Ma, Dongfang, E-mail: mdf2004@zju.edu.cn [Ocean College, Zhejiang University, Hangzhou, 310058 China (China); Wang, Dianhai [College of Civil Engineering and Architecture, Zhejiang University, Hangzhou, 310058 China (China)

    2015-10-16

    This letter develops an improved multi-value cellular automata model for heterogeneous bicycle traffic flow taking the higher maximum speed of electric bicycles into consideration. The update rules of both regular and electric bicycles are improved, with maximum speeds of two and three cells per second respectively. Numerical simulation results for deterministic and stochastic cases are obtained. The fundamental diagrams and multiple states effects under different model parameters are analyzed and discussed. Field observations were made to calibrate the slowdown probabilities. The results imply that the improved extended Burgers cellular automata (IEBCA) model is more consistent with the field observations than previous models and greatly enhances the realism of the bicycle traffic model. - Highlights: • We proposed an improved multi-value CA model with higher maximum speed. • Update rules are introduced for heterogeneous bicycle traffic with maximum speed 2 and 3 cells/s. • Simulation results of the proposed model are consistent with field bicycle data. • Slowdown probabilities of both regular and electric bicycles are calibrated.

  19. Effects of cross-anisotropy and stress-dependency of pavement layers on pavement responses under dynamic truck loading

    Directory of Open Access Journals (Sweden)

    Rafiqul A. Tarefder

    2016-06-01

    Full Text Available Previous studies by the authors have determined pavement responses under dynamic loading considering cross-anisotropy in one layer only, either the cross-anisotropic viscoelastic asphalt concrete (AC layer or the cross-anisotropic stress-dependent base layer, but not both. This study evaluates pavement stress–strain responses considering cross-anisotropy in all layers, i.e. AC, base and subbase, using finite element modeling (FEM technique. An instrumented pavement section on Interstate I-40 near Albuquerque, New Mexico was used in ABAQUS framework as model geometry. Field asphalt cores were collected and tested in the laboratory to determine the cross-anisotropy (n-values defined by horizontal to vertical modulus ratio, and other viscoelastic parameters as inputs of the model incorporated through user defined material interface (UMAT functionality in ABAQUS. Field base and subbase materials were also collected and tested in the laboratory to determine stress-dependent nonlinear elastic model parameters, as inputs of the model, again incorporated through UMAT. The model validation task was carried out using field-measured deflections and strain values under falling weight deflectometer (FWD loads at the instrumented section. The validated model was then subjected to an actual truck loading for studying cross-anisotropic effects. It was observed that horizontal tensile strain at the bottom of the AC layer and vertical strains in all layers decreased with an increase in n-value of the asphalt layer, from n < 1 (anisotropy to n=1 (isotropy. This indicates that the increase in horizontal modulus caused the decrease in layer strains. It was also observed that if the base and subbase layers were considered stress-dependent instead of linear elastic unbound layers, the horizontal tensile strain at the bottom of the asphalt layer increased and vertical strains on top of the base and subbase also increased.

  20. Effects of cross-anisotropy and stress-dependency of pavement layers on pavement responses under dynamic truck loading

    Institute of Scientific and Technical Information of China (English)

    Rafiqul A. Tarefder; Mesbah U. Ahmed; Asifur Rahman

    2016-01-01

    Previous studies by the authors have determined pavement responses under dynamic loading consid-ering cross-anisotropy in one layer only, either the cross-anisotropic viscoelastic asphalt concrete (AC) layer or the cross-anisotropic stress-dependent base layer, but not both. This study evaluates pavement stressestrain responses considering cross-anisotropy in all layers, i.e. AC, base and subbase, using finite element modeling (FEM) technique. An instrumented pavement section on Interstate I-40 near Albu-querque, New Mexico was used in ABAQUS framework as model geometry. Field asphalt cores were collected and tested in the laboratory to determine the cross-anisotropy (n-values) defined by horizontal to vertical modulus ratio, and other viscoelastic parameters as inputs of the model incorporated through user defined material interface (UMAT) functionality in ABAQUS. Field base and subbase materials were also collected and tested in the laboratory to determine stress-dependent nonlinear elastic model pa-rameters, as inputs of the model, again incorporated through UMAT. The model validation task was carried out using field-measured deflections and strain values under falling weight deflectometer (FWD) loads at the instrumented section. The validated model was then subjected to an actual truck loading for studying cross-anisotropic effects. It was observed that horizontal tensile strain at the bottom of the AC layer and vertical strains in all layers decreased with an increase in n-value of the asphalt layer, from n<1 (anisotropy) to n ¼ 1 (isotropy). This indicates that the increase in horizontal modulus caused the decrease in layer strains. It was also observed that if the base and subbase layers were considered stress-dependent instead of linear elastic unbound layers, the horizontal tensile strain at the bottom of the asphalt layer increased and vertical strains on top of the base and subbase also increased.