Sample records for bleeding pavements

  1. Bleeding time

    Bleeding time is a medical test that measures how fast small blood vessels in the skin stop bleeding. ... until the bleeding stops. The provider records the time it takes for the cuts to stop bleeding.

  2. Pavement Subgrade Performance Study

    Zhang, Wei; Ullidtz, Per; Macdonald, Robin


    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...

  3. Pavement evaluation and rehabilitation

    Ali, N.A.; Khosla, N.P.; Johnson, E.G.; Hicks, R.G.; Uzan, J.


    The 20 papers in this report deal with the following areas: determination of layer moduli using a falling weight deflectometer; evaluation of effect of uncrushed base layers on pavement performance; the effect of contact area shape and pressure distribution on multilayer systems response; sensitivity analysis of selected backcalculation procedures; performance of a full-scale pavement design experiment in Jamaica; subsealing and load-transfer restoration; development of a demonstration prototype expert system for concrete pavement evaluation; numerical assessment of pavement test sections; development of a distress index and rehabilitation criteria for continuously reinforced concrete pavements using discriminant analysis; a mechanistic model for thermally induced reflection cracking of portland cement concrete pavement with reinforced asphalt concrete overlay; New Mexico study of interlayers used in reflective crack control; status of the South Dakota profilometer; incorporating the effects of tread pattern in a dynamic tire excitation mechanism; external methods for evaluating shock absorbers for road-roughness measurements; factor analysis of pavement distresses for surface condition predictions; development of a utility evaluation for nondestructive-testing equipment used on asphalt-concrete pavements; estimating the life of asphalt overlays using long-term pavement performance data; present serviceability-roughness correlations using rating panel data; video image distress analysis technique for Idaho transportation department pavement-management system; acceptability of shock absorbers for road roughness-measuring trailers.

  4. Pavement Testing Facility

    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. Bleeding Disorders

    ... as clotting factors. If you have a bleeding disorder, you either do not have enough platelets or ... don't work the way they should. Bleeding disorders can be the result of other diseases, such ...

  6. Asphalt in Pavement Maintenance.

    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…

  7. [Gastrointestinal bleeding].

    Lanas, Ángel


    In the Digestive Disease Week in 2015 there have been some new contributions in the field of gastrointestinal bleeding that deserve to be highlighted. Treatment of celecoxib with a proton pump inhibitor is safer than treatment with nonselective NSAID and a proton pump inhibitor in high risk gastrointestinal and cardiovascular patients who mostly also take acetylsalicylic acid. Several studies confirm the need to restart the antiplatelet or anticoagulant therapy at an early stage after a gastrointestinal hemorrhage. The need for urgent endoscopy before 6-12 h after the onset of upper gastrointestinal bleeding episode may be beneficial in patients with hemodynamic instability and high risk for comorbidity. It is confirmed that in Western but not in Japanese populations, gastrointestinal bleeding episodes admitted to hospital during weekend days are associated with a worse prognosis associated with delays in the clinical management of the events. The strategy of a restrictive policy on blood transfusions during an upper GI bleeding event has been challenged. Several studies have shown the benefit of identifying the bleeding vessel in non varicose underlying gastric lesions by Doppler ultrasound which allows direct endoscopic therapy in the patient with upper GI bleeding. Finally, it has been reported that lower gastrointestinal bleeding diverticula band ligation or hemoclipping are both safe and have the same long-term outcomes. PMID:26520197

  8. Internal Bleeding

    ... 2 Diabetes, Heart Disease a Dangerous Combo Are 'Workaholics' Prone to OCD, Anxiety? ALL NEWS > Resources First ... pelvis, that are broken. Initially, internal bleeding may cause no symptoms, although an injured organ that is ...

  9. Bleeding Disorders

    ... times I'd miss work and skip the gym because I felt so lousy. So I decided ... cell called platelets. Your body also needs blood proteins called clotting factors. In people with bleeding disorders, ...

  10. Asphalt pavement temperature prediction

    Minhoto, Manuel; Pais, Jorge; Pereira, Paulo


    A 3-D finite element model (FEM) was developed to calculate the lemperature of an asphtalt rubber pavement localed in the Northeast of Portugal. The goal of the case study presented in this paper is to show the good accuracy temperature prediction tha can be obtained with this model when compared with the field pavement thermal condition obtained during a year. lnput data to the model are the hourly values for solar radiation and temperature and the mean daily value of wind speed obtained fr...

  11. Permeable Pavements at Purdue

    Knapp, Jim


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

  12. Pervious Pavement System Evaluation

    Pervious pavement is a low impact development stormwater control. The Urban Watershed Management Branch of the U.S. Environmental Protection Agency in Edison, NJ, is evaluating concrete pavers as a popular implementation. The pollutant removal of a bench-scale permeable interlo...


    Goodfellow, Paul


    BLEED & BLEND is an ambient artwork that was commissioned by Digital Media in Newcastle University's Culture Lab, as part of their data visualisation screening project: Data Elements. The aim of the project was to take an unconventional approach to interpreting and displaying scientific data through visual artworks. The work was projected onto Newcastle University's Kings Gate building in Newcastle city centre in October 2012. A useful and succinct description of Ambient Art is found in B...


    Andrzej Plewa; Marta Wasilewska; Władysław Gardziejczyk; Paweł Gierasimiuk


    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 ...

  15. Bleeding Disorders Treatment Options

    ... Pictures Young Voices Compendium of Assessment Tools Educational Games Video Library Find a Treatment Centre Haemophilia Journal About Bleeding Disorders Bleeding Disorders The Clotting Process Drugs That Can Cause Bleeding Hemophilia How Do You ...

  16. Pavement management using hyperspectral imagery

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


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

  17. Pervious Pavement System Evaluation- Abstract

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

  18. Dynamic contracting mechanism for pavement maintenance management

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


    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. Pervious Pavement System Evaluation-Poster

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

  20. High Performance Concrete Pavement in Indiana

    Nantung, Tommy E


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

  1. Recycling of asphalt pavements with asphalt rubber

    Pais, Jorge; Pereira, Paulo; Minhoto, Manuel; Baptista, António


    Pavement recycling has been an important rehabilitation technique to deal with reclaimed materials from old pavements which are usually sent to landfills. The application of this technique contributes to: i) the accomplishment of the requirements defined by the European legislation for the amount of material sent to landfills; ii) the reduction in the use of new raw materials used to produce pavement layers. The reduction of materials to be used in pavement rehabilitation has also been possib...

  2. Reducing Your Cost for Asphalt Pavements

    Evans, Alvin


    This session will discuss of how local government decision-makers can achieve greater value without sacrificing quality or service life. The session will touch upon use of Higher Recycled Asphalt Pavement (RAP), Recycled Asphalt Shingles (RAS), Asphalt Mix Design for Heavy Traffic vs. Light Traffic, Speed of Construction, Perpetual Pavement and Pavement Rehabilitation Strategies.


    Andrzej Plewa


    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.

  4. Pavement thickness evaluation using ground penetrating radar

    Harris, Dwayne Arthur

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

  5. The Concrete and Pavement Challenge

    Roman, Harry T.


    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…

  6. Tuning in to pavement radio

    Ellis, S.D.K.


    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, partic

  7. Removable Urban Pavements: An innovative, sustainable technology

    De Larrard, François; Sedran, Thierry; Balay, Jean Maurice


    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...

  8. Structural Evaluation for Maputo Airport Pavement

    Jose F.R.Diogo; LU Yang; ZHANG Hua


    Maputo Airport was initially constructed to serve mixed traffic of light and medium aircrafts. With its opening to heavier aircrafts such as B727, DC10, Airbus 340, etc. , structural improvements have become necessary. For this purpose, structural evaluation were described and performed using falling weight deflectometer. Results show that while subgrade response to loads appears more consistent with depth, surface layer of the pavement is significantly influenced by the layer thickness as well as mechanical properties of pavement materials. Load magnitude also affects pavement performance. But loading conditions show an equivalent or even greater influence on pavement performance.

  9. Mechanical Response Analysis of Asphalt Pavement Structure

    Yu Zhenqing


    Full Text Available Generally, the Chinese designed life of the high- grade asphalt concrete pavement is required 15 years, however, the designed life of the road in surface is often lower than the designed life, and even premature failure. Especially in heavy traffic conditions, the early damage of some high grade-asphalt pavement in China is serious. According to some investigations, we founded the main reason of the long-life asphalt pavement is to determine the function of each structure layer. According to the stress of pavement structure layer, so as to select the structure layer materials. Based on the viewpoint of mechanics, asphalt pavement damage mode is divided into three categories, such as top-down crack, fatigue cracking and rutting. Therefore, this paper uses ANSYS finite element software as calculation tool, the combination of road vehicle load and the primary influence on asphalt pavement structure mechanics response characteristics were analyzed. In this paper, the method of analysis is control variable: that means under different vehicle axle load, only change surface layer modulus and observe the pavement structure mechanical response trends to compare the effect. By using the same method, the response of the pavement base course parameters to the pavement mechanical structure is analyzed.

  10. Long Life Pavements; Firmes de larga duracion

    Mateos Moreno, A.; Marron Fernandez, J. O.; Perez Ayuso, J.


    The existence of long-life pavements is not new; they have been built in Europe and the United States for decades. In fact, the concept arises from the observation of in-service roads; it was verified how particular pavements, initially designed for a 20-year service life, did not seem to have reduced the bearing capacity along the time, and its maintenance necessities had been exclusively focused on the wearing course. The base idea of long-life pavements is the existence of a fatigue threshold below which the damage produced by each load application is, in practice, zero or below the healing potential of the asphalt mix. The use practice of long-life pavements design considers a pavements constituted by three asphalt layers, each one with a very specific role: a wearing course that provides with the surface characteristics, an intermediate course that provides with most of the structural capacity and a base course that provides with the fatigue resistance. Furthermore, one of the particularities is the design against specific distress mechanisms. Maintenance strategy also presents specific particularities for long-life pavements. It is essentially focused on the detection of surface deterioration, and the appropriate and timely repair, before the damage extends beyond the wearing course, putting into risk the structural integrity of the pavement. Nowadays, this new way to conceive the design, the construction and the maintenance of road pavements, constitutes one of the main challenges for pavement engineering worldwide. (Author) 5 refs.

  11. HMA Pavement Performance and Durability

    del Pilar Vivar, Eliana; Haddock, John E.


    It has long been argued that at densities higher than approximately 92 percent (air void contents lower than 8 percent), a hotmix asphalt mixture is impermeable to water. However, as densities become lower (air void contents higher) than this, small decreases in the density can yield exponential increases in permeability. The objectives of this study were to better understand the increases in hot-mix asphalt pavement performance and durability that can be gained by increasing the initial pave...

  12. [Acute gastrointestinal bleeding].

    Baumbach, Robert; Faiss, Siegbert; Cordruwisch, Wolfgang; Schrader, Carsten


    Acute gastrointestinal bleeding is a common major emergency (Internal medical or gastroenterological or medical), approximately 85 % of which occur in the upper GI tract. It is estimated that about a half of upper GI bleeds are caused by peptic ulcers. Upper GI bleeds are associated with more severe bleeding and poorer outcomes when compared to middle or lower GI bleeds. Prognostic determinants include bleeding intensity, patient age, comorbid conditions and the concomitant use of anticoagulants. A focused medical history can offer insight into the bleeding intensity, location and potential cause (along with early risk stratification). Initial measures should focus on rapid assessment and resuscitation of unstable patients. The oesophagogastroduodenoscopy (OGD) is the gold standard method for localizing the source of bleeding and for interventional therapy. Bleeding as a result of peptic ulcers is treated endoscopically with mechanical and / or thermal techniques in combination with proton pump inhibitor (PPI) therapy. When variceal bleeding is suspected, pre-interventional use of vasopressin analogues and antibiotic therapies are recommended. Endoscopically, the first line treatment of esophageal varices is endoscopic ligature therapy, whereas that for gastric varices is the use of Histoacryl injection sclerotherapy. When persistent and continued massive hemorrhage occurs in a patient with known or suspected aortic disease the possibility of an aorto-enteric fistula must be considered. PMID:27078246

  13. Nonvariceal upper gastrointestinal bleeding

    Burke, Stephen J.; Weldon, Derik; Sun, Shiliang [University of Iowa, Department of Radiology, Iowa, IA (United States); Golzarian, Jafar [University of Iowa, Department of Radiology, Iowa, IA (United States); University of Iowa, Department of Radiology, Carver College of Medicine, Iowa, IA (United States)


    Nonvariceal upper gastrointestinal bleeding (NUGB) remains a major medical problem even after advances in medical therapy with gastric acid suppression and cyclooxygenase (COX-2) inhibitors. Although the incidence of upper gastrointestinal bleeding presenting to the emergency room has slightly decreased, similar decreases in overall mortality and rebleeding rate have not been experienced over the last few decades. Many causes of upper gastrointestinal bleeding have been identified and will be reviewed. Endoscopic, radiographic and angiographic modalities continue to form the basis of the diagnosis of upper gastrointestinal bleeding with new research in the field of CT angiography to diagnose gastrointestinal bleeding. Endoscopic and angiographic treatment modalities will be highlighted, emphasizing a multi-modality treatment plan for upper gastrointestinal bleeding. (orig.)

  14. Modelling Flexible Pavement Response and Performance

    Ullidtz, Per

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

  15. Numerical Simulation of Tire-Pavement Interaction

    Srirangam, S.K.


    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

  16. Pervious Pavement System Evaluation-Paper

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

  17. Analysis and design optimization of flexible pavement

    Mamlouk, M.S.; Zaniewski, J.P.; He, W.


    A project-level optimization approach was developed to minimize total pavement cost within an analysis period. Using this approach, the designer is able to select the optimum initial pavement thickness, overlay thickness, and overlay timing. The model in this approach is capable of predicting both pavement performance and condition in terms of roughness, fatigue cracking, and rutting. The developed model combines the American Association of State Highway and Transportation Officials (AASHTO) design procedure and the mechanistic multilayer elastic solution. The Optimization for Pavement Analysis (OPA) computer program was developed using the prescribed approach. The OPA program incorporates the AASHTO equations, the multilayer elastic system ELSYM5 model, and the nonlinear dynamic programming optimization technique. The program is PC-based and can run in either a Windows 3.1 or a Windows 95 environment. Using the OPA program, a typical pavement section was analyzed under different traffic volumes and material properties. The optimum design strategy that produces the minimum total pavement cost in each case was determined. The initial construction cost, overlay cost, highway user cost, and total pavement cost were also calculated. The methodology developed during this research should lead to more cost-effective pavements for agencies adopting the recommended analysis methods.

  18. Pavement Crack Detection Using Spectral Clustering Method

    Jin Huazhong


    Full Text Available Pavement crack detection plays an important role in pavement maintaining and management, nowadays, which could be performed through remote image analysis. Thus, edges of pavement crack should be extracted in advance; in general, traditional edge detection methods don’t consider phase information and the spatial relationship between the adjacent image areas to extract the edges. To overcome the deficiency of the traditional approaches, this paper proposes a pavement crack detection algorithm based on spectral clustering method. Firstly, a measure of similarity between pairs of pixels is taken into account through orientation energy. Then, spatial relationship is needed to find regions where similarity between pixels in a given region is high and similarity between pixels in different regions is low. After that, crack edge detection is completed with spectral clustering method. The presented method has been run on some real life images of pavement crack, experimental results display that the crack detection method of this paper could obtain ideal result.

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

    Sina Mirzapour Mounes


    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.

  20. Theoretical Development and Engineering Practice of Pavements in China

    QIU Yan-jun


    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.

  1. Effects of temperature and water on pavement performance

    Badu-Tweneboah, K.; Tia, M.; Ruth, B.E.; Richardson, J.M.; Armaghani, J.M.


    The 12 papers in the report deal with the following areas: procedures for estimation of asphalt-concrete pavement moduli at in-situ temperatures; stress caused by temperature gradient in portland-cement concrete pavements; characterizing temperature effects for pavement analysis and design; temperature response of concrete pavements; an examination of environmental versus load effects on pavements; moisture in portland-cement concrete; effect of rainfall on the performance of continuously reinforced concrete pavements in Texas; effect of moisture on the structural performance of a crushed-limestone road base; water-induced distress in flexible pavement in a wet tropical climate; an evaluation of design high-water clearances for pavements; economic impact of pavement subsurface drainage; use of open-graded, free-draining layers in pavement systems; a national synthesis report.

  2. Aircraf landing gear design in respect of pavement design

    Fabre, C.; ALBIN, A; Balay, Jean Maurice


    This paper considers the close relationship between aircraft landing gear (LG) and pavement design in respect of airfield pavement compatibility. In pavement design and analysis, we usually deal with pavement structures, materials and design thickness procedure but rarely aircraft LG design This paper emphasizes key drivers, which must be considered for new aircraft LG design to achieve aircraft pavement compatibility. Several parameters such as number & size of wheels, type of gear, brakes, ...

  3. Assessment of highway pavements using GPR

    Plati, Christina; Loizos, Andreas


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

  4. Approach to bleeding patient

    Ramachandran Gopinath


    Full Text Available Managing a bleeding patient is very challenging for the perioperative physician. Bleeding in a patient would be due to inherited or acquired disorders of haemostasis. Identifying the patients at risk of bleeding and utilising prophylactic treatment protocols has good outcomes. Along with clinical signs, trends in monitoring coagulation parameters and analysing blood picture are necessary. Management of patients in the postoperative period and in intensive care unit should be focused on normalization of coagulation profile as early as possible with available blood and its products. Available recombinant factors should be given priority as per the approved indications. Exploring the surgical site should be considered for persistent bleeding because haemodynamic compromise, excessive transfusion of fluids, blood and its products and more inotropic support may have a negative impact on the patient outcome.

  5. Understanding Minor Rectal Bleeding

    ... are the possible causes of minor rectal bleeding? Hemorrhoids Anal fissures Proctitis (inflammation of the rectum) Polyps ... can be cured if detected early. What are hemorrhoids? Hemorrhoids (also called piles) are swollen blood vessels ...

  6. Nonlinear Responses of a Two Dimensional Vehicle-pavement System

    Shaohua Li


    Full Text Available The vehicle and pavement are usually investigated separately in vehicle dynamics and pavement dynamics. In this work, a new research scheme is proposed to link the vehicle and pavement model by tire loads and compute the nonlinear dynamic responses by analytical methods. A two-DOF nonlinear vehicle and a Bernoulli-Euler beam on a nonlinear elastic foundation with two simply supported ends compose the nonlinear vehicle-pavement system. The nonlinear tire loads are analytically gained using the averaging method. Then the nonlinear vibration equation of the pavement is obtained using Galerkin method and solved using the multiple scales method. The theoretical solutions are verified by numerical results and the effects of system parameters on pavement vibration are also studied. It is found that the pavement responses excited by tire loads attenuate quickly and small pavement mass, large foundation damping or foundation stiffness may decrease the pavement vibration.

  7. Permeable Pavement Research - Edison, New Jersey

    This presentation provides the background and summary of results collected at the permeable pavement parking lot monitored at the EPA facility in Edison, NJ. This parking lot is surfaced with permeable interlocking concrete pavers (PICP), pervious concrete, and porous asphalt. ...

  8. Pervious Pavement System Evaluation- Abstract 1

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

  9. Children, urban care, and everyday pavements

    Kim Kullman


    This paper takes a mundane piece of urban infrastructure, the pavement, as a starting point, approaching it through the experiences of 7–12-year-old children who journey between home and school in Helsinki, Finland. In doing so, the paper argues that the children and their travel companions are employing pavements to cultivate the caring potential of their city, whether this entails patting dogs, picking up empty bottles, or checking the safety of zebra crossings. Inspired by recent work on t...

  10. Fusing complementary images for pavement cracking measurements

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

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

    Junwei, Zhang; Jinping, Li; Xiaojuan, Quan


    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. PMID:24027444

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

    Hendel, Martin; Diab, Youssef; Royon, Laurent


    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.


    Design and operational criteria, utilization concepts, benefits and disadvantages, as well as other characteristics of porous pavements are presented in this report. Particular emphasis is placed on porous asphalt pavements, but the criteria and design approach are applicable to ...

  14. Comparative Study of French and Chinese Asphalt Pavement Design Methods

    Pierre Guy Atangana Njock; Li Yueguang


    This study deals with the comparison of French and Chinese approaches for the design of flexible pavement. The Finite Element Analysis (FEA using ANSYS) was used to compute and compare the mechanical responses in four typical pavement structures used in France and China, for respective axle type and loads. The study concluded that the maximum deflection in typical structure of stabilized asphalt pavement in China is greater than that obtained in the typical treated bases asphalt pavement in F...

  15. Porous Flame-retarded Asphalt Pavement for Highway Tunnel

    HU Shuguang; HUANG Shaolong; Ding Qingjun


    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.

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

    Cai, Wei


    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...

  17. Spills on Flat Inclined Pavements

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


    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.

  18. Bleeding during Pregnancy

    ... have placenta accreta, you are at risk of life-threatening blood loss during delivery. Your ob-gyn will plan your ... to be done right after delivery to prevent life-threatening blood loss. Can bleeding be a sign of preterm labor? ...

  19. Effect of age of permeable pavements on their infiltration function

    Boogaard, Floris; Lucke, Terry; Beecham, Simon


    This study describes field investigations designed to compare the infiltration capacities of 55 permeable pavement systems installed in the Netherlands and in Australia. The ages of the pavements varied from 1 to 12 years. Using infiltrometer testing, the performance of the pavements has been compar

  20. First trimester bleeding evaluation.

    Dogra, Vikram; Paspulati, Raj Mohan; Bhatt, Shweta


    First trimester bleeding is a common presentation in the emergency room. Ultrasound evaluation of patients with first trimester bleeding is the mainstay of the examination. The important causes of first trimester bleeding include spontaneous abortion, ectopic pregnancy, and gestational trophoblastic disease; 50% to 70% of spontaneous abortions are due to genetic abnormalities. In normal pregnancy, the serum beta hCG doubles or increases by at least 66% in 48 hours. The intrauterine GS should be visualized by TVUS with beta hCG levels between 1000 to 2000 mIU/mL IRP. Visualization of the yolk sac within the gestational sac is definitive evidence of intrauterine pregnancy. Embryonic cardiac activity can be identified with CRL of >5 mm. A GS with a mean sac diameter (MSD) of 8 mm or more without a yolk sac and a GS with an MSD of 16 mm or more without an embryo, are important predictors of a nonviable gestation. A GS with a mean sac diameter of 16 mm or more (TVUS) without an embryo is a sonographic sign of anembryonic gestation. A difference of subchorionic hematoma. The presence of an extra ovarian adnexal mass is the most common sonographic finding in ectopic pregnancy. Other findings include the tubal ring sign and hemorrhage. About 26% of ectopic pregnancies have normal pelvic sonograms on TVUS. Complete hydatidiform mole presents with a complex intrauterine mass with multiple anechoic areas of varying sizes (Snowstorm appearance). Twenty-five percent to 65% of molar pregnancies have associated theca-leutin cysts. Arteriovenous malformation of the uterus is a rare but life-threatening cause of vaginal bleeding in the first trimester. The sonographic findings in a patient with first trimester bleeding should be correlated with serum beta hCG levels to arrive at an appropriate clinical diagnosis. PMID:15905817

  1. Anemia Due to Excessive Bleeding

    ... 2 Diabetes, Heart Disease a Dangerous Combo Are 'Workaholics' Prone to OCD, Anxiety? ALL NEWS > Resources First ... needed to determine the source of bleeding. The cause of bleeding is corrected, and transfusions and iron ...

  2. Diagnosis of the Bleeding Child

    Yıldız, İnci


    Hemostasis is the body response to bleeding with the interaction of the blood vessel the platelets and the coagulation factors This article reviews the normal physiologic mechanism of hemostasis together with the diagnostic approach to the bleeding child The commonly used tests of hemostasis are described Key words: Bleeding Diagnosis Tests

  3. Summary of Construction Activities and Results from Six Initial Accelerated Pavement Tests Conducted on Asphalt Concrete Pavement Section for Modified-Binder Overlay

    Bejarano, Manuel O.; Morton, Bruce S.; Scheffy, Clark


    This report summarizes the activities and data collected during the construction of a pavement section used for investigating the performance of asphalt concrete pavements under accelerated pavement testing. This report also presents the preliminary results of six accelerated pavement tests conducted on the test section. The pavement section was constructed in September 2001 at the Pavement Research Center, located at the University of California Richmond Field Station. The construct...

  4. Structural Design of Pavement Overlays Based on Functional Parameters


    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.

  5. "Full-Scale Testing of Pavement Response"

    Ullidtz, Per; Ekdahl, Peter


    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...

  6. Viscoelastic Pavement Modeling with a Spreadsheet

    Levenberg, Eyal


    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 in a...

  7. Development of New Bituminous Pavement Design Method

    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...

  8. Permeable pavement research – Edison, New Jersey

    These are the slides for the New York City Concrete Promotional Council Pervious Concrete Seminar presentation. The basis for the project, the monitoring design and some preliminary monitoring data from the permeable pavement parking lot at the Edison Environmental Center are pre...

  9. Story: A Bleeding Watermelon

    Nor bzang


    Full Text Available A Bleeding Watermelon was written by Norsang (Nor bzang;b. 1988, a native of Dpa ris (Rab rgyas (Huazangsi 华藏寺 Township, Tianzhu 天祝 Tibetan Autonomous County,Gansu 甘肃 Province. Norsang writes: I heard that a university student opened an elevator door in a campus building still under construction. The elevator shaft was empty and he fell to his death. Many people had questions about his death. This inspired me to write this story.

  10. Dysfunctional uterine bleeding (DUB).

    Bulletti, C; Flamigni, C; Prefetto, R A; Polli, V; Giacomucci, E


    Cyclic or irregular uterine bleeding is common in perimenarchal and perimenopausal women with or without endometrial hyperplasia. The disturbance often requires surgical treatment because of its negative effects on both blood loss and abnormal endometrial growth including the development of endometrial cancer. The endometrium is often overstimulated during the perimenopausal period when estrogen/progesterone production is unbalanced. A therapeutical approach with gonadotropin-releasing hormone agonist (GnRHa) was proposed in a depot formulation (Zoladex) that induces a sustained and reversible ovarian suppression. To avoid the risk of osteoporosis and to obtain adequate endometrial proliferation and differentiation during ovarian suppression, transdermal 17-beta-estradiol and oral progestin were administered. Results of 20 cases versus 20 controls showed a reduction of metrorrhagia, a normalization of hemoglobin plasma concentration, and an adequate proliferation and secretory differentiation of the endometrium of patients with abnormal endometrial growth. Abnormal uterine bleeding is mainly due to uterine fibrosis and an inadequate estrogen and/or progesterone production or to a disordered estrogen transport from blood into the endometrium. In premenopausal women, endometrial hyperplasia may be part of a continuum that is ultimately manifested in the histological and biological pattern of endometrial carcinoma. The regression of endometrial hyperplasia obtained by using the therapeutic regimen mentioned above represents a preventive measure for endometrial cancer. Finally the normalization of blood loss offers a good medical alternative to surgery for patients with DUB. PMID:7978956


    Nam, Le Thanh; Kaito, Kiyoyuki; Kobayashi, Kiyoshi; Okizuka, Ryosuke

    In pavement management, it is important to estimate lifecycle cost, which is composed of the expenses for repairing local damages, including potholes, and repairing and rehabilitating the surface and base layers of pavements, including overlays. In this study, a model is produced under the assumption that the deterioration process of pavement is a complex one that includes local damages, which occur frequently, and the deterioration of the surface and base layers of pavement, which progresses slowly. The variation in pavement soundness is expressed by the Markov deterioration model and the Poisson hidden Markov deterioration model, in which the frequency of local damage depends on the distribution of pavement soundness, is formulated. In addition, the authors suggest a model estimation method using the Markov Chain Monte Carlo (MCMC) method, and attempt to demonstrate the applicability of the proposed Poisson hidden Markov deterioration model by studying concrete application cases.

  12. Coronary interventions in patients with bleeding and bleeding tendency

    Thach Nguyen; Lan Nguyen


    @@ In general, percutaneous coronary intervention (PCI)is contra-indicated in patients with bleeding and those that are easy to bleed because during PCI the patients need full anticoagulation to counter any thrombotic formation caused by introduction and manipulation of devices in the vascular system.

  13. An Airport Pavement Traffic Simulation Based on CPN

    Heng Hong-jun; Yang Jue


    According to the characteristics of airport pavement traffic, we discuss a method of building an airport pavement traffic model which is based on CPN theory and simulate a practical situation as well. The method overcomes the shortage of modelling with normal Petri Net theory, solves the difficult problems of airport pavement traffic such as complex traffic nets, frequent road changing, etc., refines the process of the model, and will be good for the model’s analysis and simulation.

  14. International Symposium on Pavement Life Cycle Assessment 2014

    JULLIEN, Agnès; Harvey, John


    Life Cycle Assessment (LCA) is a systems approach developed to provide decision support for questions regarding the environmental impact of industrial processes and products. The application of LCA to pavement management, design and construction helps to avoid the paradox of decisions that improve one aspect of sustainability of a pavement system, while unintentionally causing greater harm elsewhere. LCA is a field with ongoing developments and improvements. As applied to pavement, interest i...

  15. Full-Depth Pavement Reclamation with Foamed Asphalt: Final Report

    Jones, David; P. Fu; Harvey, John T; Halles, F.


    A comprehensive study on full-depth reclamation (FDR) of pavements with foamed asphalt has been completed for the California Department of Transportation by the University of California Pavement Research Center. A literature review revealed that very little research had been carried out on the reclamation of thick asphalt pavements (multiple overlays over a relatively weak base or subgrade). A mechanistic sensitivity analysis was carried out to identify key variables in the design of recycled...

  16. Integrated transportation monitoring system for both pavement and traffic

    Xue, Wenjing


    In the passing decades, the monitoring of pavements and passing vehicles was developed vigorously with the growth of information and sensing technology. Pavement monitoring is an essential part of pavement research and plays an important role in transportation system. At the same time, the monitoring system about the traffic, such as Weigh-in-Motion (WIM) system and traffic classification system, also attracted lots of attention because of their importance in traffic statistics and management...

  17. Recent Developments in Pavement Management on Irish National Roads

    Feighan, Kieran; McGowan, Ray; Casey, Tom; O’Sullivan, Andrew


    The Irish National pavement network is Ireland’s strategic road network consisting of over 5,300 centreline kilometres of road and is managed by the National Roads Authority (NRA). There is a very significant variation across the network under a variety of headings, including pavement construction, pavement age, carriageway width, lane width, geometric design and traffic volumes carried. A large proportion of the network consists of “legacy” roads that have evolved from historic routes that a...

  18. Long-Term Field Performance of Pervious Concrete Pavement

    Aleksandra Radlińska; Andrea Welker; Kathryn Greising; Blake Campbell; David Littlewood


    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 th...

  19. Pavement Response to Variable Tyre Pressure of Heavy Vehicles

    Arshad Ahmad Kamil; Haron Hairol Anuar; Abd Rahman Zanariah; Abdul Halim A.G.


    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...

  20. In-Situ Behavior of Geosynthetically Stabilized Flexible Pavement

    Appea, Alexander Kwasi


    The purpose of a geotextile separator beneath a granular base, or subbase in a flexible pavement system is to prevent the road aggregate and the underlying subgrade from intermixing. It has been hypothesized that in the absence of a geotextile, intermixing between base course aggregate and soft subgrade occurs. Nine heavily instrumented flexible pavement test sections were built in Bedford County Virginia to investigate the benefits of geosynthetic stabilization in flexible pavements. ...

  1. Permeability testing of drilling core sample from pavement

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


    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.

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

    Isamu Yoshitake; Takeo Ishida; Sunao Fukumoto


    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 pow...

  3. Hybrid green permeable pave with hexagonal modular pavement systems

    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.

  4. Hybrid green permeable pave with hexagonal modular pavement systems

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


    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.

  5. Towards noise classification of road pavements

    Freitas, Elisabete F.; Paulo, Joel; Coelho, J. L. Bento; Pereira, Paulo A. A.


    Noise classification of road surfaces has been addressed in many European countries. This paper presents the first approach towards noise classification of Portuguese road pavements. In this early stage, it aims at establishing guidelines for decision makers to support their noise reduction policies and the development of a classification system adapted to the European recommendations. A ranking to provide guidance on tire-road noise emission levels for immediate use by decisio...

  6. Smart pavement sensor based on thermoelectricity power

    Yu, Xiong; Zhang, Bin; Tao, Junliang; Liu, Zhen


    The aging infrastructure requires a proactive strategy to ensure their functionality and performance. Innovative sensors are needed to develop infrastructures that are intelligent and adaptive. A power supply strategy is among the crucial components to reduce the instrument cost and to ensure the long term function of these embedded sensors. This paper introduces the results of a preliminary study on using thermo-electricity generation to power sensors. This presents an innovative strategy for long term monitoring of pavement performance.

  7. An analysis of pavement heat flux to optimize the water efficiency of a pavement-watering method

    Pavement-watering as a technique of cooling dense urban areas and reducing the urban heat island effect has been studied since the 1990's. The method is currently considered as a potential tool for and climate change adaptation against increasing heat wave intensity and frequency. However, although water consumption necessary to implement this technique is an important aspect for decision makers, optimization of possible watering methods has only rarely been conducted. An analysis of pavement heat flux at a depth of 5 cm and solar irradiance measurements is proposed to attempt to optimize the watering period, cycle frequency and water consumption rate of a pavement-watering method applied in Paris over the summer of 2013. While fine-tuning of the frequency can be conducted on the basis of pavement heat flux observations, the watering rate requires a heat transfer analysis based on a relation established between pavement heat flux and solar irradiance during pavement insolation. From this, it was found that watering conducted during pavement insolation could be optimized to 30-min cycles and water consumption could be reduced by more than 80% while reducing the cooling effect by less than 13%. - Highlights: • The thermal effects of pavement-watering were investigated in Paris, France. • Pavement-watering was found to significantly affect pavement heat flux 5 cm deep. • When insolated, a linear relation was found between heat flux and solar radiation. • Pavement-watering did not alter its slope, but introduced a negative intercept. • Subsequent improvements of the watering period, frequency and rate are proposed

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

    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,…

  9. Monitoring asphalt pavement damages using remote sensing techniques

    Mettas, Christodoulos; Themistocleous, Kyriacos; Neocleous, Kyriacos; Christofe, Andreas; Pilakoutas, Kypros; Hadjimitsis, Diofantos


    One of the main issues in the maintenance plans of road agencies or governmental organizations is the early detection of damaged asphalt pavements. The development of a smart and non-destructive systematic technique for monitoring damaged asphalt pavements is considered a main priority to fill this gap. During the 1970's, remote sensing was used to map road surface distress, while during the last decade, remote sensing became more advanced, thereby assisting in the evolution of the identification and mapping of roads. Various techniques were used in order to explore condition, age, weaknesses and imperfections of asphalted pavements. These methods were fairly successful in the classification of asphalted surfaces and in the detection of some of their characteristics. This paper explores the state of the art of using remote sensing techniques for monitoring damaged pavements and some typical spectral profiles of various asphalt pavements in Cyprus area acquired using the SVC1024 field spectroradiometer.

  10. Fibrinogen concentrate in bleeding patients

    Wikkelsø, Anne; Lunde, Jens; Johansen, Mathias;


    Hypofibrinogenaemia is associated with increased morbidity and mortality, but the optimal treatment level, the use of preemptive treatment and the preferred source of fibrinogen remain disputed. Fibrinogen concentrate is increasingly used and recommended for bleeding with acquired haemostatic...

  11. Treatment of acute variceal bleeding

    Bendtsen, Flemming; Krag, Aleksander Ahm; Møller, Søren


    The management of variceal bleeding remains a clinical challenge with a high mortality. Standardisation in supportive and new therapeutic treatments seems to have improved survival within the last 25 years. Although overall survival has improved in recent years, mortality is still closely related...... to failure to control initial bleeding or early re-bleeding occurring in up to 30-40% of patients. Initial procedures are to secure and protect the airway, and administer volume replacement to stabilize the patient. Treatment with vasoactive drugs should be started as soon as possible, since a...... adhesives should be used. In conclusion: Improvements in resuscitation and prevention of complications have together with introduction of vasoactive drugs and refinement of endoscopic therapy majorily changed the prognosis of the patient presenting with variceal bleeding....

  12. Bleeding in the Digestive Tract

    ... lining of the esophagus, stomach, or duodenum. The bacteria Helicobacter pylori (H. pylori) and use of nonsteroidal ... paleness shortness of breath vomit that looks like coffee grounds weakness A person with acute bleeding may ...

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

    Jiang Ruinan


    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.

  14. Climate change, energy, sustainability and pavements

    Provides an integrated perspective on understanding the impacts of climate change, energy and sustainable development on transportation infrastructure systems. Presents recent technological innovations and emerging concepts in the field of green and sustainable transportation infrastructure systems with a special focus on highway and airport pavements. Written by leading experts in the field. Climate change, energy production and consumption, and the need to improve the sustainability of all aspects of human activity are key inter-related issues for which solutions must be found and implemented quickly and efficiently. To be successfully implemented, solutions must recognize the rapidly changing socio-techno-political environment and multi-dimensional constraints presented by today's interconnected world. As part of this global effort, considerations of climate change impacts, energy demands, and incorporation of sustainability concepts have increasing importance in the design, construction, and maintenance of highway and airport pavement systems. To prepare the human capacity to develop and implement these solutions, many educators, policy-makers and practitioners have stressed the paramount importance of formally incorporating sustainability concepts in the civil engineering curriculum to educate and train future civil engineers well-equipped to address our current and future sustainability challenges. This book will prove a valuable resource in the hands of researchers, educators and future engineering leaders, most of whom will be working in multidisciplinary environments to address a host of next-generation sustainable transportation infrastructure challenges.

  15. Automated management for pavement inspection system (AMPIS)

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


    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. Evaluation of base widening methods on flexible pavements in Wyoming

    Offei, Edward

    The surface transportation system forms the biggest infrastructure investment in the United States of which the roadway pavement is an integral part. Maintaining the roadways can involve rehabilitation in the form of widening, which requires a longitudinal joint between the existing and new pavement sections to accommodate wider travel lanes, additional travel lanes or modification to shoulder widths. Several methods are utilized for the joint construction between the existing and new pavement sections including vertical, tapered and stepped joints. The objective of this research is to develop a formal recommendation for the preferred joint construction method that provides the best base layer support for the state of Wyoming. Field collection of Dynamic Cone Penetrometer (DCP) data, Falling Weight Deflectometer (FWD) data, base samples for gradation and moisture content were conducted on 28 existing and 4 newly constructed pavement widening projects. A survey of constructability issues on widening projects as experienced by WYDOT engineers was undertaken. Costs of each joint type were compared as well. Results of the analyses indicate that the tapered joint type showed relatively better pavement strength compared to the vertical joint type and could be the preferred joint construction method. The tapered joint type also showed significant base material savings than the vertical joint type. The vertical joint has an 18% increase in cost compared to the tapered joint. This research is intended to provide information and/or recommendation to state policy makers as to which of the base widening joint techniques (vertical, tapered, stepped) for flexible pavement provides better pavement performance.

  17. An Innovative Strategy for Maintenance of Highway Pavement

    Sandeep Choudhary, Dr. P. K. Agarwal


    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.

  18. Evaluation of accelerated deterioration in NAPTF flexible test pavements

    Kasthurirangan GOPALAKRISHNAN


    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.

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

    Pabitra Rajbongshi


    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.

  20. Research on pavement roughness based on the laser triangulation

    Chen, Wenxue; Ni, Zhibin; Hu, Xinhan; Lu, Xiaofeng


    Pavement roughness is one of the most important factors for appraising highway construction. In this paper, we choose the laser triangulation to measure pavement roughness. The principle and configuration of laser triangulation are introduced. Based on this technology, the pavement roughness of a road surface is measured. The measurement results are given in this paper. The measurement range of this system is 50 μm. The measurement error of this technology is analyzed. This technology has an important significance to appraise the quality of highway after completion of the workload.

  1. Development of Improved Mechanistic Deterioration Models for Flexible Pavements

    Ullidtz, Per; Ertman, Hans Larsen


    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...

  2. Validation of theoretical models through measured pavement response

    Ullidtz, Per


    mechanics was quite different from the measured stress, the peak theoretical value being only half of the measured value.On an instrumented pavement structure in the Danish Road Testing Machine, deflections were measured at the surface of the pavement under FWD loading. Different analytical models were then...... used to derive the elastic parameters of the pavement layeres, that would produce deflections matching the measured deflections. Stresses and strains were then calculated at the position of the gauges and compared to the measured values. It was found that all analytical models would predict the tensile...

  3. New approach for calculating permanent deformation in asphalt pavement

    TAN Yi-qiu; CHEN Feng-chen; LIU Hao; SU Xin; DONG Ze-jiao; DONG Yu-ming


    A new approach using the Fiber Bragg Grating(FBG)sensor and viscoelastic model to monitor and analyze the internal strain and temperature of asphalt pavement is proposed.Some parameters including peak strain,temperature and loading time were calculated with the application of multi-dimensional sensors group.These parameters were incorporated with viscoelastic model of five units to evaluate the permanent deformation of pavement.An application example was conducted,and the results show that it is feasible to analyze and calculate the permanent deformation of pavement structures with FBG sensors.

  4. Research on Alkaline Filler Flame-Retarded Asphalt Pavement

    HU Shuguang; ZHANG Houji; WANG Jiaolan


    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.

  5. Use of VDOT's Pavement Management System to Proactively Plan and Monitor Pavement Maintenance and Rehabilitation Activities to Meet the Agency's Performance Target

    Hosten, Akyiaa; Chowdhury, Tanveer; Shekharan, Raja A.; Ayotte, Matthew; Coggins, Eddie


    The Virginia Department of Transportation (VDOT) has an established Pavement Management Program that includes data collection, needs assessment, performance targets, and performance-based budgeting. As a part of data collection and needs assessment, an annual survey of pavement condition is used to estimate the current and project the future pavement maintenance and rehabilitation needs. Pavement condition targets are established, and are used to monitor and assess the effectiveness of mainte...

  6. Effect of Pavement Conditions on Rolling Resistance

    Mr.Dipanjan Mukherjee


    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

  7. Endoscopic Management of Diverticular Bleeding

    Tarun Rustagi


    Full Text Available Diverticular hemorrhage is the most common reason for lower gastrointestinal bleeding (LGIB with substantial cost of hospitalization and a median length of hospital stay of 3 days. Bleeding usually is self-limited in 70–80% of cases but early rebleeding is not an uncommon problem that can be reduced with proper endoscopic therapies. Colonoscopy is recommended as first-line diagnostic and therapeutic approach. In the vast majority of patients diverticular hemorrhage can be readily managed by interventional endotherapy including injection, heat cautery, clip placement, and ligation to achieve endoscopic hemostasis. This review will serve to highlight the various interventions available to endoscopists with specific emphasis on superior modalities in the endoscopic management of diverticular bleeding.

  8. [Direct oral anticoagulant associated bleeding].

    Godier, A; Martin, A-C; Rosencher, N; Susen, S


    Direct oral anticoagulants (DOAC) are recommended for stroke prevention in atrial fibrillation and for the treatment of venous thromboembolism. However, they are associated with hemorrhagic complications. Management of DOAC-induced bleeding remains challenging. Activated or non-activated prothrombin concentrates are proposed, although their efficacy to reverse DOAC is uncertain. Therapeutic options also include antidotes: idarucizumab, antidote for dabigatran, has been approved for use whereas andexanet alpha, antidote for anti-Xa agents, and aripazine, antidote for all DOAC, are under development. Other options include hemodialysis for the treatment of dabigatran-associated bleeding and administration of oral charcoal if recent DOAC ingestion. DOAC plasma concentration measurement is necessary to guide DOAC reversal. We propose an update on DOAC-associated bleeding, integrating the availability of dabigatran antidote and the critical place of DOAC concentration measurements. PMID:27297642

  9. Long-Term Field Performance of Pervious Concrete Pavement

    Aleksandra Radlińska


    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.

  10. Application of surplus and waste materials in roads pavement making

    S.M. Mousavi; Fazli, A. H.; Rouzmehr, F.


    Nowadays there are a lot of problems about surpluses and debris made by humans all around the world. Lots of these surpluses seriously harm our natural environment. Reuse of this kind of materials in other processes like building constructions or pavement help our natural environment in every aspect. Asphalt concrete is the main part of pavements in most parts of the world with an increasing rate of production in need of more ways and roads. In this paper we will provide...

  11. Visualizing Pavement Management Data at the Project Level

    Rydholm, Timothy C.; Luhr, David R.


    As a Pavement Management System increases in maturity, so does the amount of information powering it. As the level of information grows, efficiently communicating the data becomes difficult. The Washington State Department of Transportation (WSDOT) has a long history of collecting and storing data that is electronically accessible and referenced against a Linear Referencing System (LRS). This data includes pavement surveys, contracts , capital projects, roadway configuration, maintenance acti...

  12. The reflective cracking in the pavement overlay design

    Pais, Jorge C.; Pereira, Paulo A. A.; Capitão, Silvino Dias; Sousa, J.


    This paper describes a new pavement overlay design method that takes into account the reflective cracking as the most predominant type of overlay distress. This phenomenon is characterized as the propagation of old cracks to the new pavement layer. The models proposed are based on a finite element model that closely approximates actual field phenomena based on measurements done on Arizona and Portugal. Test sections have been constructed to access the effect of overlay thickness, crack width ...

  13. Optical fiber feasibility study in Accelerated Pavement Testing facility

    Bueche, N.; Rychen, P.; Dumont, A.-G.; Santagata, E.


    The presented research has been carried out within the European project Intelligent Roads (INTRO). The major objective followed was to assess the potential of optical fiber for pavement monitoring in comparison with classical strain gauges. Thus, both measurement devices have been tested under the same conditions in a full scale Accelerated Pavement Testing (APT) at LAVOC. This facility allows the user to control different parameters such as loading configuration and temperature and, as a mat...

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

    Jay N. Meegoda


    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.

  15. Improvement of the functional pavement quality with asphalt rubber mixtures

    Fontes, Liseane P. T. L.; Pereira, Paulo A. A.; Pais, Jorge C.; Trichês, Glicério


    Skid resistance and texture are important safety characteristics which need to be considered in flexible pavement design, maintenance and rehabilitation. The main objective of this paper is to optimize surface texture characteristics in asphalt rubber pavements, mainly macrotexture to reduce splash, spray and hydroplaning and microtexture to increase friction at low and high speeds. The objective was accomplished by measuring the friction surface with two different tests: (i) B...

  16. Reliability-based Design Procedure for Flexible Pavements

    Dinegdae, Yared Hailegiorgis


    Load induced top-down fatigue cracking has been recognized recently as a major distress phenomenon in asphalt pavements. This failure mode has been observed in many parts of the world, and in some regions, it was found to be more prevalent and a primary cause of pavements failure. The main factors which are identified as potential causes of top down fatigue cracking are primarily linked to age hardening, mixtures fracture resistance and unbound layers stiffness. Mechanistic Empirical analytic...

  17. Environmental assessment of pavement infrastructure: A systematic review.

    Inyim, Peeraya; Pereyra, Jose; Bienvenu, Michael; Mostafavi, Ali


    Through a critical review and systematic analysis of pavement life cycle assessment (LCA) studies published over the past two decades, this study shows that the available information regarding the environmental impacts of pavement infrastructure is not sufficient to determine what pavement type is more environmentally sustainable. Limitations and uncertainties related to data, system boundary and functional unit definitions, consideration of use and maintenance phase impacts, are identified as the main reasons for inconsistency of reported results in pavement LCA studies. The study outcomes also highlight the need for advancement of knowledge pertaining to: (1) utilization of performance-adjusted functional units, (2) accurate estimation of use, maintenance, and end-of-life impacts, (3) incorporation of the dynamic and uncertain nature of pavement condition performance in impact assessment; (4) development of region-specific inventory data for impact estimation; and (5) consideration of a standard set of impact categories for comparison of environmental performance of different pavement types. Advancing the knowledge in these areas is critical in providing consistent and reliable results to inform decision-making toward more sustainable roadway infrastructure. PMID:27045541

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

    Jens Skarabis


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

  19. Numerical Analysis of Asphalt Pavements under Moving Wheel Loads


    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.

  20. Pavement Response to Variable Tyre Pressure of Heavy Vehicles

    Arshad Ahmad Kamil


    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.

  1. Gastrointestinal Bleeding Secondary to Calciphylaxis.

    Gupta, Nancy; Haq, Khwaja F; Mahajan, Sugandhi; Nagpal, Prashant; Doshi, Bijal


    BACKGROUND Calciphylaxis is associated with a high mortality that approaches 80%. The diagnosis is usually made when obvious skin lesions (painful violaceous mottling of the skin) are present. However, visceral involvement is rare. We present a case of calciphylaxis leading to lower gastrointestinal (GI) bleeding and rectal ulceration of the GI mucosa. CASE REPORT A 66-year-old woman with past medical history of diabetes mellitus, hypertension, end-stage renal disease (ESRD), recently diagnosed ovarian cancer, and on hemodialysis (HD) presented with painful black necrotic eschar on both legs. The radiograph of the legs demonstrated extensive calcification of the lower extremity arteries. The hospital course was complicated with lower GI bleeding. A CT scan of the abdomen revealed severe circumferential calcification of the abdominal aorta, celiac artery, and superior and inferior mesenteric arteries and their branches. Colonoscopy revealed severe rectal necrosis. She was deemed to be a poor surgical candidate due to comorbidities and presence of extensive vascular calcifications. Recurrent episodes of profuse GI bleeding were managed conservatively with blood transfusion as needed. Following her diagnosis of calciphylaxis, supplementation with vitamin D and calcium containing phosphate binders was stopped. She was started on daily hemodialysis with low calcium dialysate bath as well as intravenous sodium thiosulphate. The clinical condition of the patient deteriorated. The patient died secondary to multiorgan failure. CONCLUSIONS Calciphylaxis leading to intestinal ischemia/perforation should be considered in the differential diagnosis in ESRD on HD presenting with abdominal pain or GI bleeding. PMID:26572938

  2. Management of bleeding gastroduodenal ulcers

    Laursen, Stig Borbjerg; Jørgensen, Henrik Stig; Schaffalitzky de Muckadell, Ove B


    Description: A multidisciplinary group of Danish experts developed this guideline on management of bleeding gastroduodenal ulcers. Sources of data included published studies up to March 2011. Quality of evidence and strength of recommendations have been graded. The guideline was approved by the...

  3. An unusual cause of gastrointestinal bleed

    C K Adarsh


    Full Text Available Gastrointestinal (GI bleed often brings the patient to the emergency medical service with great anxiety. Known common causes of GI bleed include ulcers, varices, Mallory-Weiss among others. All causes of GI bleed should be considered however unusual during the evaluation. Aortoenteric fistula (AEF is one of the unusual causes of GI bleed, which has to be considered especially in patients with a history of abdominal surgery in general and aortic surgery in particular.

  4. Vitamin K deficiency bleeding of the newborn

    Vitamin K deficiency bleeding of the newborn (VKDB) is a bleeding disorder in babies. It most often develops shortly ... A lack of vitamin K may cause severe bleeding in newborn babies. Vitamin K plays an important role in blood clotting. Babies often have a ...

  5. Obscure gastrointestinal bleeding: preoperative CT-guided percutaneous needle localization of the bleeding small bowel segment.

    Heiss, Peter; Feuerbach, Stefan; Iesalnieks, Igors; Rockmann, Felix; Wrede, Christian E; Zorger, Niels; Schlitt, Hans J; Schölmerich, Jürgen; Hamer, Okka W


    A 57-year-old woman presented with obscure gastrointestinal bleeding. Double balloon enteroscopy, angiography, and surgery including intraoperative enteroscopy failed to identify the bleeding site. Multidetector computed tomography (CT) depicted active bleeding of a small bowel segment. The bleeding segment was localized by CT-guided percutaneous needle insertion and subsequently removed surgically. PMID:19328430


    Design and operational criteria, utilization concepts, benefits and disadvantages, as well as other characteristics of porous pavements are presented in this report. Particular emphasis is placed on porous asphalt pavements, but the criteria and design approach are applicable to ...

  7. Management of severe perioperative bleeding

    Kozek-Langenecker, Sibylle A; Afshari, Arash; Albaladejo, Pierre;


    The aims of severe perioperative bleeding management are three-fold. First, preoperative identification by anamesis and laboratory testing of those patients for whom the perioperative bleeding risk may be increased. Second, implementation of strategies for correcting preoperative anaemia and...... with an assessment of the quality of the evidence in order to allow anaesthetists throughout Europe to integrate this knowledge into daily patient care wherever possible. The Guidelines Committee of the European Society of Anaesthesiology (ESA) formed a task force with members of scientific...... cross-sectional surveys were selected. At the suggestion of the ESA Guideline Committee, the Scottish Intercollegiate Guidelines Network (SIGN) grading system was initially used to assess the level of evidence and to grade recommendations. During the process of guideline development, the official...

  8. Genetic Optimization Method of Asphalt Pavement Based on Rutting and Cracking Control


    Nowadays asphalt pavement structure bearing is not the main subject for pursuers to study.Comparatively,the pavement performance is more important and emphasized.Based on this,rutting and cracking analysis is introduced into pavement optimization.A optimization model based on these two considerations is also established.The genetic algorithms (GAs) is adopted to solve the model.It is an intellective method.This research provides a new idea and technique for asphalt pavement structure optimization.

  9. Comparison of Surface Characteristics of Hot-Mix Asphalt Pavement Surfaces at the Virginia Smart Road

    Davis, Robin Michelle


    Pavement surface characteristics are important to both the safety of the pavement surface and the comfort of the drivers. As of yet, texture and friction measurements have not been incorporated into the design of pavement surfaces. Seven different wearing surface mixtures, placed at the Virginia Smart Road pavement facility, were studied over a one year time period for both friction and texture properties. A locked wheel skid trailer and a laser profilometer were used to assess the pavemen...

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

    Yingwei Ren; Jingsong Shan


    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 thickn...

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

    Salour, Farhad


    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...

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

    Bekele, Abiy


    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...

  13. Role of videocapsule endoscopy for gastrointestinal bleeding

    Cristina Carretero; Ignacio Fernandez-Urien; Maite Betes; Miguel Mu(n)oz-Navas


    Obscure gastrointestinal bleeding (OGIB) is defined as bleeding of an unknown origin that persists or recurs after negative initial upper and lower endoscopies.Several techniques,such as endoscopy,arteriography,scintigraphy and barium radiology are helpful for recognizing the bleeding source;nevertheless,in about 5%-10% of cases the bleeding lesion cannot be determined.The development of videocapsule endoscopy (VCE) has permitted a direct visualization of the small intestine mucosa.We will analyze those techniques in more detail.The diagnostic yield of CE for OGIB varies from 38% to 93%,being in the higher range in those cases with obscure-overt bleeding.

  14. Scintigraphic diagnosis of lower GI bleeding

    Abdominal scintigraphy with 99mTc HSA, 99mTc Sn colloid, or 99mTc RBC was performed in 28 patients with melena to detect bleeding and determine the bleeding site in the lower gastrointestinal tract. Active bleedings and/or vascular lesions were identified in 16 patients. They were proved by antiography, endoscopy or barium enema in 14. We concluded that scintigraphy was an accurate and effective method to detect the bleeding and determine the bleeding site in the lower gastrointestinal tract. (author)

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

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


    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. PMID:24681366

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

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

  17. Development and evaluation of the model for the surface pavement temperature prediction

    B. Matić


    Full Text Available This paper examines the existing models for predicting pavement temperatures and formulates a new one using a regression equation to predict the minimum and maximum pavement surface temperatures depending on the air temperature. Also, the paper presents a model for pavement temperature prediction according to the Superpave methodology and conducts the validation of the model for measured temperatures.

  18. Bleeding

    ... Latex gloves should be in every first aid kit. People allergic to latex can use a nonlatex glove. You can catch viral hepatitis if you touch infected blood. HIV can be spread if infected blood gets into ...

  19. Low cost pavement marking materials based on plasticized sulfur

    Dale, J. M.


    Pavement marking was made more cost effective by reducing the cost of the marking materials. A low cost marking material based on sulfur was developed. Elemental sulfur is a hard, brittle, crystalline material which, on heating, melts to a thin liquid that can be spray applied. If molten elemental sulfur is spray applied to the road as markings, it will on application solidify, crack and adhere poorly to the road. The first ten high speed trucks that ride over the markings will remove them. To make a useful sulfur based pavement marking material it was necessary to chemically modify (plasticize) the sulfur and mix it with fillers and pigments such that it had all of the characteristics desired of a pavement marking material. Yellow and white formulations were developed. For identification they were given the names YS-EIGHT and WS-EIGHT for the yellow and white formulations.

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

    Ullidtz, Per; Ertman Larsen, Hans Jørgen


    Most existing pavement subgrade criteria are based on the AASHO Road Test, where only one material was tested and for only one climatic condition. To study the validity of these criteria and to refine the criteria a co-operative research program entitled the "International Pavement Subgrade...... Performance Study" was sponsored by the FHWA with American, Finnish and Danish partners. This paper describes the first test series which was carried out in the Danish Road Testing Machine (RTM).The first step in this program is a full scale test on an instrumented pavement in the Danish Road Testing Machine...... of elasticity to calculate the stresses and strains at the position of the gauges and to compare these values to the stresses and strains recorded under the rolling wheel load.Plastic strains resulting from 50 000 applications of each of two load levels (20 kN and 40 kN) were recorded, as well as the permanent...

  1. Design prediction of pavement skid resistance from laboratory tests

    Parcells, W. H.; Metheny, T. M.; Maag, R. G.


    Methods for preevaluating aggregates and paving mixtures so that predictions can be made covering skid resistance properties of proposed and in service pavement types are discussed. A correlation was established between the field testing using the data from the British Portable Tester and the Locked Wheel Pavement Friction Trailer at speeds of 40 and 55 mph. Core samples were extracted from the Locked Wheel Tester Skid Path and subjected to wear on the small wheel circular track with periodic surface friction testing. The final step was to remix and remold the cored pavement samples or make samples with new materials to obtain an 'as new' surface and again subject these samples to wear on the small wheel circular track with periodic testing.

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

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


    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.

  3. Determination of Pavement Rehabilitation Activities through a Permutation Algorithm

    Sangyum Lee


    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.

  4. Evaluation of Common Maintenance Methods for Flexible Pavements

    Asma T. Ibraheem


    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

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

    Scholer, C. F.


    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.

  6. Cold Region Pavements%寒区路面



    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.

  7. Bearing capacity evaluation of rubblized concrete pavements

    González, M.


    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

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

    Zornberg, J. G.


    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)

  9. Management of bleeding gastroduodenal ulcers

    Laursen, Stig Borbjerg; Jørgensen, Henrik Stig; Schaffalitzky de Muckadell, Ove B.


    serious ulcer bleeding is suspected and blood found in gastric aspirate, endoscopy within 12 hours will result in faster discharge and reduced need for transfusions. Endoscopic hemostasis remains indicated for high-risk lesions. Clips, thermocoagulation, and epinephrine injection are effective in...... achieving endoscopic hemostasis. Use of endoscopic monotherapy with epinephrine injection is not recommended. Intravenous high-dose proton pump inhibitor (PPI) therapy for 72 hours after successful endoscopic hemostasis is recommended as it decreases both rebleeding rate and mortality in patients with high...

  10. Bleeding complications of femoral catheterization

    CT has been used to evaluate hematomas resulting from femoral catheterization (percutaneous transluminal coronary angioplasty, cardiac catheterization, angioplasty, valvuloplasty, and venous access) in 21 patients. Four distinct types of hematoma have been identified: retroperitoneal (N = 12); intraperitoneal (N = 3); groin/thigh (N = 9); and abdominal wall (N = 5). Seven patients had hematomas in two locations. CT contributed by estimating transfusion requirement, indicating the need for more intensive monitoring, and predicting the potential need for surgery. Type 1 and 2 bleeds were the most serious and had the most sequelae. Sequelae included transfusion in 17 patients (mean, 5 units/patient) and surgery in two patients

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

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


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

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

    Huaping Wang


    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.

  13. Sandostatin therapy of acute oesophageal variceal bleeding.

    McKee, R F


    This communication deals with the emergency control of variceal bleeding rather than the prevention of rebleeding. The current main options of oesophageal tamponade, emergency sclerotherapy and drug therapy are discussed, with particular reference to the use of somatostatin. Sandostatin (Sandoz, Basel), a synthetic long-acting somatostatin analogue, was found to reduce transhepatic venous gradient by 30% with no effect on systemic haemodynamics in a study of 16 stable cirrhotic patients. In a trial comparing intravenous infusion of Sandostatin (SMS) to oesophageal tamponade (OT) in active variceal bleeding, 18 of 20 bleeds in the SMS group and 19 of 20 bleeds in the OT group were controlled at 4 h. Ten in the SMS group and 14 in the OT group had no further bleeding during the 48-hour study period. Thus SMS may be useful in the temporary control of active variceal bleeding. PMID:8359565

  14. [Diagnosis and therapy of bleeding in ENT].

    Schulz, T; Eßer, D


    Bleeding in the oral cavity, nose or ear are common events in the daily routine of ENT specialists. Apart from trivial cases that often get outpatient treatment, there are numerous cases of serious bleeding that require stationary treatment and if necessary, an operative or interventional therapy. In the following section the most frequent types of bleeding, their diagnosis and therapy will be explained. PMID:24285208

  15. Cyclical rectal bleeding in colorectal endometriosis.

    Levitt, M D; Hodby, K J; van Merwyk, A J; Glancy, R J


    Three case reports of cyclical rectal bleeding in endometriosis affecting rectum and sigmoid colon emphasize the close relationship between such cyclical bleeding and intestinal endometriosis. The cause of bleeding, however, is still unclear. The predilection of endometriotic deposits for the outer layers of the bowel wall suggests that mucosal involvement is not a prerequisite for rectal bleeding. The frequent absence of identifiable intramural haemorrhage casts doubt on the premise that intestinal endometriotic deposits 'menstruate'. The cause may simply be a transient tear in normal mucosa due to swelling of an underlying endometriotic deposit at the time of menstruation. PMID:2597100

  16. Bleed condenser tube failure in KAPP-1

    Bleed condenser, a vertical, tube and shell type heat exchanger employed in bleed circuit of primary heat transport system of PHWR is used for condensing the flashing bleed (heavy water) on shell side and cold heavy water on the tubes side. Examinations conducted at various places indicate failure due to inadequate tube expansion (hydraulic expansion) followed by crevice corrosion. Mechanical rolling of tubes to larger extent (3 to 6% wall thinning) have been specified for this particular type of service in all bleed condensers for subsequent projects. 1 tab., 4 figs

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

    Er. Devendra Kumar Choudhary


    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. Monitoring Strategies in Permeable Pavement Systems to Optimize Maintenance Scheduling

    As the surface in a permeable pavement system clogs and performance decreases, maintenance is required to preserve the design function. Currently, guidance is limited for scheduling maintenance on an as needed basis. Previous research has shown that surface clogging in a permea...

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

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


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

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

    Isamu Yoshitake


    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.

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

    Ren, D.


    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. Representative volume element of asphalt pavement for electromagnetic measurements

    Terhi Pellinen


    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.

  3. Design Basis for Fibre Reinforced Concrete (FRC) Pavements

    Bendixen, Søren; Stang, Henrik


    -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...

  4. Nitrogen Transformations in Three Types of Permeable Pavement

    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...

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

    Simonas Tamaliūnas; Henrikas Sivilevičius


    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

  6. Performance Evaluation of Flexible Pavements: A Case Study

    V.K Chakravarthi1 ,


    Full Text Available : Flexible pavements get distress during their service life because of increase in traffic particularly commercial vehicles. The present study focuses on finding the increase of magnitude of deformations from 2008 to 2015 traffic data using ANSYS for which the BRTS stretch in Visakhapatnam is considering five locations along the stretch.

  7. Ground Penetrating Radar Assessment of Flexible Road Pavement Degradation

    Sandro Colagrande


    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. Measuring Clogging with Pressure Transducers in Permeable Pavement Strips

    Two issues that have a negative affect on the long term hydrologic performance of permeable pavement systems are surface clogging and clogging at the interface with the underlying soil. Surface clogging limits infiltration capacity and results in bypass if runoff rate exceeds in...

  9. Predicting physical clogging of porous and permeable pavements

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


    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.

  10. Recent rubber crumb asphalt pavement projects in Alberta

    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)


    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.

  11. Diagnostic Strategies for Postmenopausal Bleeding

    M. C. Breijer


    Full Text Available Postmenopausal bleeding (PMB is a common clinical problem. Patients with PMB have 10%–15% chance of having endometrial carcinoma and therefore the diagnostic workup is aimed at excluding malignancy. Patient characteristics can alter the probability of having endometrial carcinoma in patients with PMB; in certain groups of patients the incidence has been reported to be as high as 29%. Transvaginal sonography (TVS is used as a first step in the diagnostic workup, but different authors have come to different conclusions assessing the accuracy of TVS for excluding endometrial carcinoma. Diagnostic procedures obtaining material for histological assessment (e.g., dilatation and curettage, hysteroscopy, and endometrial biopsy can be more accurate but are also more invasive. The best diagnostic strategy for diagnosing endometrial carcinoma in patients with PMB still remains controversial. Future research should be focussed on achieving a higher accuracy of different diagnostic strategies.

  12. The effect of loading time on flexible pavement dynamic response: a finite element analysis

    Yin, Hao; Solaimanian, Mansour; Kumar, Tanmay; Stoffels, Shelley


    Dynamic response of asphalt concrete (AC) pavements under moving load is a key component for accurate prediction of flexible pavement performance. The time and temperature dependency of AC materials calls for utilizing advanced material characterization and mechanistic theories, such as viscoelasticity and stress/strain analysis. In layered elastic analysis, as implemented in the new Mechanistic-Empirical Pavement Design Guide (MEPDG), the time dependency is accounted for by calculating the loading times at different AC layer depths. In this study, the time effect on pavement response was evaluated by means of the concept of “pseudo temperature.” With the pavement temperature measured from instrumented thermocouples, the time and temperature dependency of AC materials was integrated into one single factor, termed “effective temperature.” Via this effective temperature, pavement responses under a transient load were predicted through finite element analysis. In the finite element model, viscoelastic behavior of AC materials was characterized through relaxation moduli, while the layers with unbound granular material were assumed to be in an elastic mode. The analysis was conducted for two different AC mixtures in a simplified flexible pavement structure at two different seasons. Finite element analysis results reveal that the loading time has a more pronounced impact on pavement response in the summer for both asphalt types. The results indicate that for reasonable prediction of dynamic response in flexible pavements, the effect of the depth-dependent loading time on pavement temperature should be considered.

  13. An assessment of the skid resistance effect on traffic safety under wet-pavement conditions.

    Pardillo Mayora, José M; Jurado Piña, Rafael


    Pavement-tire friction provides the grip that is required for maintaining vehicle control and for stopping in emergency situations. Statistically significant negative correlations of skid resistance values and wet-pavement accident rates have been found in previous research. Skid resistance measured with SCRIM and crash data from over 1750km of two-lane rural roads in the Spanish National Road System were analyzed to determine the influence of pavement conditions on safety and to assess the effects of improving pavement friction on safety. Both wet- and dry-pavement crash rates presented a decreasing trend as skid resistance values increased. Thresholds in SCRIM coefficient values associated with significant decreases in wet-pavement crash rates were determined. Pavement friction improvement schemes were found to yield significant reductions in wet-pavement crash rates averaging 68%. The results confirm the importance of maintaining adequate levels of pavement friction to safeguard traffic safety as well as the potential of pavement friction improvement schemes to achieve significant crash reductions. PMID:19540980

  14. First trimester bleeding and maternal cardiovascular morbidity

    Lykke, Jacob A; Langhoff-Roos, Jens


    First trimester bleeding without miscarriage is a risk factor for complications later in the pregnancy, such as preterm delivery. Also, first trimester miscarriage has been linked to subsequent maternal ischemic heart disease. We investigated the link between maternal cardiovascular disease prior...... to and subsequent to first trimester bleeding without miscarriage....

  15. Obstetric management of adolescents with bleeding disorders.

    James, Andra H


    Adolescents with bleeding disorders who become pregnant must contend with the dual challenges of their bleeding disorder and their pregnancy. Adolescents are more likely to terminate a pregnancy than adult women, and when they do carry a pregnancy, they are more likely to deliver prematurely. Otherwise, they are at risk for the same complications that adult women with bleeding disorders experience, particularly bleeding complications postpartum. Since one half to two thirds of adolescent pregnancies are unplanned, issues related to reproduction should be addressed during routine visits with the pediatrician, hematologist or gynecologist. Girls who are at risk of being carriers for hemophilia A and B, severe von Willebrand disease, and other severe bleeding disorders should have their bleeding disorder status determined before they become pregnant. During pregnancy, a plan should be established to ensure that both mother and fetus deliver safely. Young women at risk for severe bleeding or at risk of having a severely affected infant should be referred for prenatal care and delivery to a center where, in addition to specialists in high-risk obstetrics, there is a hemophilia treatment center or a hematologist with expertise in hemostasis. Prior to delivery or any invasive procedures, young women at risk for severe bleeding should receive prophylaxis. Since administration of desmopressin may result in hyponatremia, whenever available, virally inactivated or recombinant clotting factor concentrates should be used for replacement as opposed to fresh frozen plasma or cryoprecipitate. PMID:20934895

  16. Hemospray Application in Nonvariceal Upper Gastrointestinal Bleeding

    Smith, Lyn A; Stanley, Adrian J; Bergman, Jacques J; Kiesslich, Ralf; Hoffman, Arthur; Tjwa, Eric T; Kuipers, Ernst J; von Holstein, Christer Stael; Oberg, Stefan; Brullet, Enric; Schmidt, Palle N; Iqbal, Tariq; Mangiavillano, Benedetto; Masci, Enzo; Prat, Frederic; Morris, Allan J


    Hemospray TM (TC-325) is a novel hemostatic agent licensed for use in nonvariceal upper gastrointestinal bleeding (NVUGIB) in Europe.......Hemospray TM (TC-325) is a novel hemostatic agent licensed for use in nonvariceal upper gastrointestinal bleeding (NVUGIB) in Europe....

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

    Yingwei Ren


    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.

  18. Endoscopic management of bleeding peptic ulcers

    Peptic ulcers account for more than half of the cases of non variceal upper gastrointestinal (GI) bleeding and therefore, are the focus of most of the methods of endoscopic hemostasis. Surgical intervention is now largely reserved for patients in whom endoscopic hemostasis has failed. A variety of endoscopic techniques have been employed to stop bleeding and reduce the risk of rebleeding, with no major differences in outcome between these methods. These include injection therapy, fibrin injection, heater probe, mono polar electrocautery, bipolar electrocautery, lasers and mechanical hemo clipping. The most important factor in determining outcome after gastrointestinal bleeding is rebleeding or persistent bleeding. The endoscopic appearance of an ulcer, however, provides the most useful prognostic information for bleeding. Recurrent bleeding after initial endoscopic hemostasis occurs in 15-20% of patients with a bleeding peptic ulcer. The best approach to these patients remains controversial; the current options are repeat endoscopic therapy with the same or a different technique, emergency surgery or semi elective surgery after repeat endoscopic hemostasis. The combination of epinephrine injection with thermal coagulation may be more effective than epinephrine injection alone. Newer modalities such as fibrin injection or the application of hemo clips appear promising and comparative studies are awaited. (author)

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

    Foye, Kevin C.


    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...

  20. Effects of diurnal temperature dynamics on curing of cold-emulsion reclaimed asphalt pavements

    Kiplagat Chelelgo


    Strength development in Cold-Emulsion Reclaimed Asphalt Pavements is gradual and largely dependent on the rate at which curing proceeds. Its early life strength is therefore low and presents a major challenge in material specification for mechanistic pavement design. The solution has been to subject a sample of the mixture to be used in the pavement to accelerated laboratory curing to the attainment of Equilibrium Moisture Content (EMC) condition. Fatigue and Stiffness parameters of the mix a...

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

    Ali Reza Ghanizadeh


    Pavement construction is one of the most costly parts of transportation infrastructures. Incommensurate design and construction of pavements, in addition to the loss of the initial investment, would impose indirect costs to the road users and reduce road safety. This paper aims to propose an optimization model to determine the optimal configuration as well as the optimum thickness of different pavement layers based on the Iran Highway Asphalt Paving Code Number 234 (IHAP Code 234). After deve...


    Svetlana Talakh


    Full Text Available The article presents mathematical model of non-linear subgrade half-space on the basis of the von Mises advanced yieldcriterion. We have performed computational investigations of non-rigid pavement deflected mode in plane problem statement under simulation of subgrade half-space active zone including the layers of pavement. The results receiveds how the plastoelastic deformation development influences the strength of non-rigid pavement.

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

    Huaping Wang; Wanqiu Liu; Jianping He; Xiaoying Xing; Dandan Cao; Xipeng Gao; Xiaowei Hao; Hongwei Cheng; Zhi Zhou


    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 pav...

  4. Asphalt Materials Characterization in Support of Implementation of the Proposed Mechanistic-Empirical Pavement Design Guide

    Flintsch, Gerardo W.; Loulizi, Amara; Stacey D. Diefenderfer; Khaled A. Galal; Diefenderfer, Brian K.


    The proposed Mechanistic-Empirical Pavement Design Guide (MEPDG) procedure is an improved methodology for pavement design and evaluation of paving materials. Since this new procedure depends heavily on the characterization of the fundamental engineering properties of paving materials, a thorough material characterization of mixes used in Virginia is needed to use the MEPDG to design new and rehabilitated flexible pavements. The primary objective of this project was to perform a full hot-mix a...

  5. Characterisation of pavement profile heights using accelerometer readings and a combinatorial optimisation technique

    Harris, Niall K.; González, Arturo; O'Brien, Eugene J.; McGetrick, P.


    Pavement surface profiles induce dynamic ride responses in vehicles which can potentially be used to classify road surface roughness. A novel method is proposed for the characterisation of pavement roughness through an analysis of vehicle accelerations. A combinatorial optimisation technique is applied to the determination of pavement profile heights based on measured accelerations at and above the vehicle axle. Such an approach, using low-cost inertial sensors, would provide an inexpensive a...

  6. Characterization of infiltration capacity of permeable pavements with porous asphalt surface using cantabrian fixed infiltrometer

    Rodríguez Hernández, Jorge; Castro Fresno, Daniel; Fernández Barrera, Andrés Humberto; Vega Zamanillo, Ángel


    Porous asphalt is used in Permeable Pavement Systems, but it is sensitive to surface clogging, which leads to a loss in its infiltration capacity. Test methods based on the use of permeable pavement models, which are manufactured in a laboratory and assessed under different clogging conditions, such as slope, rain, and runoff, have been widely applied to the study of permeable pavements with concrete blocks but not to the study of porous bituminous mixtures. The Cantabrian Fixed (CF) Infiltro...

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

    Myle N. James


    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.

  8. Full scale demonstration of air-purifying pavement.

    Ballari, M M; Brouwers, H J H


    Experiments concerning a full-scale demonstration of air purifying pavement in Hengelo, The Netherlands, are reported. The full width of the street was provided with concrete pavement containing TiO₂ over a length of 150 m ("DeNOx street"). Another part of the street, about 100 m, was paved with normal paving blocks ("Control street"). The outdoor monitoring was done during 26 days for a period exceeding one year, and measured parameters included traffic intensity, NO, NO₂ and ozone concentrations, temperature, relative humidity, wind speed and direction, and the visible and UV light irradiance. Prior and parallel to these field measurements, the used blocks were also measured in the lab to assess their performance. The NOx concentration was, on average, 19% (considering the whole day) and 28% (considering only afternoons) lower than the obtained values in the Control street. Under ideal weather conditions (high radiation and low relative humidity) a NOx concentration decrease of 45% could be observed. PMID:23731840

  9. Design Methodologies of Asphalt Pavement Used in China and Mozambique

    Francisco Rufino Diogo, Jose; Shubber, Ammar Abbas Mohammed; Lin, Mu Han

    This study discusses and compares Asphalt Concrete (AC) pavement design methodologies used in China and Mozambique (based on South African Transportation and Communication Commission (SATCC) methodologies). The SATCC design methodologies use California Bearing Ratio (CBR) and catalogues methods. The South African catalogues are basically used for roads with traffic less than 30 million ESAs. The design catalogues method give small thickness than CBR and Chinese methods. The Chinese and the South African design methods give nearly the same thickness; this study concludes that these methods can be used in both countries; China and Mozambique. The results also show that the strong point of Chinese method is verifying the tensile stress and allowable displacement on the pavement calculated from computer program APDS.

  10. Mechanical Properties of Asphalt Pavement Structure in Highway Tunnel

    SHI Chun-xiang; GUO Zhong-yin


    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.

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

    Sylvie Chambon


    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.

  12. Compressor bleed cooling fluid feed system

    Donahoo, Eric E; Ross, Christopher W


    A compressor bleed cooling fluid feed system for a turbine engine for directing cooling fluids from a compressor to a turbine airfoil cooling system to supply cooling fluids to one or more airfoils of a rotor assembly is disclosed. The compressor bleed cooling fluid feed system may enable cooling fluids to be exhausted from a compressor exhaust plenum through a downstream compressor bleed collection chamber and into the turbine airfoil cooling system. As such, the suction created in the compressor exhaust plenum mitigates boundary layer growth along the inner surface while providing flow of cooling fluids to the turbine airfoils.

  13. Low-cost bicycle path pavements. Final report, September 1, 1975--November 30, 1976

    Lai, J.S.


    The proposed research involves an analytic and experimental investigation to develop realistic design criteria for bicycle path pavements. The research also included evaluation of specific designs and innovative low-cost material systems for use in bicycle path pavements. An extensive literature review of currently existing and experimental bikepath pavement was also included. Results from this report indicate that the strength and durability of Class I bikepath pavements can be improved and the construction cost can be reduced through better design and construction practices and use of low-cost material systems.

  14. A Framework for Quantification of Effect of Drainage Quality on Structural and Functional Performance of Pavement

    Jitendra Gurjar, Pradeep Kumar Agarwal, Manoj Kumar Sharma


    Full Text Available Drainage quality is an important parameter which affects the highway pavement performance. Excessive water content in the pavement base, sub-base, and sub-grade soils can cause early distress and lead to a structural or functional failure of pavement. Thus, when selecting appropriate maintenance strategies the cost of pavement maintenance needs to be compared with the cost of improving the quality of drainage. Hence, there is a need to quantify the effect of various types of drainage quality on performance of the pavement. However, very few studies have investigated to what extent quality of drainage affects the performance of pavement. Therefore, this study identifies a simple framework for quantification of effect of drainage quality on structural as well as functional performance of the pavement. The proposed framework presents the structural and functional performance of the pavement is predicted in terms of deflection and roughness respectively. It is expected that this study will useful to reduce the maintenance cost of highway pavement system and hence will be useful to preserve huge highway network in India.

  15. Stress Analysis and Determination of Effective k-value for Rigid Pavement

    Kundan Meshram; H.S. Goliya; Akhilesh Poddar


    EverFE is a user-friendly 3D finite-element analysis tool for simulating the response of jointed plain concrete pavement (JPCP) systems to axle loads and environmental effects. EverFE is useful for both concrete pavement researchers and designers who must perform either complex nonlinear or simple linear stress analyses of JPCP.With help of this develop any type of model of rigid pavement considering practical condition thus getting more accurate and advance analysis for rigid pavement. It ca...

  16. Road Performance of Fiber Reinforced Asphalt Concrete Bridge Deck Pavement

    Xiu Liu; Zhaojie Sun; Decheng Feng; Yixiang Cao


    As the problem of asphalt concrete bridge deck pavement is becoming more and more serious, how to improve its road performance has become the focus of the study. Considering fiber is widely used in road engineering, wheel tracking test, flexural test, immersion marshall test and freeze-thaw splitting test were carried out to study road performance of asphalt mixture with different fiber contents, analyzing the function mechanism of fiber reinforced asphalt ...

  17. Pavement wear and airborne dust pollution in Norway

    Snilsberg, Brynhild


    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...

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

    Myle N. James; Wonchang Choi; Taher Abu-Lebdeh


    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 streng...

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

    TANG Zuquan; QIAN Jueshi; LI Zhuoqiu; WU Chuanming


    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.

  20. Use of scrap rubber in asphalt pavement surfaces

    Eaton, Robert A.; Roberts, Richard J.; Blackburn, Robert R.


    Scrap tire rubber was mixed into an asphalt concrete wearing course to study the effect of ice disbonding from the pavement surface under traffic. Rubber contents of 0, 3, 6, and 12 percent by weight were studied. Initial laboratory ice disbonding test results led to the development of a new paving material, Chunk Rubber Asphalt Concrete (CRAC), that uses larger pieces of rubber in a much denser asphalt concrete mix. Strength values doubled and ice disbonding performance was enhanced.

  1. Use of Recycled Aggregates in Riigid Pavement Construction

    Muscalu, Marius-Teodor; Andrei, Radu


    The paper presents the actual stage of analysis and laboratory studies, undertaken in the frame of postdoctoral program “Develop and Support Multidisciplinary Postdoctoral Programs in Primordial Technical Areas of National Strategy of the Research–Development–Innovation” 4D-POSTDOC, aiming to produce recycled aggregates with physical-mechanical characteristics suitable for use in rigid pavement construction. Recycled aggregates under investigation are obtained by crushing of cement concrete f...

  2. Identifying Fine Aggregates Prone to Polishing in PCC Pavements

    Fowler, David W; Rached, Marc M.


    Surface polishing in portland cement concrete (PCC) pavements leads to higher incidences of skid-related accidents on highways. This type of failure is often associated with the usage of softer fine aggregate such as limestone sands. To identify polish resistance aggregates, state agencies like TxDOT have adopted tests such as the acid insoluble residue test (AIR). Since calcium carbonate is soluble in acid, no carbonate sand passes the AIR test which has a minimum limit of 60% in Texas. This...

  3. The Research on the Cracks of the Asphalt Pavement

    OuYangZiqiang; Li Chunge


    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

  4. The Research on the Cracks of the Asphalt Pavement



    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

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

    Jay N. Meegoda; Shengyan Gao


    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 a...


    YU Xinhua


    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.

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

    Yuan Goulin; Chen Rongshen


    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.


    Mandula, Jan; Olexa, Tomaš; Holubka, Mariya; Salaiova, Brigita


    Waste tires must be recycled in environmentally safe ways that meet civil engineering concerns while fulfilling standards for construction materials. Used tires can be processed into rubber powders with particle sizes of 0–2 mm, a suitable fine aggregate for mixing into road pavements. We tested asphalt mixtures with rubber added using the dry method, comparing their properties with a traditional mixture. We tested asphalt–rubber mixtures with rubber incorporated at either ambient temperature...

  9. Reinforcing Effects of Carbon Black on Asphalt Binder for Pavement

    Yamaguchi, Katsuyuki; Sasaki, Iwao; Nishizaki, Itaru; Meiarashi, Seishi; Moriyoshi, Akihiro


    Carbon black, used as a reinforcing filler for rubber materials, was evaluated for asphalt binders in pavements. Carbon black added to straight asphalt within 20 wt% caused an increase in the elastic modulus and a decrease in the viscosity of the asphalt, especially at temperatures higher than room temperature. Addition of carbon black raised the maximum service temperature of asphalt in the category of the binder performance grade according to the SHRP (Strategic Highway Research Program) sp...

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

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


    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...

  11. Integration of Sustainability Rating Tools in Contemporary Pavement Management Systems

    Maher, Michael; Kazmierowski, Tom; Navarra, Michael


    There is growing demand around the world for public agencies to implement sustainable initiatives into public infrastructure projects. Sustainability principles need to be integrated seamlessly into all decision making processes, especially when it relates to public expenditures on vital infrastructure. While agreeing with the principles of sustainability, many agencies struggle with how to implement these objectives in a systematic manner. Pavement sustainability can be evaluated using sever...

  12. Texture friction relationship: from texture empirical decomposition to pavement friction

    Kane, Malal; RADO, Zoltan; CEREZO, Véronique; TIMMONS, Andrew; DO, Minh Tan


    This work investigates the friction-texture relationship: starting from a decomposition method of the pavement texture that is part of a new signal processing so called “Huang Hilbert Transformation” to texture parameters-friction relation. This method allows empirical decomposition of the texture profile to a set of basic profiles in a limited number, so called “Intrinsic Mode Functions” or IMF. From the obtained IMFs, a set of four new functions so called “Base...

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

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


    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.

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

    Fidelis O. OKAFOR


    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.


    Rosa Cristina Cecche Lintz


    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. Numerical Simulation of Moving Load on Concrete Pavements

    Lajčáková Gabriela


    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.

  17. CLSM bleed water reduction test results

    Previous testing by BSRI/SRTC/Raytheon indicated that the CLSM specified for the Tank 20 closure generates about 6 gallons (23 liters) of bleed water per cubic yard of material (0.76 m3).1 This amount to about 10 percent of the total mixing water. HLWE requested that the CLSM mix be optimized to reduce bleed water while maintaining flow. Elimination of bleed water from the CLSM mix specified for High-Level Waste Tank Closure will result in waste minimization, time savings and cost savings. Over thirty mixes were formulated and evaluated at the on-site Raytheon Test Laboratory. Improved low bleed water CLSM mixes were identified. Results are documented in this report

  18. Management of radiation-induced rectal bleeding.

    Laterza, Liboria; Cecinato, Paolo; Guido, Alessandra; Mussetto, Alessandro; Fuccio, Lorenzo


    Pelvic radiation disease is one of the major complication after radiotherapy for pelvic cancers. The most commonly reported symptom is rectal bleeding which affects patients' quality of life. Therapeutic strategies for rectal bleeding are generally ignored and include medical, endoscopic, and hyperbaric oxygen treatments. Most cases of radiation-induced bleeding are mild and self-limiting, and treatment is normally not indicated. In cases of clinically significant bleeding (i.e. anaemia), medical therapies, including stool softeners, sucralfate enemas, and metronidazole, should be considered as first-line treatment options. In cases of failure, endoscopic therapy, mainly represented by argon plasma coagulation and hyperbaric oxygen treatments, are valid and complementary second-line treatment strategies. Although current treatment options are not always supported by high-quality studies, patients should be reassured that treatment options exist and success is achieved in most cases if the patient is referred to a dedicated centre. PMID:24101202

  19. Dysfunctional Uterine Bleeding (DUB) (For Teens)

    ... the body's hormones. Problems like compulsive exercise , not eating healthy foods, or too much stress can cause hormone changes. Some severe cases of AUB are caused by bleeding disorders such as von Willebrand disease . What Are the ...

  20. Genetic analysis of bleeding disorders.

    Edison, E; Konkle, B A; Goodeve, A C


    Molecular genetic analysis of inherited bleeding disorders has been practised for over 30 years. Technological changes have enabled advances, from analyses using extragenic linked markers to next-generation DNA sequencing and microarray analysis. Two approaches for genetic analysis are described, each suiting their environment. The Christian Medical Centre in Vellore, India, uses conformation-sensitive gel electrophoresis mutation screening of multiplexed PCR products to identify candidate mutations, followed by Sanger sequencing confirmation of variants identified. Specific analyses for F8 intron 1 and 22 inversions are also undertaken. The MyLifeOurFuture US project between the American Thrombosis and Hemostasis Network, the National Hemophilia Foundation, Bloodworks Northwest and Biogen uses molecular inversion probes (MIP) to capture target exons, splice sites plus 5' and 3' sequences and to detect F8 intron 1 and 22 inversions. This allows screening for all F8 and F9 variants in one sequencing run of multiple samples (196 or 392). Sequence variants identified are subsequently confirmed by a diagnostic laboratory. After having identified variants in genes of interest through these processes, a systematic procedure determining their likely pathogenicity should be applied. Several scientific societies have prepared guidelines. Systematic analysis of the available evidence facilitates reproducible scoring of likely pathogenicity. Documentation of frequency in population databases of variant prevalence and in locus-specific mutation databases can provide initial information on likely pathogenicity. Whereas null mutations are often pathogenic, missense and splice site variants often require in silico analyses to predict likely pathogenicity and using an accepted suite of tools can help standardize their documentation. PMID:27405681

  1. Practical research on the modified rubber powder asphalt pavement engineering%橡胶粉改性沥青路面工程实践研究

    孟建建; 勾煜


    Through comprehensively considering features and influential factors of rubber powder asphalt, the paper describes the production and construction technology of the new rubber power modified asphalt pavement from aspects of raw material selection of rubber powder, basic asphalt, coarse aggregate, fine aggregate and filling materials, the design and production, transportation, paving and rolling and forming of rubber powder asphalt mixture. Practice proves that rubber powder asphalt pavement has great effect of bleeding and sliding resistance and noise resistance. Through nearly two years' operation and return visit, it turns out that the pavement eveness is good without potholes. In addition, the proprietors are satisfied with the highway conditions.%综合考虑橡胶粉沥青的特点及其影响因素,从橡胶粉、基质沥青、粗集料、细集料和填料等原材料的选用,橡胶粉沥青混合料的设计与生产、运输、摊铺以及碾压成型等角度,详细阐述了一种新型的橡胶粉改性沥青路面的生产与施工工艺,实践证明:橡胶粉沥青路面具有良好的泌水性和抗滑、防噪效果,经过近两年的运行和回访表明,路面平整度等状况良好,无车辙、无坑洞,业主反映较好。

  2. Cough-induced Tracheobronchial Mucosal Bleeding.

    Hira, Harmanjit Singh


    A 56-year-old man presented with moderate hemoptysis. It was preceded by a severe bout of cough. Flexible bronchoscopy showed diffuse tracheobronchial mucosal petechiae and bleeding. The patient was not suffering with any coagulopathies. He did not receive antiplatelet drugs. Hemoptysis resolved with cough suppressant. Subsequent bronchoscopy revealed the complete resolution of petechiae. The mechanism of bleeding after the bout of coughing is discussed. PMID:23169019

  3. Abnormal uterine bleeding: a clinicohistopathological analysis

    Anupamasuresh Y; Suresh YV; Prachi Jain*,


    Background: Abnormal uterine bleeding (AUB) is one of the most common problem for the patients and the gynecologists. It adversely effects on the quality of life and psychology of women. It is of special concern in developing country as it adds to the causes of anemia. Management of Abnormal Uterine Bleeding (AUB) is not complete without tissue diagnosis especially in perimenopausal and post-menopausal women. Histological characteristics of endometrial biopsy material as assessed by light mic...

  4. Management of nonvariceal upper gastrointestinal bleeding

    E Wee


    Full Text Available Nonvariceal upper gastrointestinal bleeding is unique from variceal bleeding in terms of patient characteristics, management, rebleeding rates, and prognosis, and should be managed differently. The majority of nonvariceal upper gastrointestinal bleeds will not rebleed once treated successfully. The incidence is 80 to 90% of all upper gastrointestinal bleeds and the mortality is between 5 to 10%. The causes include nonacid-related ulceration from tumors, infections, inflammatory disease, Mallory-Weiss tears, erosions, esophagitis, dieulafoy lesions, angiodysplasias, gastric antral vascular ectasia, and portal hypertensive gastropathy. Rarer causes include hemobilia, hemosuccus pancreaticus, and aortoenteric fistulas. Hematemesis and melena are the key features of bleeding from the upper gastrointestinal tract, but fresh per rectal bleeding may be present in a rapidly bleeding lesion. Resuscitation and stabilization before endoscopy leads to improved outcomes. Fluid resuscitation is essential to avoid hypotension. Though widely practiced, there is currently insufficient evidence to show that routine red cell transfusion is beneficial. Coagulopathy requires correction, but the optimal international normalized ratio has not been determined yet. Risk stratification scores such as the Rockall and Glasgow-Blatchford scores are useful to predict rebleeding, mortality, and to determine the urgency of endoscopy. Evidence suggests that high-dose proton pump inhibitors (PPI should be given as an infusion before endoscopy. If patients are intolerant of PPIs, histamine-2 receptor antagonists can be given, although their acid suppression is inferior. Endoscopic therapy includes thermal methods such as coaptive coagulation, argon plasma coagulation, and hemostatic clips. Four quadrant epinephrine injections combined with either thermal therapy or clipping reduces mortality. In hypoxic patients, endoscopy masks allow high-flow oxygen during upper


    Hassan Mansouritorghabeh


    Full Text Available Introduction: Male circumcision practice is an invasive procedure that is using worldwide. It makes challenges to haemostatic system and its possible haemorrhagic side effects are more serious in bleeding individuals than normal subjects. In most cases, it can be complete controlled using infusion of appropriate amount of coagulation factors before and post circumcision.Aim: We aim to documentation type of coagulation therapy and post circumcision practice haemorrhagic presentation among 463 bleeder males of both common and rare bleeding disorders in north eastern part of country.Methods: We retrospectively gathered information using evaluation medical records in 3 major hospitals during last 15 years and list of patients with bleeding disorders that obtained from haemophilia center. Also a call phone established for each bleeder person to complete data and updating of them. The survey took time from Sep 2009- Mar 2011. The designed question form included data on doing circumcision or not? types of treatment before and post the procedure and occurrence of bleeding episodes after the surgery.Results: Overall among 424 cases with various common and rare bleeding disorders who had circumcised, 239 cases (56.3% had passed the procedure with bleeding experience, while 185 cases (43.7% had passed it successfully and without noticeable bleeding experience. The types of coagulation therapy in each group have been cited.Conclusion: The circumcision practice in unequipped medical center for bleeder ones may make challenges for them and medical services. Also it needed supervision of expert haematologist for adjusting treatment to ensure control of unwanted bleeding

  6. Transcatheter arterial embolization for traumatic bleeding control

    Ryu, Choon Wook; Lee, Sang Kwon; Suh, Kyung Jin; Kim, Tae Heon; Kim, Yong Joo; Kang, Duck Sik [Kyungpook National University College of Medicine, Taegu (Korea, Republic of)


    Angiography is essential for the detection of bleeding vessels in traumatic vascular injury. Immediately after the diagnosis, transcatheter embolization can be performed for the control of bleeding effectively and easily with proper use of embolic materials. Transcatheter embolization is believed to be the treatment of choice when emergency control is needed, where surgical approach is difficult and in those who are poor candidate for surgery. We have tried bleeding control in 18 cases of trauma over recent 4 years. The results were as follows; 1. Causes of bleeding(cases): Blunt or penetrating trauma (10), latrogenic trauma (8), (Postoperative (5), Needle biopsy (2), Percutaneous hepatic procedure (1)) 2. Embolized vessels: Renal artery branches (8), Hepatic artery branches (2), Arteries supplying chest wall (2), External carotid artery branches (3), Internal carotid artery (1), Circumflex humeral artery (1), Internal iliac artery branches (1). 3. Embolic agents: Gelfoam cubes (16), Stainless steel coils (3), Detachable latex balloon (1). 4. Successful bleeding control was achieved in 17 cases and reduction of the amount of bleeding in one case without significant complications.

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

    Loizos, Andreas; Plati, Christina


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

  8. Characterizing Pavement Surface Distress Conditions with Hyper-Spatial Resolution Natural Color Aerial Photography

    Su Zhang


    Full Text Available Roadway pavement surface distress information is critical for effective pavement asset management, and subsequently, transportation management agencies at all levels (i.e., federal, state, and local dedicate a large amount of time and money to routinely evaluate pavement surface distress conditions as the core of their asset management programs. However, currently adopted ground-based evaluation methods for pavement surface conditions have many disadvantages, like being time-consuming and expensive. Aircraft-based evaluation methods, although getting more attention, have not been used for any operational evaluation programs yet because the acquired images lack the spatial resolution to resolve finer scale pavement surface distresses. Hyper-spatial resolution natural color aerial photography (HSR-AP provides a potential method for collecting pavement surface distress information that can supplement or substitute for currently adopted evaluation methods. Using roadway pavement sections located in the State of New Mexico as an example, this research explored the utility of aerial triangulation (AT technique and HSR-AP acquired from a low-altitude and low-cost small-unmanned aircraft system (S-UAS, in this case a tethered helium weather balloon, to permit characterization of detailed pavement surface distress conditions. The Wilcoxon Signed Rank test, Mann-Whitney U test, and visual comparison were used to compare detailed pavement surface distress rates measured from HSR-AP derived products (orthophotos and digital surface models generated from AT with reference distress rates manually collected on the ground using standard protocols. The results reveal that S-UAS based hyper-spatial resolution imaging and AT techniques can provide detailed and reliable primary observations suitable for characterizing detailed pavement surface distress conditions comparable to the ground-based manual measurement, which lays the foundation for the future application

  9. A Method to Estimate the Dynamic Displacement and Stress of a Multi-layered Pavement with Bituminous or Concrete Materials

    LU, ZHENG; Yao, Hailin; Zhang, JingBo


    In this research work, a method to estimate the dynamic characteristics of a multilayered pavement with bituminous or concrete materials is proposed. A mechanical model is established to investigate the dynamic displacement and stress of the multi-layered pavement structure. Both the flexible and the rigid pavements, corresponding to bituminous materials and concrete materials, respectively, are studied. The theoretical solutions of the multi-layered pavement structure are deduced considering...

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

    Hongyan Ma; Dongsheng Wang; Changjun Zhou; Decheng Feng


    In order to implement the Mechanistic-Empirical Pavement Design Guide (MEPDG) to design and maintain asphalt pavements in China, it is necessary to calibrate transfer functions of distresses in MEPDG with local conditions, including traffics, environment, and materials as well as measured pavement distresses data in field. Comprehensive single factor sensitivity analyses of factors that influence thermal cracking of asphalt pavements were conducted utilizing the MEPDG low temperature cracking...

  11. 14 CFR 23.1111 - Turbine engine bleed air system.


    ... using maximum bleed air must be established. (c) Hazardous contamination of cabin air systems may not... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Turbine engine bleed air system. 23.1111... Induction System § 23.1111 Turbine engine bleed air system. For turbine engine bleed air systems,...


    V. A. Osinovskaya


    Full Text Available The problem of low durability of flexible pavement is one of the most important problems of road economy. For example, the actual service life of asphalt pavement in Russia about 3 … 5 years. The bad condition of highways is an obstacle for the development of the national economy and leads to a significant annual economic losses.At present, this problem has no exact solution. Even at the seeming good road conditions of Europe and America the problem of low durability is no less important in these countries. And this problem becomes more and more actual every year.Our scientific researches allowed to make a hypothesis that the projected of pavements are not have the necessary durability yet not of a stage of designing because in strength calculations did not take into account the vibration of road constructions.Very actual the vibration loading becomes today as is now significantly changed the nature of loading of pavements. As a result the deflections of a pavements are reduced, but the increased vibration of pavements accelerated processes of destruction and significantly reduced durability.The theory of vibration destruction developed by the author allows to adjust the vibration, to form the vibration resistance pavements, and also to forecast a residual life of pavements that will more effectively develop repair actions.

  13. Characterization and modelling of self healing of bituminous materials towards durable asphalt pavement

    Qiu, J.; Van de Ven, M.F.C.; Schlangen, H.E.J.G.; Wu, S.; Molenaar, A.A.A.


    The traffic volume and the number of heavy vehicles are growing enormously nowadays. There is a need for designing a durable asphalt pavement with innovative technologies. Pavement structures and materials with self healing and self repairing capability are believed to be very useful in such a syste

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

    Dave, Eshan V.


    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…

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

    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.

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

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


    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.

  17. 23 CFR 970.208 - Federal lands pavement management system (PMS).


    ... 23 Highways 1 2010-04-01 2010-04-01 false Federal lands pavement management system (PMS). 970.208... HIGHWAYS NATIONAL PARK SERVICE MANAGEMENT SYSTEMS National Park Service Management Systems § 970.208 Federal lands pavement management system (PMS). In addition to the requirements provided in § 970.204,...

  18. Secondary electric power generation with minimum engine bleed

    Tagge, G. E.


    Secondary electric power generation with minimum engine bleed is discussed. Present and future jet engine systems are compared. The role of auxiliary power units is evaluated. Details of secondary electric power generation systems with and without auxiliary power units are given. Advanced bleed systems are compared with minimum bleed systems. A cost model of ownership is given. The difference in the cost of ownership between a minimum bleed system and an advanced bleed system is given.

  19. Immediate bleeding complications in dental implants: A systematic review

    Balaguer Martí, José Carlos; Peñarrocha Oltra, David; Balaguer Martínez, José; Peñarrocha Diago, Miguel


    Objective: A review is made of the immediate or immediate postoperative bleeding complications in dental implants, with a view to identifying the areas of greatest bleeding risk, the causes of bleeding, the length of the implants associated with bleeding, the most frequently implicated blood vessels, and the treatments used to resolve these complications. Material and Methods: A Medline (PubMed) and Embase search was made of articles on immediate bleeding complications in dental implants publ...


    V. Verenko


    Full Text Available The paper presents results of experimental investigations and points out the fact that conventional approaches to design and calculations of road pavements that presuppose application of porous asphalt concrete on compact bedding can cause some deformations and destructions initiated due to humidity migration in large internal material pores and lead to material destruction during warm season of the year when water is characterized by high activity. Such processes result in bitumen washing-out, white spot occurrence on the pavement and quick destruction of the pavement.The paper proposes to reconsider existing approaches to design and calculation of road pavements, estimation of reliability and service-ability levels of the applied construction materials. In particular it is necessary to calculate a road pavement with respect to thermo-physical action while excluding condensate and humidity accumulation in porous materials. 

  1. Numerical simulation on the thermal response of heat-conducting asphalt pavements

    Using asphalt pavements as a solar collector is a subject of current interest all over the world because the sun provides a cheap and abundant source of clean and renewable energy, which can be captured by black asphalt pavements. A heat-conducting device is designed to absorb energy from the sun. In order to validate what parameters are critical in the asphalt collector, a finite element model is developed to predict the thermal response of the heat-conducting device compared to the conventional asphalt mixture. Some factors that may affect the asphalt pavement collector are considered, including the coefficient of heat conductivity of the asphalt pavement, the distance between pipes with the medium, water, and the pipe's diameter. Ultimately, the finite element model can provide pavement engineers with an efficient computational tool that can be a guide to the conductive asphalt solar collector's experiment in the laboratory.


    V. Poroch


    Full Text Available Actual treatment of bleeding duodenal ulcer is most frequently medical but also surgical. The aim of this study is to assess the factors that influence the outcomes for a group of 67 patients suffering of bleeding duodenal ulcer. Out of 67 patients considered in this study, 53 were men (79.1% and 14 were women (20.9%. The average age was 52 years for men and 53 years for women (range 19-86 years. 59 (88% were patients with known medical history of peptic ulcer disease. Endoscopy has been performed for 64 patients (95.6%. Specific medical treatment was started immediately for all patients. For 47 patients (70.1% the hemorrhage stopped with conservative treatment, 8 patients (12% benefit by endoscopic treatment and 12 patients (17.9% underwent surgery. The postoperative morbidity rate was 16.7%. Comorbidities were present in 43 patients (64.2%. Failure of medical conservative treatment has been observed in 7 cases (13%, and failure of endoscopic procedures in 2 cases (20%. The risk factors involved in therapy outcomes of bleeding duodenal ulcer are: age, the severity of hemorrhage confirmed by endoscopy, the hemorrhagic episodes in medical history and the time of surgery. Conclusion: The prognosis of bleeding duodenal ulcer after bleeding is highly correlated with the time that the treatment starts, the severity of hemorrhage, comorbid conditions and age.

  3. Analysis of Load Stress for Asphalt Pavement of Lean Concrete Base

    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.

  4. Modeling of energy dissipation processes in a pavement – vehicle system

    A.M. Kirillov


    Full Text Available The law of conservation of energy for a ‘pavement – vehicle’ system manifests itself primarily in the fact that for any temperature and operating conditions of a road asphalt concrete pavement the potential energy of gravity and the kinetic energy of a vehicle are partially transformed upon contact with the road pavement into elastic deformation energy or thermal energy, while a part of the energy dissipates. These types of energy are to some extent transformed into the internal energy of the road pavement, altering its energy balance and causing destructive processes. The initial level of the internal pavement energy changes while the road is used, on the one hand, through regular contributions from vehicles and from solar raditation, and, on the other hand, from compensating for viscoelastic deformation. Understanding these changes will allow to develop new and more efficient methods for monitoring the pavement condition, as well as a scientifically valid system of scheduling the repairs. In this article, we have assessed the level and the significance of the contribution of the work done by the moving vehicles over the pavement, and of the thermal radiation to the internal pavement energy gain. We have constructed a physical and mathematical model of energy dissipation and storage in the ‘pavement – vehicle’ system accounting for viscoelastic deformation and thermal radiation. We have designed an algorithm allowing to determine a scientifically based repair interval for asphalt concrete pavement. It is shown that the maximum plasticity for some ranges of speeds and transport weights may serve as a criterion of the recommended operating conditions of the road.

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

    Injun, Song


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

  6. Accuracy of rockall score for in hospital re bleeding among cirrhotic patients with variceal bleed

    To assess the diagnostic accuracy of Roc kall scoring system for predicting in-hospital re-ble- eding in cirrhotic patients presenting with variceal bleed. Material and Methods: This descriptive case series study was conducted at Department of Medicine Combined Military Hospital Lahore from December 2013 to May 2014. We included patients with liver cirrhosis who presented with upper GI bleeding and showed varices as the cause of bleeding on endoscopy. Clinical and endoscopic features were noted to calculate Rockall score. Patients with score < 2 and > 8 were included. After treating with appropriate pharmacological and endoscopic therapy, patients were followed for re-bleeding for 10 days. Diagnostic accuracy was assessed by calculating sensitivity, specificity, positive and negative predictive values using 2 x 2 tables. Results: In the study, 175 patients were included. Mean age was 51.5 ± 1.22 years. Male to female ratio was 1.5 to 1.0 out of 175 patients, 157 patients (89.7%) were of low risk group (score = 2) while 18 patients (10.3%) were in high risk group (score > 8). In low risk group, re-bleeding occurred only in 2 patients (1.2%) while in high risk group, re-bleeding occurred in 14 patients (78%). Rockall score was found to have good diagnostic accuracy with sensitivity of 87.5%, specificity of 97.48%, positive predictive value of 77.8% and negative predictive value of 98.7%. Conclusion: In cases of variceal bleed, frequency of re-bleed is less in patients who are in low risk category with lower Rockall score and high in high risk patients with higher rockall score. The Rockall score has a good diagnostic accuracy in prediction of re-bleed in variceal bleeding. (author)

  7. Synthesis report: D-cracking in portland cement concrete pavements

    Thompson, S. R.; Olsen, M. P. J.; Dempsey, B. J.


    The mechanisms and testing procedures for D-cracking in portland cement concrete pavements are examined. Benefication procedures are also investigated. The three general responses to freezing in the aggregate/paste system include elastic accommodation, high internal pressure, and high external pressure. It is found that the critical aggregate parameters influencing D-cracking are degree of saturation, maximum particle size, permeability, porosity, and pore size distribution. Evaluation of present laboratory testing procedures indicated that the ASTM C666, VPI slow-cool, Mercury Porosimetry, and Iowa Pore Index Tests correlated the best with field performance of concrete with respect to D-cracking.

  8. Application of matter-element analysis based on entropy right to evaluate the pavement condition in permafrost region


    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.

  9. How I manage heavy menstrual bleeding.

    Pai, Menaka; Chan, Anthony; Barr, Ronald


    Heavy menstrual bleeding (HMB) is a common clinical problem; population-based studies estimate that approximately 10-35% of women report this symptom during their lifetime, while about 5% of women consult a physician for evaluation of HMB. Patients with HMB account for 15% of all referrals to gynaecologists and are frequently seen by haematologists in bleeding disorder clinics as well. Heavy menstrual bleeding can be caused by a wide variety of local and systemic factors, so a careful clinical and laboratory evaluation is often necessary to determine the aetiology and guide appropriate management. This review discusses the definition, causes and clinical outcomes of HMB. It outlines a diagnostic approach and focuses on medical (as opposed to surgical) treatments. Throughout, areas of controversy and opportunities for further research are highlighted. PMID:23829452

  10. Fibrinogen concentrate for bleeding - a systematic review

    Lunde, J; Stensballe, J; Wikkelsø, A;


    Fibrinogen concentrate as part of treatment protocols increasingly draws attention. Fibrinogen substitution in cases of hypofibrinogenaemia has the potential to reduce bleeding, transfusion requirement and subsequently reduce morbidity and mortality. A systematic search for randomised controlled...... trials (RCTs) and non-randomised studies investigating fibrinogen concentrate in bleeding patients was conducted up to November 2013. We included 30 studies of 3480 identified (7 RCTs and 23 non-randomised). Seven RCTs included a total of 268 patients (165 adults and 103 paediatric), and all were...... mortality were lacking. Weak evidence from RCTs supports the use of fibrinogen concentrate in bleeding patients, primarily in elective cardiac surgery, but a general use of fibrinogen across all settings is only supported by non-randomised studies with serious methodological shortcomings. It seems pre...