WorldWideScience

Sample records for blowup pavements

  1. Blowups of Heterotic Orbifolds using Toric Geometry

    CERN Document Server

    Nibbelink, Stefan Groot

    2007-01-01

    Heterotic orbifold models are promising candidates for models with MSSM like spectra. But orbifolds only correspond to a special place in moduli space, the bigger picture is described by the moduli space of Calabi-Yau spaces. In this talk we will make explicit connections between both points of view. To this end we study blowups of orbifold singularities using both explicit constructions and toric geometry techniques. We show that matching of all orbifold models in blowups are possible.

  2. Blow-up: A Free Lunch?

    Directory of Open Access Journals (Sweden)

    Jan Koenderink

    2012-02-01

    Full Text Available We consider operations that change the size of images, either shrinks or blow-ups. Image processing offers numerous possibilities, put at everyone's disposal with such computer programs as Adobe Photoshop. We consider a different class of operations, aimed at immediate visual awareness, rather than pixel arrays. We demonstrate cases of blow-ups that do not sacrifice apparent resolution. This apparent information gain is due to “amodal occlusion.”

  3. QUANTUM COHOMOLOGY OF BLOWUPS OF SURFACES AND ITS FUNCTORIALITY PROPERTY

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    In this article, using the WDVV equation, the author first proves that all Gromov-Witten invariants of blowups of surfaces can be computed from the Gromov-Witten invariants of itself by some recursive relations. Furthermore, it may determine the quantum product on blowups. It also proves that there is some degree of functoriality of the big quantum cohomology for a blowup.

  4. Blow-up: A free lunch?

    NARCIS (Netherlands)

    Koenderink, J.J.; Richards, W.; Van Doorn, A.J.

    2012-01-01

    We consider operations that change the size of images, either shrinks or blow-ups. Image processing offers numerous possibilities, put at everyone’s disposal with such computer programs as Adobe Photoshop. We consider a different class of operations, aimed at immediate visual awareness, rather than

  5. Concrete Pavement Joint Deterioration

    OpenAIRE

    2016-01-01

    Concrete pavements are an important part of our national infrastructure. In recent years the relatively small number of reported joints deteriorating prematurely in concrete pavements around Indiana has increased. Changes over the past 45 years in INDOT specification, pavement materials, designs and construction practices, and current de-icing materials were examined and related to the durability of concrete at the joints of existing pavements. A survey of concrete pavements across the state ...

  6. Pavement management and rehabilitation of portland cement concrete pavements

    Science.gov (United States)

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

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

  7. Batch By Batch Longitudinal Emittance Blowup MD

    CERN Document Server

    Mastoridis, T; Butterworth, A; Jaussi, M; Molendijk, J

    2012-01-01

    The transverse bunch emittance increases significantly at 450 GeV from the time of injection till the ramp due to IBS. By selectively blowing up the longitudinal emittance of the incoming batch at each injection, it should be possible to reduce the transverse emittance growth rates due to IBS. An MD was conducted on April 22nd 2012 to test the feasibility and performance of the batch-by-batch longitudinal emittance blowup. There were three main goals during the MD. First, to test the developed hardware, firmware, and software for the batch-by-batch blowup. Then, to measure the transverse emittance growth rates of blown-up and "witness" batches to quantify any improvement, and finally to test the ALLInjectSequencer class, which deals with the complicated gymnastics of introducing or masking the new batch to various RF loops.

  8. Compact heterotic orbifolds in blow-up

    CERN Document Server

    Nibbelink, Stefan Groot; Plöger, Felix; Trapletti, Michele; Vaudrevange, Patrick K S

    2008-01-01

    We compare heterotic string models on orbifolds with supergravity models on smooth compact spaces, obtained by resolving the orbifold singularities. Our main focus is on heterotic E8xE8 models on the resolution of the compact T^6/Z_3 orbifold with Wilson lines. We explain how different gauge fluxes at various resolved fixed points can be interpreted in blow down as Wilson lines. Even when such Wilson lines are trivial from the orbifold perspective, they can still lead to additional symmetry breaking in blow-up. Full agreement is achieved between orbifold and resolved models, at the level of gauge interactions, massless spectrum and anomaly cancellation. In this matching the blow-up modes are of crucial importance: they play the role of model-dependent axions involved in the cancellation of multiple anomalous U(1)'s on the resolution. We illustrate various aspects by investigating blow-ups of a Z_3 MSSM model with two Wilson lines: if all its fixed points are resolved simultaneously, the SM gauge group is nece...

  9. Simultaneous and non-simultaneous blow-up and uniform blow-up profiles for reaction-diffusion system

    Directory of Open Access Journals (Sweden)

    Zhengqiu Ling

    2012-11-01

    Full Text Available This article concerns the blow-up solutions of a reaction-diffusion system with nonlocal sources, subject to the homogeneous Dirichlet boundary conditions. The criteria used to identify simultaneous and non-simultaneous blow-up of solutions by using the parameters p and q in the model are proposed. Also, the uniform blow-up profiles in the interior domain are established.

  10. Permeable pavement study (Edison)

    Data.gov (United States)

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

  11. Pavement Subgrade Performance Study

    DEFF Research Database (Denmark)

    Zhang, Wei; Ullidtz, Per; Macdonald, Robin

    1998-01-01

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

  12. Blow-up in nonlinear Schroedinger equations. II. Similarity structure of the blow-up singularity

    DEFF Research Database (Denmark)

    Rypdal, K.; Juul Rasmussen, Jens

    1986-01-01

    invariance and generalizations of the latter. This generalized "quasi-invariance" reveals the nature of the blow-up singularity and resolves an old controversy. Most of the previous work has been done on the cubic nonlinearity. We generalize the results to an arbitrary power nonlinearity....

  13. TOTAL VERSUS SINGLE POINT BLOW-UP SOLUTIONS FOR A SEMILINEAR PARABOLIC EQUATION

    Institute of Scientific and Technical Information of China (English)

    Yang Ming

    2007-01-01

    In this paper, we investigate the blow-up set of solutions of a parabolic equation with localized and non-localized reactions. We completely classify blow-up solutions into total blow-up cases and single point blow-up cases.

  14. Pavement Testing Facility

    Data.gov (United States)

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

  15. Pavement Testing Facility

    Data.gov (United States)

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

  16. Heterotic Mini-landscape in blow-up

    CERN Document Server

    Bizet, Nana Geraldine Cabo

    2013-01-01

    Localization properties of fields in compact extra dimensions are crucial ingredients for string model building, particularly in the framework of orbifold compactifications. Realistic models often require a slight deviation from the orbifold point, that can be analyzed using field theoretic methods considering (singlet) fields with nontrivial vacuum expectation values. Some of these fields correspond to blow-up modes that represent the resolution of orbifold singularities. Improving on previous analyses we give here an explicit example of the blow-up of a model from the heterotic Mini-landscape. An exact identification of the blow-up modes at various fixed points and fixed tori with orbifold twisted fields is given. We match the massless spectra and identify the blow-up modes as non-universal axions of compactified string theory. We stress the important role of the Green-Schwarz anomaly polynomial for the description of the resolution of orbifold singularities.

  17. Asphalt in Pavement Maintenance.

    Science.gov (United States)

    Asphalt Inst., College Park, MD.

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

  18. Concrete Block Pavements

    Science.gov (United States)

    1983-03-01

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

  19. Blow-up estimates for semilinear parabolic systems coupled in an equation and a boundary condition

    Institute of Scientific and Technical Information of China (English)

    王明新

    2001-01-01

    This paper deals with the blow-up rate estimates of solutions for semilinear parabolic systems coupled in an equation and a boundary condition. The upper and lower bounds of blow-up rates have been obtained.

  20. On the Blow-up Phenomena of Cauchy Problem for the Camassa- Holm Equation

    Institute of Scientific and Technical Information of China (English)

    LIU Yongqin; WANG Weike

    2006-01-01

    We focus on the blow-up phenomena of Cauchy problem for the Camassa-Holm equation. Blow-up can occur only in the form of wave-breaking, i.e. the solution is bounded but its slope becomes unbounded in finite time. We proved that there is such a point that its slope becomes infinite exactly at breaking time. We also gave the precise blow-up rate and the blow-up set.

  1. Blow-up Mechanism of Classical Solutions to Quasilinear Hyperbolic Systems in the Critical Case

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    This paper deals with the blow-up phenomenon, particularly, the geometric blow-up mechanism, of classical solutions to the Cauchy problem for quasilinear hyperbolic systems in the critical case. We prove that it is still the envelope of the same family of characteristics which yields the blowup of classical solutions to the Cauchy problem in the critical case.

  2. Finite Time Blowup in a Realistic Food-Chain Model

    KAUST Repository

    Parshad, Rana

    2013-05-19

    We investigate a realistic three-species food-chain model, with generalist top predator. The model based on a modified version of the Leslie-Gower scheme incorporates mutual interference in all the three populations and generalizes several other known models in the ecological literature. We show that the model exhibits finite time blowup in certain parameter range and for large enough initial data. This result implies that finite time blowup is possible in a large class of such three-species food-chain models. We propose a modification to the model and prove that the modified model has globally existing classical solutions, as well as a global attractor. We reconstruct the attractor using nonlinear time series analysis and show that it pssesses rich dynamics, including chaos in certain parameter regime, whilst avoiding blowup in any parameter regime. We also provide estimates on its fractal dimension as well as provide numerical simulations to visualise the spatiotemporal chaos.

  3. Periodicity and blowup in a two-species cooperating model

    DEFF Research Database (Denmark)

    Lin, Zhigui; Liu, Jiahong; Pedersen, Michael

    2011-01-01

    In this paper, the cooperating two-species Lotka–Volterra model is discussed. The existence and asymptotic behavior of T -periodic solutions for the periodic reaction diffusion system under homogeneous Dirichlet boundary conditions are first investigated. The blowup properties of solutions...... for the same system are then given. It is shown that periodic solutions exist if the intra-specific competitions are strong whereas blowup solutions exist under certain conditions if the intra-specific competitions are weak. Numerical simulations and a brief discussion are also presented in the last section....

  4. Blow-up of solution for a generalized Boussinesq equation

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    This paper studies the initial boundary value problem for a generalized Boussinesq equation and proves the existence and uniqueness of the local generalized solution of the problem by using the Galerkin method. Moreover, it gives the sufficient conditions of blow-up of the solution in finite time by using the concavity method.

  5. Numerical blowup in two-dimensional Boussinesq equations

    CERN Document Server

    Yin, Zhaohua

    2009-01-01

    In this paper, we perform a three-stage numerical relay to investigate the finite time singularity in the two-dimensional Boussinesq approximation equations. The initial asymmetric condition is the middle-stage output of a $2048^2$ run, the highest resolution in our study is $40960^2$, and some signals of numerical blowup are observed.

  6. Pavement Snow Melting

    Energy Technology Data Exchange (ETDEWEB)

    Lund, John W.

    2005-01-01

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

  7. DRAINAGE AND FLEXIBLE PAVEMENT PERFORMANCE

    Directory of Open Access Journals (Sweden)

    SIDDHARTHA ROKADE

    2012-04-01

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

  8. Precast Concrete Pavements

    Science.gov (United States)

    1981-11-01

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

  9. Uniform Blow-Up Rates and Asymptotic Estimates of Solutions for Diffusion Systems with Nonlocal Sources

    Directory of Open Access Journals (Sweden)

    Zhoujin Cui

    2007-01-01

    Full Text Available This paper investigates the local existence of the nonnegative solution and the finite time blow-up of solutions and boundary layer profiles of diffusion equations with nonlocal reaction sources; we also study the global existence and that the rate of blow-up is uniform in all compact subsets of the domain, the blow-up rate of |u(t|∞ is precisely determined.

  10. Numerical study of blow-up in the Davey-Stewartson system

    KAUST Repository

    Klein, Christian

    2013-03-01

    Nonlinear dispersive partial differential equations such as the nonlinear Schrödinger equations can have solutions that blow up. We numerically study the long time behavior and potential blow-up of solutions to the focusing Davey-Stewartson II equation by analyzing perturbations of the lump and the Ozawa solutions. It is shown in this way that both are unstable to blow-up and dispersion, and that blow-up in the Ozawa solution is generic.

  11. Blowup Analysis for a Nonlocal Diffusion Equation with Reaction and Absorption

    Directory of Open Access Journals (Sweden)

    Yulan Wang

    2012-01-01

    Full Text Available We investigate a nonlocal reaction diffusion equation with absorption under Neumann boundary. We obtain optimal conditions on the exponents of the reaction and absorption terms for the existence of solutions blowing up in finite time, or for the global existence and boundedness of all solutions. For the blowup solutions, we also study the blowup rate estimates and the localization of blowup set. Moreover, we show some numerical experiments which illustrate our results.

  12. Remarks on the Blow-Up Solutions for the Critical Gross-Pitaevskii Equation

    Directory of Open Access Journals (Sweden)

    Xiaoguang Li

    2013-01-01

    Full Text Available This paper is concerned with the blow-up solutions of the critical Gross-Pitaevskii equation, which models the Bose-Einstein condensate. The existence and qualitative properties of the minimal blow-up solutions are obtained.

  13. Energy Decaying and Blow-Up of Solution for a Kirchhoff Equation with Strong Damping

    Institute of Scientific and Technical Information of China (English)

    YANG Zhifeng; QIU Dehua

    2009-01-01

    The initial boundary value problem for a Kirchhoff equation with Lipschitz type continuous coefficient is studied on bounded domain. Under some conditions, the energy decaying and blow-up of solution are discussed. By refining method, the exponent decay estimates of the energy function and the estimates of the life span of blow-up solutions are given.

  14. The blowup mechanism for 3-D quasilinear wave equations with small data

    Institute of Scientific and Technical Information of China (English)

    尹会成

    2000-01-01

    For a class of special three-dimensional quasilinear wave equations, we study the blowup mechanism of classical solutions. More precisely, under the nondegenerate conditions, any radially symmetric solution with small initial data is shown to develop singularities in the second order derivatives while the first order derivatives and itself remain continuous, moreover the blowup of solution is of "cusp type".

  15. Geotextiles in Flexible Pavement Construction

    Science.gov (United States)

    Alungbe, Gabriel D.

    2004-01-01

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

  16. Pavement roughness and skid properties

    Science.gov (United States)

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

  17. Blow-up of generalized complex 4-manifolds

    CERN Document Server

    Cavalcanti, Gil R

    2009-01-01

    We introduce blow-up and blow-down operations for generalized complex 4-manifolds. Combining these with a surgery analogous to the logarithmic transform, we then construct generalized complex structures on nCP2 # m \\bar{CP2} for n odd, a family of 4-manifolds which admit neither complex nor symplectic structures unless n=1. We also extend the notion of a symplectic elliptic Lefschetz fibration, so that it expresses a generalized complex 4-manifold as a fibration over a two-dimensional manifold with boundary.

  18. Parallel Computation of Persistent Homology using the Blowup Complex

    Energy Technology Data Exchange (ETDEWEB)

    Lewis, Ryan [Stanford Univ., CA (United States); Morozov, Dmitriy [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2015-04-27

    We describe a parallel algorithm that computes persistent homology, an algebraic descriptor of a filtered topological space. Our algorithm is distinguished by operating on a spatial decomposition of the domain, as opposed to a decomposition with respect to the filtration. We rely on a classical construction, called the Mayer--Vietoris blowup complex, to glue global topological information about a space from its disjoint subsets. We introduce an efficient algorithm to perform this gluing operation, which may be of independent interest, and describe how to process the domain hierarchically. We report on a set of experiments that help assess the strengths and identify the limitations of our method.

  19. UNIFORM BLOW-UP PROFILES FOR HEAT EQUATIONS WITH COUPLING NONLOCAL SOURCES OF ASYMMETRIC MIXED TYPE NONLINEARITIES

    Institute of Scientific and Technical Information of China (English)

    Kong Linghua; Wang Jinhuan; Zheng Sining

    2012-01-01

    This article deals with a nonlocal heat system subject to null Dirichlet boundary conditions,where the coupling nonlocal sources consist of mixed type asymmetric nonlinearities.We at first give the criterion for simultaneous blow-up of solutions,and then establish the uniform blow-up profiles of solutions near the blow-up time.It is observed that not only the simultaneous blow-up rates of the two components u and v are asymmetric,but also the blow-up rates of the same component u (or v) may be in different levels under different dominations.

  20. Resistance blow-up effect in micro-circuit engineering

    Science.gov (United States)

    Tan, Michael L. P.; Saxena, Tanuj; Arora, Vijay K.

    2010-12-01

    The nonlinearity in the I- V characteristics of a scaled-down micro/nano-scale resistive channel is shown to elevate the DC and signal resistance as current approaches its saturation value. The deviation from traditional circuit engineering takes place when the applied voltage is increased beyond the critical voltage V c = ( V t/ ℓ) L, where V t is the thermal voltage, ℓ is the ohmic mean free path, and L is the length of the conducting channel. This resistance blow-up is more pronounced for a smaller-length resistor in a micro-circuit of two resistors with same ohmic value. The power consumed P = VI not only is lower but also is a linear function of voltage V as compared to the quadratic rise with V in the ohmic regime. The resistance blow-up effect also gives enhanced RC time constant for transients when a digital signal switches from low to high or vice versa. These results are of immense value to circuit designers and those doing device characterization to extract parasitic and transport parameters.

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

    OpenAIRE

    Andrzej Plewa; Marta Wasilewska; Władysław Gardziejczyk; Paweł Gierasimiuk

    2015-01-01

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

  2. Stable Self-Similar Blow-Up Dynamics for Slightly {L^2}-Supercritical Generalized KDV Equations

    Science.gov (United States)

    Lan, Yang

    2016-07-01

    In this paper we consider the slightly {L^2}-supercritical gKdV equations {partial_t u+(u_{xx}+u|u|^{p-1})_x=0}, with the nonlinearity {5 < p < 5+\\varepsilon} and {0 < \\varepsilon≪ 1}. We will prove the existence and stability of a blow-up dynamics with self-similar blow-up rate in the energy space {H^1} and give a specific description of the formation of the singularity near the blow-up time.

  3. Blow-up of solutions to parabolic inequalities in the Heisenberg group

    Directory of Open Access Journals (Sweden)

    Ibtehal Azman

    2015-06-01

    Full Text Available We establish a Fujita-type theorem for the blow-up of nonnegative solutions to a certain class of parabolic inequalities in the Heisenberg group. Our proof is based on a duality argument.

  4. BLOW-UP CRITERION OF SMOOTH SOLUTIONS TO THE MHD EQUATIONS IN BESOV SPACES

    Institute of Scientific and Technical Information of China (English)

    YUAN Baoquan

    2005-01-01

    In this paper we discuss the logarithmic Sobolev inequalities in Besov spaces,and show their applications to the blow-up criterion of smooth solutions to the incompressible magneto-hydrodynamics equations.

  5. Controlled Transverse Blow-up of Highenergy Proton Beams for Aperture Measurements and Loss Maps

    CERN Document Server

    Hӧfle, W; Redaelli, S; Schmidt, R; Valuch, D; Wollmann, D; Zerlauth, M

    2012-01-01

    A technique was developed to blow-up transversely in a controlled way high energy proton beams in the LHC. The technique is based on band limited white noise excitation that is injected into the transverse damper feedback loop. The injected signal can be gated to selectively blow-up individual trains of bunches. The speed of transverse blow-up can be precisely controlled. This opens the possibility to perform safely and efficiently aperture measurements and loss maps with high intensity bunch trains well above stored beam energies that are considered to be safe. In particular, lengthy procedures for measurements at top energy, otherwise requiring multiple fills of individual bunches, can be avoided. In this paper, the method is presented and results from beam measurements are discussed and compared with alternative blowup methods.

  6. BPS relations from spectral problems and blowup equations

    CERN Document Server

    Grassi, Alba

    2016-01-01

    Recently an exact duality between topological string and the spectral theory of operators constructed from mirror curves to toric Calabi-Yau threefolds has been proposed. At the same time an exact quantization condition for the cluster integrable systems associated to these geometries has been conjectured. The consistency between the two approaches leads to an infinite set of constraints for the refined BPS invariants of the toric Calabi-Yau threefolds. We show that, for the Y^{N,m} geometries, these constraints can be derived from the K-theoretic blowup equations for SU(N) SYM with generic Chern-Simons invariant m. In particular this furnishes a proof of the BPS constraints in the case of m = 0.

  7. Global Dynamics, Blow-Up, and Bianchi Cosmology

    CERN Document Server

    Ben-Gal, Nitsan; Buchner, Johannes; Hell, Juliette; Karnauhova, Anna; Liebscher, Stefan; Rendall, Alan; Smith, Brian; Stuke, Hannes; Väth, Martin; Fiedler, Bernold

    2016-01-01

    Many central problems in geometry, topology, and mathematical physics lead to questions concerning the long-time dynamics of solutions to ordinary and partial differential equations. Examples range from the Einstein field equations of general relativity to quasilinear reaction-advection-diffusion equations of parabolic type. Specific questions concern the convergence to equilibria, the existence of periodic, homoclinic, and heteroclinic solutions, and the existence and geometric structure of global attractors. On the other hand, many solutions develop singularities in finite time. The singularities have to be analyzed in detail before attempting to extend solutions beyond their singularities, or to understand their geometry in conjunction with globally bounded solutions. In this context we have also aimed at global qualitative descriptions of blow-up and grow-up phenomena.

  8. Numerical diagnostics of solution blowup in differential equations

    Science.gov (United States)

    Belov, A. A.

    2017-01-01

    New simple and robust methods have been proposed for detecting poles, logarithmic poles, and mixed-type singularities in systems of ordinary differential equations. The methods produce characteristics of these singularities with a posteriori asymptotically precise error estimates. This approach is applicable to an arbitrary parametrization of integral curves, including the arc length parametrization, which is optimal for stiff and ill-conditioned problems. The method can be used to detect solution blowup for a broad class of important nonlinear partial differential equations, since they can be reduced to huge-order systems of ordinary differential equations by applying the method of lines. The method is superior in robustness and simplicity to previously known methods.

  9. Fukushima plutonium effect and blow-up regimes in neutron-multiplying media

    CERN Document Server

    Rusov, V D; Vaschenko, V M; Linnik, E P; Zelentsova, T N; Beglaryan, M E; Chernegenko, S A; Kosenko, S I; Molchinikolov, P A; Smolyar, V P; Grechan, E V

    2012-01-01

    It is shown that the capture and fission cross-sections of 238U and 239Pu increase with temperature within 1000-3000K range, in contrast to those of 235U, that under certain conditions may lead to the so-called blow-up modes, stimulating the anomalous neutron flux and nuclear fuel temperature growth. Some features of the blow-up regimes in neutron-multiplying media are discussed.

  10. Periodic blow-up solutions and their limit forms for the generalized Camassa-Holm equation

    Institute of Scientific and Technical Information of China (English)

    Zhengrong Liu; Boling Guo

    2008-01-01

    In this paper, we consider the generalized Camassa-Holm equation ut + 2kux -uxxt + au2ux = 2uxuxx-uuxxxUnder substitution ζ = x - ct, some new explicit periodic wave solutions and their limit forms are presented through some special phase orbits. These periodic wave solutions tend to infinity on ζ - u plane periodically. Thus we call them periodic blow-up solutions. To our knowledge, such periodic blow-up solutions have not been found in any other equations.

  11. Extremal K\\"ahler metrics on blow-ups of parabolic ruled surfaces

    OpenAIRE

    Tipler, Carl

    2011-01-01

    New examples of extremal K\\"ahler metrics on blow-ups of parabolic ruled surfaces are constructed. The method is based on the gluing construction of Arezzo, Pacard and Singer. This enables to endow ruled surfaces of the form $\\mathbb{P}(\\mathcal{O}\\oplus L)$ with special parabolic structures such that the associated iterated blow-up admits an extremal metric of non-constant scalar curvature.

  12. On the blow-up of four dimensional Ricci flow singularities

    CERN Document Server

    Máximo, Davi

    2012-01-01

    In this paper we prove a conjecture by Feldman-Ilmanen-Knopf in \\cite{FIK} that the gradient shrinking soliton metric they constructed on the tautological line bundle over $\\CP^1$ is the uniform limit of blow-ups of a type I Ricci flow singularity on a closed manifold. We use this result to show that limits of blow-ups of Ricci flow singularities on closed four dimensional manifolds do not necessarily have non-negative Ricci curvature.

  13. Blowup results for the KGS system with higher order Yukawa coupling

    Energy Technology Data Exchange (ETDEWEB)

    Shi, Qi-Hong, E-mail: shiqh03@163.com [Department of Applied Mathematics, Lanzhou University of Technology, Lanzhou, Gansu 730050 (China); Li, Wan-Tong [School of Mathematics and Statistics, Lanzhou University, Lanzhou, Gansu 730000 (China); Wang, Shu [College of Applied Sciences, Beijing University of Technology, Beijing 100124 (China)

    2015-10-15

    In this paper, we investigate the Klein-Gordon-Schrödinger (KGS) system with higher order Yukawa coupling in spatial dimensions N ≥ 3. We establish a perturbed virial type identity and prove blowup results relied on Lyapunov functionals for KGS system with a negative energy level. Additionally, we give a result with respect to the blowup rate in finite time for the radial solution in 3 spatial dimensions.

  14. Quantifying Evaporation in a Permeable Pavement System

    Science.gov (United States)

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

  15. Dynamic contracting mechanism for pavement maintenance management

    NARCIS (Netherlands)

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

    2013-01-01

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

  16. On the Blowup Phenomenon for N-coupled Focusing Schro¨dinger System in Rd (d≥ 3)

    Institute of Scientific and Technical Information of China (English)

    Xing Dong TANG; Ji Hui ZHANG

    2014-01-01

    We study blow-up, global existence and ground state solutions for the N-coupled focusing nonlinear Schr¨odinger equations. Firstly, using the Nehari manifold approach and some variational techniques, the existence of ground state solutions to the equations (CNLS) is established. Secondly, under certain conditions, finite time blow-up phenomena of the solutions is derived. Finally, by in-troducing a refined version of compactness lemma, the L2 concentration for the blow-up solutions is obtained.

  17. Field Investigation of High Performance Pavements in Virginia

    OpenAIRE

    2005-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Andrzej Plewa

    2015-07-01

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

  19. The Concrete and Pavement Challenge

    Science.gov (United States)

    Roman, Harry T.

    2012-01-01

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

  20. Longitudinal emittance blowup in the large hadron collider

    CERN Document Server

    Baudrenghien, P

    2013-01-01

    The Large Hadron Collider (LHC) relies on Landau damping for longitudinal stability. To avoid decreasing the stability margin at high energy, the longitudinal emittance must be continuously increased during the acceleration ramp. Longitudinal blowup provides the required emittance growth. The method was implemented through the summer of 2010. Band-limited RF phase-noise is injected in the main accelerating cavities during the whole ramp of about 11min. Synchrotron frequencies change along the energy ramp, but the digitally created noise tracks the frequency change. The position of the noise-band, relative to the nominal synchrotron frequency, and the bandwidth of the spectrum are set by pre-defined constants, making the diffusion stop at the edges of the demanded distribution. The noise amplitude is controlled by feedback using the measurement of the average bunch length. This algorithm reproducibly achieves the programmed bunch length of about 1.2ns, at flat top with low bunch-to-bunch scatter and provides a...

  1. A BLOW-UP CRITERION FOR 3-D NON-RESISTIVE COMPRESSIBLE HEAT-CONDUCTIVE MAGNETOHYDRODYNAMIC EQUATIONS WITH INITIAL VACUUM

    Institute of Scientific and Technical Information of China (English)

    Xu Xinying

    2012-01-01

    In this paper; we prove a blow-up criterion of strong solutions to the 3-D viscous and non-resistive magnetohydrodynamic equations for compressible heat-conducting flows with initial vacuum.This blow-up criterion depends only on the gradient of velocity and the temperature,which is similar to the one for compressible Navier-Stokes equations.

  2. On Blowup for time-dependent generalized Hartree-Fock equations

    CERN Document Server

    Hainzl, Christian; Lewin, Mathieu; Schlein, Benjamin

    2009-01-01

    We prove finite-time blowup for spherically symmetric and negative energy solutions of Hartree-Fock and Hartree-Fock-Bogoliubov type equations, which describe the evolution of attractive fermionic systems (e. g. white dwarfs). Our main results are twofold: First, we extend the recent blowup result of [Hainzl and Schlein, Comm. Math. Phys. \\textbf{287} (2009), 705--714] to Hartree-Fock equations with infinite rank solutions and a general class of Newtonian type interactions. Second, we show the existence of finite-time blowup for spherically symmetric solutions of a Hartree-Fock-Bogoliubov model, where an angular momentum cutoff is introduced. We also explain the key difficulties encountered in the full Hartree-Fock-Bogoliubov theory.

  3. Local-in-Space Criteria for Blowup in Shallow Water and Dispersive Rod Equations

    Science.gov (United States)

    Brandolese, Lorenzo

    2014-08-01

    We unify a few of the best known results on wave breaking for the Camassa-Holm equation (by R. Camassa, A. Constantin, J. Escher, L. Holm, J. Hyman and others) in a single theorem: a sufficient condition for the breakdown is that is strictly negative in at least one point . Such blowup criterion looks more natural than the previous ones, as the condition on the initial data is purely local in the space variable. Our method relies on the introduction of two families of Lyapunov functions. Contrary to McKean's necessary and sufficient condition for blowup, our approach applies to other equations that are not integrable: we illustrate this fact by establishing new local-in-space blowup criteria for an equation modeling nonlinear dispersive waves in elastic rods.

  4. Blow-up in p-Laplacian heat equations with nonlinear boundary conditions

    Science.gov (United States)

    Ding, Juntang; Shen, Xuhui

    2016-10-01

    In this paper, we investigate the blow-up of solutions to the following p-Laplacian heat equations with nonlinear boundary conditions: {l@{quad}l}(h(u))_t =nabla\\cdot(|nabla u|pnabla u)+k(t)f(u) &{in } Ω×(0,t^{*}), |nabla u|ppartial u/partial n=g(u) &on partialΩ×(0,t^{*}), u(x,0)=u0(x) ≥ 0 & {in } overline{Ω},. where {p ≥ 0} and {Ω} is a bounded convex domain in {RN}, {N ≥ 2} with smooth boundary {partialΩ}. By constructing suitable auxiliary functions and using a first-order differential inequality technique, we establish the conditions on the nonlinearities and data to ensure that the solution u( x, t) blows up at some finite time. Moreover, the upper and lower bounds for the blow-up time, when blow-up does occur, are obtained.

  5. Blowup Phenomenon of Solutions for the IBVP of the Compressible Euler Equations in Spherical Symmetry.

    Science.gov (United States)

    Cheung, Ka Luen; Wong, Sen

    2016-01-01

    The blowup phenomenon of solutions is investigated for the initial-boundary value problem (IBVP) of the N-dimensional Euler equations with spherical symmetry. We first show that there are only trivial solutions when the velocity is of the form c(t)|x| (α-1) x + b(t)(x/|x|) for any value of α ≠ 1 or any positive integer N ≠ 1. Then, we show that blowup phenomenon occurs when α = N = 1 and [Formula: see text]. As a corollary, the blowup properties of solutions with velocity of the form [Formula: see text] are obtained. Our analysis includes both the isentropic case (γ > 1) and the isothermal case (γ = 1).

  6. LIMITING BEHAVIOR OF BLOW-UP SOLUTIONS OF THE NLSE WITH A STARK POTENTIAL

    Institute of Scientific and Technical Information of China (English)

    Zhu Shihui; Zhang Jian

    2012-01-01

    This article is concerned with blow-up solutions of the Cauchy problem of critical nonlinear Schr(o)dinger equation with a Stark potential.By using the variational characterization of corresponding ground state,the limiting behavior of blow-up solutions with critical and small super-critical mass are obtained in the natural energy space ∑ ={u ∈ H1; ∫RN [x|2|u|2dx < +o}.Moreover,an interesting concentration property of the blow-up solutions with critical mass is gotten,which reads that |u(t,x)|2→‖Q‖2L2δx =x1 as t→ T.

  7. Simplified Pavement Design for LPAs: Introduction to PaveXpress

    OpenAIRE

    2015-01-01

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

  8. Improving the distribution and reducing the magnitude of pavement damage

    Science.gov (United States)

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

    1980-08-01

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

  9. Investigation of perpetual pavement using finite element modelling

    Directory of Open Access Journals (Sweden)

    Monireh Zokaei

    2016-06-01

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

  10. Blow-up conditions for two dimensional modified Euler-Poisson equations

    Science.gov (United States)

    Lee, Yongki

    2016-09-01

    The multi-dimensional Euler-Poisson system describes the dynamic behavior of many important physical flows, yet as a hyperbolic system its solution can blow-up for some initial configurations. This article strives to advance our understanding on the critical threshold phenomena through the study of a two-dimensional modified Euler-Poisson system with a modified Riesz transform where the singularity at the origin is removed. We identify upper-thresholds for finite time blow-up of solutions for the modified Euler-Poisson equations with attractive/repulsive forcing.

  11. Blow-Up Analysis for a Quasilinear Degenerate Parabolic Equation with Strongly Nonlinear Source

    Directory of Open Access Journals (Sweden)

    Pan Zheng

    2012-01-01

    Full Text Available We investigate the blow-up properties of the positive solution of the Cauchy problem for a quasilinear degenerate parabolic equation with strongly nonlinear source ut=div(|∇um|p−2∇ul+uq,  (x,t∈RN×(0,T, where N≥1, p>2 , and m, l,  q>1, and give a secondary critical exponent on the decay asymptotic behavior of an initial value at infinity for the existence and nonexistence of global solutions of the Cauchy problem. Moreover, under some suitable conditions we prove single-point blow-up for a large class of radial decreasing solutions.

  12. THE SIMULTANEOUS AND NON-SIMULTANEOUS BLOW-UP CRITERIA FOR A DIFFUSION SYSTEM

    Institute of Scientific and Technical Information of China (English)

    Zhengqiu LING; Zejia WANG; Guoqiang ZHANG

    2013-01-01

    This paper investigates the finite time blow-up of nonnegative solutions for a nonlinear diffusion system with a more complicated source term,which is a product of localized source,local source,and weight function,and complemented by homogeneous Dirichlet boundary conditions.The criteria are proposed to identify simultaneous and nonsimultaneous blow-up solutions.Moreover,the related classification for the four parameters in the model is optimal and complete.The results extend those in Zhang and Yang [12].

  13. Blow-up phenomena and persistence property for the modified b-family of equations

    Science.gov (United States)

    Wang, Ying; Zhu, Min

    2017-02-01

    In this paper, we study the blow-up mechanism and persistence property of solutions to the modified b-family of equations. The dynamics of the blow-up quantity along the characteristics is established by the Riccati-type differential inequality with various parameters. The key feature of the method is to refine the analysis on the growth rate of the relative ratio between solution and its gradient by performing a vertical shift. Furthermore, the persistence results for the solution are established in weighted spaces.

  14. Removable Urban Pavements: An innovative, sustainable technology

    OpenAIRE

    2012-01-01

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

  15. Improving Data Quality for Pavement Management System

    OpenAIRE

    2015-01-01

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

  16. Enhancing pavements for thermal applications

    OpenAIRE

    Keikhaei Dehdezi, Pejman

    2012-01-01

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

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

    Science.gov (United States)

    2014-01-01

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

  18. Blowup in stagnation-point form solutions of the inviscid 2d Boussinesq equations

    Science.gov (United States)

    Sarria, Alejandro; Wu, Jiahong

    2015-10-01

    The 2d Boussinesq equations model large scale atmospheric and oceanic flows. Whether its solutions develop a singularity in finite-time remains a classical open problem in mathematical fluid dynamics. In this work, blowup from smooth nontrivial initial velocities in stagnation-point form solutions of this system is established. On an infinite strip Ω = { (x, y) ∈ [ 0, 1 ] ×R+ }, we consider velocities of the form u = (f (t, x), - yfx (t, x)), with scalar temperature θ = yρ (t, x). Assuming fx (0, x) attains its global maximum only at points xi* located on the boundary of [ 0, 1 ], general criteria for finite-time blowup of the vorticity - yfxx (t, xi*) and the time integral of fx (t, xi*) are presented. Briefly, for blowup to occur it is sufficient that ρ (0, x) ≥ 0 and f (t, xi*) = ρ (0, xi*) = 0, while - yfxx (0, xi*) ≠ 0. To illustrate how vorticity may suppress blowup, we also construct a family of global exact solutions. A local-existence result and additional regularity criteria in terms of the time integral of ‖fx (t, ṡ) ‖ L∞ ([ 0, 1 ]) are also provided.

  19. Finite time blow-up for a wave equation with a nonlocal nonlinearity

    CERN Document Server

    Fino, Ahmad; Georgiev, Vladimir

    2010-01-01

    In this article, we study the local existence of solutions for a wave equation with a nonlocal in time nonlinearity. Moreover, a blow-up results are proved under some conditions on the dimensional space, the initial data and the nonlinear forcing term.

  20. Magnetic virial identities and applications to blow-up for Schroedinger and wave equations

    Energy Technology Data Exchange (ETDEWEB)

    Garcia, Andoni, E-mail: andoni.garcia@ehu.es [Departamento de Matematicas, Universidad del Pais Vasco, Apartado 644, 48080 Bilbao (Spain)

    2012-01-13

    We prove blow-up results for the solution of the initial-value problem with negative energy of the focusing mass-critical and supercritical nonlinear Schroedinger and the focusing energy-subcritical nonlinear wave equations with electromagnetic potential. (paper)

  1. Blow-up estimates for semilinear parabolic systems coupled in an equation and a boundary condition

    Institute of Scientific and Technical Information of China (English)

    WANG; Mingxin(

    2001-01-01

    [1]Wang, S., Wang, M. X., Xie, C. H., Reaction-diffusion systems with nonlinear boundary conditions, Z. angew. Math.Phys., 1997, 48(6): 994-1001.[2]Fila, M., Quittner, P., The blow-up rate for a semilinear parabolic system, J. Math. Anal. Appl., 1999, 238: 468-476.[3]Hu, B., Remarks on the blow-up estimate for solutions of the heat equation with a nonlinear boundary condition, Differential Integral Equations, 1996, 9(5): 891-901.[4]Hu, B. , Yin, H. M., The profile near blow-up time for solution of the heat equation with a nonlinear boundary condition,Trans. of Amer. Math. Soc., 1994, 346: 117-135.[5]Amann, H., Parabolic equations and nonlinear boundary conditions, J. of Diff. Eqns., 1988, 72: 201-269.[6]Deng, K., Blow-up rates for parabolic systems, Z. angew. Math. Phys. ,1996, 47: 132-143.[7]Fila, M., Levine, H. A., On critical exponents for a semilinear parabolic system coupled in an equation and a boundary condition, J. Math. Anal. Appl., 1996, 204: 494-521.

  2. Blow-up in nonlinear Schroedinger equations. I. A general review

    DEFF Research Database (Denmark)

    Juul Rasmussen, Jens; Rypdal, K.

    1986-01-01

    The general properties of a class of nonlinear Schroedinger equations: iut + p:∇∇u + f(|u|2)u = 0 are reviewed. Conditions for existence, uniqueness, and stability of solitary wave solutions are presented, along with conditions for blow-up and global existence for the Cauchy problem....

  3. Numerical Simulation of Tire-Pavement Interaction

    NARCIS (Netherlands)

    Srirangam, S.K.

    2015-01-01

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

  4. Load Response Analysis of Asphalt Pavement

    Directory of Open Access Journals (Sweden)

    Xiao Zhijun

    2016-01-01

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

  5. Uniform blow-up profiles and boundary layer for a parabolic system with localized nonlinear reaction terms

    Institute of Scientific and Technical Information of China (English)

    LI Huiling; WANG Mingxin

    2005-01-01

    This paper deals with the blow-up properties of the solution to a semilinear parabolic system with localized nonlinear reaction terms, subject to the null Dirichlet boundary condition. We first give sufficient conditions for that the classical solution blows up in the finite time, secondly give necessary conditions and a sufficient condition for that two components blow up simultaneously, and then obtain the uniform blow-up profiles in the interior. Finally we describe the asymptotic behavior of the blow-up solution in the boundary layer.

  6. Theoretical Development and Engineering Practice of Pavements in China

    Institute of Scientific and Technical Information of China (English)

    QIU Yan-jun

    2008-01-01

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

  7. Effective flow resistivity of highway pavements.

    Science.gov (United States)

    Rochat, Judith L; Read, David R

    2013-12-01

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

  8. On blow-up "twistors" for the Navier--Stokes equations in $R^3$: a view from reaction-diffusion theory

    OpenAIRE

    Galaktionov, V. A.

    2009-01-01

    Various formal blow-up scenarious for the Navier--Stokes equaitons in 3D are discussed. A particular interest is payed to "twistor mechanisms" based on angular logarithmic blow-up travelling waves, and to a formation of "blow-up tornado" about the singular stationary Slezkin--Landau solutions (1934--44) of a submerged jet. A survey on various related aspects of singularity analysis for nonlinear parabolic PDEs is enclosed.

  9. Blow-up for an evolution p-laplace system with nonlocal sources and inner absorptions

    Directory of Open Access Journals (Sweden)

    Liu Dengming

    2011-01-01

    Full Text Available Abstract This paper investigates the blow-up properties of positive solutions to the following system of evolution p-Laplace equations with nonlocal sources and inner absorptions { u t − div ( | ∇ u | p − 2 ∇ u = ∫ Ω v m d x − α u r , x ∈ Ω ,   t > 0, v t − div ( | ∇ v | q − 2 ∇ v = ∫ Ω u n d x − β v s , x ∈ Ω ,   t > 0 with homogeneous Dirichlet boundary conditions in a smooth bounded domain Ω ∈ RN (N ≥ 1, where p, q > 2, m, n, r, s ≥ 1, α, β > 0. Under appropriate hypotheses, the authors discuss the global existence and blow-up of positive weak solutions by using a comparison principle. 2010 Mathematics Subject Classification: 35B35; 35K60; 35K65; 35K57.

  10. Profile of Blow-up Solution to Hyperbolic System with Nonlocal Term

    Institute of Scientific and Technical Information of China (English)

    Zhi Wen DUAN; Kwang Ik KIM

    2007-01-01

    This paper is concerned with a nonlocal hyperbolic system as follows:utt=△u+(∫Ωvdx)p for x∈RN,t>0, utt=△v+(∫Ωvdx)q for x∈RN,t>0,u(x,0)=u0(x),ut(x,0)=u01(x) for x∈RN,v(x,0)=u0(x),vt(x,0)=v01(x) for x∈RN,where 1 ≤ N ≤ 3, p ≥ 1, q ≥ 1 and pq > 1. Here the initial values are compactly supported andΩ(∈) RN is a bounded open region. The blow-up curve, blow-up rate and profile of the solution arediscussed.

  11. LHC MD 1087: Controlled Longitudinal Emittance Blow-up with Short Bunches

    CERN Document Server

    Timko, Helga; Esteban Muller, Juan; Jaussi, Michael; Lasheen, Alexandre; Shaposhnikova, Elena; CERN. Geneva. ATS Department

    2017-01-01

    The aim of the MD was to study the controlled longitudinal emittance blow-up applied during the ramp with bunches that are slightly shorter than operational. Earlier MDs in 2015 have shown that with a short target bunch length, the blow-up is less controlled and a bifurcation of bunch lengths occurs. The presented measurements show that the bifurcation is independent of the presence of the bunch length feedback, pointing towards an intensity-dependent phenomenon, originating from a synchrotron frequency shift with intensity. Accurate measurements of synchrotron frequency shift with intensity are presented as well. The measurements took place between 22nd August 2016, 19:00 and 23rd August 2016, 04:00.

  12. PSB beam longitudinal blow-up by phase modulation with the digital LLRF prototype system

    CERN Document Server

    Angoletta, M E; Butterworth, A; Findlay, A; Jaussi, M; Leinonen, P; Molendijk, J; Sanchez-Quesada, J

    2014-01-01

    The PSB will be upgraded to a new, Digital Low-Level RF (DLLRF) system in 2014 at the injectors’ restart after LS1. This DLLRF is an evolution of that successfully deployed in LEIR and comprises new hardware, software and implementation strategies. Machine development studies have been carried out in the PSB over recent years with the existing LEIR-style hardware installed in PSB ring four. These studies have allowed testing approaches and validating implementation strategies. This note focuses on a series of MDs carried out during the 2011 run where a new implementation of the longitudinal beam blow-up obtained by phase modulation was tested. Test results and effects on the beam are show for a CNGS-type beam. Finally, an overview is given of the final longitudinal blow-up implementation planned with the new hardware, which will be operationally deployed in 2014.

  13. On-road Bicycle Pavement Markings

    Data.gov (United States)

    Allegheny County / City of Pittsburgh / Western PA Regional Data Center — A mile by mile breakdown of the on-street bicycle pavement markings installed within the City of Pittsburgh. These include bike lanes, shared lane markings...

  14. Global existence and blowup of solutions for the multidimensional sixth-order "good" Boussinesq equation

    Science.gov (United States)

    Runzhang, Xu; Yanbing, Yang; Bowei, Liu; Jihong, Shen; Shaobin, Huang

    2015-06-01

    This paper is concerned with the Cauchy problem of solutions for some nonlinear multidimensional "good" Boussinesq equation of sixth order at three different initial energy levels. In the framework of potential well, the global existence and blowup of solutions are obtained together with the concavity method at both low and critical initial energy level. Moreover by introducing a new stable set, we present some sufficient conditions on initial data such that the weak solution exists globally at supercritical initial energy level.

  15. On blowup dynamics in the Keller-Segel model of chemotaxis

    CERN Document Server

    Dejak, S I; Lushnikov, P M; Sigal, I M

    2013-01-01

    We investigate the (reduced) Keller-Segel equations modeling chemotaxis of bio-organisms. We present a formal derivation and partial rigorous results of the blowup dynamics of solution of these equations describing the chemotactic aggregation of the organisms. Our results are confirmed by numerical simulations and the formula we derive coincides with the formula of Herrero and Vel\\'{a}zquez for specially constructed solutions.

  16. Blow-up Estimates of the Positive Solution of a Parabolic System

    DEFF Research Database (Denmark)

    Pedersen, Michael; Zhigui, Lin

    1999-01-01

    This paper establishes the blowup estimates for the systems: $u_t-\\Delta u=0,$ $v_t-\\Delta v=0$ in $B_R\\times (0,T)$, $B_R\\subset\\Bbb R^n$, with the nonlinear boundary conditions $\\frac{\\partial u}{\\partial \\eta}=u^{m_1}v^{n_1}$ and $\\frac{\\partial v}{\\partial \\eta}=u^{m_2}v^{n_2}$ on $S_R\\times ...

  17. BLOW-UP ESTIMATES FOR A NON-NEWTONIAN FILTRATION SYSTEM

    Institute of Scientific and Technical Information of China (English)

    杨作东; 陆启韶

    2001-01-01

    The prior estimate and decay property of positive solutions are derived for a system of quasi-linear elliptic differential equations first. Hence, the result of non-existence for differential equation system of radially nonincreasing positive solutions is implied. By using this non-existence result, blow-up estimates for a class quasi-linear reaction-diffusion systems (non-Newtonian filtration systems ) are established, which extends the result of semi- linear reaction- diffusion ( Fujita type ) systems .

  18. The Blow-Up Rate for Strongly Perturbed Semilinear Wave Equations in the Conformal Case

    Energy Technology Data Exchange (ETDEWEB)

    Hamza, M. A., E-mail: ma.hamza@fst.rnu.tn; Saidi, O., E-mail: saidi.omar@hotmail.fr [Université de Tunis El Manar, Faculté des Sciences de Tunis, LR03ES04 Èquations aux dérivées partielles et applications (Tunisia)

    2015-12-15

    We consider in this work some class of strongly perturbed for the semilinear wave equation with conformal power nonlinearity. We obtain an optimal estimate for a radial blow-up solution and we have also obtained two less stronger estimates. These results are achieved in three-steps argument by the construction of a Lyapunov functional in similarity variables and the Pohozaev identity derived by multiplying (1.14) by y∂{sub y}w.

  19. Open-Graded Bases for Airfield Pavements.

    Science.gov (United States)

    1987-07-01

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

  20. Pavement Performance Index for Indian rural roads

    Directory of Open Access Journals (Sweden)

    Abhay Tawalare

    2016-09-01

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

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

    Science.gov (United States)

    Junwei, Zhang; Jinping, Li; Xiaojuan, Quan

    2013-01-01

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

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

    CERN Document Server

    Hendel, Martin; Diab, Youssef; Royon, Laurent

    2014-01-01

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

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

    OpenAIRE

    Cai, Wei

    2015-01-01

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

  4. Porous Flame-retarded Asphalt Pavement for Highway Tunnel

    Institute of Scientific and Technical Information of China (English)

    HU Shuguang; HUANG Shaolong; Ding Qingjun

    2008-01-01

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

  5. Knowledge Discovery and Pavement Performance: Intelligent Data Mining

    NARCIS (Netherlands)

    Miradi, M.

    2009-01-01

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

  6. Pavement Sealcoat, PAHs, and the Environment

    Science.gov (United States)

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

    2011-12-01

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

  7. Spills on Flat Inclined Pavements

    Energy Technology Data Exchange (ETDEWEB)

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

    2004-03-01

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

  8. Blow-Up Criterion of Weak Solutions for the 3D Boussinesq Equations

    Directory of Open Access Journals (Sweden)

    Zhaohui Dai

    2015-01-01

    Full Text Available The Boussinesq equations describe the three-dimensional incompressible fluid moving under the gravity and the earth rotation which come from atmospheric or oceanographic turbulence where rotation and stratification play an important role. In this paper, we investigate the Cauchy problem of the three-dimensional incompressible Boussinesq equations. By commutator estimate, some interpolation inequality, and embedding theorem, we establish a blow-up criterion of weak solutions in terms of the pressure p in the homogeneous Besov space Ḃ∞,∞0.

  9. Regular solutions for multiplicative stochastic Landau-Lifshitz-Gilbert equation and blow-up phenomena

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    The two-dimensional Landau-Lifshitz-Gilbert equation of motion for a classical magnetic moment perturbed by a multiplicative noise is considered. This equation is highly nonlinear in nature and, for this reason, many mathematical results in stochastic partial differential equations (SPDEs) cannot be applied. The aim of this work is to introduce the difference method to handle SPDEs and prove the existence of regular martingale solutions in dimension two. Some blow-up phenomena are presented, which are drastically different from the deterministic case. Finally, to yield correct thermal-equilibrium properties, Stratonovitch integral is used instead of It?o integral.

  10. On the Blow-up Criterion of Smooth Solutions to the MHD System in BMO Space

    Institute of Scientific and Technical Information of China (English)

    Bao-quan Yuan

    2006-01-01

    In this paper we study the blow-up criterion of smooth solutions to the incompressible magnetohydrodynamics system in BMO space. Let (u(x,t),b(x,t)) be smooth solutions in (0, T). It is shown that the solution (u(x, t), b(x, t)) can be extended beyond t = T if (u(x, t), b(x, t)) ∈ L1(0, T; BMO) or the vorticity(rot u(x, t), rot b(x, t)) ∈ L1 (0, T; BMO) or the deformation (Def u(x, t), Def b(x, t)) ∈ L1 (0, T; BMO).

  11. Global existence and blowup of solutions to a free boundary problem for mutualistic model

    Institute of Scientific and Technical Information of China (English)

    KIM; KwangIk

    2010-01-01

    This article is concerned with a system of semilinear parabolic equations with a free boundary,which arises in a mutualistic ecological model.The local existence and uniqueness of a classical solution are obtained.The asymptotic behavior of the free boundary problem is studied.Our results show that the free problem admits a global slow solution if the inter-specific competitions are strong,while if the inter-specific competitions are weak there exist the blowup solution and global fast solution.

  12. Critical Blow-Up and Global Existence for Discrete Nonlinear p-Laplacian Parabolic Equations

    Directory of Open Access Journals (Sweden)

    Soon-Yeong Chung

    2014-01-01

    Full Text Available The goal of this paper is to investigate the blow-up and the global existence of the solutions to the discrete p-Laplacian parabolic equation utx,t=Δp,wux,t+λux,tp-2ux,t, x,t∈S×0,∞, ux,t=0, x,t∈∂S×0,∞, ux,0=u0, depending on the parameters p>1 and λ>0. Besides, we provide several types of the comparison principles to this equation, which play a key role in the proof of the main theorems. In addition, we finally give some numerical examples which exploit the main results.

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

    Science.gov (United States)

    Diniz, E. V.

    1980-08-01

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

  14. Structural Design of Pavement Overlays Based on Functional Parameters

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

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

  15. "Full-Scale Testing of Pavement Response"

    DEFF Research Database (Denmark)

    Ullidtz, Per; Ekdahl, Peter

    1998-01-01

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

  16. Asphalt for draining pavement; Haisuisei hosoyo asphalt

    Energy Technology Data Exchange (ETDEWEB)

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

    1994-12-28

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

  17. Cracking of open traffic rigid pavement

    Directory of Open Access Journals (Sweden)

    Niken Chatarina

    2017-01-01

    Full Text Available The research is done by observing the growth of real structure cracking in Natar, Lampung, Indonesia compared to C. Niken’s et al research and literature study. The rigid pavement was done with open traffic system. There are two main crack types on Natar rigid pavement: cracks cross the road, and cracks spreads on rigid pavement surface. The observation of cracks was analyzed by analyzing material, casting, curing, loading and shrinkage mechanism. The relationship between these analysis and shrinkage mechanism was studied in concrete micro structure. Open traffic make hydration process occur under vibration; therefore, fresh concrete was compressed and tensioned alternately since beginning. High temperature together with compression, cement dissociation, the growth of Ca2+ at very early age leads abnormal swelling. No prevention from outside water movement leads hydration process occur with limited water which caused spreads fine cracks. Limited water improves shrinkage and plastic phase becomes shorter; therefore, rigid pavement can’t accommodate the abnormal swelling and shrinking alternately and creates the spread of cracks. Discontinuing casting the concrete makes both mix under different condition, the first is shrink and the second is swell and creates weak line on the border; so, the cracks appear as cracks across the road.

  18. Viscoelastic Pavement Modeling with a Spreadsheet

    DEFF Research Database (Denmark)

    Levenberg, Eyal

    2016-01-01

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

  19. Blow-up of solutions for the sixth-order thin film equation with positive initial energy

    Indian Academy of Sciences (India)

    Wenjun Liu; Kewang Chen

    2015-10-01

    In this paper, a sixth-order parabolic thin film equation with the initial boundary condition is considered. By using the improved energy estimate method and by constructing second-order elliptic problem, a blow-up result for certain solution with positive initial energy is established, which is an improve over the previous result of Li and Liu.

  20. The Blow-up Rate for Positive Solutions of Indefinite Parabolic Problems and Related Liouville Type Theorems

    Institute of Scientific and Technical Information of China (English)

    Ruixiang XING

    2009-01-01

    In this paper,we derive an upper bound estimate of the blow-up rate for positive solutions of indefinite parabolic equations from Liouville type theorems. We also use moving plane method to prove the related Liouville type theorems for semilinear parabolic problems.

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

    OpenAIRE

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

    2008-01-01

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

  2. Permeability testing of drilling core sample from pavement

    Institute of Scientific and Technical Information of China (English)

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

    2008-01-01

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

  3. Hybrid green permeable pave with hexagonal modular pavement systems

    Science.gov (United States)

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

    2013-06-01

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

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

    OpenAIRE

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

    2009-01-01

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

  5. A novel micromechanics based approach in modeling pavement response

    Science.gov (United States)

    Bhattacharya, Arun

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

  6. Existence and Blowup Results for Asymptotically Euclidean Initial Data Sets Generated by the Conformal Method

    CERN Document Server

    Dilts, James

    2016-01-01

    For each set of (freely chosen) seed data, the conformal method reduces the Einstein constraint equations to a system of elliptic equations, the conformal constraint equations. We prove an admissibility criterion, based on a (conformal) prescribed scalar curvature problem, which provides a necessary condition on the seed data for the conformal constraint equations to (possibly) admit a solution. We then consider sets of asymptotically Euclidean (AE) seed data for which solutions of the conformal constraint equations exist, and examine the blowup properties of these solutions as the seed data sets approach sets for which no solutions exist. We also prove that there are AE seed data sets which include a Yamabe nonpositive metric and lead to solutions of the conformal constraints. These data sets allow the mean curvature function to have zeroes.

  7. Evolution PDEs with nonstandard growth conditions existence, uniqueness, localization, blow-up

    CERN Document Server

    Antontsev, Stanislav

    2015-01-01

    This monograph offers the reader a treatment of the theory of evolution PDEs with nonstandard growth conditions. This class includes parabolic and hyperbolic equations with variable or anisotropic nonlinear structure. We develop methods for the study of such equations and present a detailed account of recent results. An overview of other approaches to the study of PDEs of this kind is provided. The presentation is focused on the issues of existence and uniqueness of solutions in appropriate function spaces, and on the study of the specific qualitative properties of solutions, such as localization in space and time, extinction in a finite time and blow-up, or nonexistence of global in time solutions. Special attention is paid to the study of the properties intrinsic to solutions of equations with nonstandard growth.

  8. Renormalization group formalism for incompressible Euler equations and the blowup problem

    CERN Document Server

    Mailybaev, Alexei A

    2012-01-01

    The paper develops the renormalization group (RG) theory for compressible and incompressible inviscid flows, which describes universal scaling of singularities developing in finite (blowup) or infinite time from smooth initial conditions of finite energy. In this theory, the time evolution is substituted by the equivalent evolution given by the RG equations with increasing scaling parameter. Stationary states of the RG equations correspond to self-similar singular solutions. If such a stationary state is an attractor, the corresponding self-similar solution describes universal asymptotic form of a singularity for generic initial conditions. First, we consider the inviscid Burgers equation, where the complete RG analysis is carried out. We prove that the shock formation is described asymptotically by the universal self-similar solution. Then the RG formalism is extended to incompressible Euler equations. Renormalization schemes with single and multiple spatial scales are developed, describing possible asymptot...

  9. Investigations of the LHC Emittance Blow-Up During the 2012 Proton Run

    CERN Document Server

    Kuhn, M; Baudrenghien, P; Emery, J; Guerrero, A; Hofle, W; Kain, V; Lamont, M; Mastoridis, T; Roncarolo, F; Sapinski, M; Schaumann, M; Steinhagen, R; Trad, G; Valuch, D

    2013-01-01

    About 30 % of the potential luminosity performance is lost through the different phases of the LHC cycle, mainly due to transverse emittance blow-up. Measuring the emittance growth is a difficult task with high intensity beams and changing energies. Improvements of the LHC transverse profile instrumentation helped to study various effects. A breakdown of the growth through the different phases of the LHC cycle is given as well as a comparison with the data from the LHC experiments for transverse beam size. In 2012 a number of possible sources and remedies have been studied. Among these are intra beam scattering, 50 Hz noise and the effect of the transverse damper gain. The results of the investigations are summarized in this paper. Requirements for transverse profile instrumentation for post LHC long shutdown operation to finally tackle the emittance growth are given as well.

  10. Design of Road Pavement Using Recycled Aggregate

    Science.gov (United States)

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

    2016-10-01

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

  11. Effect of induced deformation on NDT pavement evaluation

    Science.gov (United States)

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

    1999-02-01

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

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

    Science.gov (United States)

    Asphalt Inst., College Park, MD.

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

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

    DEFF Research Database (Denmark)

    Ullidtz, Per; Ertman Larsen, Hans Jørgen

    1997-01-01

    Most existing pavement subgrade criteria are based on the AASHO Road Test, where only one material was tested and for only one climatic condition. To study the validity of these criteria and to refine the criteria a co-operative research program entitled the "International Pavement Subgrade Perfo...

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

    Science.gov (United States)

    Cai, Yingchun; Zhang, Yamin

    2011-06-01

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

  15. Global existence and blow-up of solutions to a parabolic system with nonlocal sources and boundaries

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    This paper deals with a semi-linear parabolic system with nonlinear nonlocal sources and nonlocal boundaries.By using super-and sub-solution techniques,we first give the sufficient conditions that the classical solution exists globally and blows up in a finite time respectively,and then give the necessary and sufficient conditions that two components u and v blow up simultaneously.Finally,the uniform blow-up profiles in the interior are presented.

  16. Global existence and blow-up of solutions to a parabolic system with nonlocal sources and boundaries

    Institute of Scientific and Technical Information of China (English)

    Ling-hua KONG; Ming-xin WANG

    2007-01-01

    This paper deals with a semi-linear parabolic system with nonlinear nonlocal sources and nonlocal boundaries. By using super- and sub-solution techniques, we first give the sufficient conditions that the classical solution exists globally and blows up in a finite time respectively, and then give the necessary and sufficient conditions that two components u and v blow up simultaneously. Finally, the uniform blow-up profiles in the interior are presented.

  17. GLOBAL EXISTENCE AND BLOW-UP PHENOMENA OF CLASSICAL SOLUTIONS FOR THE SYSTEM OF COMPRESSIBLE ADIABATIC FLOW THROUGH POROUS MEDIA

    Institute of Scientific and Technical Information of China (English)

    刘法贵; 孔德兴

    2004-01-01

    By means of maximum principle for nonlinear hyperbolic systems,the results given by HSIAO Ling and D.Serre was improved for Cauchy problem of compressible adiabatic flow through porous media,and a complete result on the global existence and the blow-up phenomena of classical solutions of these systems.These results show that the dissipation is strong enough to preserve the smoothness of 'small ' solution.

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

    Science.gov (United States)

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

    2015-05-01

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

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

    Directory of Open Access Journals (Sweden)

    Jiang Ruinan

    2015-01-01

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

  20. Wavelet-aided pavement distress image processing

    Science.gov (United States)

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

    2003-11-01

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

  1. Tire Footprint Affects Hydroplaning On Wet Pavement

    Science.gov (United States)

    Yager, Thomas J.

    1989-01-01

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

  2. An Innovative Strategy for Maintenance of Highway Pavement

    Directory of Open Access Journals (Sweden)

    Sandeep Choudhary, Dr. P. K. Agarwal

    2013-05-01

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

  3. Evaluation of accelerated deterioration in NAPTF flexible test pavements

    Institute of Scientific and Technical Information of China (English)

    Kasthurirangan GOPALAKRISHNAN

    2008-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Pabitra Rajbongshi

    2016-01-01

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

  5. Automated management for pavement inspection system (AMPIS)

    Science.gov (United States)

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

    2003-08-01

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

  6. Blow-up criterion for 2-D Boussinesq equations in bounded domain

    Institute of Scientific and Technical Information of China (English)

    HU Langhua; JIAN Huaiyu

    2007-01-01

    We extend the results for 2-D Boussinesq equations from R2 to a bounded domain Ω.First, as for the existence of weak solutions, we trans form Boussinesq equations to a nonlinear evolution equation Ut + A(t, U) = O.In stead of using the methods of fundamental solutions in the case of entire R2, we study the qualities of F(u,v) = (u.▽)v to get some useful estimates for A(t, U), which helps us to conclude the local-in-time existence and uniqueness of solutions.Second, as for blow-up criterions, we use energy methods, Sobolev inequalities and Gronwall inequality to con trol‖θ‖Hs(Ω) and ‖u‖H8(Ω) by ‖▽θ‖L∞(Ω) and‖▽u‖L∞(Ω).Furthermore,‖▽θ‖L∞(Ω) can control ‖▽u‖L∞(Ω) by using vorticity transportation equations.At last, ‖▽θ‖Mφ(Ω) can control ‖▽θ‖L∞(Ω).Thus, we can find a blow up criterion in the form of limt→T* ∫to‖▽θ(.,τ)‖Mφ(Ω)dτ= ∞.

  7. Self-Similar Blowup Solutions to the 2-Component Camassa-Holm Equations

    CERN Document Server

    Yuen, Manwai

    2010-01-01

    In this article, we study the self-similar solutions of the 2-component Camassa-Holm equations% \\begin{equation} \\left\\{ \\begin{array} [c]{c}% \\rho_{t}+u\\rho_{x}+\\rho u_{x}=0,\\\\ m_{t}+2um_{x}+um_{x}+\\sigma\\rho\\rho_{x}=0, \\end{array} \\right. \\end{equation} with \\begin{equation} m=u-\\alpha^{2}u_{xx}. \\end{equation} By the separation method, we can obtain a class of blowup or global solutions for $\\sigma=1$ or $-1$. In particular, for the integrable system with $\\sigma=1$, we have the collapsing solutions:% \\begin{equation} \\left\\{ \\begin{array} [c]{c}% \\rho(t,x)=\\left\\{ \\begin{array} [c]{c}% \\frac{f\\left( \\eta\\right) }{a(3t)^{1/3}},\\text{ for }\\eta^{2}<-\\xi\\alpha ^{2},\\\\ 0,\\text{ for }\\eta^{2}\\geq-\\xi\\alpha^{2}% \\end{array} \\right. ,u(t,x)=\\frac{\\overset{\\cdot}{a}(3t)}{a(3t)}x,\\\\ \\overset{\\cdot\\cdot}{a}(s)-\\frac{\\xi}{3a(s)^{1/3}}=0,\\text{ }a(0)=a_{0}% <0,\\text{ }\\overset{\\cdot}{a}(0)=a_{1},\\\\ f(\\eta)=\\frac{1}{\\xi}\\sqrt{\\xi\\eta^{2}+\\left( \\xi\\alpha\\right) ^{2}}, \\end{array} \\right. \\end{equation} where $\\e...

  8. Blowup phenomena for the compressible euler and euler-poisson equations with initial functional conditions.

    Science.gov (United States)

    Wong, Sen; Yuen, Manwai

    2014-01-01

    We study, in the radial symmetric case, the finite time life span of the compressible Euler or Euler-Poisson equations in R (N) . For time t ≥ 0, we can define a functional H(t) associated with the solution of the equations and some testing function f. When the pressure function P of the governing equations is of the form P = Kρ (γ) , where ρ is the density function, K is a constant, and γ > 1, we can show that the nontrivial C (1) solutions with nonslip boundary condition will blow up in finite time if H(0) satisfies some initial functional conditions defined by the integrals of f. Examples of the testing functions include r (N-1)ln(r + 1), r (N-1) e (r) , r (N-1)(r (3) - 3r (2) + 3r + ε), r (N-1)sin((π/2)(r/R)), and r (N-1)sinh r. The corresponding blowup result for the 1-dimensional nonradial symmetric case is also given.

  9. A Digital System for Longitudinal Emittance Blow-Up in the LHC

    CERN Document Server

    JaussI, M; Baudrenghien, P; Butterworth, A; Sanchez-Quesada, J; Shaposhnikova, E; Tuckmantel, J

    2011-01-01

    In order to preserve beam stability with nominal bunch intensity in the LHC, longitudinal emittance blow-up is performed during the energy ramp by injecting phase noise in the main accelerating cavities. The noise spectrum spans a small frequency band around the synchrotron frequency. It is generated continuously in software and streamed digitally into the Digital Signal Processor (DSP) of the Beam Control system where it is added to the pick-up signal of the beam phase loop, resulting in a phase modulation of the accelerating RF. In order to achieve reproducible results, a feedback system, using as input the measured bunch lengths averaged over each ring, controls the strength of the excitation, allowing the operator to simply set a target bunch length. The spectrum of the noise is adjusted to excite the core of the bunch only, extending to the desired bunch length. As it must follow the evolution of the synchrotron frequency through the ramp, it is automatically calculated by the LHC settings management sof...

  10. BLOW-UP SOLUTIONS FOR A CLASS OF NONLINEAR PARABOLIC EQUATIONS WITH MIXED BOUNDARY CONDITIONS

    Institute of Scientific and Technical Information of China (English)

    DING Juntang; LI Shengjia

    2005-01-01

    The type of problem under consideration is{ut = (△)(a(u)b(x)(△)u) + g(x,q,t)f(u)in D(0,T),u=0onГ1×(0,T), (e)u/(e)u+ +σ(x,t)u = 0 on Г2×(0,T),Г1∪Г2=(e)D, u(x,0) = uo(x) ≥ 0,(≠) 0 in( ̄D),where D is a smooth bounded domain of RN,q=|(△)u|2.By constructing an auxiliary function and using Hopf's maximum principles on it,existence theorems of blow-up solutions,upper bound of “blow-up time” and upper estimates of “blow-up rate” axe given under suitable assumptions on a,b,f,g,σ and initial date uo(x).The obtained results are applied to some examples in which a,b,f,g and σ are power functions or exponential functions.

  11. A Computational Investigation of the Finite-Time Blow-Up of the 3D Incompressible Euler Equations Based on the Voigt Regularization

    CERN Document Server

    Larios, Adam; Titi, Edriss S; Wingate, Beth

    2015-01-01

    We report the results of a computational investigation of two recently proved blow-up criteria for the 3D incompressible Euler equations. These criteria are based on an inviscid regularization of the Euler equations known as the 3D Euler-Voigt equations. The latter are known to be globally well-posed. Moreover, simulations of the 3D Euler-Voigt equations also require less resolution than simulations of the 3D Euler equations for fixed values of the regularization parameter $\\alpha>0$. Therefore, the new blow-up criteria allow one to gain information about possible singularity formation in the 3D Euler equations indirectly; namely, by simulating the better-behaved 3D Euler-Voigt equations. The new criteria are only known to be sufficient criteria for blow-up. Therefore, to test the robustness of the inviscid-regularization approach, we also investigate analogous criteria for blow-up of the 1D Burgers equation, where blow-up is well-known to occur.

  12. Research on Alkaline Filler Flame-Retarded Asphalt Pavement

    Institute of Scientific and Technical Information of China (English)

    HU Shuguang; ZHANG Houji; WANG Jiaolan

    2006-01-01

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

  13. Development of Improved Mechanistic Deterioration Models for Flexible Pavements

    DEFF Research Database (Denmark)

    Ullidtz, Per; Ertman, Hans Larsen

    1998-01-01

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

  14. Morphological Algorithms For The Analysis Of Pavement Structure

    Science.gov (United States)

    Grivas, Dimitri A.; Skolnick, Michael M.

    1989-11-01

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

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

    OpenAIRE

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

    2015-01-01

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

  16. Effect of Pavement Conditions on Rolling Resistance

    Directory of Open Access Journals (Sweden)

    Mr.Dipanjan Mukherjee

    2014-07-01

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

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

    Science.gov (United States)

    Clark, Peter U.

    1991-05-01

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

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

    Science.gov (United States)

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

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

  19. Ground Penetrating Radar Assessment of Flexible Road Pavement Degradation

    OpenAIRE

    Sandro Colagrande; Danilo Ranalli; Marco Tallini

    2011-01-01

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

  20. Field environmental evaluation plan for sulfur use in pavements

    Science.gov (United States)

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

    1982-07-01

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

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

    Directory of Open Access Journals (Sweden)

    Jay N. Meegoda

    2015-12-01

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

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

    Science.gov (United States)

    1990-12-01

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

  3. Development of New Bituminous Pavement Design Method

    DEFF Research Database (Denmark)

    Ullidtz, Per

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

  4. Pavement Response to Variable Tyre Pressure of Heavy Vehicles

    Directory of Open Access Journals (Sweden)

    Arshad Ahmad Kamil

    2016-01-01

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

  5. Numerical Analysis of Asphalt Pavements under Moving Wheel Loads

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

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

  6. SELF-SIMILAR SOLUTIONS AND BLOW-UP PHENOMENA FOR A TWO-COMPONENT SHALLOW WATER SYSTEM

    Institute of Scientific and Technical Information of China (English)

    Shouming ZHOU; Chunlai MU; Liangchen WANG

    2013-01-01

    In this article,we consider a two-component nonlinear shallow water system,which includes the famous 2-component Camassa-Holm and Degasperis-Procesi equations as special cases.The local well-posedess for this equations is established.Some sufficient conditions for blow-up of the solutions in finite time are given.Moreover,by separation method,the self-similar solutions for the nonlinear shallow water equations are obtained,and which local or global behavior can be determined by the corresponding Emden equation.

  7. Estimates for the resolvent kernel of the Laplacian on p.c.f. self similar fractals and blowups

    CERN Document Server

    Rogers, Luke G

    2010-01-01

    We provide a method for obtaining upper estimates of the resolvent kernel of the Laplacian on a post-critically finite self-similar fractal that relies on a self-similar series decomposition of the resolvent. Decay estimates on the positive real axis are proved by analyzing functions satisfying an interior eigenfunction condition with positive eigenvalue. These lead to estimates on the complement of the negative real axis via the Phragmen-Lindelof theorem. Applications are given to kernels for functions of the Laplacian, including the heat kernel, and to proving the existence of a self-similar series decomposition for the Laplacian resolvent on fractal blowups.

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

    Science.gov (United States)

    2007-04-01

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

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

    Science.gov (United States)

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

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

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

    Science.gov (United States)

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

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

    Science.gov (United States)

    2013-09-01

    emergency or contingency airfield opera - tions. This report presents the results of accelerated pavement testing including the passes-to-failure, surface...9-in.-diam Geokon® earth pressure cells (EPC) capable of measuring up to 200 psi that were installed at the base-PCC interface at 10 locations as...Center deflections. 0 10 20 30 40 50 60 70 80 90 100 0 1000 2000 3000 4000 5000 6000 7000 8000 9000 10000 N or m al ize d  De fle ct io n,  m ils

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

    Science.gov (United States)

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

    2014-06-15

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

  13. Pavement Evaluation and Maintenance Decisions Based on Fuzzy Inference Systems

    Directory of Open Access Journals (Sweden)

    Beltrán-Calvo Gloria Inés

    2014-07-01

    Full Text Available The remaining service life and maintenance decisions of existing pavements are highly dependent on stiffness and deterioration conditions throughout their operation. A non-conventional fuzzy logic based methodology is proposed in this work to address the stiffness-deterioration condition and conservation decisions, by means of three Fuzzy Inference Systems. Analysis were conducted using a database gathered from field tests performed on three and four layer pavement systems, that included traditional layer structuring and pavements having a subbase stiffer than their granular base. Information about layer thicknesses, magnitude and severity of structural distresses, and parameters and indicators derived from deflection testing by impulse load devices were used. The developed systems, allowed representing expert knowledge and linguistic variables of subjective and qualitative nature, commonly used to describe the severity levels of deterioration; thus they can be involved into structural characterization of pavements. Results were also expressed linguistically, to facilitate their interpretation and understanding. Based on the high quality of results obtained, it seems reasonable to conclude that the proposed systems could be used confidently for assessing and making decisions about pavement conservation, with low computational cost.

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

    Directory of Open Access Journals (Sweden)

    Ding Fei

    2017-01-01

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

  15. Acoustical estimation of parameters of porous road pavement

    Science.gov (United States)

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

    2012-11-01

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

  16. RAPID INSPECTION OF PAVEMENT MARKINGS USING MOBILE LIDAR POINT CLOUDS

    Directory of Open Access Journals (Sweden)

    H. Zhang

    2016-06-01

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

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

    Science.gov (United States)

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

    2016-06-01

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

  18. Determination of Pavement Rehabilitation Activities through a Permutation Algorithm

    Directory of Open Access Journals (Sweden)

    Sangyum Lee

    2013-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

    Zornberg, J. G.

    2014-02-01

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

  20. Evaluation of Common Maintenance Methods for Flexible Pavements

    Directory of Open Access Journals (Sweden)

    Asma T. Ibraheem

    2011-01-01

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

  1. Cold Region Pavements%寒区路面

    Institute of Scientific and Technical Information of China (English)

    GuyDore

    2002-01-01

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

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

    Science.gov (United States)

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

    2006-01-01

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

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

    Science.gov (United States)

    Scholer, C. F.

    1980-12-01

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

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

    Directory of Open Access Journals (Sweden)

    Huaping Wang

    2014-05-01

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

  5. Bearing capacity evaluation of rubblized concrete pavements

    Directory of Open Access Journals (Sweden)

    González, M.

    2009-03-01

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

  6. Phenomena of Blowup and Global Existence of the Solution to a Nonlinear Schrödinger Equation

    Directory of Open Access Journals (Sweden)

    Xiaowei An

    2013-01-01

    Full Text Available We consider the following Cauchy problem: -iut=Δu-V(xu+f(x,|u|2u+(W(x⋆|u|2u, x∈ℝN,t>0, u(x, 0=u0(x,x∈ℝN, where V(x and W(x are real-valued potentials and V(x≥0 and W(x is even, f(x,|u|2 is measurable in x and continuous in |u|2, and u0(x is a complex-valued function of x. We obtain some sufficient conditions and establish two sharp thresholds for the blowup and global existence of the solution to the problem.

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

    Directory of Open Access Journals (Sweden)

    Isamu Yoshitake

    2015-08-01

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

  8. Evaluating Pavement Cracks with Bidimensional Empirical Mode Decomposition

    Directory of Open Access Journals (Sweden)

    Nii Attoh-Okine

    2008-05-01

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

  9. Ground Penetrating Radar Assessment of Flexible Road Pavement Degradation

    Directory of Open Access Journals (Sweden)

    Sandro Colagrande

    2011-01-01

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

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

    NARCIS (Netherlands)

    Ren, D.

    2015-01-01

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

  11. Nitrogen Transformations in Three Types of Permeable Pavement

    Science.gov (United States)

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

  12. Representative volume element of asphalt pavement for electromagnetic measurements

    Directory of Open Access Journals (Sweden)

    Terhi Pellinen

    2015-02-01

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

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

    Science.gov (United States)

    Rajbongshi, Pabitra; Thongram, Sonika

    2016-09-01

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

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

    NARCIS (Netherlands)

    Huurman, M.

    1996-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Er. Devendra Kumar Choudhary

    2014-06-01

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

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

    OpenAIRE

    Simonas Tamaliūnas; Henrikas Sivilevičius

    2011-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Simonas Tamaliūnas

    2011-04-01

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

  18. Nutrient infiltrate concentrations from three permeable pavement types.

    Science.gov (United States)

    Brown, Robert A; Borst, Michael

    2015-12-01

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

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

    Directory of Open Access Journals (Sweden)

    Rong-xia Xia

    2015-01-01

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

  20. Predicting physical clogging of porous and permeable pavements

    Science.gov (United States)

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

    2013-02-01

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

  1. Recent rubber crumb asphalt pavement projects in Alberta

    Energy Technology Data Exchange (ETDEWEB)

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

    2003-07-01

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

  2. Blow-up of Solution for the Nonlinear Sobolev-Galpern Equation%非线性Sobolev-Galpern型方程解的Blow-up性质

    Institute of Scientific and Technical Information of China (English)

    张恩彪; 江成顺

    2009-01-01

    In this paper,the initial boundary value problems of the nonlinear Sobolev Galpern equation are studied.The existence,uniqueness of local solution for the problem are obtained by means of a special Green's function and the contraction mapping principle.Finally,the blow-up of solution in finite time under some assumed conditions is proved with the aid of Jensen's inequality.

  3. On the blow-up criterion of strong solutions for the MHD equations with the Hall and ion-slip effects in R3}

    Science.gov (United States)

    Gala, Sadek; Ragusa, Maria Alessandra

    2016-04-01

    In this paper, we establish a blow-up criterion of strong solutions to the 3D incompressible magnetohydrodynamics equations including two nonlinear extra terms: the Hall term (quadratic with respect to the magnetic field) and the ion-slip term (cubic with respect to the magnetic field). This is an improvement of the recent results given by Fan et al. (Z Angew Math Phys, 2015).

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

    Science.gov (United States)

    Brattebo, Benjamin O; Booth, Derek B

    2003-11-01

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

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

    Directory of Open Access Journals (Sweden)

    Yingwei Ren

    2014-01-01

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

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

    Science.gov (United States)

    2015-03-27

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

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

    Science.gov (United States)

    2010-06-01

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

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

    OpenAIRE

    Chen Zhang; Hainian Wang; Zhanping You; Biao Ma

    2015-01-01

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

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

    OpenAIRE

    Foye, Kevin C.

    2011-01-01

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

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

    Science.gov (United States)

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

    2010-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Sylvie Chambon

    2011-01-01

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

  12. Investigations of the dynamics of road pavement reflectance

    Institute of Scientific and Technical Information of China (English)

    Kang Jiang; Kai Yu; Yongchao Zhao

    2012-01-01

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

  13. Mechanical Properties of Asphalt Pavement Structure in Highway Tunnel

    Institute of Scientific and Technical Information of China (English)

    SHI Chun-xiang; GUO Zhong-yin

    2008-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Myle N. James

    2011-01-01

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

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

    Science.gov (United States)

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

    2015-12-01

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

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

    Science.gov (United States)

    1994-08-01

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

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

    OpenAIRE

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

    2007-01-01

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

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

    Institute of Scientific and Technical Information of China (English)

    Yuan Goulin; Chen Rongshen

    2006-01-01

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

  19. The Research on the Cracks of the Asphalt Pavement

    Directory of Open Access Journals (Sweden)

    OuYangZiqiang

    2015-07-01

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

  20. Pavement wear and airborne dust pollution in Norway

    OpenAIRE

    Snilsberg, Brynhild

    2008-01-01

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

  1. Evaluation of Nontraditional Airfield Pavement Surfaces for Contingency Operations

    Science.gov (United States)

    2014-01-01

    a layer of single -sized coarse aggregate, followed by vibrating fine aggregates, into the voids (dry-bound macadam) or using water to flush the... single surface treatment application is called a single bituminous surface treatment or chip seal and, when two or more successive layers of single ...Stabilized layer failure In evaluating a macadam or surface-treated pavement , if the binder no longer holds the aggregate in place (usually due to

  2. DYNAMIC JOINT LOAD TRANSFER EFFICIENCY OF RIGID PAVEMENT

    Directory of Open Access Journals (Sweden)

    YU Xinhua

    2011-02-01

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

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

    Science.gov (United States)

    1990-10-01

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

  4. Evaluation of Procedures for Backcalculation of Airfield Pavement Moduli

    Science.gov (United States)

    2015-08-01

    94/11. McLean, VA: U.S. Department of Transportation , Federal Highway Administration (FHWA). ERDC/GSL TR-15-31 143 Lytton, R.L. 1989...compared to processes utilized by other transportation agencies and those proposed by academia. Airfield deflection data were then analyzed using current...aircraft. As tire pressures and aircraft weights have increased steadily during this time, the design and evaluation software– Pavement- Transportation

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

    Institute of Scientific and Technical Information of China (English)

    TANG Zuquan; QIAN Jueshi; LI Zhuoqiu; WU Chuanming

    2006-01-01

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

  6. EVALUATION OF TIRE RUBBER DISPOSAL IN CONCRETE FOR PAVEMENTS

    Directory of Open Access Journals (Sweden)

    Rosa Cristina Cecche Lintz

    2009-12-01

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

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

    Directory of Open Access Journals (Sweden)

    Fidelis O. OKAFOR

    2010-12-01

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

  8. EVALUATION OF TIRE RUBBER DISPOSAL IN CONCRETE FOR PAVEMENTS

    Directory of Open Access Journals (Sweden)

    Rosa Cristina Cecche Lintz

    2009-01-01

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

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

    Science.gov (United States)

    Fullová, Daša; Đurčanská, Daniela

    2016-12-01

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

  10. Numerical Simulation of Moving Load on Concrete Pavements

    Directory of Open Access Journals (Sweden)

    Lajčáková Gabriela

    2015-06-01

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

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

    Directory of Open Access Journals (Sweden)

    Mubaraki Muhammad

    2016-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Fullová Daša

    2016-12-01

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

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

    Directory of Open Access Journals (Sweden)

    Paulo Boulos Filho

    2016-07-01

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

  14. Global Existence and Finite Time Blow-Up for Critical Patlak-Keller-Segel Models with Inhomogeneous Diffusion

    CERN Document Server

    Bedrossian, Jacob

    2011-01-01

    The $L^1$-critical parabolic-elliptic Patlak-Keller-Segel system is a classical model of chemotactic aggregation in micro-organisms well-known to have critical mass phenomena. In this paper we study this critical mass phenomenon in the context of Patlak-Keller-Segel models with spatially varying diffusivity and decay rate of the chemo-attractant. The primary tool for the proof of global existence below the critical mass is the use of pseudo-differential operators to precisely evaluate the leading order quadratic portion of the potential energy (interaction energy). Under the assumption of radial symmetry, blow-up is proved above critical mass using a maximum-principle type argument based on comparing the mass distribution of solutions to a barrier consisting of the unique stationary solutions of the scale-invariant PKS. Although effective where standard Virial methods do not apply, this method seems to be dependent on the assumption of radial symmetry. For technical reasons we work in dimensions three and hig...

  15. Investigation of mechanical properties of pavement through electromagnetic techniques

    Science.gov (United States)

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

    2014-05-01

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

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

    Science.gov (United States)

    Eyles, C. H.

    1994-01-01

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

  17. 76 FR 67018 - Notice to Manufacturers of Airport In-Pavement Stationary Runway Weather Information Systems

    Science.gov (United States)

    2011-10-28

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

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

    Science.gov (United States)

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

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

    Science.gov (United States)

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

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

    Science.gov (United States)

    Dave, Eshan V.

    2009-01-01

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

  1. 23 CFR 973.208 - Indian lands pavement management system (PMS).

    Science.gov (United States)

    2010-04-01

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

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

    Science.gov (United States)

    1991-06-01

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

  3. 23 CFR 970.208 - Federal lands pavement management system (PMS).

    Science.gov (United States)

    2010-04-01

    ... 23 Highways 1 2010-04-01 2010-04-01 false Federal lands pavement management system (PMS). 970.208... Federal lands pavement management system (PMS). In addition to the requirements provided in § 970.204, the..., surface type, or other criteria the NPS deems appropriate. (c) The PMS shall be designed to fit the...

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

    NARCIS (Netherlands)

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

    2016-01-01

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

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

    NARCIS (Netherlands)

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

    2014-01-01

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

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

    Science.gov (United States)

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

    2013-06-01

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

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

    Directory of Open Access Journals (Sweden)

    Saurabh Jain

    2013-09-01

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

  8. 78 FR 26847 - Including Specific Pavement Types in Federal-aid Highway Traffic Noise Analyses

    Science.gov (United States)

    2013-05-08

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

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

    Science.gov (United States)

    Ahsanuzzaman, Md

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

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

    Science.gov (United States)

    Pate, John S.; Verboom, William H.

    2009-01-01

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

  11. Road Edge of Pavement, Edge of Pavement - polygon digitized by Furgro Earthdata, Published in 2008, 1:2400 (1in=200ft) scale, Effingham County Board Of Commissioners.

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — This Road Edge of Pavement dataset, published at 1:2400 (1in=200ft) scale, was produced all or in part from Orthoimagery information as of 2008. It is described as...

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

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Evaluation of pavement performance is one of the most important issues in a pavement-management system.By employing the concept of entropy,the matter-element model for evaluating pavement is established,and the weights of the evaluation indices are obtained from surveying data.By calculating the degree of dependence of the matter-element model,the pavement performance evaluation can be obtained by this method.The results show that the matter-element model based on entropy right has good performance for evaluating the pavement condition in permafrost region.

  13. Assessment of porous asphalt pavement performance: hydraulics and water quality

    Science.gov (United States)

    Briggs, J. F.; Ballestero, T. P.; Roseen, R. M.; Houle, J. J.

    2005-05-01

    The objective of this study is to focus on the water quality treatment and hydraulic performance of a porous asphalt pavement parking lot in Durham, New Hampshire. The site was constructed in October 2004 to assess the suitability of porous asphalt pavement for stormwater management in cold climates. The facility consists of a 4-inch asphalt open-graded friction course layer overlying a high porosity sand and gravel base. This base serves as a storage reservoir in-between storms that can slowly infiltrate groundwater. Details on the design, construction, and cost of the facility will be presented. The porous asphalt pavements is qualitatively monitored for signs of distress, especially those due to cold climate stresses like plowing, sanding, salting, and freeze-thaw cycles. Life cycle predictions are discussed. Surface infiltration rates are measured with a constant head device built specifically to test high infiltration capacity pavements. The test measures infiltration rates in a single 4-inch diameter column temporarily sealed to the pavement at its base. A surface inundation test, as described by Bean, is also conducted as a basis for comparison of results (Bean, 2004). These tests assess infiltration rates soon after installation, throughout the winter, during snowmelt, after a winter of salting, sanding, and plowing, and after vacuuming in the spring. Frost penetration into the subsurface reservoir is monitored with a frost gauge. Hydrologic effects of the system are evaluated. Water levels are monitored in the facility and in surrounding wells with continuously logging pressure transducers. The 6-inch underdrain pipe that conveys excess water in the subsurface reservoir to a riprap pad is also continuously monitored for flow. Since porous asphalt pavement systems infiltrate surface water into the subsurface, it is important to assess whether water quality treatment performance in the subsurface reservoir is adequate. The assumed influent water quality is

  14. Rutting Prediction in Asphalt Pavement Based on Viscoelastic Theory

    Directory of Open Access Journals (Sweden)

    Nahi Mohammed Hadi

    2016-01-01

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

  15. Numerical modeling of inelastic structures at loading of steady state rolling. Thermo-mechanical asphalt pavement computation

    Science.gov (United States)

    Wollny, Ines; Hartung, Felix; Kaliske, Michael

    2016-05-01

    In order to gain a deeper knowledge of the interactions in the coupled tire-pavement-system, e.g. for the future design of durable pavement structures, the paper presents recent results of research in the field of theoretical-numerical asphalt pavement modeling at material and structural level, whereby the focus is on a realistic and numerically efficient computation of pavements under rolling tire load by using the finite element method based on an Arbitrary Lagrangian Eulerian (ALE) formulation. Inelastic material descriptions are included into the ALE frame efficiently by a recently developed unsplit history update procedure. New is also the implementation of a viscoelastic cohesive zone model into the ALE pavement formulation to describe the interaction of the single pavement layers. The viscoelastic cohesive zone model is further extended to account for the normal pressure dependent shear behavior of the bonding layer. Another novelty is that thermo-mechanical effects are taken into account by a coupling of the mechanical ALE pavement computation to a transient thermal computation of the pavement cross-section to obtain the varying temperature distributions of the pavement due to climatic impact. Then, each ALE pavement simulation considers the temperature dependent asphalt material model that includes elastic, viscous and plastic behavior at finite strains and the temperature dependent viscoelastic cohesive zone formulation. The temperature dependent material parameters of the asphalt layers and the interfacial layers are fitted to experimental data. Results of coupled tire-pavement computations are presented to demonstrate potential fields of application.

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

    OpenAIRE

    1996-01-01

    Concrete block pavements (c.b.p.) commonly consist of concrete blocks placed over a granular substructure. As a result of wheel load passages permanent strains will slowly develop in the substructure and cause rutting. This paper is about the prediction of the permanent strain development in the substructure and the associated rutting on the basis of the results of repeated load triaxial tests and analytical models. By discussing the behaviour of three c.b.p.'s it is shown that insight into c...

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

    DEFF Research Database (Denmark)

    Bendixen, Søren; Stang, Henrik

    1996-01-01

    -crack opening relationship can beused to descibe the properties of fibre reinforced concrete (FRC) intension and how the stress-crack opening relationship can beapplied in a simple design scheme for pavements. The projectincludes development of design tools, experiments to determine thestress-crack opening......The paper summarises a Ph.D. project on development of a new design basis for fibre reinforced concrete ground slabs. The stress-crack openingrelationship is a well know basic material property of theso-called fictitious crack model for concrete. In the presentstudy it is shown how the stress...

  18. Effects of cross-anisotropy and stress-dependency of pavement layers on pavement responses under dynamic truck loading

    Directory of Open Access Journals (Sweden)

    Rafiqul A. Tarefder

    2016-06-01

    Full Text Available Previous studies by the authors have determined pavement responses under dynamic loading considering cross-anisotropy in one layer only, either the cross-anisotropic viscoelastic asphalt concrete (AC layer or the cross-anisotropic stress-dependent base layer, but not both. This study evaluates pavement stress–strain responses considering cross-anisotropy in all layers, i.e. AC, base and subbase, using finite element modeling (FEM technique. An instrumented pavement section on Interstate I-40 near Albuquerque, New Mexico was used in ABAQUS framework as model geometry. Field asphalt cores were collected and tested in the laboratory to determine the cross-anisotropy (n-values defined by horizontal to vertical modulus ratio, and other viscoelastic parameters as inputs of the model incorporated through user defined material interface (UMAT functionality in ABAQUS. Field base and subbase materials were also collected and tested in the laboratory to determine stress-dependent nonlinear elastic model parameters, as inputs of the model, again incorporated through UMAT. The model validation task was carried out using field-measured deflections and strain values under falling weight deflectometer (FWD loads at the instrumented section. The validated model was then subjected to an actual truck loading for studying cross-anisotropic effects. It was observed that horizontal tensile strain at the bottom of the AC layer and vertical strains in all layers decreased with an increase in n-value of the asphalt layer, from n < 1 (anisotropy to n=1 (isotropy. This indicates that the increase in horizontal modulus caused the decrease in layer strains. It was also observed that if the base and subbase layers were considered stress-dependent instead of linear elastic unbound layers, the horizontal tensile strain at the bottom of the asphalt layer increased and vertical strains on top of the base and subbase also increased.

  19. Effects of cross-anisotropy and stress-dependency of pavement layers on pavement responses under dynamic truck loading

    Institute of Scientific and Technical Information of China (English)

    Rafiqul A. Tarefder; Mesbah U. Ahmed; Asifur Rahman

    2016-01-01

    Previous studies by the authors have determined pavement responses under dynamic loading consid-ering cross-anisotropy in one layer only, either the cross-anisotropic viscoelastic asphalt concrete (AC) layer or the cross-anisotropic stress-dependent base layer, but not both. This study evaluates pavement stressestrain responses considering cross-anisotropy in all layers, i.e. AC, base and subbase, using finite element modeling (FEM) technique. An instrumented pavement section on Interstate I-40 near Albu-querque, New Mexico was used in ABAQUS framework as model geometry. Field asphalt cores were collected and tested in the laboratory to determine the cross-anisotropy (n-values) defined by horizontal to vertical modulus ratio, and other viscoelastic parameters as inputs of the model incorporated through user defined material interface (UMAT) functionality in ABAQUS. Field base and subbase materials were also collected and tested in the laboratory to determine stress-dependent nonlinear elastic model pa-rameters, as inputs of the model, again incorporated through UMAT. The model validation task was carried out using field-measured deflections and strain values under falling weight deflectometer (FWD) loads at the instrumented section. The validated model was then subjected to an actual truck loading for studying cross-anisotropic effects. It was observed that horizontal tensile strain at the bottom of the AC layer and vertical strains in all layers decreased with an increase in n-value of the asphalt layer, from n<1 (anisotropy) to n ¼ 1 (isotropy). This indicates that the increase in horizontal modulus caused the decrease in layer strains. It was also observed that if the base and subbase layers were considered stress-dependent instead of linear elastic unbound layers, the horizontal tensile strain at the bottom of the asphalt layer increased and vertical strains on top of the base and subbase also increased.

  20. Sustainable Development Factors in Pavement Life-Cycle: Highway/Airport Review

    Directory of Open Access Journals (Sweden)

    Peyman Babashamsi

    2016-03-01

    Full Text Available Sustainability has gained as much importance as management in business. Sustainable pavement development as a business practice should involve making evaluations according to the triple bottom line in the pavement life-cycle. Despite the current approaches to evaluating the social as well as economic and environmental feasibility of pavement projects (involving highway and airport infrastructure, there has recently been a lack of consensus on a methodology to guarantee sustainability upon assessment and analysis during the pavement life-cycle. As sustainability is a complex issue, this study intends to further explore sustainability and elaborate on its meaning. The second step involves a general depiction of the major sustainability appraisal tools, namely cost-benefit analysis, life-cycle cost analysis, life-cycle assessment, multi-criteria decision-making, environmental impact assessment and social life-cycle assessment, and an explanation of their cons and pros. Subsequently, the article addresses the application of an organized methodology to highlight the main factors or concepts that should be applied in sustainable pavement development and, more specifically, in sustainable pavement management. In the final step, research recommendations toward sustainability are given. This study is aimed to assist decision-makers in pavement management to plan sustainability frameworks in accordance with probable boundaries and restrictions.

  1. Dynamic considerations in pavement layers moduli evaluation using falling weight deflectometer

    Science.gov (United States)

    Shoukry, Samir N.; Martinelli, David R.; Selezneva, Olga I.

    1996-11-01

    Falling weight deflectometer (FWD) test is employed by many state highway agencies for the nondestructive evaluation of pavement layers moduli. The accuracy of test results changes significantly for different pavement systems and may results in misleading conclusions. In this study, explicit finite element analysis was used to investigate the behavior of pavement layers under the action of an impact load. The time dependent dynamic responses of origin and flexible pavements were compared and significant differences in behavior were observed. Analysis of the time-histories of vertical deformations propagating through the pavement depth reveals that the displacements measured on the surface layer at standard FWD sensors' positions may not be indicative of the displacements of underlying layers. Computer results are provided for the extreme cases of fully bonded and unbonded pavement layers' interfaces. The results of the analysis reveal that the dynamic displacement patterns are much more complicated than the static ones. Animation of the model results indicates that near-surface pavement layers may behave as a set of composite plates resting on an elastic foundation in absence of bonds between the layers interfaces. If there are strong bonds, the near surface layers behave as a single composite solid resting on elastic foundation.

  2. Analytical prediction and field validation of transient temperature field in asphalt pavements

    Institute of Scientific and Technical Information of China (English)

    陈嘉祺; 李亮; 汪浩

    2015-01-01

    This work presented the development and validation of an analytical method to predict the transient temperature field in the asphalt pavement. The governing equation for heat transfer was based on heat conduction radiation and convection. An innovative time-dependent function was proposed to predict the pavement surface temperature with solar radiation and air temperature using dimensional analysis in order to simplify the complex heat exchange on the pavement surface. The parameters for the time-dependent pavement surface temperature function were obtained through the regression analysis of field measurement data. Assuming that the initial pavement temperature distribution was linear and the influence of the base course materials on the temperature of the upper asphalt layers was negligible, a close-form analytical solution of the temperature in asphalt layers was derived using Green’s function. Finally, two numerical examples were presented to validate the model solutions with field temperature measurements. Analysis results show that the solution accuracy is in agreement with field data and the relative errors at a shallower depth are greater than those at a deeper one. Although the model is not sensitive to dramatic changes in climatic factors near the pavement surface, it is applicable for predicting pavement temperature field in cloudless days.

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

    Science.gov (United States)

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

    2016-03-22

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

  4. Investigating the Effects of "Cool" Solar Reflective Pavements on California Climate

    Science.gov (United States)

    Mohegh, M.; Ban-Weiss, G. A.; Levinson, R.; Rosado, P.

    2015-12-01

    Implementing "Cool pavement" is a local mitigation strategy that can reduce urban heat islands. We investigated the climate impacts of widespread deployment of cool pavements by increasing the albedo of the pavements from 0.1 to 0.5 to understand the efficiency of cool pavements in reducing the temperature in California's urban areas. A validated parameterization of WRF model coupled with Single Layer Urban Canopy Model (SLUCM) is employed to simulate the effects of pavements at the bottom of canopy on urban heat islands. The results show local surface air temperature reductions, peaking at late morning and late evening which coincides with the lowest boundary layer height in the day time. Summer time temperature reductions up to 0.62 K in the evening (20:00 local) and 0.32 K in afternoon (14:00) in California are predicted. The cooling effects of 15 cities in California are sampled and analyzed. The average temperature reductions for the cities in California show 0.32 K temperature reduction per 0.1 total albedo reduction in the afternoon (14:00) which is consistent with the previous works. The linear relation between temperature reductions and the albedo increase is used to estimate the effect of cool pavements in "No Canopy" state, which can be used as an upper bound of the effects of cool pavements.

  5. Determination of allowable subgrade frost heave with the pavement roughness index in numerical analysis

    Institute of Scientific and Technical Information of China (English)

    HongYan Ma; Feng Zhang; DeCheng Feng; Bo Lin

    2015-01-01

    Frost heave is an upward swelling of soil during cryogenic conditions in cold regions. It is caused by the accumulation of ice crystals in subgrade soil, which grow upwards when freezing temperatures penetrate into the subgrade. This study establishes the allowable soil subgrade frost heave based on the roughness standard of asphalt pavement in China, and aims to balance the pavement design and frost heave resistance of subgrades in cold regions. We formulated a mechanical model of pavement supported by the boundary conditions of differential frost heave, based on the elastic layered system theory. The differential soil subgrade frost heave was modeled as a sinusoidal function, and the allowable frost heave and the roughness index were modeled as the displacement boundaries for the top and bottom of the pavement structure. Then the allowable frost heave was back-calculated according to the roughness standard. Numerical results show that the allowable frost heave depends on the pavement structure, material properties, the highway grade, and other factors. In order to ensure that the actual soil subgrade frost heave is lower than the allowable frost heave, pavement structures and materials need to be selected and designed carefully. The numerical method proposed here can be applied to establish the frost heave re-sistance of subgrade when the pavement structure and materials are determined.

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

    Directory of Open Access Journals (Sweden)

    Ali Reza Ghanizadeh

    2016-01-01

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

  7. Symmetry-plane model of 3D Euler flows and mapping to regular systems to improve blowup assessment using numerical and analytical solutions

    CERN Document Server

    Mulungye, Rachel M; Bustamante, Miguel D

    2014-01-01

    Motivated by the work on stagnation-point type exact solutions (with infinite energy) of 3D Euler fluid equations by Gibbon et al. (1999) and the subsequent demonstration of finite-time blowup by Constantin (2006) we introduce a one-parameter family of models of the 3D Euler fluid equations on a 2D symmetry plane. Our models are seen as a deformation of the 3D Euler equations which respects the variational structure of the original equations so that explicit solutions can be found for the supremum norms of the basic fields. The value of the model's parameter determines if there is finite-time blowup, and the singularity time can be computed explicitly in terms of the initial conditions and the model's parameter. We use a representative parameter value, for which the solution blows up in finite-time, as a benchmark for the systematic study of errors in numerical solutions. We compare numerical integrations of our "original" model with a "mapped" version of these equations. The mapped version is a globally regu...

  8. 可压缩反应气体模型的一致爆破率%Uniform Blow-Up Rate for a Compressible Reactive Gas Model

    Institute of Scientific and Technical Information of China (English)

    徐润章; 姜晓丽; 刘杰

    2012-01-01

    研究一类带有非线性非局部源项的可压缩反应气体模型方程的Dirichlet初始边界值问题.在一些假设条件下,证明了爆破率在有界域的所有紧子集中是一致的,并且证明了爆破率只与非线性非局部源的指数有关,而与扩散项的指数无关.%The Dirichlet initial-boundary value problem of a compressible reactive gas model equation with nonlocal nonlinear source term was studied. For certain conditions, it is proved that the blow-up rate is uniform in all compact subsets of the domain and the blow-up rate is irrelative to the exponent of the diffusion term, but relative to the exponent of the nonlocal nonlinear source.

  9. Sustainable Drainage Practices in Spain, Specially Focused on Pervious Pavements

    Directory of Open Access Journals (Sweden)

    Jorge Rodriguez-Hernandez

    2013-01-01

    Full Text Available The Spanish climate is full of contrasts, with torrential rains and long droughts; under these conditions, appropriate water management is essential. In Spain, until the end of the twentieth century, water management and legislative development lagged behind other more developed countries. Nowadays, great efforts are being made to reverse this situation and improve both water management and legislation in order to control the two main problems related to stormwater management in cities: floods and diffuse pollution. In this context, Sustainable Urban Drainage Systems (SUDS were developed as the main solution to these problems. The study of these techniques started in the 1970s in the USA, but they were not studied in Spain until 1993 when the University of Cantabria and CLABSA started to look into solutions for stormwater management. After 20 years of research and application, sustainable drainage in Spain is still behind other countries in spite of the efforts to change this situation, notably by the University of Cantabria with 10 years of experience in these techniques, mainly regarding pervious pavements, where more than 13 related research projects have been carried out. The future challenges focus on the application of pervious pavements for Urban Hydrological Rehabilitation.

  10. ESTIMATION OF THE CONCRETE PAVEMENT TEMPERATURE FIELDS AND THEIR GRADIENTS

    Directory of Open Access Journals (Sweden)

    M. K. Pshembaev

    2015-01-01

    Full Text Available The heat fluxes impact on the road-dressing concrete surfacing under different regions climatic conditions of the construction and maintenance dramatically degrades their solidity, corroding-, shiftingand frost-resistance, and ultimately – the service durability. The source of deformation processes is the character of the gradient temperature fields in the road dressing materials developing with both protracted (static and short run (dynamic heat-and-mass impacts that forward destruction of the pavement surface layers being in contact with free air. In addition, pulsating hydrodynamic pressures appear in the pores of moisture-laden pavement as a result of the vehicular traffic that foster material structure disruption of the surface layers leading to irreversible deformation incipiency (cracks etc.. The authors report of developing a С++ computer program for temperature and gradient fields engineering evaluations of the road dressings made of materials with various surfacing and free-air thermophysical characteristics in line with boundary conditions of the 3rd kind for semi-bounded body. The paper presents the evaluation results in form of graphical curves of the temperature allocation along the surfacing thickness as function of its initial temperature and thermophysical characteristics of the concrete. 

  11. Permeable pavement and stormwater management systems: a review.

    Science.gov (United States)

    Imran, H M; Akib, Shatirah; Karim, Mohamed Rehan

    2013-01-01

    Uncontrolled stormwater runoff not only creates drainage problems and flash floods but also presents a considerable threat to water quality and the environment. These problems can, to a large extent, be reduced by a type of stormwater management approach employing permeable pavement systems (PPS) in urban, industrial and commercial areas, where frequent problems are caused by intense undrained stormwater. PPS could be an efficient solution for sustainable drainage systems, and control water security as well as renewable energy in certain cases. Considerable research has been conducted on the function of PPS and their improvement to ensure sustainable drainage systems and water quality. This paper presents a review of the use of permeable pavement for different purposes. The paper focuses on drainage systems and stormwater runoff quality from roads, driveways, rooftops and parking lots. PPS are very effective for stormwater management and water reuse. Moreover, geotextiles provide additional facilities to reduce the pollutants from infiltrate runoff into the ground, creating a suitable environment for the biodegradation process. Furthermore, recently, ground source heat pumps and PPS have been found to be an excellent combination for sustainable renewable energy. In addition, this study has identified several gaps in the present state of knowledge on PPS and indicates some research needs for future consideration.

  12. Wavelet-based pavement image compression and noise reduction

    Science.gov (United States)

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

    2005-08-01

    For any automated distress inspection system, typically a huge number of pavement images are collected. Use of an appropriate image compression algorithm can save disk space, reduce the saving time, increase the inspection distance, and increase the processing speed. In this research, a modified EZW (Embedded Zero-tree Wavelet) coding method, which is an improved version of the widely used EZW coding method, is proposed. This method, unlike the two-pass approach used in the original EZW method, uses only one pass to encode both the coordinates and magnitudes of wavelet coefficients. An adaptive arithmetic encoding method is also implemented to encode four symbols assigned by the modified EZW into binary bits. By applying a thresholding technique to terminate the coding process, the modified EZW coding method can compress the image and reduce noise simultaneously. The new method is much simpler and faster. Experimental results also show that the compression ratio was increased one and one-half times compared to the EZW coding method. The compressed and de-noised data can be used to reconstruct wavelet coefficients for off-line pavement image processing such as distress classification and quantification.

  13. Detection of asphalt pavement cracks using remote sensing techniques

    Science.gov (United States)

    Mettas, Christodoulos; Agapiou, Athos; Themistocleous, Kyriacos; Neocleous, Kyriacos; Hadjimitsis, Diofantos G.

    2016-10-01

    Deterioration of asphalt road pavements is inevitable throughout its life cycle. There are several types of deterioration that take place on these surfaces, like surface defects and deformations. One of the most common asphalt defects is cracking. Fatigue, transverse, longitudinal, reflective, edge, block and slippage are types of cracking that can be observed anywhere in the world. Monitoring and preventative/periodic maintenance of these types of wears are two very important actions that have to take place to avoid "costly" solutions. This paper aims to introduce the spectral characteristics of uncracked (healthy) and cracked asphalt surfaces which can give a new asphalt crack index. This is performed through remote sensing applications in the area of asphalt pavements. Multispectral images can be elaborated using the index to enhance crack marks on asphalt surfaces. Ground spectral signatures were acquired from both uncracked and cracked asphalted areas of Cyprus (Limassol). Evaluation separability indices can be used to identify the optimum wavelength regions that can distinguish better the uncracked and cracked asphalt surfaces. The results revealed that the spectral sensitivity for the enhancement of cracked asphalt was detected using the Euclidean, Mahalanobis and Cosine Distance Indices in the Vis range (approximately at 450 nm) and in the SWIR 1 range (approximately at 1750 nm).

  14. Locating voids beneath pavement using pulsed electromagnetic waves

    Science.gov (United States)

    Steinway, W. J.; Echard, J. D.; Luke, C. M.

    1981-11-01

    The feasibility of using pulsed electromagnetic wave technology for locating and sizing voids beneath reinforced and nonreinforced portland cement concrete pavements is determined. The data processing techniques developed can be implemented to provide information for void depth and sizing to + or - 1/2 in. and spatial location within + or - 6 in. A very short pulse radar directly connected to a microcomputer was chosen as the equipment necessary to obtain measurements. This equipment has the required accuracy and reliability, and is a cost effective solution for the void locating problem. The radar provides a signal return from voids that has unique characteristics that can be examined to provide information regarding the location, depth, and shape of the void. The microcomputer provides a means of real time processing to extract the information from the radar signal return and record the results. Theoretical modeling of signal returns from voids led to suitable techniques for locating and sizing voids beneath the pavement. Analysis and application of these techniques to radar measurements verified the theoretical predictions that radar can be used to determine the location, size, and shape of actual voids.

  15. Evaluation of Warm-Mix Asphalt Technologies for Use on Airfield Pavements

    Science.gov (United States)

    2013-12-01

    Auburn, AL: National Center for Asphalt Technology. Cooley Jr., L. A. 2003. Evaluation of Pavement Permeability in Mississippi. Auburn, AL: National...ER D C/ G SL T R -1 2 -3 Evaluation of Warm-Mix Asphalt Technologies for Use on Airfield Pavements G eo te ch n ic al a n d S tr u ct...default. ERDC/GSL TR-12-3 February 2012 (Revised December 2013) Evaluation of Warm-Mix Asphalt Technologies for Use on Airfield Pavements

  16. The Dependence of Physical Mechanical Properties of Concrete Pavement Blocks on Coarse Aggregate Type

    Directory of Open Access Journals (Sweden)

    Malaiškienė Jurgita

    2014-12-01

    Full Text Available The aim of this research is to determine the dependences of the physical mechanical properties of vibropressed concrete (pavement blocks on the type of coarse aggregate used in the main layer. Sustainability of concrete pavement blocks is a really important matter. Five different batches of pavement blocks were produced, changing the consistence ratio of coarse aggregate in the main layer. There are two types of course aggregate: crushed gravel and granite. The consistence of a facing layer was not changed. All tests: density, tensile split strength, water absorption for vibro-pressed concrete units were made according to EN 1338:2003+AC2006.

  17. The effect of aggregate density on pavement performance of SMA-13 asphalt mixture

    Directory of Open Access Journals (Sweden)

    Qiao Yinping

    2016-05-01

    Full Text Available This paper chooses the top layer SMA-13 asphalt mixture material as the research object. Basalt was selected as pavement material, and modified SBS asphalt was used as a cementing material. Two basalt aggregates with different densities were used to carry out standard Marshall test in the laboratory.Aimed at the volume parameters of the asphalt mixture carry on anaiysis,and obtian the effect of aggregate density on pavement performance of SMA-13 asphalt mixture, which is that the density of aggregate has a significant effect on the void ratio, saturation, and the gap rate of the aggregate, thus affecting the pavement performance of the asphalt mixture

  18. CBR-Beta Design Procedure for Aggregate-Surfaced Airfield Pavements

    Science.gov (United States)

    2014-03-01

    ER D C/ G SL T R- 14 -6 CBR-Beta Design Procedure for Aggregate- Surfaced Airfield Pavements G eo te ch ni ca l a nd S tr uc tu re s...surfaces. The original flexible pavement design procedure of paved surfaces, which is based on the California Bearing Ratio (CBR) and the α-factor...Alpha-factor), was also extended and applied to the design and evaluation of aggregate-surfaced pavements . With the reformulation of the CBR-Alpha for

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2001-11-21

    The objective of this study is to evaluate the life cycle costs and market barriers associated with using reflective paving materials in streets and parking lots as a way to reduce the urban heat island effect. We calculated and compared the life cycle costs of conventional asphalt concrete (AC) pavements to those of other existing pavement technologies with higher reflectivity-portland cement concrete (PCC), porous pavements, resin pavements, AC pavements using light-colored chip seals, and AC pavements using light-colored asphalt emulsion additives. We found that for streets and parking lots, PCC can provide a cost-effective alternative to conventional AC when severely damaged pavements must be completely reconstructed. We also found that rehabilitating damaged AC streets and intersections with thin overlays of PCC (ultra-thin white topping) can often provide a cost-effective alternative to standard rehabilitation techniques using conventional AC. Chip sealing is a common maintenance treatment for low-volume streets which, when applied using light-colored chips, could provide a reflective pavement surface. If the incremental cost of using light-colored chips is low, this chip sealing method could also be cost-effective, but the incremental costs of light-colored chips are as of yet uncertain and expected to vary. Porous pavements were found to have higher life cycle costs than conventional AC in parking lots, but several cost-saving features of porous pavements fell outside the boundaries of this study. Resin pavements were found to be only slightly more expensive than conventional AC, but the uncertainties in the cost and performance data were large. The use of light-colored additives in asphalt emulsion seal coats for parking lot pavements was found to be significantly more expensive than conventional AC, reflecting its current niche market of decorative applications. We also proposed two additional approaches to increasing the reflectivity of conventional AC

  20. 一类具阻尼的非线性双曲方程解的blow-up%The blow-up of solutions of a class of nonlinear damped hyperbolic equation

    Institute of Scientific and Technical Information of China (English)

    呼青英; 陆军

    2003-01-01

    The blow-up property of a nonlinear damped hyperbolic equation,which describes the motion of the neo-Hookean elastomer rod,is proven.%本文讨论了一类描述新胡克弹性杆运动的具阻尼的非线性双曲方程解的blow up性质.

  1. 一般非线性渗流方程广义解的存在唯一性与Blow-up%Existence,Uniqueness and Blow-up of Generalized Solutions to General Nonlinear Filtration Equations

    Institute of Scientific and Technical Information of China (English)

    霍振宏; 李海峰

    2008-01-01

    In this paper,we consider nonnegative solutions to Cauchy problem for the general nonlinear filtration equations ut-Dj(aij(x,t,u)Diφ(u))+bi(t,u)Diu+C(x,t,u)=0,and obtain the existence,uniqueness and blow-up in finite time of these solutions under some structure conditions.

  2. Microsurfacing – An Eco-Efficient Tool for Road Safety and Pavement Maintenance

    Directory of Open Access Journals (Sweden)

    Rajesh S. Gujar

    2013-11-01

    Full Text Available With the development of infrastructure, in rapidly developing modern era, frequent maintenance of existing infrastructure, especially roads is of prime importance.  Microsurfacing is a preventive maintenance technique (preventative maintenance strategy aims at producing the most cost-effective improvements in pavement quality and life involving three to six millimeter sized bitumen aggregate treated with a special emulsion.  The layer is neatly laid down on road section requiring maintenance.  This paper aims at focusing on the contributions made by researchers on Microsurfacing as a tool for pavement maintenance and repair.  Although the technique is finding its place in Indian sub-continents little late, but nevertheless it is universally considered as an inevitable tool as far as preventive pavement maintenance is concerned and should be used to extend life of the underlying pavement

  3. The Effect of Cement Stabilized Subgrade on Cost of the Flexible Pavement

    Directory of Open Access Journals (Sweden)

    Baha Vural Kök

    2012-03-01

    Full Text Available The road authorities aim roads that are resistant, with less maintenance, with high traffic security, with long life and economic. It is difficult to have an economic pavement construction on the subgrade with weak bearing capacity. In this study the effect of the cement stabilization on the weak subgrade and pavement costs has been studied. For this purpose the California Bearing Ratio (CBR of a weak subgrade that has been stabilized with 4% - 16% cement have been determined. The effect of the increase in the CBR on the pavement costs has been determined thanks to MATLAB program by considering thousands of alternatives. Consequently, the optimum cement content between the decrease on the pavement costs with increase on subgrade' CBR value and the additional costs spent to increase the CBR value has been determined.

  4. Mechanical Behavior and Failure Mechanism of Recycled Semi-lfexible Pavement Material

    Institute of Scientific and Technical Information of China (English)

    DING Qingjun; ZHAO Mingyu; SHEN Fan; ZHANG Xiaoqiang

    2015-01-01

    The mechanical behavior and failure mechanism of recycled semi-lfexible pavement material were investigated by different scales method. The macroscopic mechanical behavior of samples was studied by static and dynamic splitting tensile tests on mechanics testing system (MTS). The mechanical analysis in micro scale was carried out by material image analysis method and ifnite element analysis system. The strains of recycled semi-lfexible pavement material on samples surface and in each phase materials were obtained. The test results reveal that the performance of recovered asphalt binder was the major determinant on the structural stability of recycled semi-lfexible pavement material. The asphalt binder with high viscoelasticity could delay the initial cracking time and reduce the residual strain under cyclic loading conditions. The failure possibility order of each phase in recycled semi-flexible pavement material was asphalt binder, reclaimed aggregate, cement paste and virgin aggregate.

  5. Permeable Pavement Research at NRMRL’s Urban Watershed Research Facility (Poster 2)

    Science.gov (United States)

    Assess pollutant removal efficiency of porous pavement systems with regard to parking lot runoff. Bench-scale study will examine: Discharge volume Flow rate Total suspended solids (TSS) of influent vs. effluent Use of a geotextile permeable filter fabric...

  6. PHYSIOLOGICAL INFORMATION FOR PAVEMENT HEALTH MONITORING BASED ON SURFACE RIDE QUALITY

    Science.gov (United States)

    Tomiyama, Kazuya; Kawamura, Akira; Takahashi, Kiyoshi; Ishida, Tateki

    Pavement ride quality testing has traditionally been based on subjective questionnaire ratings. The questionnaire survey has ability to directly measure the sense of road users' ride quality. However, it is difficult to quantify the evaluation results based on the questionnaire due to its lack of objectivity. This study examines pavement health monitoring method using physiological information such as heart rate variability (HRV) for detecting mental stress of road users toward pavement ride quality. First, a results of a driving simulator experiment shows that potential mental stress caused by road roughness can be observed in high-frequency oscillations in 0.15-0.4Hz of HRV processed by continuous wavelet transform. Then, the high-frequency oscillations of HRV is summarized as an index related to the mental stress that makes objective ride quality evaluation possible. Finally, this study indicates that the index contributes to improve the accuracy of pavement health monitoring based on surface ride quality.

  7. Verification of Traffic Speed Deflectometer Measurements Using Instrumented Pavements in South Africa

    OpenAIRE

    Kannemeyer, Louw; Lategan, W.; Mckellar, A.

    2014-01-01

    Structural Session 2: Evaluation of Deflection Devices Moderated by Doug Chalman This presentation was held at the Pavement Evaluation 2014 Conference, which took place from September 15-18, 2014 in Blacksburg, Virginia. Presentation only

  8. Investigation of Applicability and Use of a Pavement Response Model with High Speed Deflection Devices (HSDDs)

    OpenAIRE

    Siddharthan, Rajaratnam V.; Nasimifar, Mahdi; Rada, Gonzalo R; Nazarian, Soheil; Sivaneswaran, Nadarajah; Thyagarajan, Senthilmurugan

    2014-01-01

    Structural Session 4: Future Applications Moderated by Trenton Clark This presentation was held at the Pavement Evaluation 2014 Conference, which took place from September 15-18, 2014 in Blacksburg, Virginia. Presentation only

  9. Performance Prediction of the NCAT Test Track Pavements Using Mechanistic Models

    Science.gov (United States)

    LaCroix, Andrew Thomas

    In the pavement industry in the United States of America, there is an increasing desire to improve the pavement construction quality and life for new and rehabilitated pavements. In order to improve the quality of the pavements, the Federal Highway Administration (FHWA) has pursued a performance-related specification (PRS) for over 20 years. The goal of PRS is to provide material and construction (M/C) properties that correlate well with pavement performance. In order to improve upon the PRS projects developed in WesTrack (NCHRP 9-20) and the MEPDG-based PRS (NCHRP 9-22), a set of PRS tests and models are proposed to provide a critical link between pavement performance and M/C properties. The PRS testing is done using the asphalt mixture performance tester (AMPT). The proposed PRS focuses on rutting and fatigue cracking of asphalt mixtures. The mixtures are characterized for their stiffness, fatigue behavior, and rutting resistance using a dynamic modulus (|E*|) test, a fatigue test, and a triaxial stress sweep (TSS) test, respectively. Information from the fatigue test characterizes the simplified viscoelastic continuum damage (S-VECD) model. Once the stiffness is reduced to a certain level, the material develops macro-cracks and fails. The TSS test is used to characterize a viscoplastic (VP) model. The VP model allows the prediction of the rut depth beneath the center of the wheel. The VECD and VP models are used within a layered viscoelastic (LVE) pavement model to predict fatigue and rutting performance of pavements. The PRS is evaluated by comparing the predictions to the field performance at the NCAT pavement test track in Opelika, Alabama. The test track sections evaluated are part of the 2009 test cycle group experiment, which focused on WMA, high RAP (50%), and a combination of both. The fatigue evaluation shows that all sections would last at least 18 years at the same traffic rate. The sections do not show any cracking, suggesting the sections are well

  10. Construction and Instrumentation of Full-Scale Geogrid Reinforced Pavement Test Sections

    Science.gov (United States)

    2008-04-01

    Nathan Lamie, and Troy W. Arnold Cold Regions Research and Engineering Laboratory U.S. Army Engineer Research and Development Center 72 Lyme Road...models compatible with NCHRP 1-37A, Guide for Mechanistic-Empirical Design of New and Rehabilitated Pavement Structures (available from http...Mechanistic-Empirical Design of New and Rehabilitated Pavement Structures (http://www.trb.org/mepdg/) (NCHRP 2004). The overall objectives of TPF-5(010) were

  11. Structural Improvements of Flexible Pavements Using Geosynthetics for Base Course Reinforcement

    Science.gov (United States)

    2009-10-01

    Engineering Laboratory 72 Lyme Road Hanover, NH 03755-1290 Final report Approved for public release; distribution is unlimited. Prepared for Federal...these cases.) Empirical rutting models presented in NCHRP 1-37A, Guide for Mechanistic-Empirical Design of New and Rehabilitated Pavement Structures...Mechanistic- Empirical Design of New and Rehabilitated Pavement Structures (http://www.trb.org/mepdg/). The research effort included the development of

  12. Cooler reflective pavements give benefits beyond energy savings: durability and illumination

    Energy Technology Data Exchange (ETDEWEB)

    Pomerantz, Melvin; Akbari, Hashem; Harvey, John T.

    2000-06-01

    City streets are usually paved with asphalt concrete because this material gives good service and is relatively inexpensive to construct and maintain. We show that making asphalt pavements cooler, by increasing their reflection of sunlight, may lead to longer lifetime of the pavement, lower initial costs of the asphalt binder, and savings on street lighting and signs. Excessive glare due to the whiter surface is not likely to be a problem.

  13. Research on the relationship between water stability and aggregate gradation of asphalt pavement

    OpenAIRE

    Zhao Bing; Zhao Bo

    2015-01-01

    In the early destruction of asphalt pavement, water damage is the most major form.In this paper, experimental study was conducted on the composition of asphalt concrete,Marshall specimens were made in different types of aggregate gradation with the same kind of asphalt. Water immersion tests were conducted in order to analysis the relationship between the water stability and aggregate gradation of asphalt pavement.

  14. Research on the relationship between water stability and aggregate gradation of asphalt pavement

    Directory of Open Access Journals (Sweden)

    Zhao Bing

    2015-05-01

    Full Text Available In the early destruction of asphalt pavement, water damage is the most major form.In this paper, experimental study was conducted on the composition of asphalt concrete,Marshall specimens were made in different types of aggregate gradation with the same kind of asphalt. Water immersion tests were conducted in order to analysis the relationship between the water stability and aggregate gradation of asphalt pavement.

  15. Paint Pavement Marking Performance Prediction Model That Includes the Impacts of Snow Removal Operations

    Science.gov (United States)

    2011-03-01

    Hypothesized that snow plows wear down mountain road pavement markings. 2007 Craig et al. -Edge lines degrade slower than center/skip lines 2007...retroreflectivity to create the models. They discovered that paint pavement markings last 80% longer on Portland Cement Concrete than Asphalt Concrete at low AADT...retroreflectivity, while yellow markings lost 21%. Lu and Barter attributed the sizable degradation to snow removal, sand application, and studded

  16. Development of Mechanistic-Empirical Pavement Design for Tropical Climate Using Cement-Treated Base Layer

    OpenAIRE

    Aderinola, O.S

    2016-01-01

    A mechanistic-empirical pavement design method is developed characterising cement-treated base layers for pavement design in Nigeria or other similar tropical and subtropical countries. Asphalt Concrete surface, Subbase and Aggregate base were characterised based on back calculation data from Claros et al (1986) while cement-treated base layer was based on modulus tests that had been conducted by past researchers. Failure criteria for the Asphalt Concrete fatigue failure and the s...

  17. Basics of a Good Road - Concrete Pavements: Road Scholar Program Part I

    OpenAIRE

    2014-01-01

    This 3-hour course will provide the basic knowledge needed to design, build, and maintain concrete pavements at a local level. Attendees will hear industry experts discuss the many applications for concrete pavements in our industry and the emerging innovations in the field of mix designs and maintenance. Attendees will receive core course credit for core course #6: Basics of a Good Road. Attendees who have already attended this core course will receive 3 Road Scholar points.

  18. Basics of a Good Road - Concrete Pavements: Road Scholar Program Part II

    OpenAIRE

    2014-01-01

    This 3-hour course will provide the basic knowledge needed to design, build, and maintain concrete pavements at a local level. Attendees will hear industry experts discuss the many applications for concrete pavements in our industry and the emerging innovations in the field of mix designs and maintenance. Attendees will receive core course credit for core course #6: Basics of a Good Road. Attendees who have already attended this core course will receive 3 Road Scholar points.

  19. 投稿须知%Construction Technology for Fast-Track Concrete Pavement

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    In this paper, one of new contents: construction technology for fast-track concrete pavement is introduced in 《Technical Specification for Construction of Highway Cement Concrete Pavements》 (JTG F30) which is revised in 2010 in order to not only provide high-quality and long-lasting life, but also reduce the time of engineering in the new construction, reconstruction and resurfacing maintain of cement concrete pavements, to quickly and early open public traffic, and to reduce traffic interruptions.

  20. The design and analysis on asphalt concrete pavement%沥青混凝土路面设计分析

    Institute of Scientific and Technical Information of China (English)

    王星茹

    2016-01-01

    This paper introduced the design process of urban road asphalt pavement,discussed the material and type of asphalt concrete pave-ment,from the pavement structure combination design,pavement design index,pavement structure layer calculation and other aspects,elabora-ted the design method of asphalt concrete pavement,made the asphalt pavement meet the structure strength and stability requirements.%介绍了城市道路沥青路面设计的流程,论述了沥青混凝土面层的材料与类型,从路面结构组合设计、路面设计指标、路面结构层计算等方面,阐述了沥青混凝土路面的设计方法,使沥青路面满足结构强度和稳定性的要求.

  1. Validation of theoretical models through measured pavement response

    DEFF Research Database (Denmark)

    Ullidtz, Per

    1999-01-01

    performance. The analytical models are based on a number of simplifications with respect to reality and must be verified experimentally.Different pressure gauges were installed in a sand, assumed to be a semi-infinite halfspace. The surface of the sand was loaded by a Falling Weight Deflectometer (FWD......) at different lateral positions with respect to the gauges. An integration of the stresses measured at the plane of the gauges showed that the total load recorded by the gauges was close to the loade imposed by the FWD, cofirming the reliability of the gauges. The theoretical stress calculated using continuum...... 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...

  2. Applying AHP—Based CBR to Estimate Pavement Maintenance Cost

    Institute of Scientific and Technical Information of China (English)

    Jui-Sheng Chou

    2008-01-01

    The cost-efficacy control of maintenance operations in developing countries has become critical to the infrastructure asset management after highway construction.To effectively manage numerous projects annually with limited resources,it is necessary to reasonably estimate costs during the process of making maintenance project selection decisions.This study outlines the modeling of case-based reasoning (CBR) estimation that compares and retrieves the most similar instance across the case library.Four CBR ap- proaches were presented and assessed in terms of their mean absolute prediction error rates.The resulting model demonstrates the ability of estimating the pavement maintenance project costs with the satisfactory accuracy at the early stages.

  3. Environmental history recorded in aeolian deposits under stone pavements, Mojave Desert, USA

    Science.gov (United States)

    Dietze, Michael; Dietze, Elisabeth; Lomax, Johanna; Fuchs, Markus; Kleber, Arno; Wells, Stephen G.

    2016-01-01

    Reconstructing the evolution of arid landscapes is challenged by limited availability of appropriate environmental archives. A widespread surface feature - stone pavement - traps aeolian fines and forms a special accretionary archive. Seven stone pavement-covered sections on basalt flows in the eastern Mojave Desert are condensed into a composite section, comprising five sedimentological units supported by an OSL-based chronology. Three of the units are of accretionary nature and each is covered by a stone pavement. They were deposited > 50.9-36.6 ka, < 36.6-14.2 ka and < 14.2 ka, and they are intimately coupled with the history of nearby Lake Mojave, which advances the current understanding of regional aeolian activity. End-member modeling analysis of grain-size distributions yielded seven sediment transport regimes. The accretionary system operates in two modes: A) episodic formation of a stone pavement by lateral processes once a vesicular horizon has formed on a barren surface; and B) accretion of dust and eventual burial of the clast layer. These findings improve current concepts about stone pavement evolution and their environmental proxy function in arid landscapes. Stone pavement-covered accretionary deposits are a new key archive that allows quantifying the relative importance of dust accretion, slope processes, soil formation and vegetation cover.

  4. Comparative field permeability measurement of permeable pavements using ASTM C1701 and NCAT permeameter methods.

    Science.gov (United States)

    Li, Hui; Kayhanian, Masoud; Harvey, John T

    2013-03-30

    Fully permeable pavement is gradually gaining support as an alternative best management practice (BMP) for stormwater runoff management. As the use of these pavements increases, a definitive test method is needed to measure hydraulic performance and to evaluate clogging, both for performance studies and for assessment of permeability for construction quality assurance and maintenance needs assessment. Two of the most commonly used permeability measurement tests for porous asphalt and pervious concrete are the National Center for Asphalt Technology (NCAT) permeameter and ASTM C1701, respectively. This study was undertaken to compare measured values for both methods in the field on a variety of permeable pavements used in current practice. The field measurements were performed using six experimental section designs with different permeable pavement surface types including pervious concrete, porous asphalt and permeable interlocking concrete pavers. Multiple measurements were performed at five locations on each pavement test section. The results showed that: (i) silicone gel is a superior sealing material to prevent water leakage compared with conventional plumbing putty; (ii) both methods (NCAT and ASTM) can effectively be used to measure the permeability of all pavement types and the surface material type will not impact the measurement precision; (iii) the permeability values measured with the ASTM method were 50-90% (75% on average) lower than those measured with the NCAT method; (iv) the larger permeameter cylinder diameter used in the ASTM method improved the reliability and reduced the variability of the measured permeability.

  5. Statistical classification of road pavements using near field vehicle rolling noise measurements.

    Science.gov (United States)

    Paulo, Joel Preto; Coelho, J L Bento; Figueiredo, Mário A T

    2010-10-01

    Low noise surfaces have been increasingly considered as a viable and cost-effective alternative to acoustical barriers. However, road planners and administrators frequently lack information on the correlation between the type of road surface and the resulting noise emission profile. To address this problem, a method to identify and classify different types of road pavements was developed, whereby near field road noise is analyzed using statistical learning methods. The vehicle rolling sound signal near the tires and close to the road surface was acquired by two microphones in a special arrangement which implements the Close-Proximity method. A set of features, characterizing the properties of the road pavement, was extracted from the corresponding sound profiles. A feature selection method was used to automatically select those that are most relevant in predicting the type of pavement, while reducing the computational cost. A set of different types of road pavement segments were tested and the performance of the classifier was evaluated. Results of pavement classification performed during a road journey are presented on a map, together with geographical data. This procedure leads to a considerable improvement in the quality of road pavement noise data, thereby increasing the accuracy of road traffic noise prediction models.

  6. Field validation of road roughness evaluation using in-pavement strain sensors

    Science.gov (United States)

    Zhang, Z.; Deng, F.; Huang, Y.; Bridgelall, R.

    2016-04-01

    Most transportation agencies now collect pavement roughness data using the inertial profilers, which requires instrumented vehicles and technicians with specialized training to interpret the results. The extensive labor requirements of the profiling activities limit data collection for portions of the national highway system to at most once per year, resulting in outdated roughness data for decision making of maintenance needs. In this paper, a real-time roughness evaluation method was developed by linking the output of durable in-pavement strain sensors to road roughness level. The durable in-pavement sensors will continuously provide information of road roughness in real time after they are installed and calibrated during the road construction until the service life of the associated pavement. Field tests validated the developed strain method by comparison with standard inertial profiling method and the connected-vehicle method. The comparison of the results from the field tests approves the effectiveness of the developed road roughness evaluation method using in-pavement strain sensors, which can be further applied practically for needed concrete pavements.

  7. Sensitivity analysis of asphalt-pavement structure dynamic responses under heavy load

    Directory of Open Access Journals (Sweden)

    ZHANG Lijuan

    2015-04-01

    Full Text Available With the 3-Dimensional finite-element dynamic model,the influence of axis-load,axis-speed,and pavement structure parameters on dynamic performance of pavement structure is studied.The results show that with the increase in load,the dynamic response of pavement is nearly proportional to axis-load and increases noticeably;Axis-speed influences the dynamic response to some extent.With the increase of axis-speed,dynamic response of pavement structure increases firstly.With axis-speed further increasing,dynamic response of pavement structure then decreases gradually.For fatigue failure,the influence of heavy-load with common moving speed is much greater than that of static load.Among the pavement structure parameters,thickness of surface-layer has a significant effect on shear stress and the compression stress at road surface.Subgrade modulus has a significant effect on road surface deflection,tensile stress at the bottom of subbase,and compression-strain at the top of subgrade.

  8. Thermal behavior of an asphalt pavement in the laboratory and in the parking lot.

    Science.gov (United States)

    Martinkauppi, J B; Mäkiranta, A; Kiijärvi, J; Hiltunen, E

    2015-01-01

    The urban, constructed areas are full of buildings and different kinds of pavements and have a noticeable lack of trees and flora. These areas are accumulating the heat from the Sun, people, vehicles, and constructions. One interesting heat collector is the asphalt pavement. How does the heat transfer to different layers under the pavement or does it? What are the temperatures under the pavement in Finland where the winter can be pretty hard? How can those temperatures be measured accurately? These are the main questions this paper gives the preliminary answers to. First the thermal behavior of asphalt and the layers beneath are researched in the laboratory and then the measurement field is bored and dug in the parking in the Western coast of Finland, 63°5'45'' N. Distributed temperature sensing method was found to be a good choice for temperature measurements. Thermal behavior of pavement has been monitored in different layers and the preliminary results have been published here. The goal of this research is to assess the applicability of asphalt pavements for heat energy collection.

  9. Study of the Effect of Temperature Changes on the Elastic Modulus of Flexible Pavement Layers

    Directory of Open Access Journals (Sweden)

    Mohd Raihan Taha

    2013-02-01

    Full Text Available In general, the stiffness of flexible pavement is influenced by environmental changes, whereby temperature and rainfall affect the asphalt layer and non-asphalt layer, such as the subgrade, respectively. Normally, the effect of temperature on flexible pavement can be measured using two methods. The first is a destructive test whereby core samples are tested in a laboratory using a Universal Testing Machine (UTM. The second is a non-destructive in situ test using equipment such as a Falling Weight Deflectometer (FWD and Spectral Analysis of Surface Waves (SASW. This study was conducted to investigate the effect of temperature at different tensile levels on the Soekarno-Hatta and Purwakarta Cikampek roads in Bandung, West Java, Indonesia. It is observed that different tensile levels and testing methods result in various elastic modulus values of flexible pavement. The higher the temperature applied to the flexible pavement layer, the more the elastic modulus values decrease. In contrast, the lower the temperature imposed on the flexible pavement layer, the more the elastic modulus values increase. Different testing methods (FWD, UTM and SASW on the flexible pavement layer are also affected by temperature changes.

  10. Thermal Behavior of an Asphalt Pavement in the Laboratory and in the Parking Lot

    Directory of Open Access Journals (Sweden)

    J. B. Martinkauppi

    2015-01-01

    Full Text Available The urban, constructed areas are full of buildings and different kinds of pavements and have a noticeable lack of trees and flora. These areas are accumulating the heat from the Sun, people, vehicles, and constructions. One interesting heat collector is the asphalt pavement. How does the heat transfer to different layers under the pavement or does it? What are the temperatures under the pavement in Finland where the winter can be pretty hard? How can those temperatures be measured accurately? These are the main questions this paper gives the preliminary answers to. First the thermal behavior of asphalt and the layers beneath are researched in the laboratory and then the measurement field is bored and dug in the parking in the Western coast of Finland, 63°5′45′′ N. Distributed temperature sensing method was found to be a good choice for temperature measurements. Thermal behavior of pavement has been monitored in different layers and the preliminary results have been published here. The goal of this research is to assess the applicability of asphalt pavements for heat energy collection.

  11. Research on nonlinear constitutive relationship of permanent deformation in asphalt pavements

    Institute of Scientific and Technical Information of China (English)

    PENG; Miaojuan; XU; Zhihong

    2006-01-01

    To predict correctly the rut depths in asphalt pavements,a new nonlinear viscoelastic-elastoplastic constitutive model of permanent deformation in asphalt pavements is presented.The model combines a generalized Maxwell model with an elastoplastic one.Then from the creep theory,the linear and nonlinear constitutive equations of the generalized Maxwell model are obtained.From the nonlinear finite element method for the rutting of the asphalt pavement,the rut depths of 4 asphalt-aggregate mixtures are obtained.And the results are compared with the ones from the finite element method by SHRP and the experiments by SWK/UN.The results in this paper are better than the ones by SHRP,and agree with the ones of the experiment by SWK/UN.This shows that the nonlinear viscoelastic-elastoplastic constitutive model,which is presented in this paper for the rutting of the asphalt pavement,is effective.The properties,such as nonlinear elasticity,plasticity,viscoelasticity and nonlinear viscoelasticity,which affect the rutting of an asphalt pavement,can be shown in the model.And the characteristics of the permanent deformation of the asphalt pavement can be presented entirely in the model.

  12. Adaptive Road Crack Detection System by Pavement Classification

    Directory of Open Access Journals (Sweden)

    Alejandro Amírola

    2011-10-01

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

  13. Pavement Management for Local Agencies: How to do More with less with the Three Legged Stool System

    OpenAIRE

    Barnhardt, Blair

    2013-01-01

    Pavement management is important for agencies to maintain their critical infrastructure. By using the core principles of asset management, pavement assessment, and candidate selection, an agency is able to address pavement distresses with routine maintenance and prevent good and fair roads from becoming bad roads. This presentation discusses the many ways agencies have successfully managed their way to an improved overall road network even during the most challenging times.

  14. DESERT PAVEMENTS AND SOILS ON BASALTIC PYROCLASTIC DEPOSITS AT LATHROP WELLS AND RED CONE VOLCANOES, SOUTHERN NEVADA

    Energy Technology Data Exchange (ETDEWEB)

    G.A. Valentine; C.D. Harrington

    2005-08-10

    Formation of desert pavement and accretionary soils are intimately linked in arid environments such as the Mojave Desert. Well-sorted fallout scoria lapilli at Lathrop Wells (75-80 ky) and Red Cone ({approx}1 Ma) volcanoes (southern Nevada) formed an excellent starting material for pavement, allowing infiltration of eolian silt and fine sand that first clogs the pore space of underlying tephra and then aggrades and develops vesicular A (Av) horizons. Variations in original pyroclast sizes provide insight into minimum and maximum clast sizes that promote pavement and soil formation: pavement becomes ineffective when clasts can saltate under the strongest winds, while clasts larger than coarse lapilli are unable to form an interlocking pavement that promotes silt accumulation (necessary for Av development). Contrary to predictions that all pavements above altitudes of {approx}400 m would have been ''reset'' in their development after late Pleistocene vegetation advances (about 15 ka), the soils and pavements show clear differences in maturity between the two volcanoes. This indicates that either the pavement soils develop slowly over many 10,000's of years and then are very stable, or that, if they are disrupted by vegetation advances, subsequent pavements are reestablished with successively more mature characteristics.

  15. DESERT PAVEMENTS AND SOILS ON BASALTIC PYROCLASTIC DEPOSITS AT LATHROP WELLS AND RED CONE VOLCANOES, SOUTHERN NEVADA ABSTRACT

    Energy Technology Data Exchange (ETDEWEB)

    G.A. Valentine; C.D. Harrington

    2005-08-26

    Formation of desert pavement and accretionary soils are intimately linked in arid environments such as the Mojave Desert. Well-sorted fallout scoria lapilli at Lathrop Wells (75-80 ky) and Red Cone ({approx}1 Ma) volcanoes (southern Nevada) formed an excellent starting material for pavement, allowing infiltration of eolian silt and fine sand that first clogs the pore space of underlying tephra and then aggrades and develops vesicular A (Av) horizons. Variations in original pyroclast sizes provide insight into minimum and maximum clast sizes that promote pavement and soil formation: pavement becomes ineffective when clasts can saltate under the strongest winds, while clasts larger than coarse lapilli are unable to form an interlocking pavement that promotes silt accumulation (necessary for Av development). Contrary to predictions that all pavements above altitudes of {approx}400 m would have been ''reset'' in their development after late Pleistocene vegetation advances (about 15 ka), the soils and pavements show clear differences in maturity between the two volcanoes. This indicates that either the pavements/soils develop slowly over many 10,000's of years and then are very stable, or that, if they are disrupted by vegetation advances, subsequent pavements are reestablished with successively more mature characteristics.

  16. Numerical analysis of applying special pavements to solve the frost heave diseases of high-speed railway roadbeds in seasonally frozen ground regions

    Institute of Scientific and Technical Information of China (English)

    Chang Yuan; FuJun Niu; QiHao Yu; XinBin Wang; Lei Guo; YanHui You

    2015-01-01

    The Haerbin-Dalian Passenger Dedicated Line is the first high-speed railway constructed in the seasonally frozen ground regions of northeastern China. Frost heave diseases occurred in the first winter of its operation (between October 2012 and January 2013), and frost heave was observed mainly in the roadbed fills that were considered not susceptible to frost heave. This paper proposes applying two special pavements — black pavement and insulation-black pavement — to improve the thermal regime of the roadbed. Three numerical models of the roadbed temperature field were built based on the field con-ditions of the Changchun section (D3K692+840 to D3K692+860). The results show that: (1) Compared with cement pave-ment, black pavement and insulation-black pavement could reduce the freezing index at the roadbed surface by 37% and 64%, respectively, which could influence the maximum frozen depth; (2) the maximum frozen depths under the black pavement and insulation-black pavement were respectively 1.3–1.4 m and 1 m. Compared with cement pavement, they could reduce the maximum frozen depth by 0.4 m and 0.7–0.8 m, respectively, which would reduce the permitted amount of frost heave by 4 mm and 7–8 mm, which would meet the deformation limit established by theCode for Design on Special Subgrade of Railway; (3) the freezing periods of the black pavement and the insulation-black pavement were, respectively, approximately four months and two months. Compared with cement pavement, they could reduce the freezing period by approximately 19 days and 40 days, respectively, and delay the initial freezing time by 9 days and 18 days; and (4) compared with cement pavement, black pavement and black-insulation pavement could reduce the frozen areas of roadbeds in the cold season, which suggests that these two special pavements could provide better thermal stability for roadbeds.

  17. Work Plan for: "Investigation of Noise, Durability, Permeability and Friction Performance Trends for Asphaltic Pavement Surface Types," PPRC Strategic Plan Item 4.16

    OpenAIRE

    Harvey, John T

    2005-01-01

    The central purpose of this research is to support the Caltrans Quiet Pavement Pilot Program. The research conforms with FHWA guidance provided to State DOTs that conduct tire/pavement noise research. The broader purpose of this research is to support the Caltrans Quieter Pavements Road Map and Work Plan, with goals and objectives that address quiet as well as permeable asphalt surfaces for pavements. Results from this research will identify best practice for selecting asphaltic surf...

  18. State of the Art of Pavement Response Monitoring Systems for Roads and Airfields Symposium Held March 6-9, 1989 in West Lebanon, New Hampshire,

    Science.gov (United States)

    1989-09-01

    will be states, the IMS must be able to collected from SHA records. Where count accommodate a wide variety of data are missing, " backcasting " and...pavements is needed to develop future 1.ad i,.duced deflections, and slab policies on pavement design, construc- t,-":jct gradients. Field instru- tion...acquisition system capable of fast sampling rates is re- quired. Data collection of in-service pavements will help shape future policies on pavement design

  19. On-site inspections of pavement damages evolution using GPR

    Science.gov (United States)

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

    2014-05-01

    Ground-penetrating radar (GPR) is being increasingly used for pavements maintenance due to the wide range of applications spanning from physical to geometrical inspections, thereby allowing for a reliable diagnosis of the main causes of road structural damages. In this work, an off-ground GPR system was used to investigate a large-scale rural road network. Two sets of surveys were carried out in different time periods, with the main goals to i) localize the most critical sections; ii) monitor the evolution of previous damages and localize newborn deep faults, although not revealed at the pavement surface level; iii) analyze the causes of both evolution and emergence of faults by considering environmental and human factors. A 1-GHz GPR air-launched antenna was linked to an instrumented van for collecting data at traffic speed. Other support techniques (e.g. GPS data logger, odometer, HD video camera) were used for cross-checking,. Such centre frequency of investigation along with a 25-ns time window allow for a signal penetration of 900 mm, consistent with the deepest layer interfaces. The bottom of the array was 400 mm over the surface, with a minimum distance of 1200 mm from the van body. Scan length of maximum 10 km were provided for avoiding heavy computational loads. The rural road network was located in the District of Rieti, 100 km north from Rome, Italy, and mostly develops in a hilly and mountainous landscape. In most of the investigated roads, the carriageway consists in two lanes of 3.75 meters wide and two shoulders of 0.50 meters wide. A typical road section includes a HMA layer (65 mm average thickness), a base layer (100 mm average thickness), and a subbase layer (300 mm average thickness), as described by pavement design charts. The first set of surveys was carried out in two days at the beginning of spring in moderately dry conditions. Overall, 320-km-long inspections were performed in both travel directions, thereby showing a productivity of

  20. Reuse of Lathe Waste Steel Scrap in Concrete Pavements

    Directory of Open Access Journals (Sweden)

    Pooja Shrivastavaa

    2014-12-01

    Full Text Available These project works assess on the study of the workability and mechanical strength properties of the concrete reinforced with industrialized waste fibers or the recycled fibers. In each lathe industries wastes are available in form of steel scraps are yield by the lathe machines in process of finishing of different machines parts and dumping of these wastes in the barren soil contaminating the soil and ground water that builds an unhealthy environment. Now a day’s these steel scraps as a waste products used by innovative construction industry and also in transportation and highway industry. In addition to get sustainable progress and environmental remuneration, lathe scrap as worn-recycle fibers with concrete are likely to be used. When the steel scrap reinforced in concrete it acquire a term; fiber reinforced concrete and steel fibers in concrete defined as steel fiber reinforced concrete (SFRC.Different experimental studies are done to identify about fresh and hardened concrete properties of steel scrap fiber reinforced concrete (SSFRC and their mechanical properties are found to be increase due to the addition of steel scrap in concrete i.e. compressive strength, flexural strength, impact strength, fatigue strength and split tensile strength were increased but up to 0.5-2% scrap content . When compared with usual concrete to SSFRC, flexural strength increases by 40% and considerable increases in tensile and compressive strength. These steel scrap also aid to improve the shrinkage reduction, cracking resistance i.e. preventing crack propagation and modulus of elasticity. The workability of fresh SSFRC are carried out by using slump test but it restricted to less scrap contents. This work focuses on the enhancement of structural strength and improvement in fatigue life of concrete pavements by reuse of scrap steel in concrete. These concrete roads with SSFRC promises an appreciably eminent design life, offer superior serviceability and

  1. Impact of Vehicle Class and Tire Pressure on Pavement Performance in MEPDG

    Directory of Open Access Journals (Sweden)

    Mohamed I. E. Attia

    2014-10-01

    Full Text Available The new Mechanistic-Empirical Pavement Design Guide (MEPDG design and analysis procedures defines the exact traffic loading by defining the specific number of each vehicle class and the use of axle load distribution factors instead of the equivalent single axle load (ESAL. The number of traffic inputs (parameters in MEPDG was found to be 17024. This research aimed to evaluate the sensitivity of the predicted flexible pavement distress to vehicle class and tire pressure in MEPDG. To evaluate the impact of vehicle (truck class on pavement sections, different cases of loading were analyzed. For each case, the MEPDG Ver. 1.1 was used to evaluate the effect of tire pressure by solving each case for a tire pressure of 120 and 140 psi. The effect of the traffic parameters on asphalt pavement (AC rutting, base rutting, subgrade rutting, international roughness index (IRI, longitudinal cracking and fatigue (alligator cracking were investigated. It was found that vehicle class distribution (VCD would cause clear impact (comparable to the effect of AADTT level only if the major traffic is of specific class (very light or very heavy. If this is not the case, the vehicle class distribution will not be a significant factor that affects the final design because most of the trucks had similar impact on flexible pavement distresses. The impact of tire pressure is clear on longitudinal cracking, fatigue cracking and AC rutting, and have no significant impact on both base and subgrade rutting.

  2. Approaches for a 3D assessment of pavement evenness data based on 3D vehicle models

    Directory of Open Access Journals (Sweden)

    Andreas Ueckermann

    2015-04-01

    Full Text Available Pavements are 3D in their shape. They can be captured in three dimensions by modern road mapping equipment which allows for the assessment of pavement evenness in a more holistic way as opposed to current practice which divides into longitudinal and transversal evenness. It makes sense to use 3D vehicle models to simulate the effects of 3D surface data on certain functional criteria like pavement loading, cargo loading and driving comfort. In order to evaluate the three criteria mentioned two vehicle models have been created: a passenger car used to assess driving comfort and a truck-semitrailer submodel used to assess pavement and cargo loading. The vehicle models and their application to 3D surface data are presented. The results are well in line with existing single-track (planar models. Their advantage over existing 1D/2D models is demonstrated by the example of driving comfort evaluation. Existing “geometric” limit values for the assessment of longitudinal evenness in terms of the power spectral density could be used to establish corresponding limit values for the dynamic response, i.e. driving comfort, pavement loading and cargo loading. The limit values are well in line with existing limit values based on planar vehicle models. They can be used as guidelines for the proposal of future limit values. The investigations show that the use of 3D vehicle models is an appropriate and meaningful way of assessing 3D evenness data gathered by modern road mapping systems.

  3. Development of Performance Models for a Typical Flexible Road Pavement in Nigeria

    Directory of Open Access Journals (Sweden)

    Adebayo Oladipo Owolabi

    2012-09-01

    Full Text Available The results of a study conducted to facilitate the development of road pavement performance models that are appropriate for Nigeria and similar developing countries andcould predict the rate of deterioration over their lifespan have been presented. Comprehensive investigations were carried out on the expressway linking Lagos (the economic nerve centre of Nigeria with Ibadan (the largest city in West Africa - apparently one of the most heavily trafficked roads in the country. Data relating to traffic characteristics, pavement condition ratings, distress types, pavement thickness, roughness index, rainfall and temperature, were collected. Models were developed to determine Pavement Condition Score (PCS and International Roughness Index (IRI. Stepwise Regression was used to analyse the data and quantify the impact of key input parameters on the PCS and IRI. Parameters such as depth of ruts and area of pot holes were found to be statistically significant in predicting PCS while number of patches, length of longitudinal cracks and depth of ruts were statistically significant in predicting IRI. The models can be used for planning road maintenance programs, thus minimizing the need for comprehensive data collection on pavement condition before the maintenance exercise, which is costly and time consuming.

  4. State-of-the-art review of the applications of nanotechnology in pavement materials

    Science.gov (United States)

    Castillo, Luis, Jr.

    The use of nanotechnology in pavement materials is one main area that shows great promise and has the potential to change commonly used materials. This will develop more effective solutions to achieve the desired performance. The overall objective of this work is to present a state-of-the-art literature review of nano-science-based principles to improve the performance and, ultimately, the life cycle of transportation construction materials. This work will be organized into two different parts. The first part will consist of six sections: applications of nanotechnology in concrete pavements, applications of nanotechnology in asphalt pavement, application of nanotechnology in general soils, cost-benefit analysis, challenges, and trends to the future. In addition, a current practice review was performed from a literature review that included a questionnaire of the knowledge and opinion about nanotechnology, which included students, general contractors, teachers, engineers, and architects. The second part will deal with the advancement of the application of nanotechnology in pavement materials for different developed countries. Because nanotechnology is relatively a young field in pavement materials, limited research has been conducted in North America, Europe, and Asia. A comparison of the advancement of nano-science-based principles, as applied to the performance and life cycle of transportation materials, for the three continents will be carried out in a summarized manner.

  5. The Greenhouse Gas Emission from Portland Cement Concrete Pavement Construction in China.

    Science.gov (United States)

    Ma, Feng; Sha, Aimin; Yang, Panpan; Huang, Yue

    2016-06-24

    This study proposes an inventory analysis method to evaluate the greenhouse gas (GHG) emissions from Portland cement concrete pavement construction, based on a case project in the west of China. The concrete pavement construction process was divided into three phases, namely raw material production, concrete manufacture and pavement onsite construction. The GHG emissions of the three phases are analyzed by a life cycle inventory method. The CO₂e is used to indicate the GHG emissions. The results show that for 1 km Portland cement concrete pavement construction, the total CO₂e is 8215.31 tons. Based on the evaluation results, the CO₂e of the raw material production phase is 7617.27 tons, accounting for 92.7% of the total GHG emissions; the CO₂e of the concrete manufacture phase is 598,033.10 kg, accounting for 7.2% of the total GHG emissions. Lastly, the CO₂e of the pavement onsite construction phase is 8396.59 kg, accounting for only 0.1% of the total GHG emissions. The main greenhouse gas is CO₂ in each phase, which accounts for more than 98% of total emissions. N₂O and CH₄ emissions are relatively insignificant.

  6. PAHs underfoot: Contaminated dust from coal-tar sealcoated pavement is widespread in the United States

    Science.gov (United States)

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

    2009-01-01

    We reported in 2005 that runoff from parking lots treated with coal-tar-based sealcoat was a major source of polycyclic aromatic hydrocarbons (PAHs) to streams in Austin, Texas. Here we present new data from nine U. S. cities that show nationwide patterns in concentrations of PAHs associated with sealcoat Dust was swept from parking lots in six cities in the central and eastern U. S., where coal-tar-based sealcoat dominates use, and three cities in the western U. S., where asphalt-based sealcoat dominates use. For six central and eastern cities, median ?? PAH concentrations in dust from sealcoated and unsealcoated pavement are 2200 and 27 mg/kg, respectively. For three western cities, median ?? PAH concentrations in dust from sealcoated and unsealcoated pavement are similar and very low (2. 1 and 0. 8 mg/kg, respectively). Lakes in the central and eastern cities where pavement was sampled have bottom sediments with higher PAH concentrations than do those in the western cities relative to degree of urbanization. Bottom-sediment PAH assemblages are similar to those of sealcoated pavement dust regionally, implicating coal-tar-based sealcoat as a PAH source to the central and eastern lakes. Concentrations of benzo[a]pyrene in dust from coal-tar sealcoated pavement and adjacent soils greatly exceed generic soil screening levels, suggesting that research on human-health risk is warranted.

  7. Research on construction technology for orthotropic steel deck pavement of Haihe River Chunyi Bridge

    Science.gov (United States)

    Xue, Y. C.; Qian, Z. D.; Zhang, M.

    2017-01-01

    In order to ensure the good service quality of orthotropic steel deck pavement of Haihe River Chunyi Bridge in Tianjin, and to reduce the occurrence of pavement diseases like lateral and longitudinal cracks, the key working procedures such as steel deck cleaning, anticorrosive coating, bonding layer spraying, seam cutting, epoxy asphalt concrete’s mixing, transportation, paving and compaction were studied. The study was based on the main features of epoxy asphalt concrete which is the pavement materials of Haihe River Chunyi Bridge, and combined with the basic characteristics and construction conditions of Haihe River Chunyi Bridge. Furthermore, some processing measures like controlling time and temperature, continuous paving with two pavers, lateral feeding, and improving the compaction method were proposed. The project example shows that the processing measures can effectively solve the technical difficulties in the construction of orthotropic steel deck pavement of Haihe River Chunyi Bridge, can greatly improve the construction speed and quality, and can provide reference for the same kinds of orthotropic steel deck pavement construction.

  8. Effects on evaporation rates from different water-permeable pavement designs.

    Science.gov (United States)

    Starke, P; Göbel, P; Coldewey, W G

    2011-01-01

    The urban water balance can be attenuated to the natural by water-permeable pavements (WPPs). Furthermore, WPPs have a 16% higher evaporation rate than impermeable pavements, which can lead to a better urban climate. Evaporation rates from pavements are influenced by the pavement surface and by the deeper layers. By a compared evaporation measurement between different WPP designs, the grain size distribution of the sub-base shows no influence on the evaporation rates in a significant way. On the contrary, a sub-base made of a twin-layer decreases the evaporation by 16% compared to a homogeneous sub-base. By a change in the colour of the paving stone, 19% higher evaporation rates could be achieved. A further comparison shows that the transpiration-effect of the grass in grass pavers increases the evaporation rates more than threefold to pervious concrete pavements. These high evapotranspiration rates can not be achieved with a pervious concrete paving stone. In spite of this, the broad field of application of the pervious concrete paving stone increases the importance in regard to the urban climate.

  9. Application of viscoelastic continuum damage approach to predict fatigue performance of Binzhou perpetual pavements

    Directory of Open Access Journals (Sweden)

    Wei Cao

    2016-04-01

    Full Text Available For this study, the Binzhou perpetual pavement test sections constructed in Shandong Province, China, were simulated for long-term fatigue performance using the layered viscoelastic pavement analysis for critical distresses (LVECD finite element software package. In this framework, asphalt concrete was treated in the context of linear viscoelastic continuum damage theory. A recently developed unified fatigue failure criterion that defined the boundaries of the applicable region of the theory was also incorporated. The mechanistic modeling of the fatigue mechanisms was able to accommodate the complex temperature variations and loading conditions of the field pavements in a rigorous manner. All of the material models were conveniently characterized by dynamic modulus tests and direct tension cyclic fatigue tests in the laboratory using cylindrical specimens. By comparing the obtained damage characteristic curves and failure criteria, it is found that mixtures with small aggregate particle sizes, a dense gradation, and modified asphalt binder tended to exhibit the best fatigue resistance at the material level. The 15-year finite element structural simulation results for all the test sections indicate that fatigue performance has a strong dependence on the thickness of the asphalt pavements. Based on the predicted location and severity of the fatigue damage, it is recommended that Sections 1 and 3 of the Binzhou test sections be employed for perpetual pavement design.

  10. Life Cycle Assessment of Pavements: A Critical Review of Existing Literature and Research

    Energy Technology Data Exchange (ETDEWEB)

    Santero, Nicholas; Masanet, Eric; Horvath, Arpad

    2010-04-20

    This report provides a critical review of existing literature and modeling tools related to life-cycle assessment (LCA) applied to pavements. The review finds that pavement LCA is an expanding but still limited research topic in the literature, and that the existing body of work exhibits methodological deficiencies and incompatibilities that serve as barriers to the widespread utilization of LCA by pavement engineers and policy makers. This review identifies five key issues in the current body of work: inconsistent functional units, improper system boundaries, imbalanced data for asphalt and cement, use of limited inventory and impact assessment categories, and poor overall utility. This review also identifies common data and modeling gaps in pavement LCAs that should be addressed in future work. These gaps include: the use phase (rolling resistance, albedo, carbonation, lighting, leachate, and tire wear and emissions), asphalt fumes, feedstock energy of bitumen, traffic delay, the maintenance phase, and the end-of-life phase. This review concludes with a comprehensive list of recommendations for future research, which shed light on where improvements in knowledge can be made that will benefit the accuracy and comprehensiveness of pavement LCAs moving forward.

  11. Network level pavement evaluation with 1 mm 3D survey system

    Directory of Open Access Journals (Sweden)

    Kelvin C.P. Wang

    2015-12-01

    Full Text Available The latest iteration of PaveVision3D Ultra can obtain true 1 mm resolution 3D data at full-lane coverage in all 3 directions at highway speed up to 60 mph. This paper introduces the PaveVision3D Ultra technology for rapid network level pavement survey on approximately 1280 center miles of Oklahoma interstate highways. With sophisticated automated distress analyzer (ADA software interface, the collected 1 mm 3D data provide Oklahoma Department of Transportation (ODOT with comprehensive solutions for automated evaluation of pavement surface including longitudinal profile for roughness, transverse profile for rutting, predicted hydroplaning speed for safety analysis, and cracking and various surface defects for distresses. The pruned exact linear time (PELT method, an optimal partitioning algorithm, is implemented to identify change points and dynamically determine homogeneous segments so as to assist ODOT effectively using the available 1 mm 3D pavement surface condition data for decision-making. The application of 1 mm 3D laser imaging technology for network survey is unprecedented. This innovative technology allows highway agencies to access its options in using the 1 mm 3D system for its design and management purposes, particularly to meet the data needs for pavement management system (PMS, pavement ME design and highway performance monitoring system (HPMS.

  12. Analysing the accuracy of pavement performance models in the short and long terms: GMDH and ANFIS methods

    NARCIS (Netherlands)

    Ziari, H.; Sobhani, J.; Ayoubinejad, J.; Hartmann, T.

    2016-01-01

    The accuracy of pavement performance prediction is a critical part of pavement management and directly influences maintenance and rehabilitation strategies. Many models with various specifications have been proposed by researchers and used by agencies. This study presents nine variables affecting pa

  13. Mechanics based model for predicting structure-induced rolling resistance (SRR) of the tire-pavement system

    Science.gov (United States)

    Shakiba, Maryam; Ozer, Hasan; Ziyadi, Mojtaba; Al-Qadi, Imad L.

    2016-11-01

    The structure-induced rolling resistance of pavements, and its impact on vehicle fuel consumption, is investigated in this study. The structural response of pavement causes additional rolling resistance and fuel consumption of vehicles through deformation of pavement and various dissipation mechanisms associated with inelastic material properties and damping. Accurate and computationally efficient models are required to capture these mechanisms and obtain realistic estimates of changes in vehicle fuel consumption. Two mechanistic-based approaches are currently used to calculate vehicle fuel consumption as related to structural rolling resistance: dissipation-induced and deflection-induced methods. The deflection-induced approach is adopted in this study, and realistic representation of pavement-vehicle interactions (PVIs) is incorporated. In addition to considering viscoelastic behavior of asphalt concrete layers, the realistic representation of PVIs in this study includes non-uniform three-dimensional tire contact stresses and dynamic analysis in pavement simulations. The effects of analysis type, tire contact stresses, pavement viscoelastic properties, pavement damping coefficients, vehicle speed, and pavement temperature are then investigated.

  14. Proportioning of Steel Fibre Reinforced Concrete Mixes for Pavement Construction and Their Impact on Environment and Cost

    Directory of Open Access Journals (Sweden)

    Stelios Kallis

    2011-07-01

    Full Text Available Steel fibre reinforced concrete (SFRC is a construction material investigated for more than 40 years including for pavement applications. A number of studies have demonstrated the technical merits of SFRC pavements over conventional concrete pavements; however little work has been carried out on the environmental and economical impact of SFRC during the pavement’s life cycle. Therefore, extended research was undertaken within the framework of the EU funded project “EcoLanes” to estimate the environmental and economical loadings of SFRC pavements. The innovative concept of the project is the use of recycled steel tyre-cord wire as concrete fibre reinforcement, which provides additional environmental benefits for tyre recycling over landfilling. Within the project framework a demonstration of a steel-fibre-reinforced roller-compacted concrete (SFR-RCC pavement was constructed in a rural area in Cyprus. In order to assess the economical and environmental picture of the demonstration pavement, life cycle cost analysis (LCCA and life cycle assessment (LCA studies were undertaken, which also compared the under study pavement design with four conventional alternatives. The main output of the studies is that SFR-RCC is more environmentally and economically sustainable than others. In addition, various concrete mix designs were investigated by considering parameters such as fibre type and dosage, cement type, and transportation distances to the construction site. Fibre dosage has been highlighted as a crucial factor compared with economical and environmental loadings in SFR-RCC pavement construction.

  15. Recycled asphalt pavement - fly ash geopolymers as a sustainable pavement base material: Strength and toxic leaching investigations.

    Science.gov (United States)

    Hoy, Menglim; Horpibulsuk, Suksun; Rachan, Runglawan; Chinkulkijniwat, Avirut; Arulrajah, Arul

    2016-12-15

    In this research, a low-carbon stabilization method was studied using Recycled Asphalt Pavement (RAP) and Fly Ash (FA) geopolymers as a sustainable pavement material. The liquid alkaline activator (L) is a mixture of sodium silicate (Na2SiO3) and sodium hydroxide (NaOH), and high calcium FA is used as a precursor to synthesize the FA-RAP geopolymers. Unconfined Compressive Strength (UCS) of RAP-FA blend and RAP-FA geopolymer are investigated and compared with the requirement of the national road authorities of Thailand. The leachability of the heavy metals is measured by Toxicity Characteristic Leaching Procedure (TCLP) and compared with international standards. The Scanning Electron Microscopy (SEM) analysis of RAP-FA blend indicates the Calcium Aluminate (Silicate) Hydrate (C-A-S-H) formation, which is due to a reaction between the high calcium in RAP and high silica and alumina in FA. The low geopolymerization products (N-A-S-H) of RAP-FA geopolymer at NaOH/Na2SiO3=100:0 are detected at the early 7days of curing, hence its UCS is lower than that of RAP-FA blend. The 28-day UCS of RAP-FA geopolymers at various NaOH/Na2SiO3 ratios are significantly higher than that of the RAP-FA blend, which can be attributed to the development of geopolymerization reactions. With the input of Na2SiO3, the highly soluble silica from Na2SiO3 reacted with leached silica and alumina from FA and RAP and with free calcium from FA and RAP; hence the coexistence of N-A-S-H gel and C-A-S-H products. Therefore, the 7-day UCS values of RAP-FA geopolymers increase with decreasing NaOH/Na2SiO3 ratio. TCLP results demonstrated that there is no environmental risk for both RAP-FA blends and RAP-FA geopolymers in road construction. The geopolymer binder reduces the leaching of heavy metal in RAP-FA mixture. The outcomes from this research will promote the move toward increased applications of recycled materials in a sustainable manner in road construction.

  16. Cytokinin signaling regulates pavement cell morphogenesis in Arabidopsis

    Institute of Scientific and Technical Information of China (English)

    Hongjiang Li; Tongda Xu; Deshu Lin; Mingzhang Wen; Mingtang Xie; Jér(o)me Duclercq; Agnieszka Bielach

    2013-01-01

    The puzzle piece-shaped Arabidopsis leaf pavement cells (PCs) with interdigitated lobes and indents is a good model system to investigate the mechanisms that coordinate cell polarity and shape formation within a tissue.Auxin has been shown to coordinate the interdigitation by activating ROP GTPase-dependent signaling pathways.To identify additional components or mechanisms,we screened for mutants with abnormal PC morphogenesis and found that cytokinin signaling regulates the PC interdigitation pattern.Reduction in cytokinin accumulation and defects in cytokinin signaling (such as in ARR7-over-expressing lines,the ahk3cre1 cytokinin receptor mutant,and the ahp12345 cytokinin signaling mutant) enhanced PC interdigitation,whereas over-production of cytokinin and over-activation of cytokinin signaling in an ARR20 over-expression line delayed or abolished PC interdigitation throughout the cotyledon.Genetic and biochemical analyses suggest that cytokinin signaling acts upstream of ROPs to suppress the formation of interdigitated pattern.Our results provide novel mechanistic understanding of the pathways controlling PC shape and uncover a new role for cytokinin signaling in cell morphogenesis.

  17. GPR abilities in investigation of the pavement transversal cracks

    Science.gov (United States)

    Krysiński, Lech; Sudyka, Jacek

    2013-10-01

    This paper describes the results of an investigation into the capabilities of the GPR technique within the field of pavement crack diagnostics. Initially, laboratory tests were performed on prototypes simulating idealized cracks. Next, long-term visual observation and repeated GPR scanning were performed, on three roads of semi-rigid construction, several hundreds of meters long and subjected to heavy traffic. Furthermore, a road of rigid construction was tested, having a more than 70-year history of use. In several cases the cracks were probed by drillings, in order to recognize structures responsible for signal generation, or to explain reasons of signal lacking. The main result of this work is a list of GPR indications of cracks, which can be noticed on echograms. It was created through a correlation of the visually-observed cracks with the corresponding echograms, with decimeter accuracy. Several types of GPR responses were classified and linked to possible categories of crack structures, or to processes associated with the presence of cracks (as crumbling, erosion, and lithological alterations). The poor visibility of cracks was also studied, due to small crack size, or to the blurred character of the damaged area, or else to masking effects related to coarse grains in the asphalt mixture. The efficiency of the proposed method for the identification and localization of cracks is higher when a long-term GPR observation is performed.

  18. Road dust from pavement wear and traction sanding

    Energy Technology Data Exchange (ETDEWEB)

    Kupiainen, K.

    2007-07-01

    Vehicles affect the concentrations of ambient airborne particles through exhaust emissions, but particles are also formed in the mechanical processes in the tire-road interface, brakes, and engine. Particles deposited on or in the vicinity of the road may be re-entrained, or resuspended, into air through vehicle-induced turbulence and shearing stress of the tires. A commonly used term for these particles is 'road dust'. The processes affecting road dust emissions are complex and currently not well known. Road dust has been acknowledged as a dominant source of PM10 especially during spring in the sub-arctic urban areas, e.g. in Scandinavia, Finland, North America and Japan. The high proportion of road dust in sub-arctic regions of the world has been linked to the snowy winter conditions that make it necessary to use traction control methods. Traction control methods include dispersion of traction sand, melting of ice with brine solutions, and equipping the tires with either metal studs (studded winter tires), snow chains, or special tire design (friction tires). Several of these methods enhance the formation of mineral particles from pavement wear and/or from traction sand that accumulate in the road environment during winter. When snow and ice melt and surfaces dry out, traffic-induced turbulence makes some of the particles airborne. A general aim of this study was to study processes and factors underlying and affecting the formation and emissions of road dust from paved road surfaces. Special emphasis was placed on studying particle formation and sources during tire road interaction, especially when different applications of traction control, namely traction sanding and/or winter tires were in use. Respirable particles with aerodynamic diameter below 10 micrometers (PM10) have been the main concern, but other size ranges and particle size distributions were also studied. The following specific research questions were addressed: (i) How do traction

  19. The use of reflective and permeable pavements as a potential practice for heat island mitigation and stormwater management

    Science.gov (United States)

    Li, H.; Harvey, J. T.; Holland, T. J.; Kayhanian, M.

    2013-03-01

    To help address the built environmental issues of both heat island and stormwater runoff, strategies that make pavements cooler and permeable have been investigated through measurements and modeling of a set of pavement test sections. The investigation included the hydraulic and thermal performance of the pavements. The permeability results showed that permeable interlocking concrete pavers have the highest permeability (or infiltration rate, ˜0.5 cm s-1). The two permeable asphalt pavements showed the lowest permeability, but still had an infiltration rate of ˜0.1 cm s-1, which is adequate to drain rainwater without generating surface runoff during most typical rain events in central California. An increase in albedo can significantly reduce the daytime high surface temperature in summer. Permeable pavements under wet conditions could give lower surface temperatures than impermeable pavements. The cooling effect highly depends on the availability of moisture near the surface layer and the evaporation rate. The peak cooling effect of watering for the test sections was approximately 15-35 °C on the pavement surface temperature in the early afternoon during summer in central California. The evaporative cooling effect on the pavement surface temperature at 4:00 pm on the third day (25 h after watering) was still 2-7 °C lower compared to that on the second day, without considering the higher air temperature on the third day. A separate and related simulation study performed by UCPRC showed that full depth permeable pavements, if designed properly, can carry both light-duty traffic and certain heavy-duty vehicles while retaining the runoff volume captured from an average California storm event. These preliminarily results indicated the technical feasibility of combined reflective and permeable pavements for addressing the built environment issues related to both heat island mitigation and stormwater runoff management.

  20. Research on segregation evaluation methods of asphalt pavement based on air voids distribution

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Eye observation was used to evaluate the segregation degree of asphalt pavement, which was not much creditable. To the asphalt pavement, road surface texture measuring method which has appeared recently can identify gradational segregation; but it can't reflect the influence of the temperature segregation. However,using infrared temperature detector to evaluate the segregation must be taken during paving, which brings much inconvenience. In this paper, measuring the air voids distribution using non-nuclear density gauge to evaluate asphalt pavement segregation was introduced. Result shows that this method can directly reflect the comprehensive results of the two types of segregation in a high efficient and accurate way. Moreover, using the sketch map of segregation area can help to analyze the segregation reason visually.

  1. Road pavement condition mapping and assessment using remote sensing data based on MESMA

    Science.gov (United States)

    Pan, Y.; Zhang, X.; Jin, X.; Yu, H.; Rao, J.; Tian, S.; Luo, L.; Li, C.

    2016-04-01

    Remote sensing can be used to monitor changes of asphalt pavement condition because of the spectral change of aged asphalt material. However, owing to coarse spatial resolution of images and the limited width of roads ambient land cover types (e.g. vegetation, buildings, and soil) affect the spectral signal and add significant variability and uncertainty to analysis of road conditions. To overcome this problem, Multiple Endmember Spectral Mixture Analysis (MESMA) was tested to map asphalt pavement condition using WorldView-2 satellite imagery with eight bands spanning from visible to near infrared. Results indicated that MESMA run in a three-endmember model models mixed-pavement pixels well with a low average RMSE (0.01).

  2. New Technology and Experimental Study on Snow-Melting Heated Pavement System in Tunnel Portal

    Directory of Open Access Journals (Sweden)

    Jinxing Lai

    2015-01-01

    Full Text Available In recent years, with the rapid growth of economy and sharp rise of motor vehicles in China, the pavement skid resistance in tunnel portals has become increasingly important in cold region. However, the deicing salt, snow removal with machine, and other antiskid measures adopted by highway maintenance division have many limitations. To improve the treatment effect, we proposed a new snow-melting approach employing electric heat tracing, in which heating cables are installed in the structural layer of road. Through the field experiment, laboratory experiment, and numerical investigation, structure type, heating power, and preheating time of the flexible pavement heating system in tunnel portal were systematically analyzed, and advantages of electric heat tracing technology in improving the pavement skid resistance in tunnel portal were also presented. Therefore, such new technology, which offers new snow-melting methods for tunnel portal, bridge, mountainous area, and large longitudinal slope in cold region, has promising prospect for extensive application.

  3. 3-D cohesive finite element model for application in structural analysis of heavy duty composite pavements

    DEFF Research Database (Denmark)

    Skar, Asmus; Poulsen, Peter Noe

    2015-01-01

    , it can be shown that adequately good prediction of the structural response of composite pavements is obtained for monotonic loading without significant computational cost, making the model applicable for engineering design purpose. It is envisaged that the methodology implemented in this study can...... options and would yield unrealistic results in ultimate loading conditions. Cohesive modelling is one of the primary methods to handle localised damage in quasi-brittle materials, e.g., concrete, describing the potential crack in a discrete manner. To increase the versatility of existing methods...... this paper presents a numerical analysis of the fracture behaviour of cement bound granular mixtures in composite concrete block pavement systems applying a cohesive model. The functionality of the proposed model is compared to experimental investigations of beam bending tests. The pavement is modelled...

  4. Viscoroute 2.0: a tool for the simulation of moving load effects on asphalt pavement

    CERN Document Server

    Chabot, Armelle; Deloffre, Lydie; Duhamel, Denis

    2010-01-01

    As shown by strains measured on full scale experimental aircraft structures, traffic of slow-moving multiple loads leads to asymmetric transverse strains that can be higher than longitudinal strains at the bottom of asphalt pavement layers. To analyze this effect, a model and a software called ViscoRoute have been developed. In these tools, the structure is represented by a multilayered half-space, the thermo-viscoelastic behaviour of asphalt layers is accounted by the Huet-Sayegh rheological law and loads are assumed to move at constant speed. First, the paper presents a comparison of results obtained with ViscoRoute to results stemming from the specialized literature. For thick asphalt pavement and several configurations of moving loads, other ViscoRoute simulations confirm that it is necessary to incorporate viscoelastic effects in the modelling to well predict the pavement behaviour and to anticipate possible damages in the structure.

  5. Application of cluster analysis to preventive maintenance scheme design of pavement

    Institute of Scientific and Technical Information of China (English)

    ZENG Feng; ZHANG Xiao-ning

    2009-01-01

    To quantitatively identify the maintenance demand for each highway segments in the pavement main-tenance scheme design, a mathematical model of uniform segment division was established and an approach of applying cluster analysis theory to the uniform segment division and evaluation of pavement maintenance demand was proposed.The actual maintenance project of a highway carried out in Guangdong province was cited as an example to demonstrate the validity of the proposed method.It is proved that the cluster analysis can eliminate human factors in classification without being constrained by the quantities of samples, considering muhiple pavement distress indexes and the continuity of samples.Thus it is evident that cluster analysis is an efficient analytical tool in uniform segment division and evaluation of maintenance demand.

  6. Analysis on durability of asphalt pavement%沥青路面耐久性分析

    Institute of Scientific and Technical Information of China (English)

    车守忠

    2011-01-01

    简要介绍了我国沥青混凝土路面使用现状,针对沥青路面的损坏问题进行了分析,分别阐述了影响沥青路面耐久性的内部因素和外部因素,从原材料、配合比、防水设计等方面入手提出了耐久性改善措施,以期指导实践。%This paper briefly introduced the current situation of asphalt concrete pavements in our country,according to the damage problems of asphalt pavement made analysis,elaborated separately the internal factors and external factors which affect the durability of asphalt pavement,put forward durability improvement measures from raw materials,mixing ratio,waterproof design and other aspects,in order to guide practice.

  7. Plastic Damage Model to Evaluate the Fracture Size of Semi-Rigid Base Pavement

    Directory of Open Access Journals (Sweden)

    Cao Peng

    2013-01-01

    Full Text Available A simple supported beam model has been presented to simulate the response of semi-rigid pavement structure, which are consistent of the upper layer, middle layer, bottom layer, base and sub base course, during the cycle vehicle loading. This mechanics model coupled with plastic-damage mechanics model could simulate the limit broken of the pavement structure in condition that soil base layer losing bearing capacity gradually. In the meanwhile, numerical calculations based on preceding mechanics model, using the FEM software ABAQUS, have been used to define the broken size of beam. The results indicated that: when the size of simple supported beam expanded to 10 m, brittle damage could happen immediately, Just the standard vehicle loading (about 0.7 Mpa has been implement once. Objective of this study is to provide a physical and rather concrete explanation for the style and concept of the semi-rigid pavement brittle broken.

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

    Directory of Open Access Journals (Sweden)

    Kevin C. Foye

    2011-01-01

    Full Text Available 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 experiences of a design-build contractor integrating a geosynthetic ground improvement program with a RAP base during the reconstruction of a 1.95 ha asphalt parking lot. Field observations of base course construction with RAP explore some of the implications of laboratory findings. A number of interesting observations on the technical, construction, and economic issues resulting from the project challenges and the use of RAP are presented.

  9. Oxygen demand of aircraft and airfield pavement deicers and alternative freezing point depressants

    Science.gov (United States)

    Corsi, Steven R.; Mericas, Dean; Bowman, George

    2012-01-01

    Aircraft and pavement deicing formulations and other potential freezing point depressants were tested for biochemical oxygen demand (BOD) and chemical oxygen demand (COD). Propylene glycol-based aircraft deicers exhibited greater BOD5 than ethylene glycol-based aircraft deicers, and ethylene glycol-based products had lower degradation rates than propylene glycol-based products. Sodium formate pavement deicers had lower COD than acetate-based pavement deicers. The BOD and COD results for acetate-based pavement deicers (PDMs) were consistently lower than those for aircraft deicers, but degradation rates were greater in the acetate-based PDM than in aircraft deicers. In a 40-day testing of aircraft and pavement deicers, BOD results at 20°C (standard) were consistently greater than the results from 5°C (low) tests. The degree of difference between standard and low temperature BOD results varied among tested products. Freshwater BOD test results were not substantially different from marine water tests at 20°C, but glycols degraded slower in marine water than in fresh water for low temperature tests. Acetate-based products had greater percentage degradation than glycols at both temperatures. An additive component of the sodium formate pavement deicer exhibited toxicity to the microorganisms, so BOD testing did not work properly for this formulation. BOD testing of alternative freezing point depressants worked well for some, there was little response for some, and for others there was a lag in response while microorganisms acclimated to the freezing point depressant as a food source. Where the traditional BOD5 test performed adequately, values ranged from 251 to 1,580 g/kg. Where the modified test performed adequately, values of BOD28 ranged from 242 to 1,540 g/kg.

  10. Comparative Evaluation of Pavement Crack Detection Using Kernel-Based Techniques in Asphalt Road Surfaces

    Science.gov (United States)

    Miraliakbari, A.; Sok, S.; Ouma, Y. O.; Hahn, M.

    2016-06-01

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

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

    Directory of Open Access Journals (Sweden)

    A. Miraliakbari

    2016-06-01

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

  12. LOW-NOISE PAVEMENT AS A WAY OF LIMITATION OF TRAFFIC NOISE LEVEL

    Directory of Open Access Journals (Sweden)

    Władysław Gardziejczyk

    2014-11-01

    Full Text Available Road surface can significantlyreduce the trafficnoise level. Depending on the characteristic of the upper surface layers the differences between the maximum rolling noise levels from passing vehicles to reach values about 10 dB (A. A special group is low-noise pavements characterized by the presence of voids above 15%. Application the porous asphalt layers or asphalt mixture type BBTM affects a significantreduction the width of land surrounded the roads where permissible equivalent sound level is exceeded. Such solutions in some cases can replace acoustic barriers. Road pavements with a higher content of voids require proper maintenance because their acoustic performances are reduced during operation.

  13. Certification Tests on Cold Patch Asphalt Repair Materials for Use in Airfield Pavements

    Science.gov (United States)

    2010-06-01

    was then applied for 60 sec to the specimens, and the deviator stress of 90 psi was applied. The test was terminated when 4% strain was reached or... pavements . ERDC-GSL TR-05-07. Vicksburg, MS: U.S. Army Engineer Research and Development Center. U.S. Air Force. 2008a. Testing protocol for rigid spall...ER D C/ G SL T R- 10 -1 4 Certification Tests on Cold Patch Asphalt Repair Materials for Use in Airfield Pavements G eo te ch ni

  14. Assessment of low temperature cracking in asphalt pavement mixes and rheological performance of asphalt binders

    Science.gov (United States)

    Sowah-Kuma, David

    Government spends a lot of money on the reconstruction and rehabilitation of road pavements in any given year due to various distresses and eventual failure. Low temperature (thermal) cracking, one of the main types of pavement distress, contributes partly to this economic loss, and comes about as a result of accumulated tensile strains exceeding the threshold tensile strain capacity of the pavement. This pavement distress leads to a drastic reduction of the pavement's service life and performance. In this study, the severity of low temperature (thermal) cracking on road pavements selected across the Province of Ontario and its predicted time to failure was assessed using the AASTHO Mechanistic-Empirical Pavement Design Guide (MEPDG) and AASHTOWARE(TM) software, with inputs such as creep compliance and tensile strength from laboratory test. Highway 400, K1, K2, Y1, Sasobit, Rediset LQ, and Rediset WMX were predicted to have a pavement in-service life above 15 years. Additionally, the rheological performance of the recovered asphalt binders was assessed using Superpave(TM) tests such as the dynamic shear rheometer (DSR) and bending beam rheometer (BBR). Further tests using modified standard protocols such as the extended bending beam rheometer (eBBR) (LS-308) test method and double-edge notched tension (DENT) test (LS-299) were employed to evaluate the failure properties associated with in service performance. The various rheological tests showed K1 to be the least susceptible to low temperature cracking compared to the remaining samples whiles Highway 24 will be highly susceptible to low temperature cracking. X-ray fluorescence (XRF) analysis was performed on the recovered asphalt binders to determine the presence of metals such as zinc (Zn) and molybdenum (Mo) believed to originate from waste engine oil, which is often added to asphalt binders. Finally, the severity of oxidative aging (hardening) of the recovered asphalt binders was also evaluated using the

  15. System Identification Method for Evaluating the Effect of Thickness Error on Backcalculated Pavement Layer Moduli

    Institute of Scientific and Technical Information of China (English)

    ZHONG Yan-hui; WANG Fu-ming; ZHANG Bei; CAI Ying-chun

    2004-01-01

    Based on system identification theory and FWD testing data, the effect of thickness error on backcalculating pavement layer moduli is studied and the method of singular value decomposition (SVD) is presented to solve the morbidity problem of sensitivity matrix in this paper.The results show that the thickness error has great effects on the backcalculated pavement layer moduli. The error of backcalculated moduli can be controlled within the range of ±15% by limiting the thickness error within the range of ±5%.

  16. Assessment of the Remaining Life of Bituminous Layers in Road Pavements

    Directory of Open Access Journals (Sweden)

    Kálmán Adorjányi

    2017-02-01

    Full Text Available In this paper, a mechanistic-empirical approach is presented for the assessment of bearing capacity condition of asphalt pavement layers by Falling Weight Deflectometer measurements and laboratory fatigue tests. The bearing capacity condition ratio was determined using past traffic data and the remaining fatigue life which was determined from multilayer pavement response model. The traffic growth rate was taken into account with finite arithmetic and geometric progressions. Fatigue resistance of layers’ bituminous materials was obtained with indirect tensile fatigue tests. Deduct curve of condition scores was derived with Weibull distribution.

  17. Polymer concrete for precast repair of continuously reinforced concrete pavement on IH 30, near Mt. Pleasant

    Science.gov (United States)

    Meyer, A. M.; McCullough, B. F.; Fowler, D. W.

    1981-08-01

    Two punchout repairs made in a continuously reinforced concrete pavement (CRCP) using precast portland cement panels are described. The two repairs, one 1.44 sq. ft., the other 36 sq. ft., were completed and opened to traffic in one afternoon. This technique provides a rapid method of repair that produces a repair that is structurally as good or better than the surrounding pavement. With a trained crew, the repair time can be reduced and thus reducing lane closure time. Since lane closure time is a critical consideration in high volume highways, this method is cost effective in those areas.

  18. Enhancing the resolution of gpr spectra for pavement engineering applications

    Science.gov (United States)

    Benedetto, F.; Benedetto, A.

    2012-04-01

    Ground Penetrating Radar (GPR) is a geophysical method that uses radar pulses to image the subsurface. This non-destructive method uses electromagnetic radiation and detects the reflected signals from subsurface structures. It can detect objects, changes in material, and voids and cracks. GPR has many applications in a number of fields. In the field of civil engineering one of the most advanced technologies used for road pavement monitoring is based on the deployment of advanced GPR systems. One of the most relevant causes of road pavement damage is often referable to water intrusion in structural layers. In this context, GPR has been recently proposed as a method to estimate moisture content in a porous medium without preventive calibration. Hence, the development of methods to obtain an estimate of the moisture content is a crucial research field involving economic, social and strategic aspects in road safety for a great number of public and private Agencies. In particular, a recent new approach was proposed to estimate moisture content in a porous medium basing on the theory of Rayleigh scattering, showing a shift of the frequency peak of the GPR spectrum towards lower frequencies as the moisture content increases in the soil. The weakness characterizing this approach is represented by the needs of high resolution signals, whereas GPR spectra are affected by low resolution. Hence, the rising requirement for high resolution leads to specific demands for improved prediction methods. Recently, a new technique combining the response of the conventional fast Fourier transform (FFT, well known for its high-precision receiving signal level) with that of the MUSIC (multiple signal classification) algorithm, well known for its super-resolution capacity has been proposed. This combined method has been proved to obtain a high precision level in quantifying the shift of the frequency peak of the GPR spectrum. This combined method can perform a reliable coarse estimate of

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

    Directory of Open Access Journals (Sweden)

    Hui Wang

    2016-01-01

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

  20. Mechanistic Methodology for Airport Pavement Design with Engineering Fabrics. Volume 1. Theoretical and Experimental Bases.

    Science.gov (United States)

    1984-08-01

    DOTIFAAIPM-8419,, Mechanistic Methodology for Program Engineering& Airport Pavement Design with Maintenance Service Engineerin Washington, D.C. 20591...Reflective cracks require labor intensive operations for crack sealing and patching, thus becoming a significant maintenance expense item. The problem of...models or prediciting allowable critical strains are not available. The problems are complicated further by the fact that since asphaltic concrete is a

  1. Fast segmentation of industrial quality pavement images using Laws texture energy measures and k -means clustering

    Science.gov (United States)

    Mathavan, Senthan; Kumar, Akash; Kamal, Khurram; Nieminen, Michael; Shah, Hitesh; Rahman, Mujib

    2016-09-01

    Thousands of pavement images are collected by road authorities daily for condition monitoring surveys. These images typically have intensity variations and texture nonuniformities that make their segmentation challenging. The automated segmentation of such pavement images is crucial for accurate, thorough, and expedited health monitoring of roads. In the pavement monitoring area, well-known texture descriptors, such as gray-level co-occurrence matrices and local binary patterns, are often used for surface segmentation and identification. These, despite being the established methods for texture discrimination, are inherently slow. This work evaluates Laws texture energy measures as a viable alternative for pavement images for the first time. k-means clustering is used to partition the feature space, limiting the human subjectivity in the process. Data classification, hence image segmentation, is performed by the k-nearest neighbor method. Laws texture energy masks are shown to perform well with resulting accuracy and precision values of more than 80%. The implementations of the algorithm, in both MATLAB® and OpenCV/C++, are extensively compared against the state of the art for execution speed, clearly showing the advantages of the proposed method. Furthermore, the OpenCV-based segmentation shows a 100% increase in processing speed when compared to the fastest algorithm available in literature.

  2. EVALUATION OF RUTTING DEPTH IN FLEXIBLE PAVEMENTS BY USING FINITE ELEMENT ANALYSIS AND LOCAL EMPIRICAL MODEL

    Directory of Open Access Journals (Sweden)

    Alaa H. Abed

    2012-01-01

    Full Text Available The objective of this research is to predict rut depth in local flexible pavements. Predication model in pavement performance is the process that used to estimate the parameter values which related to pavement structure, environmental condition and traffic loading. The different local empirical models have been used to calculate permanent deformation which include environmental and traffic conditions. Finite element analysis through ANSYS computer software is used to analyze two dimensional linear elastic plane strain problem through (Plane 82 elements. Standard Axle Load (ESAL of 18 kip (80 kN loading on an axle with dual set of tires, the wheel spacing is 13.5 in (343 mm with tire contact pressure of 87 psi (0.6 MPa is used. The pavement system is assumed to be an elastic multi-layers system with each layer being isotropic, homogeneous with specified resilient modulus and Poisson ratio. Each layer is to extend to infinity in the horizontal direction and have a finite thickness except the bottom layer. The analysis of results show that, although, the stress level decrease 14% in the leveling course and 27% in the base course, the rut depth is increased by 12 and 28% in that layers respectively because the material properties is changed.

  3. Dynamics of vehicle-pavement coupled system based on a revised flexible roller contact tire model

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    A revised flexible roller contact tire model (RFRC tire model) is proposed, which considers not only the geometric and flexible filtering effect, but also tire damping and pavement displacement. A vehi- cle-pavement coupled system is modeled as a two DOF oscillator moving along a simply supported beam on a linear viscoelastic foundation. By using the Galerkin’s and Direct Integral method, dynamical responses of the vehicle-pavement coupled system are obtained based on the RFRC tire model and the traditional single point contact tire model (SPC tire model). The simulation results are compared with test data and the validity of the proposed RFRC tire model is verified. Differences between the two models are also investigated. It is found that the dynamical behaviors for both models agree with each other quite well when road surface roughness is a long harmonic wave. On the other hand, they are different under short harmonic wave or impulse road excitation. Thus the RFRC tire model should be used to compute the tire force and investigate dynamical responses of vehicle and pavement.

  4. Modelling of composite concrete block pavement systems applying a cohesive zone model

    DEFF Research Database (Denmark)

    Skar, Asmus; Poulsen, Peter Noe

    This paper presents a numerical analysis of the fracture behaviour of the cement bound base material in composite concrete block pavement systems, using a cohesive zone model. The functionality of the proposed model is tested on experimental and numerical investigations of beam bending tests...

  5. Quantifying Evaporation and Evaluating Runoff Estimation Methods in a Permeable Pavement System - abstract

    Science.gov (United States)

    Studies on quantifying evaporation in permeable pavement systems are limited to few laboratory studies that used a scale to weigh evaporative losses and a field application with a tunnel-evaporation gauge. A primary objective of this research was to quantify evaporation for a la...

  6. A hybrid strategy in selecting diverse combinations of innovative sustainable materials for asphalt pavements

    Directory of Open Access Journals (Sweden)

    Baron Colbert

    2016-04-01

    Full Text Available This project integrates recent innovations of recycled materials used in designing and building sustainable pavements. An increasing environmental awareness and the demand for improving economic and construction efficiencies, through measures such as construction warrantees and goals to reduce air pollution under the Kyoto Protocol, have increased the efforts to implement sustainable materials in roadways. The objective of this research is to develop a systematic approach toward selecting optimum combinations of sustainable materials for the construction of asphalt pavements. The selected materials, warm mix asphalt (WMA, recycled asphalt shingles (RAS, and reclaimed asphalt pavement (RAP were incorporated in this study. The results of this research are intended to serve as guidelines in the selection of the mixed sustainable materials for asphalt pavements. The approach developed from this project draws upon previous research efforts integrating graphical modeling with optimizing the amount of sustainable materials based on the performance. With regard to moisture susceptibility and rutting potential test results, as well as the MIM analysis based on a 95% confidence interval, the rutting performance and moisture susceptibility of asphalt mixtures are not significantly different regardless of the percentages of RAS, RAP, or WMA. The optimum mixture choices could be made by the plant emission rankings with consideration of the optimal WMA types, percentages of RAS/RAP, and WMA production temperatures. The WMA mixtures prepared with 75% RAP and Advera® WMA have produced the lowest CO2 emissions among the investigated mixture types.

  7. Permeable Pavement Research at NRMRL’s Urban Watershed Research Facility

    Science.gov (United States)

    The results of a bench-scale study of a porous pavement parking lot. Flow rates and total suspended solids (TSS) removal are discussed for systems with a geotextile filter fabric liner in place and those without. The systems with a liner have ~20% better TSS removal performance a...

  8. Coal-tar-based pavement sealcoat, polycyclic aromatic Hydrocarbons (PAHs), and environmental health

    Science.gov (United States)

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

    2011-01-01

    Studies by the U.S. Geological Survey (USGS) have identified coal-tar-based sealcoat-the black, viscous liquid sprayed or painted on asphalt pavement such as parking lots-as a major source of polycyclic aromatic hydrocarbon (PAH) contamination in urban areas for large parts of the Nation. Several PAHs are suspected human carcinogens and are toxic to aquatic life.

  9. The development and geometry of shape change in Arabidopsis thaliana cotyledon pavement cells

    Directory of Open Access Journals (Sweden)

    Halsey Leah E

    2011-02-01

    Full Text Available Abstract Background The leaf epidermis is an important architectural control element that influences the growth properties of underlying tissues and the overall form of the organ. In dicots, interdigitated pavement cells are the building blocks of the tissue, and their morphogenesis includes the assembly of specialized cell walls that surround the apical, basal, and lateral (anticlinal cell surfaces. The microtubule and actin cytoskeletons are highly polarized along the cortex of the anticlinal wall; however, the relationships between these arrays and cell morphogenesis are unclear. Results We developed new quantitative tools to compare population-level growth statistics with time-lapse imaging of cotyledon pavement cells in an intact tissue. The analysis revealed alternating waves of lobe initiation and a phase of lateral isotropic expansion that persisted for days. During lateral isotropic diffuse growth, microtubule organization varied greatly between cell surfaces. Parallel microtubule bundles were distributed unevenly along the anticlinal surface, with subsets marking stable cortical domains at cell indentations and others clearly populating the cortex within convex cell protrusions. Conclusions Pavement cell morphogenesis is discontinuous, and includes punctuated phases of lobe initiation and lateral isotropic expansion. In the epidermis, lateral isotropic growth is independent of pavement cell size and shape. Cortical microtubules along the upper cell surface and stable cortical patches of anticlinal microtubules may coordinate the growth behaviors of orthogonal cell walls. This work illustrates the importance of directly linking protein localization data to the growth behavior of leaf epidermal cells.

  10. Definition of Research Needs to Address Airport Pavement Distress in Cold Regions

    Science.gov (United States)

    1989-05-01

    the crack. Cedergren and of airport pavements have been addressed in an Godfrey (i974) note that 70’ of surface runoff FAA Advisory Circular (U.S...improvements in as- neering Laboratory. phalt concrete mix performance that may be Cedergren , H.R. and Godfrey, K.A. (1974) Wa- realized. ter: Key

  11. New U.S. pavement design guide will have major impact in Canada

    Energy Technology Data Exchange (ETDEWEB)

    Hein, D.

    2002-03-31

    The potential impacts and benefits that are likely to accrue to Canada with the upcoming release of the 2002 Pavement Design Guide of the American Association of State Highway and Transportation Officials (ASSHTO) are reviewed. The impact will be felt through AASHTO's 2002 mechanistic-empirical design method, a multi-level hierarchical approach based on design data requirements reflecting roadway classification and current roadway use configurations. A significant departure from the previous system is the emphasis on vehicle axle load distribution rather than equivalent single axle loads to evaluate pavement loading over service life. Specific benefits include: (1) consideration of inherent variations in materials, traffic and environmental factors in construction processes facilitating agency managers to be better able to weigh life cycle costs and cash flow in their decision making processes; (2) enhanced cost-responsibility studies through the improved ability to evaluate consequences of new pavement loading conditions; (3) ability of designers to use available and evolving materials ; (4) improved evaluation of premature pavement failures through better diagnostic techniques; and (5) better assessment of the effects of aging and that of the freeze-thaw cycle through better environmental data and analysis.

  12. Water Quality Performance of Three Side-by-Side Permeable Pavement Surface Materials: Three Year Update

    Science.gov (United States)

    Communities are increasingly installing structural low impact development (LID) practices to mange stormwater and reduce pollutant loads associated with stormwater runoff. Permeable pavement is a LID practice that has limited research on working-scale, side-by-side performance o...

  13. Re-Evaluation of the AASHTO-Flexible Pavement Design Equation with Neural Network Modeling

    Science.gov (United States)

    Tiğdemir, Mesut

    2014-01-01

    Here we establish that equivalent single-axle loads values can be estimated using artificial neural networks without the complex design equality of American Association of State Highway and Transportation Officials (AASHTO). More importantly, we find that the neural network model gives the coefficients to be able to obtain the actual load values using the AASHTO design values. Thus, those design traffic values that might result in deterioration can be better calculated using the neural networks model than with the AASHTO design equation. The artificial neural network method is used for this purpose. The existing AASHTO flexible pavement design equation does not currently predict the pavement performance of the strategic highway research program (Long Term Pavement Performance studies) test sections very accurately, and typically over-estimates the number of equivalent single axle loads needed to cause a measured loss of the present serviceability index. Here we aimed to demonstrate that the proposed neural network model can more accurately represent the loads values data, compared against the performance of the AASHTO formula. It is concluded that the neural network may be an appropriate tool for the development of databased-nonparametric models of pavement performance. PMID:25397962

  14. Dynamics of vehicle-pavement coupled system based on a revised flexible roller contact tire model

    Institute of Scientific and Technical Information of China (English)

    YANG ShaoPu; LI ShaoHua; LU YongJie

    2009-01-01

    A revised flexible roller contact tire model (RFRC tire model) is proposed, which considers not only the geometric and flexible filtering effect, but also tire damping and pavement displacement. A vehi-cle-pavement coupled system is modeled as a two DOF oscillator moving along a simply supported beam on a linear viscoelastic foundation. By using the Galerkin's and Direct Integral method, dynamical responses of the vehicle-pavement coupled system are obtained based on the RFRC tire model and the traditional single point contact tire model (SPC tire model). The simulation results are compared with test data and the validity of the proposed RFRC tire model is verified. Differences between the two models are also investigated. It is found that the dynamical behaviors for both models agree with each other quite well when road surface roughness is a long harmonic wave. On the other hand, they are different under short harmonic wave or impulse road excitation. Thus the RFRC tire model should be used to compute the tire force and investigate dynamical responses of vehicle and pavement.

  15. Agency and Design: Pavement Failure in the Transmilenio Project, Bogotá, Colombia

    DEFF Research Database (Denmark)

    Pineda, Andres Felipe Valderrama

    Transmilenio is the world’s first mass rapid bus transit system designed and built for the city of Bogotá, Colombia. Its first phase was developed and built during the years 1998-2000. The concrete pavement of the cities main corridor, Avenida Caracas and Autopista Norte, was designed and re...

  16. Re-evaluation of the AASHTO-flexible pavement design equation with neural network modeling.

    Science.gov (United States)

    Tiğdemir, Mesut

    2014-01-01

    Here we establish that equivalent single-axle loads values can be estimated using artificial neural networks without the complex design equality of American Association of State Highway and Transportation Officials (AASHTO). More importantly, we find that the neural network model gives the coefficients to be able to obtain the actual load values using the AASHTO design values. Thus, those design traffic values that might result in deterioration can be better calculated using the neural networks model than with the AASHTO design equation. The artificial neural network method is used for this purpose. The existing AASHTO flexible pavement design equation does not currently predict the pavement performance of the strategic highway research program (Long Term Pavement Performance studies) test sections very accurately, and typically over-estimates the number of equivalent single axle loads needed to cause a measured loss of the present serviceability index. Here we aimed to demonstrate that the proposed neural network model can more accurately represent the loads values data, compared against the performance of the AASHTO formula. It is concluded that the neural network may be an appropriate tool for the development of databased-nonparametric models of pavement performance.

  17. Re-evaluation of the AASHTO-flexible pavement design equation with neural network modeling.

    Directory of Open Access Journals (Sweden)

    Mesut Tiğdemir

    Full Text Available Here we establish that equivalent single-axle loads values can be estimated using artificial neural networks without the complex design equality of American Association of State Highway and Transportation Officials (AASHTO. More importantly, we find that the neural network model gives the coefficients to be able to obtain the actual load values using the AASHTO design values. Thus, those design traffic values that might result in deterioration can be better calculated using the neural networks model than with the AASHTO design equation. The artificial neural network method is used for this purpose. The existing AASHTO flexible pavement design equation does not currently predict the pavement performance of the strategic highway research program (Long Term Pavement Performance studies test sections very accurately, and typically over-estimates the number of equivalent single axle loads needed to cause a measured loss of the present serviceability index. Here we aimed to demonstrate that the proposed neural network model can more accurately represent the loads values data, compared against the performance of the AASHTO formula. It is concluded that the neural network may be an appropriate tool for the development of databased-nonparametric models of pavement performance.

  18. Dynamic Response of a Rigid Pavement Plate Based on an Inertial Soil

    Science.gov (United States)

    Gibigaye, Mohamed; Yabi, Crespin Prudence; Alloba, I. Ezéchiel

    2016-01-01

    This work presents the dynamic response of a pavement plate resting on a soil whose inertia is taken into account in the design of pavements by rational methods. Thus, the pavement is modeled as a thin plate with finite dimensions, supported longitudinally by dowels and laterally by tie bars. The subgrade is modeled via Pasternak-Vlasov type (three-parameter type) foundation models and the moving traffic load is expressed as a concentrated dynamic load of harmonically varying magnitude, moving straight along the plate with a constant acceleration. The governing equation of the problem is solved using the modified Bolotin method for determining the natural frequencies and the wavenumbers of the system. The orthogonal properties of eigenfunctions are used to find the general solution of the problem. Considering the load over the center of the plate, the results showed that the deflections of the plate are maximum about the middle of the plate but are not null at its edges. It is therefore observed that the deflection decreased 18.33 percent when the inertia of the soil is taken into account. This result shows the possible economic gain when taking into account the inertia of soil in pavement dynamic design. PMID:27382639

  19. "Comparison of some Structural Analyses Methods used for the Test Pavement in the Danish Road Testing Machine

    DEFF Research Database (Denmark)

    Baltzer, S.; Zhang, W.; Macdonald, R.;

    1998-01-01

    A flexible test pavement, instrumented to measure stresses and strains in the three primary axes with the upper 400 mm of the subgrade, has been constructed and load tested in the Danish Road Testing Machine (RTM). One objective of this research, which is part of the International Pavement Subgrade...... methods used for the RTM test pavement with data from FWD testing undertaken after the construction and loading programmes. Multilayer linear elastic forward and backcalculation methods, a finite element program and MS Excel spreadsheet based methods are compared....

  20. 高寒地区沥青路面设计%Asphalt Pavement Design in High Latitudeand Cold Regions

    Institute of Scientific and Technical Information of China (English)

    程军勤

    2015-01-01

    Combining with the development of highway pavement and key factors in pavement design,the selection of pavement structural layers in high latitude and cold regions is discussed in this paper,which can be seen as preference to similar projects.%从青海省公路路面设计的发展及设计中的关键要素等方面入手,探讨了高寒地区路面各结构层的选择,为同类地区的路面设计提供参考。

  1. Assessment of Load Capacity of the Airport Pavement Structure With the Use of the Acn-Pcn Method

    Directory of Open Access Journals (Sweden)

    Wesołowski Mariusz

    2014-12-01

    Full Text Available The structures of the airport pavements are designed for defined operational time, assuming the predicted intensity and structure of the air traffic. The safety of air operations conducted by aircrafts on airport pavements depends mostly on their load capacity and design. Therefore, the load capacity inspections should be performed periodically, as the information about the current operational condition of the airport pavement is the basis for decisions on types of aircrafts allowed for traffic, as well as traffic intensity and dates of renovation or modernization works.

  2. Structural analyses of a rigid pavement overlaying a sub-surface void

    Science.gov (United States)

    Adam, Fatih Alperen

    Pavement failures are very hazardous for public safety and serviceability. These failures in pavements are mainly caused by subsurface voids, cracks, and undulation at the slab-base interface. On the other hand, current structural analysis procedures for rigid pavement assume that the slab-base interface is perfectly planar and no imperfections exist in the sub-surface soil. This assumption would be violated if severe erosion were to occur due to inadequate drainage, thermal movements, and/or mechanical loading. Until now, the effect of erosion was only considered in the faulting performance model, but not with regards to transverse cracking at the mid-slab edge. In this research, the bottom up fatigue cracking potential, caused by the combined effects of wheel loading and a localized imperfection in the form of a void below the mid-slab edge, is studied. A robust stress and surface deflection analysis was also conducted to evaluate the influence of a sub-surface void on layer moduli back-calculation. Rehabilitative measures were considered, which included a study on overlay and fill remediation. A series regression of equations was proposed that provides a relationship between void size, layer moduli stiffness, and the overlay thickness required to reduce the stress to its original pre-void level. The effect of the void on 3D pavement crack propagation was also studied under a single axle load. The amplifications to the stress intensity was shown to be high but could be mitigated substantially if stiff material is used to fill the void and impede crack growth. The pavement system was modeled using the commercial finite element modeling program Abaqus RTM. More than 10,000 runs were executed to do the following analysis: stress analysis of subsurface voids, E-moduli back-calculation of base layer, pavement damage calculations of Beaumont, TX, overlay thickness estimations, and mode I crack analysis. The results indicate that the stress and stress intensity are, on

  3. Volatilization of polycyclic aromatic hydrocarbons from coal-tar-sealed pavement

    Science.gov (United States)

    Van Metre, Peter C.; Majewski, Michael S.; Mahler, Barbara J.; Foreman, William T.; Braun, Christopher L.; Wilson, Jennifer T.; Burbank, Teresa L.

    2012-01-01

    Coal-tar-based pavement sealants, a major source of PAHs to urban water bodies, are a potential source of volatile PAHs to the atmosphere. An initial assessment of volatilization of PAHs from coal-tar-sealed pavement is presented here in which we measured summertime gas-phase PAH concentrations 0.03 m and 1.28 m above the pavement surface of seven sealed (six with coal-tar-based sealant and one with asphalt-based sealant) and three unsealed (two asphalt and one concrete) parking lots in central Texas. PAHs also were measured in parking lot dust. The geometric mean concentration of the sum of eight frequently detected PAHs (ΣPAH8) in the 0.03-m samples above sealed lots (1320 ng m-3) during the hottest part of the day was 20 times greater than that above unsealed lots (66.5 ng m-3). The geometric mean concentration in the 1.28-m samples above sealed lots (138 ng m-3) was five times greater than above unsealed lots (26.0 ng m-3). Estimated PAH flux from the sealed lots was 60 times greater than that from unsealed lots (geometric means of 88 and 1.4 μg m-2 h-1, respectively). Although the data set presented here is small, the much higher estimated fluxes from sealed pavement than from unsealed pavement indicate that coal-tar-based sealants are emitting PAHs to urban air at high rates compared to other paved surfaces.

  4. Environmental history recorded in eolian deposits under stone pavements, eastern Mojave Desert, USA

    Science.gov (United States)

    Wells, Stephen; Fuchs, Markus; Dietze, Elisabeth; Lomax, Johanna; Kleber, Arno; Dietze, Michael

    2016-04-01

    Reconstructing the evolution of arid landscapes is challenged by the limited availability of appropriate environmental archives. A widespread surface feature of arid landscapes - stone pavement - traps eolian fines and can form an accretionary archive, growing with time and thereby recording essential information about the conditions under which it evolves. Based on a regional example in the eastern Mojave Desert, USA, seven stone pavement-covered soil-sediment sections on 560 and 270 ka old basalt flows are condensed to a correlation framework, comprising five distinct, successive sedimentological units. An OSL-based chronology enables correlation of this new sediment archive with other environmental archives from the region. Three of the stratigraphic units are of accretionary nature and the top of each unit is mantled by a new generation of stone pavement. These stratigraphic units were deposited between >32.3-20.4 ka, 20.4-16.5 ka and younger than 16.5 ka, appearing to be strongly coupled with the history of the nearby ancient Lake Mojave and enhancing our knowledge of the eolian activity in this area. End-member modelling analysis of sampled grain-size distributions allows identification of a local detritus component, four separate eolian components and two distinct clay enrichment components, contributing different quantities of sediment sources to the five stratigraphic units. These findings improve current concepts about the evolution of stone pavements and their role as conveyers of information about environmental conditions in arid landscapes. Stone pavement-covered accretionary sediment deposits are a new key archive that allows quantifying the relative importance of dust accretion, slope processes, soil formation and vegetation cover.

  5. Pavement Sealcoat, PAHs, and Water Quality of Urban Water Bodies: An Overview

    Science.gov (United States)

    Mahler, B. J.; Van Metre, P. C.; Ingersoll, C.; Kunz, J. L.; Kienzler, A.; Devaux, A.; Bony, S.

    2014-12-01

    Coal-tar-based (CT) sealcoat is used to protect and beautify the asphalt pavement of driveways and parking lots primarily in the central, southern, and northeastern U.S. and in Canada. CT sealcoat typically is 20 to 35 percent crude coal tar or coal-tar pitch and contains from 50,000 to 100,000 mg/kg PAHs, about 1,000 times more than asphalt-based (AS) sealcoat or asphalt itself. Tires and snowplows abrade the friable sealcoat surface into fine particles—PAH concentrations in fine particles (dust) from CT-sealcoated pavement are about 1,000 times higher than in dust from AS-sealcoated pavement (median total PAH concentrations 2,200 and 2.1 mg/kg, respectively). Use of CT sealcoat has several implications for urban streams and lakes. Source apportionment modeling has indicated that, in regions where CT sealcoat is prevalent, particles from sealcoated pavement are contributing the majority of the PAHs to recently deposited lake sediment, with implications for ecological health. Acute 2-d toxicity of runoff from CT-sealcoated pavement to stream biota, demonstrated for a cladoceran (Ceriodaphnia dubia) and fathead minnows (Pimephales promelas), continues for samples collected as long as weeks or months following sealcoat application. Using the fish-liver cell line RGL-W1, runoff collected as much as 36 days following CT-sealcoat application has been demonstrated to cause DNA damage and impair DNA repair capacity. These results demonstrate that CT runoff is a potential hazard to aquatic ecosystems for at least several weeks after sealant application, and that exposure to sunlight can enhance toxicity and genetic damage. Recent research has provided direct evidence that restricting use of CT sealcoat in a watershed can lead to a substantial reduction in PAH concentrations in receiving water bodies.

  6. Implications of Use of Coal-Tar-Based Pavement Sealcoat on Urban Water Quality

    Science.gov (United States)

    Van Metre, P. C.

    2015-12-01

    Coal-tar-based (CT) sealcoat is used to protect and improve the appearance of asphalt pavement of driveways and parking lots primarily in the central and eastern U.S. and in Canada. CT sealcoat typically is 20 to 35% crude coal tar or coal-tar pitch and contains from 50,000 to 100,000 mg/kg polycyclic aromatic hydrocarbons (PAH), about 1,000 times more than asphalt-based (AS) sealcoat or asphalt itself. Tires and snowplows abrade the friable sealcoat surface into fine particles—median total PAH concentrations in dust from CT-sealcoated pavement are 2,200 mg/kg compared to a median concentration of 11 mg/kg for dust from unsealed pavement. Use of CT sealcoat has several implications for urban streams and lakes. Source apportionment modeling has indicated that, in regions where CT sealcoat is prevalent, particles from sealcoated pavement are contributing the majority of the PAHs to recently deposited lake sediment, often resulting in sediment concentrations above toxicity thresholds based on effects-based sediment quality guidelines. Acute 2-day laboratory toxicity testing of simulated runoff from CT-sealcoated pavement to a cladoceran (Ceriodaphnia dubia) and fathead minnows (Pimephales promelas) demonstrated that toxicity continues for samples collected for weeks or months following sealcoat application and that toxicity is enhanced by exposure to UV light. Using the fish-liver cell line RTL-W1, runoff collected as much as 36 days following CT-sealcoat application has been demonstrated to cause DNA damage and impair DNA repair capacity. These results demonstrate that CT runoff is a potential hazard to aquatic ecosystems and that exposure to sunlight can enhance toxicity and genetic damage. Recent research has provided direct evidence that restricting use of CT sealcoat in a watershed can lead to a substantial reduction in PAH concentrations in receiving water bodies.

  7. Relation Between PAHs and Coal-Tar-Based Pavement Sealant in Urban Environments (Invited)

    Science.gov (United States)

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

    2010-12-01

    Since 2003, coal-tar-based sealant products have come under increased scrutiny as a source of PAHs in urban environments. Sealant (or sealcoat) is the black, shiny substance often applied to asphalt pavement, in particular parking lots and driveways, for esthetic and maintenance purposes. Coal-tar-based sealant, one of the two primary pavement sealant types on the market, typically is 20-35 percent coal-tar pitch, a known carcinogen that is more than 50 percent polycyclic aromatic hydrocarbons (PAHs). The PAH content of the coal-tar-based sealant product is about 1,000 times that of a similar, asphalt-based product, on average. This difference is reflected in regional differences in sealant use and PAH concentrations in pavement dust. In the central and eastern U.S., where the coal-tar-based formulation is prevalent, ΣPAH in mobile particles from sealed pavement have been shown to be about 1,000 times higher than in the western U.S., where the asphalt-based formulation is prevalent (the median ΣPAH concentrations are 2,200 mg/kg in the central and eastern U.S. and 2.1 mg/kg in the western U.S.). Source apportionment modeling indicates that, in the central and eastern U.S., particles from sealed pavement are contributing the majority of the PAHs in recently deposited (post-1990) lake sediment, with implications for ecological health, and that coal-tar-based sealant is the primary cause of upward trends in PAHs in U.S. urban lakes. From the standpoint of human health, research indicates that mobile particles from parking lots with coal-tar-based sealant are tracked indoors, resulting in elevated PAH concentrations in house dust. Coal-tar-based sealcoat being applied to an asphalt parking lot at the University of Texas Pickle Research Center.

  8. Pavement testing by integrated geophysical methods: Feasibility, resolution and diagnostic potential

    Science.gov (United States)

    Orlando, Luciana; Cardarelli, Ettore; Cercato, Michele; De Donno, Giorgio; Di Giambattista, Luca

    2017-01-01

    This work is focused on the assessment of the diagnostic potential of several geophysical methods when applied to the investigation of a rigid airport pavement. The potential and limit of each technique are evaluated as well as the added value deriving from their integration. Firstly, we reconstruct a high-resolution image of the pavement by a large electromagnetic and georadar screening. An advanced processing of georadar data, implemented through the picking of the arrival times of reflections for each profile, provides a quantitative estimation of the deviation between the design and the as-built thickness of layers. Additionally, electrical tomography has been applied to unequivocally identify the anomalous zones, where higher values of resistivity would be associated to porous zones that are prone to degradation and failure. The seismic tomographic survey had the additional purpose to recover the mechanical properties of the pavement in terms of both P- and S-waves and consequently of elastic constants (Poisson's ratio), whose values were consistent with those recovered in literature. The anomalies detected by each technique are consistent in their indications and they can be correlated to failure phenomena occurring at layer interfaces within the pavement structure or to unexpected variations of the layer thicknesses. The cost-effective geophysical campaign has validated the four-layered system deduced from the original design and has been used to reconstruct a high-resolution map of the pavement in order to discriminate fractures, crack-prone areas or areas where the as-built differs from the original design.

  9. Hydraulic and treatment performance of pervious pavements under variable drying and wetting regimes.

    Science.gov (United States)

    Yong, C F; Deletic, A; Fletcher, T D; Grace, M R

    2011-01-01

    Pervious pavements are an effective stormwater treatment technology. However, their performance under variable drying and wetting conditions have yet to be tested, particularly under a continuous time scale. This paper reports on the clogging behaviour and pollutant removal efficiency of three pervious pavement types over 26 accelerated years. These pavements were monolithic porous asphalt (PA), Permapave (PP) and modular Hydrapave (HP). Over a cycle of 13 days, the period of which was equivalent to the average annual Brisbane, Australia rainfall (1,200 mm), the pavements were randomly dosed with four different flows. Drying events of 3 h duration were simulated during each flow. Inflow and outflow samples were collected and analysed for Total Suspended Solids (TSS), Total Phosphorus (TP) and Total Nitrogen (TN). To evaluate the rate of clogging, a 1 in 5 year Brisbane storm event was simulated in the 6th, 8th, 12th, 16th, 20th and 24th week. Under normal dosing conditions, none of the pavements showed signs of clogging even after 15 years. However, under storm conditions, both PA and HP started to clog after 12 years, while PP showed no signs of clogging after 26 years. The drying and various flow events showed no effects in TSS removal, with all systems achieving a removal of approximately 100%. The average TP removal was 20% for all flows except for low flow, which had a significant amount of leaching over time. Leaching from TN was also observed during all flows except high flow. The TSS, TP and TN results observed during storm events were similar to that of high flow.

  10. Energy harvesting in pavement from passing vehicles with piezoelectric composite plate for ice melting

    Science.gov (United States)

    Faisal, Farjana; Wu, Nan; Kapoor, Kartik

    2016-04-01

    An energy harvester in the road pavement made from a piezoelectric composite plate is designed and studied to collect energy from the passing vehicles for the ice melting aim. Piezoelectric material has the ability to produce electric charge on its surface when strain takes place due to any external loading. Based on this property, a rectangular composite plate harvester is developed consisting of piezoelectric material as the energy generation coating layer and A514 steel as the substrate layer to realize the energy harvesting process from the variable pressure generated in the road pavement by passing vehicles. Based on Westergaards stress model, a numerical model is developed to calculate the three dimensional stress distribution in the pavement. Numerical simulations are conducted to study the optimization of various parameters of the harvester, such as depth of the harvester in the pavement, length and width as well as thicknesses of piezoelectric layer and the substrate. By taking in to consideration the maximum stress that can be sustained by both of the piezoelectric material and also the substrate material, an optimum design of the piezoelectric couple composite plate energy harvester is suggested. It is seen that the maximum output power, which can be generated by a single patch of 0.2m*0.2m*0.0026m dimension with a vehicle passing at 22.2 m/s, can reach up to 23.36 W. With the well-designed pavement energy harvesters, it is feasible to collect enough energy to rise the temperature of the ice with the thickness of 1cm covering a 5m width road by 20 degree Celsius within 2.5 hours. This technique can be applied to melt the ice on the roads and bridges especially in cold countries.

  11. Managing sidewalk pavement maintenance: A case study to increase pedestrian safety

    Directory of Open Access Journals (Sweden)

    Maria Vittoria Corazza

    2016-06-01

    Full Text Available Comfort is a major requirement in planning pedestrian facilities. Pedestrians walk where they feel comfortable and when they do not feel at ease, they walk elsewhere. A typical example is that filthy, distressed, or too narrow sidewalks induce pedestrians to walk on carriageways. This behaviour jeopardizes road safety and highly dangerous to most users, leave them vulnerable. Unsuitable pavements can be the result of irregular maintenance operations to restore evenness after shock damage, weather phenomena, installation of equipment (e.g., posts, fences, urban furniture with a reduction of walkable surface, or substandard repair work on pavements and patches due to emergency operations. These problems can be solved with an appropriate maintenance management system, which optimizes financial resources to make smart decisions about how to intervene with an adequate and lasting maintenance operation. This paper defines an evaluation index for sidewalk conditions as a part of an efficient set-up of a Sidewalk Management System, which is similar to the better known Road Management System. The study relies on surveys, as well as the classification and analysis of sidewalk distresses. The authors adapted an index already standardized by ASTM for roads and airports: the Pavement Condition Index (PCI. PCI has been modified to consider the specific types on the sidewalks studied within this paper. To validate the method, a case study of a residential district in Rome, Italy, was carried out. The chosen area lacks regular maintenance and has therefore resulted in a network of unsafe sidewalks. Frequent detour routes were surveyed and related to the level of distresses within a general assessment of safety. This study concentrates on sidewalks with flexible pavements because this type of pavement is the only one adopted in the survey areas and, in general, throughout Italy.

  12. Road Edge of Pavement, Road Edge of Pavement in Iredell County, NC from 2005 Orthophotography, Published in 2005, 1:2400 (1in=200ft) scale, Iredell County GIS.

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — This Road Edge of Pavement dataset, published at 1:2400 (1in=200ft) scale, was produced all or in part from Orthoimagery information as of 2005. It is described as...

  13. Road Edge of Pavement, Pavement Condition Ratings and Maintenance Designations per Street Centerline. Updated frequently by Public Works Streets Division, Published in 2006, 1:1200 (1in=100ft) scale, City of Asheville Public Works Department.

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — This Road Edge of Pavement dataset, published at 1:1200 (1in=100ft) scale, was produced all or in part from Field Observation information as of 2006. It is described...

  14. 沥青路面冷再生技术在路面维修中的应用%Application of Cold Recycling Technology of Asphalt Pavement in the Pavement Repair

    Institute of Scientific and Technical Information of China (English)

    冯国龙

    2014-01-01

    This paper analyzed several main causes of the damage of asphalt pavement and simply introduced the main techniques of the cold recycling technology of asphalt pave-ment. The author also introduced the concrete applying meth-ods of the cold regeneration technique of asphalt pavement in pavement repair.%本文针对沥青路面出现损坏的几个主要原因进行了分析,简单介绍了沥青路面冷再生技术的主要工艺,并且介绍了沥青路面冷再生技术在路面维修中的具体使用方法。

  15. Study of the Raveling Resistance of Porous Asphalt Pavements Used in Sustainable Drainage Systems Affected by Hydrocarbon Spills

    Directory of Open Access Journals (Sweden)

    Jorge Rodriguez-Hernandez

    2015-12-01

    Full Text Available Permeable pavements are one of the most commonly-used sustainable drainage systems (SuDS in urban areas for managing stormwater runoff problems. Porous asphalt is widely used in surface layers of permeable pavement systems, where it can suffer from accidental oil spills from vehicles. Oil spills affect bituminous mixes through the solvent action of the hydrocarbons on the bitumen, reducing the raveling resistance of asphalt pavements. In order to assess the raveling resistance in porous asphalt pavements, the Cantabro abrasion test was performed on 200 test samples after applying controlled oil spills. Three different types of binders were used: conventional bitumen, polymer-modified bitumen and special fuel-resistant bitumen. After analyzing the results, it was concluded that the most suitable bitumen to protect against oil leakages is the polymer-modified one, which is far better than the other two types of bitumen tested.

  16. Road Edge of Pavement, Published in Not Provided, 1:12000 (1in=1000ft) scale, Geospatial Viz.

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — This Road Edge of Pavement dataset, published at 1:12000 (1in=1000ft) scale, was produced all or in part from Road Centerline Files information as of Not Provided....

  17. Thermal stresses of flexible pavement with consideration of temperature-dependent material characteristics using stiffness matrix method

    Science.gov (United States)

    Geng, Litao; Ren, Ruibo; Zhong, Yang; Xu, Qian

    2011-02-01

    The asphalt pavement is regarded as a multilayered elastic half space axisymmetrical body. By introducing the relationship between material characteristics and temperature into the fundamental equations of thermoelasticity and using mathematic methods of Laplace and Hankel integral transformation, the stiffness matrix for a layer is derived firstly. Then the global stiffness matrix is established for multilayered elastic half space using the finite element concepts in which layers are completely contacted. Therefore, explicit solution for thermal stresses of the asphalt pavement is obtained from the solution of the algebra equation formed by global stiffness matrix and the inverse Hankel and Laplace integral transformation. Because the elements of matrix do not include positive exponential function, the calculation is not overflowed and the shortages of transfer matrix method are overcome. This approach serves as a better model for real pavement structure as it takes into account the relationships between the material characteristics and temperature in the pavement system.

  18. 城市砌块路面设计分析%On design for urban block pavement

    Institute of Scientific and Technical Information of China (English)

    王星茹

    2015-01-01

    介绍了城市砌块路面材料的技术要求,分析了砌块路面的组合结构,采用弹性层状理论,对砌块路面设计方法进行了阐述,探讨了人行道与车行道典型的路面结构形式,给出了砌块路面设计的相关数据。%The paper introduces the technical requirements for the urban block pavement materials,analyzes the composite structure of the block pavement,adopts the elastic layer theory to illustrate the design method for the block pavement,and explores the typical pavement structures be-tween sidewalks and carriageways with related data.

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

    OpenAIRE

    Hui Wang; Zepeng Fan; Jiupeng Zhang

    2016-01-01

    The rutting performance of asphalt pavement structure relies on the high temperature properties of asphalt mixture as well as the pavement structure and thickness. In order to investigate the influence of the structure and thickness, a full-depth wheel tracking test is developed in this research by improving the conventional wheel tracking test apparatus. The newly proposed test method is capable of varying its load speed and load size, controlling its specimen temperature gradient, and simul...

  20. Effects of reclaimed asphalt pavement on indirect tensile strength test of foamed asphalt mix tested in dry condition

    Science.gov (United States)

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

    2013-06-01

    Indirect tensile strength (ITS) test was conducted to analyse strength of the foamed asphalt mixes incorporating reclaimed asphalt pavement. Samples were tested for ITS after cured in the oven at 40°C for 72 hours. This testing condition known as dry condition or unconditioned. Laboratory results show that reclaimed asphalt pavement (RAP) contents insignificantly affect the ITS results. ITS results significantly affected by foamed bitumen contents.

  1. 桥面铺装与小箱梁的共同作用试验%Experiment of Coaction of Bridge Deck Pavement and Small Box Girder

    Institute of Scientific and Technical Information of China (English)

    钱寅泉; 周正茂; 袁桂芳; 王素娟

    2012-01-01

    Load tests on a single small box girder and a bridge were carried out to evaluate the effects of deck pavement by comparing the deflections of the girders before and after the pavement surfaced. The comprehensive elastic modulus was obtained from the test before pavement surfaced, and the coaction degree of the bridge deck pavement and the girders was obtained by comparing the flexural inertia moment corresponding to the deflection in the test after pavement surfaced with the theoretical flexural inertia moment corresponding to the supposed thickness of the pavement in work. The results from these tests show that (1) the rough interface could greatly improve the coaction degree of bridge deck pavement with girders, which could reach 100% ; (2) in general cases, the extent of the coaction of bridge deck pavement with girders could reach 70% , and for a pavement with thickness of 8 cm, the thickness of the pavement in coaction could be taken as 60% or 3 cm in thickness could be substracted from the pavement in design; (3 ) the pavement could improve the uniformity of the transverse load distribution. Load tests on a single small box girder and a bridge were carried out to evaluate the effects of deck pavement by comparing the deflections of the girders before and after the pavement surfaced. The comprehensive elastic modulus was obtained from the test before pavement surfaced, and the coaction degree of the bridge deck pavement and the girders was obtained by comparing the flexural inertia moment corresponding to the deflection in the test after pavement surfaced with the theoretical flexural inertia moment corresponding to the supposed thickness of the pavement in work. The results from these tests show that (1) the rough interface could greatly improve the coaction degree of bridge deck pavement with girders, which could reach 100% ; (2) in general cases, the extent of the coaction of bridge deck pavement with girders could reach 70% , and for a pavement with

  2. 论沥青路面早期损坏的预防措施%Discussion on prevention measures of early damages of asphalt pavement

    Institute of Scientific and Technical Information of China (English)

    汪香莲

    2011-01-01

    Combining with the present asphalt concrete pavement construction and caused pavement early damages,this paper analysed the reasons and preventive measures of pavement early damages from pavement structure layer,mixing ratio design,raw materials,construction control and other aspects,in order to reduce the early damage of asphalt pavement,prolong the service life of pavement.%结合当前沥青混凝土路面施工及产生的路面早期破坏,从路面结构层、配合比设计、原材料、施工控制等方面分析了路面早期破坏的原因及预防措施,以减少沥青路面早期损坏,延长路面使用寿命。

  3. 京秦高速公路路面早期破坏原因%Early Damage Reason of Jingqin Expressway Pavement

    Institute of Scientific and Technical Information of China (English)

    李伯威

    2012-01-01

    Common damage causes of asphalt design, thickness design, mixing design, pavement pavement quality are put forward. pavement are analyzed. From the aspects of pavement structure field construction and so on, technical measures for improving%对沥青路面常见病害产生的原因进行分析,并从路面结构设计、厚度设计、配合比设计及路面现场施工等方面提出提高路面质量的技术措施。

  4. State of the art and practice of pavement anti-icing and de-icing techniques

    Institute of Scientific and Technical Information of China (English)

    WenBing Yu; Xin Yi; Ming Guo; Lin Chen

    2014-01-01

    Pavement snow and icing are worldwide problems, but effective countermeasures are just beginning to be developed in China. The two most common snow and ice removal methods are mechanical clearance and chemical melting, and the advantages and disadvantages of each approach are discussed here, including environmental and structural damage caused by corrosive snow melting agents. New developments in chemical melting agents and mechanical equipment are discussed, and an overview of alternative thermal melting systems is presented, including the use of geothermy and non-geothermal heating systems utilizing solar energy, electricity, conductive pavement materials, and infrared/microwave applications. Strategic recommendations are made for continued enhancement of public safety in snow and ice conditions.

  5. A Review on Using Crumb Rubber in Reinforcement of Asphalt Pavement

    Directory of Open Access Journals (Sweden)

    Nuha Salim Mashaan

    2014-01-01

    Full Text Available An immense problem affecting environmental pollution is the increase of waste tyre vehicles. In an attempt to decrease the magnitude of this issue, crumb rubber modifier (CRM obtained from waste tyre rubber has gained interest in asphalt reinforcement. The use of crumb rubber in the reinforcement of asphalt is considered as a smart solution for sustainable development by reusing waste materials, and it is believed that crumb rubber modifier (CRM could be an alternative polymer material in improving hot mix asphalt performance properties. In this paper, a critical review on the use of crumb rubber in reinforcement of asphalt pavement will be presented and discussed. It will also include a review on the effects of CRM on the stiffness, rutting, and fatigue resistance of road pavement construction.

  6. A New Form of the General Solution of the Elastic Space Axisymmetric Problem in Pavement Mechanics

    Directory of Open Access Journals (Sweden)

    Jia Liang

    2016-01-01

    Full Text Available In order to analyze the stress and displacement of pavement, a new form of the general solution of the elastic space axisymmetric problem is proposed by the method of mathematics reasoning. Depending on the displacement function put forward by Southwell, displacement function is derived based on Hankel transform and inverse Hankel transform. A new form of the general solution of the elastic space axisymmetric problem has been set up according to a few basic equations as the geometric equations, constitutive equations, and equilibrium equations. The present solution applies to elastic half-space foundation and Winkler foundation; the stress and displacement of pavement are obtained by mathematical deduction. The example results show that the proposed method is practically feasible.

  7. Work flow of signal processing data of ground penetrating radar case of rigid pavement measurements

    Energy Technology Data Exchange (ETDEWEB)

    Handayani, Gunawan [The Earth Physics and Complex Systems Research Group (Jl. Ganesa 10 Bandung Indonesia) gunawanhandayani@gmail.com (Indonesia)

    2015-04-16

    The signal processing of Ground Penetrating Radar (GPR) requires a certain work flow to obtain good results. Even though the Ground Penetrating Radar data looks similar with seismic reflection data, but the GPR data has particular signatures that the seismic reflection data does not have. This is something to do with coupling between antennae and the ground surface. Because of this, the GPR data should be treated differently from the seismic signal data processing work flow. Even though most of the processing steps still follow the same work flow of seismic reflection data such as: filtering, predictive deconvolution etc. This paper presents the work flow of GPR processing data on rigid pavement measurements. The processing steps start from raw data, de-Wow process, remove DC and continue with the standard process to get rid of noises i.e. filtering process. Some radargram particular features of rigid pavement along with pile foundations are presented.

  8. The Effect of Joint Width on Structural Performance of Asphalt Block Pavements

    Directory of Open Access Journals (Sweden)

    Ahmed Abdelgalil

    2014-02-01

    Full Text Available Asphalt blocks have been occasionally used around the world as a road pavement, but there have been very limited studies being done to evaluate the effect of joint width (spacing between the blocks on the structural performance of asphalt paving blocks. This study explains the experimental study to assess the performance and properties of asphalt paving blocks laid with different joint widths between the blocks i.e., 0, 2 and 3 mm, respectively. A total of 250 asphalt paving blocks was manufactured and tested in the laboratory to ascertain the density, air voids, the compressive strength and the rut depth and displacement occurred in asphalt paving block. The design compressive load of single asphalt paving block is 166 kN. The test results showed that the joint width plays a vital role on the performance of asphalt block pavement. Asphalt paving blocks were laid as closely in contact as possible (0 mm yields the best structural performance.

  9. A review on using crumb rubber in reinforcement of asphalt pavement.

    Science.gov (United States)

    Mashaan, Nuha Salim; Ali, Asim Hassan; Karim, Mohamed Rehan; Abdelaziz, Mahrez

    2014-01-01

    An immense problem affecting environmental pollution is the increase of waste tyre vehicles. In an attempt to decrease the magnitude of this issue, crumb rubber modifier (CRM) obtained from waste tyre rubber has gained interest in asphalt reinforcement. The use of crumb rubber in the reinforcement of asphalt is considered as a smart solution for sustainable development by reusing waste materials, and it is believed that crumb rubber modifier (CRM) could be an alternative polymer material in improving hot mix asphalt performance properties. In this paper, a critical review on the use of crumb rubber in reinforcement of asphalt pavement will be presented and discussed. It will also include a review on the effects of CRM on the stiffness, rutting, and fatigue resistance of road pavement construction.

  10. Design of Highway Subgrade Pavement%公路路基路面设计研究

    Institute of Scientific and Technical Information of China (English)

    郝志锋

    2014-01-01

    This paper introduces the main contents and requirements of highway subgrade pavement design, especially the design of road safety engineering systems;road user behavior and road safety inspection system specification is analyzed to provide some reference for the design of highway subgrade pavement.%简要介绍了公路路基路面设计的主要内容和要求,特别对公路安全工程系统、公路用户行为规范和公路安全检查系统的设计进行了分析,为公路路基路面的设计提供一些参考。

  11. Field Performance of Asphalt Pavements with New Technologies in Northern Nevada

    Science.gov (United States)

    Faeth, Benjamin Michael

    The Regional Transportation Commission (RTC) of the Washoe Valley Area has been tasked to determine if three advanced asphalt pavement technologies and one modified aggregate gradation are suitable for implementation within Reno, Stead, and Sparks Nevada. This was accomplished through research and test roads and Intersections to determine if Recycled Asphalt Pavement (RAP), Warm Mix Asphalt (WMA), Polymer-Modified Asphalt Binder, and the Type 2-R aggregate gradation were succeeding in their design plans. Over the course of several years the streets being used by RTC to test the technologies are succeeding within their design lifespans, and the Intersections being used to test the Type 2-R aggregate gradation are showing significant resistance to rutting. Due to the roads and Intersections not being more than 10 years old, these conclusions are subject to change over time.

  12. Dynamic response of concrete pavement structure with asphalt isolating layer under moving loads

    Directory of Open Access Journals (Sweden)

    Jianmin Wu

    2014-12-01

    Full Text Available A three-dimensional finite element model (3D FEM is built using ABAQUS to analyze the dynamic response of a concrete pavement structure with an asphalt isolating layer under moving loads. The 3D model is prepared and validated in the state of no asphalt isolating layer. Stress and deflection at the critical load position are calculated by changing thickness, modulus of isolating layer and the combination between the isolating layer and concrete slab. Analysis result shows that the stress and deflection of the concrete slab increase with the increase of thickness. The stress and deflection of the concrete slab decrease with the increase of combination between the isolating layer and concrete slab. The influence of changing the isolating layer modulus to the stress and deflection of the concrete slab is not significant. From the results, asphalt isolating layer design is suggested in concrete pavement.

  13. INVESTIGATION OF SKID RESISTANCE PROPERTIES OF AGGREGATES USED IN AFYONKARAHISAR CITY PAVEMENTS

    Directory of Open Access Journals (Sweden)

    Cahit GÜRER

    2007-02-01

    Full Text Available For a safe driving, pavement surface aggregates must have superior physical and mechanical properties. Although high rate of accidents is mainly due to drivers errors, pavement surface properties affect significantly occurance of traffic accidents. The most important factor in the highways leading to traffic accidents are the skid resistance. In this study, adherence test with Vialit plate, Nicholson stripping test, accelerated polishing test (PSV were carried out on four aggregate samples which were used in seal coats and hot mix asphalt in Afyonkarahisar City. Results were compared with values of specification limits. The results showed that particularly limestone aggregates polishing stone values are poorer than volcanic aggregates sample. Especially, use of aggregates having a good polishing resistance, will be an important factor increasing driving safety.

  14. Evaluation of Precast Portland Cement Concrete Panels for Airfield Pavement Repairs

    Science.gov (United States)

    2015-05-01

    space for thermal expansion of the parent PCC and panels. Dowels that are too small or weak grout around the dowels could also cause high stress...resulting from either settlement of the pavement from a weak foundation or significant abrupt surface deterioration. Elevation changes in excess of 3...face is calculated using the equation tP zM 0 2 . (E.14) To calculate the deflection at the face of the joint (x=0) where the maxi - mum

  15. The Application of Impact Echo Scanning on Nondestructive Test of Pavement

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    A new nondestructive test method-Impact Echo Scanning was introduced. Application of this method on pavement structure test was discussed. A method to increase the measurement accuracy of the test on multi-layers was proposed, and was verified by field test. The test results show that the basic structural information can obtained rapidly and accurately by 3-D scanning of the impact echo system.

  16. Wear particles generated from studded tires and pavement induces inflammatory reactions in mouse macrophage cells.

    Science.gov (United States)

    Lindbom, John; Gustafsson, Mats; Blomqvist, Göran; Dahl, Andreas; Gudmundsson, Anders; Swietlicki, Erik; Ljungman, Anders G

    2007-06-01

    Health risks associated with exposure to airborne particulate matter (PM) have been shown epidemiologically as well as experimentally, pointing to both respiratory and cardiovascular effects. These health risks are of increasing concern in society, and to protect public health, a clarification of the toxic properties of particles from different sources is of importance. Lately, wear particles generated from traffic have been recognized as a major contributing source to the overall particle load, especially in the Nordic countries where studded tires are used. The aim of this study was to further investigate and compare the ability to induce inflammatory mediators of different traffic-related wear particles collected from an urban street, a subway station, and studded tire-pavement wear. Inflammatory effects were measured as induction of nitric oxide (NO), IL-6, TNF-alpha, arachidonic acid (AA), and lipid peroxidation after exposure of the murine macrophage like cell line RAW 264.7. In addition, the redox potential of the particles was measured in a cell-free system. The results show that all particles tested induce IL-6, TNF-alpha, and NO, and those from the urban street were the most potent ones. In contrast, particles collected from a subway station were most potent to induce lipid peroxidation, AA release, and formation of ROS. Particles from studded tire-pavement wear, generated using a road simulator, were able to induce inflammatory cytokines, NO, lipid peroxidation, and ROS formation. Interestingly, particles generated from pavement containing granite as the main stone material were more potent than those generated from pavement containing quartzite as the main stone material.

  17. A Novel Method for Evaluating Fatigue Properties of Bonding Layers Used in Bridge Deck Pavement

    Institute of Scientific and Technical Information of China (English)

    ZHOU Jie; WU Shaopeng; HAN Jun; LIU Gang; ZHANG Guang

    2009-01-01

    A new method was used to evaluate the fatigue properties of the bonding layer used in the bridge deck pavement. The shear fatigue test of three bonding layers was conducted on a dy-namic shear rheometer(DSR). The fatigue formulas were gained for these layers. The experimental results indicate that, at the same torque level or at the same frequency, neoprene latex asphalt bonding layer exhibits excellent fatigue performance when compared to other two bonding layers.

  18. Further developments in self-fertilising geotextiles for use in pervious pavements.

    Science.gov (United States)

    Newman, A P; Nnadi, E O; Duckers, L J; Cobley, A J

    2011-01-01

    Geotextiles incorporating inorganic nutrients (particularly phosphorous) to enhance the growth of oil degrading microoganisms when geotextiles are used in pervious pavement applications have been shown to be effective in the past. However the cost and manufacturing difficulties have been a barrier to their use. A polypropylene random mat geotextile incorporating an alternative polymer additive as a source of phosphorus has been investigated as a potential self-fertilising geotextile. Experiments are reported which investigate nutrient leach rates, biofilm formation and biodegradation activity.

  19. Development of Laboratory Testing Criteria for Evaluating Cementitious, Rapid-Setting Pavement Repair Materials

    Science.gov (United States)

    2011-04-01

    Materials Lucy P. Priddy Geotechnical and Structures Laboratory U.S. Army Engineer Research and Development Center 3909 Halls Ferry Road Vicksburg...approved for repairs larger than core hole patches on Department of Defense (DOD) airfield pavements due to premature rutting caused by high tire ...and resistance to abrasion and scaling as important performance characteristics for repair materials (Wilson et al. 1999). Another study rec- ommended

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

    Directory of Open Access Journals (Sweden)

    Chen Zhang

    2015-02-01

    Full Text Available Longitudinal cracking is one of the most important distresses of asphalt pavement in permafrost regions. The sensitivity analysis of design parameters for asphalt pavement can be used to study the influence of every parameter on longitudinal cracking, which can help optimizing the design of the pavement structure. In this study, 20 test sections of Qinghai–Tibet Highway were selected to conduct the sensitivity analysis of longitudinal cracking on material parameter based on Mechanistic-Empirical Pavement Design Guide (MEPDG and single factorial sensitivity analysis method. Some computer aided engineering (CAE simulation techniques, such as the Latin hypercube sampling (LHS technique and the multiple regression analysis are used as auxiliary means. Finally, the sensitivity spectrum of material parameter on longitudinal cracking was established. The result shows the multiple regression analysis can be used to determine the remarkable influence factor more efficiently and to process the qualitative analysis when applying the MEPDG software in sensitivity analysis of longitudinal cracking in permafrost regions. The effect weights of the three parameters on longitudinal cracking in descending order are air void, effective binder content and PG grade. The influence of air void on top layer is bigger than that on middle layer and bottom layer. The influence of effective asphalt content on top layer is bigger than that on middle layer and bottom layer, and the influence of bottom layer is slightly bigger than middle layer. The accumulated value of longitudinal cracking on middle layer and bottom layer in the design life would begin to increase when the design temperature of PG grade increased.

  1. The Efficiency Analysis of Low Impact Development Applied in Taiwan: A Case Study of Porous Pavement

    Science.gov (United States)

    Huang, Y. H.; Liu, H. J.; Hsu, N. S.; Chang, F. M.

    2014-12-01

    Low Impact Development (LID) has been developed since the end of 1990s. Lots of successful experience based on this new technology have been made. Taiwan Executive Yuan is conducting a six-year (2014~2019) program "Integrated River Basin Management Plan" applying LID to build sponge cities. Construction and Planning Agency, Ministry of the Interior is editing the manual of LID technology for Taiwan. However, since the hydrological environments, physiographic conditions, climates, the strength and frequency of disasters in Taiwan are different from that in America, this study takes the first laboratory experiment and model simulation to evaluate the efficiency of application of LID in Taiwan.LID Facilities includes porous pavement, rain garden, green roof, tree box filter facilities and so on, and in this study, porous pavement is taken as an example for discussion. In the part of laboratory experiments, the sand box experiments is designed to operate with the specified rainfall return period calculated by Horton formula and rainfall characteristics of Taipei. Then the outflow hydrograph in each designed rainfall of specified return period can be evaluated. As for model simulation, this study constructs LID simulation elements by SWMM model and tests the suitability for simulation of the outflow hydrograph obtained from experiments, and definitely quantifies the efficiency of water retention and flood reduction of porous pavement. The results fits well with the experimental observation data with less than 10% error of pick flow. It suggests that, with LID simulation elements constructed in this study, the efficiency of LID in actual on-site application can be evaluated.The results shows that porous pavement is able to delay arrival time of pick about 5% ~10% and reduce the pick flow about 5%~20%, and hold the ability of near 3~5% water retention. It proves that application of LID can retain water and reduce flood in Taiwan.

  2. Recent advances in the evaluation of the strength and deformation properties of flexible pavements using GPR

    Science.gov (United States)

    Tosti, Fabio; Bianchini Ciampoli, Luca; Benedetto, Andrea; Alani, Amir M.; Loizos, Andreas; D'Amico, Fabrizio

    2016-04-01

    Even though there is plenty of literature contributions related to the non-destructive evaluation of road pavements using ground-penetrating radar (GPR), with several purposes spanning from the layer thicknesses evaluation to the detection of highly wet spots in the subsurface, there is still a lack of highly-reliable results concerning the mechanical assessment of road pavements, by using this technology. This work endeavours to face this topic and proposes a semi-empirical model for predicting the elastic modulus of a flexible pavement, by employing GPR. Data were collected over three different road sections within the districts of Madrid and Guadalajara, Spain. In particular, GPR surveys were carried out at the speed of traffic over the roads N320 and N211 in the district of Gadalajara and the road N320 in the district of Madrid, for a total of 39 kilometers, approximately. In particular, air-coupled radar systems with a 1000 MHz center frequency antenna and two different 2000 MHz center frequency antennas, mounted onto an instrumented vehicle, were here employed. The calibration of the model was then performed by exploiting ground-truth data coming from other non-destructive technologies. In more details, an instrumented lorry equipped with a curviameter, namely, a deflection tool capable to collect and process continuously and in real time the mechanical response of the flexible pavement, was used in the above road sections. Promising results are here presented, and the potential of GPR for monitoring the mechanical performances of a road network is also proved. Acknowledgement The Authors thank COST, for funding the Action TU1208 "Civil Engineering Applications of Ground Penetrating Radar."

  3. Patología de pavimentos articulados Pathology of interlocking pavements

    Directory of Open Access Journals (Sweden)

    Carlos Hernando Higuera Sandoval

    2010-07-01

    Full Text Available Este artículo presenta los resultados de un proyecto de grado sobre patología de pavimentos articulados, el cual fue elaborado con el propósito de hacer una recolección de los deterioros típicos de los pavimentos articulados construidos con adoquines de concreto o de ladrillo; y de esta forma, elaborar un catálogo de deterioros para este tipo de estructuras que facilitará la identificación y cuantificación de los deterioros en una inspección visual. El segundo propósito de este proyecto, es la formulación para Colombia de una metodología que permita determinar el Índice de Condición de las estructuras de pavimentos articulados.This article presents the results of a thesis on pathology of interlocking pavements, which objective was to make a compilation of typical damages of interlocking pavements constructed with concrete or brick pavers and, in this way, to elaborate a catalogue of damages for this kind of structures which will make the identification and quantification of deteriorations possible in a visual inspection. The second purpose of this project is the formulation of a methodology which allows determining the Index of pavement conditions for Colombia.

  4. Influence of shock absorber condition on pavement fatigue using relative damage concept

    Directory of Open Access Journals (Sweden)

    Pablo Kubo

    2015-12-01

    Full Text Available Considering the importance of the road transportation nowadays, concerns related to pavement deterioration and maintenance have become relevant subjects. Especially for commercial vehicles, the vertical dynamic load (characterized by the tire-road interaction is directly related to wear on the road surface. Given this, the main objective of this paper is to analyse effects of vertical loads applied on the flexible pavement, considering the variation of the condition of shock absorbers from a truck's front suspension. The measurements were performed on a rigid truck, with 2 steering front axles, in a durability test track located in Brazil. With a constant load of 6 tons on the front suspension (the maximum allowed load on front axles according to Brazilian legislation, 3 different shock absorber conditions were evaluated: new, used and failed. By applying the relative damage concept, it is possible to conclude that the variation of the shock absorber conditions will significantly affect the vertical load applied on the pavement. Although the results clearly point to a dependent relationship between the load and the condition of the shock absorbers, it is recommended to repeat the same methodology, in future to analyse the influence of other quarter car model variants (such as spring rate, mass and tire spring stiffness.

  5. Performance Prediction Modelling for Flexible Pavement on Low Volume Roads Using Multiple Linear Regression Analysis

    Directory of Open Access Journals (Sweden)

    C. Makendran

    2015-01-01

    Full Text Available Prediction models for low volume village roads in India are developed to evaluate the progression of different types of distress such as roughness, cracking, and potholes. Even though the Government of India is investing huge quantum of money on road construction every year, poor control over the quality of road construction and its subsequent maintenance is leading to the faster road deterioration. In this regard, it is essential that scientific maintenance procedures are to be evolved on the basis of performance of low volume flexible pavements. Considering the above, an attempt has been made in this research endeavor to develop prediction models to understand the progression of roughness, cracking, and potholes in flexible pavements exposed to least or nil routine maintenance. Distress data were collected from the low volume rural roads covering about 173 stretches spread across Tamil Nadu state in India. Based on the above collected data, distress prediction models have been developed using multiple linear regression analysis. Further, the models have been validated using independent field data. It can be concluded that the models developed in this study can serve as useful tools for the practicing engineers maintaining flexible pavements on low volume roads.

  6. Temporal evolution modeling of hydraulic and water quality performance of permeable pavements

    Science.gov (United States)

    Huang, Jian; He, Jianxun; Valeo, Caterina; Chu, Angus

    2016-02-01

    A mathematical model for predicting hydraulic and water quality performance in both the short- and long-term is proposed based on field measurements for three types of permeable pavements: porous asphalt (PA), porous concrete (PC), and permeable inter-locking concrete pavers (PICP). The model was applied to three field-scale test sites in Calgary, Alberta, Canada. The model performance was assessed in terms of hydraulic parameters including time to peak, peak flow and water balance and a water quality variable (the removal rate of total suspended solids). A total of 20 simulated storm events were used for model calibration and verification processes. The proposed model can simulate the outflow hydrographs with a coefficient of determination (R2) ranging from 0.762 to 0.907, and normalized root-mean-square deviation (NRMSD) ranging from 13.78% to 17.83%. Comparison of the time to peak flow, peak flow, runoff volume and TSS removal rates between the measured and modeled values in model verification phase had a maximum difference of 11%. The results demonstrate that the proposed model is capable of capturing the temporal dynamics of the pavement performance. Therefore, the model has great potential as a practical modeling tool for permeable pavement design and performance assessment.

  7. Development of Mechanistic-Empirical Pavement Design for Tropical Climate Using Cement-Treated Base Layer

    Directory of Open Access Journals (Sweden)

    O. S. Aderinola

    2016-08-01

    Full Text Available A mechanistic-empirical pavement design method is developed characterising cement-treated base layers for pavement design in Nigeria or other similar tropical and subtropical countries. Asphalt Concrete surface, Subbase and Aggregate base were characterised based on back calculation data from Claros et al (1986 while cement-treated base layer was based on modulus tests that had been conducted by past researchers. Failure criteria for the Asphalt Concrete fatigue failure and the subgrade rutting failure were based on those by Claros and Ijeh (1987 for Nigerian pavements. Cracking criterion used for the cement-treated layer was that developed by Otee et al. (1982. The comparison between the Soil-Cement and Aggregate base showed that at a low Equivalent Single Axle Load (ESAL (0.5 million repetitions was considered, the use of Aggregate base was better than Soil-Cement base. That for Aggregate base and Cement-Treated Gravel Base showed that the Cement-Treated Gravel Base was better than the Aggregate base at high ESAL (2.5 million repetitions was considered

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

    Directory of Open Access Journals (Sweden)

    Marcelo GONZALEZ

    2016-09-01

    Full Text Available This paper presents the feasibility of superhydrophobic films to create the nano-lotus leaf effect on concrete surface and their influence on sound absorption and friction properties of concrete for application in rigid pavements. The study involved an evaluation of nanomaterials at the laboratory scale to analyze the effects of microtexture modification on the friction and sound absorption of concrete pavement. A number of laboratory specimens were produced by applying different amounts of nano-lotus leaf coating on the top of the textured concrete surface. The British pendulum test was used to measure the friction number, and an impedance tube was used to determine the sound absorption coefficient. Laboratory results indicate that nano-lotus leaf coated concrete can maintain the required friction property for rigid pavement, but may not increase the noise absorption. Further research must be carried out to determine possible benefit of the lotus leaf effect for reducing hydroplaning, particularly during heavy rainfall.DOI: http://dx.doi.org/10.5755/j01.ms.22.3.7638

  9. Pavement thickness and stabilised foundation layer assessment using ground-coupled GPR

    Science.gov (United States)

    Hu, Jinhui; Vennapusa, Pavana K. R.; White, David J.; Beresnev, Igor

    2016-07-01

    Experimental results from field and laboratory investigations using a ground-coupled ground penetrating radar (GPR), dielectric measurement, magnetic imaging tomography (MIT) and dynamic cone penetrometer (DCP) tests are presented. Dielectric properties of asphalt pavement and stabilised and unstabilised pavement foundation materials were evaluated in the laboratory in frozen and unfrozen conditions. Laboratory test results showed that dielectric properties of materials back-calculated from GPR in comparison to dielectric gauge measurements are strongly correlated and repeatable. For chemically stabilised materials, curing time affected the dielectric properties of the materials. Field tests were conducted on asphalt pavement test sections with different foundation materials (stabilised and unstabilised layers), drainage conditions and layer thicknesses. GPR and MIT results were used to determine asphalt layer thicknesses and were compared with measured core thicknesses, while GPR and DCP were used to assess foundation layer profiles. Asphalt thicknesses estimated from GPR showed an average error of about 11% using the dielectric gauge values as input. The average error reduced to about 4% when calibrated with cores thicknesses. MIT results showed thicknesses that are about 9% higher than estimated using GPR. Foundation layer thicknesses could not be measured using GPR due to variations in moisture conditions between the test sections, which is partly attributed to variations in gradation and drainage characteristics of the subbase layer.

  10. Using Recycled Glass and Zeolite in Concrete Pavement to Mitigate Heat Island and Reduce Thermal Cracks

    Directory of Open Access Journals (Sweden)

    Erhan Burak Pancar

    2016-01-01

    Full Text Available Urban heat island (UHI effect is built environmental issue related to pavements. It is desired to reduce pavement high surface temperature in summer to mitigate UHI effect. High surface temperature also affects slab temperature difference (the top surface temperature minus the bottom surface temperature of the slab. The increased slab temperature difference induces a high possibility of cracking in concrete roads. The prime aim of this study was to reduce the slab surface temperature by using recycled glass as a fine aggregate and zeolite as cement in concrete. Recycled glass was used to replace fine aggregate in proportions of 10%, 20%, and 30% by total weight of aggregate. Zeolite replaced Portland cement in proportions of 10% and 30% for three different proportions of recycled glass concrete mixtures. Optimum proportions were determined by examining mechanical properties of samples and alkali-silica reactions. It was noticed that using recycled glass and zeolite together in concrete reduces pavement surface temperature and temperature gradient in summer.

  11. Laser Scanning on Road Pavements: A New Approach for Characterizing Surface Texture

    Directory of Open Access Journals (Sweden)

    Gabriele Bitelli

    2012-07-01

    Full Text Available The surface layer of road pavement has a particular importance in relation to the satisfaction of the primary demands of locomotion, such as security and eco-compatibility. Among those pavement surface characteristics, the “texture” appears to be one of the most interesting with regard to the attainment of skid resistance. Specifications and regulations, providing a wide range of functional indicators, act as guidelines to satisfy the performance requirements. This paper describes an experiment on the use of laser scanner techniques on various types of asphalt for texture characterization. The use of high precision laser scanners, such as the triangulation types, is proposed to expand the analysis of road pavement from the commonly and currently used two-dimensional method to a three-dimensional one, with the aim of extending the range of the most important parameters for these kinds of applications. Laser scanners can be used in an innovative way to obtain information on areal surface layer through a single measurement, with data homogeneity and representativeness. The described experience highlights how the laser scanner is used for both laboratory experiments and tests in situ, with a particular attention paid to factors that could potentially affect the survey.

  12. Laser scanning on road pavements: a new approach for characterizing surface texture.

    Science.gov (United States)

    Bitelli, Gabriele; Simone, Andrea; Girardi, Fabrizio; Lantieri, Claudio

    2012-01-01

    The surface layer of road pavement has a particular importance in relation to the satisfaction of the primary demands of locomotion, such as security and eco-compatibility. Among those pavement surface characteristics, the "texture" appears to be one of the most interesting with regard to the attainment of skid resistance. Specifications and regulations, providing a wide range of functional indicators, act as guidelines to satisfy the performance requirements. This paper describes an experiment on the use of laser scanner techniques on various types of asphalt for texture characterization. The use of high precision laser scanners, such as the triangulation types, is proposed to expand the analysis of road pavement from the commonly and currently used two-dimensional method to a three-dimensional one, with the aim of extending the range of the most important parameters for these kinds of applications. Laser scanners can be used in an innovative way to obtain information on areal surface layer through a single measurement, with data homogeneity and representativeness. The described experience highlights how the laser scanner is used for both laboratory experiments and tests in situ, with a particular attention paid to factors that could potentially affect the survey.

  13. The Upper Eocene crustose coralline algal pavement in the Colli Berici, north-eastern Italy

    Directory of Open Access Journals (Sweden)

    Davide Bassi

    2005-10-01

    Full Text Available A crustose coralline algal pavement, identified in Upper Eocene (Priabonian shallow water, middleramp carbonates in north-eastern Italy (Colli Berici, Southern Alps, represents a rare example of this facies.The crustose pavement consists of a coralline crust bindstone with a wackestone-packstone matrix, and is characterised by the dominance of crustose coralline thalli composed primarily of melobesioids (Lithothamnion and Mesophyllum and mastophoroids (Spongites, Lithoporella, Neogoniolithon. In places the coralline bindstone can be seen to develop from isolated encrusting-to-foliose thalli which bifurcate and join to form an open framework interbedded with matrix debris from crusts. Various forms of rhodoliths occur commonly within this facies. The largest discoidal rhodoliths (up to 12 cm of large diameter show an inner arrangement consisting of loosely packed laminar (encrusting-to-foliose coralline thalli with a high percentage of constructional voids (50-63%. Accessory components are represented by larger hyaline perforated foraminifera such as nummulitids and orthophragminids. This facies formed in a ramp palaeoenvironment characterised by relatively low hydrodynamic energy and low rates of sedimentation. Channelised structures present within the facies were formed by return currents which swept the middle ramp creating such distal structures. Further toward the distal middle-ramp the return currents decreased in energy and discharged nutrients allowing the mesotrophic crustose coralline algal pavement to develop.

  14. Energy consumption comparison for different asphalt pavements rehabilitation techniques used in Chile

    Energy Technology Data Exchange (ETDEWEB)

    Thenoux, Guillermo; Dowling, Rafael [School of Engineering, Universidad Catolica de Chile, Vicuna Mackenna 4860 Macul, Santiago (Chile); Gonzalez, Alvaro [Department of Civil Engineering, University of Canterbury, Private Bag 4800, Christchurch 8020 (New Zealand)

    2007-02-15

    In developing countries without the availability of reliable pavement management systems, recycling techniques may offer the best alternative for pavement structural rehabilitation. However, for many government officials and contractors there is a clear understanding of the technical advantages of recycling but not a clear perspective of cost saving. Since cost is a relative value among different regions of any country the following work makes an energy analysis of the construction process of the three different rehabilitation techniques available in Chile. Three different structural pavement rehabilitation alternatives were studied and compared using an energy consumption methodology: circle Asphalt overlay; circle Reconstruction; circle Cold in place recycling with foamed asphalt. The methodology considers different project scenarios by combining expected traffic and soil support values. For each rehabilitation technique and scenario, the construction processes were analyzed and the design layers were transformed to equivalent energy units (MJ/m{sup 2}). Results show that cold in place recycling utilizes the lowest amount of energy compared with reconstruction or an asphalt overlay in all the scenarios studied, producing more differences when rehabilitating roads for less trafficked roads. The study also concludes that aggregate haulage distance is the most sensitive factor on total energy consumption when comparing the three alternatives. (author)

  15. Exploration under pavement by electromagnetic subsurface profiling. Hosoka ni okeru roban rosho heno haaku

    Energy Technology Data Exchange (ETDEWEB)

    Kaneko, C.; Miyatsu, Y.; Seki, M. (Construction Project Consultant Co. Ltd., Osaka (Japan))

    1994-05-01

    This paper reports explorations on change in roadbeds and subgrades under pavement by means of an electromagnetic wave method (underground radar method). The paper summarizes the measurement principle of this exploration method, the measurement equipment (consisting of a control unit, an antenna unit, and an image output unit), and data analysis and processing. It is indicated that the quality of the exploration result is governed by the antenna used, whereas a reference is shown for selecting antennas according to the exploration objects (embedded pipes, underground cavities, and pavement thickness) and depths of the explorations. The paper then lists examples of explorations conducted by using antennas with a frequency of 500 MHz. The explorations include the following cases: cavities directly below concrete seals (with a thickness of 10 cm), hume pipes (with a diameter of 10 cm) embedded in a depth of 1.1 m under asphalt pavement, clearances existing in subgrades, loosened ground bed believed to have been caused by immersion, and clearances (depth of 70 cm) existing in ground beds behind bridge piers. 5 refs., 9 figs., 2 tabs.

  16. Numerical Investigation of Design Strategies to Achieve Long-Life Pavements

    CERN Document Server

    Ghauch, Ziad G

    2011-01-01

    Increasing the HMA base thickness and modifying the HMA mixture properties to improve the resistance to fatigue cracking are among the most popular methods for achieving long-lasting pavements. Such methods are based on the idea of reducing the tensile strain at the bottom of the HMA layer below the Fatigue Endurance Limit (FEL), a level of strain below which no cumulative damage occurs to the HMA mixture. This study investigates the effectiveness of several design strategies involved in long-life, perpetual pavement design. A 3D Finite Element model of the pavement involving a linear viscoelastic constitutive model for HMA materials and non-uniform tire contact stresses is developed using ABAQUS 6.11. The effects of asphalt base course thickness and mixture type, rich binder layer, and aggregate subbase layer are examined. Four asphalt base course mixture types, namely dense graded, polymer modified, high modulus, and standard binder, are studied as a function of the asphalt base course thickness. The result...

  17. A fiber-reinforced composite structure for the repair of thermally cracked bituminous pavements

    Science.gov (United States)

    Frantzen, Jeffrey Alan

    1998-10-01

    The apparatus under development in this project is a structural component or beam fabricated from a fiber reinforced plastic composite (FRPC). The FRPC beam is a structural repair component intended to bridge a deteriorated thermal crack in full depth bituminous pavements or partial depth bituminous pavements over portland cement concrete. The bridging action provided by the FRPC beam is intended to minimize roughness through the repaired area for up to five years, eliminate reappearance of the deteriorated crack, and provide a controlled expansion crack that can be treated with standard sealing techniques. This apparatus is designed for maintenance use as a field expedient, semi-permanent repair using tools that are commonly available at the Area Maintenance level. Three FRPC beams were constructed for field trial in a thermally cracked, full depth bituminous pavement on US-36 east of Hiawatha, Kansas. Each of the beams were instrumented with bonded metal foil strain gages and field installation by KDOT Maintenance forces was done in August and September of 1997. The FRPC beams have been evaluated since installation and this evaluation will continue for up to five years. Evaluation of the beams has been accomplished through static load tests using the strain gage instrumentation and Falling Weight Deflectometer measurements. The FRPC beams have performed satisfactorily as of the date of writing.

  18. Global Existence and Blow-up for a System of Nonlocal Wave Equations%一个局部波动方程组的解的全局存在性与爆破

    Institute of Scientific and Technical Information of China (English)

    邓铿

    2005-01-01

    我们研究初始值问题(e)u1/(e)t2=(e)2u1/(e)x2+‖u2(·,t)‖p, (e)2u2/(e)t2=(e)2u2/(e)x2+‖u1(·,t)‖q,-∞0,u1(x,0)=f1(x), (e)u1/(e)t(x,0)=g1(x),u2(x,0)=f2(x), (e)u2/(e)t(x,0)=g2(x),- ∞0,u1(x,0)=f1(x), (e)u1/(e)t(x,0)=g1(x),u2(x,0)=f2(x), (e)u2/(e)t(x,0)=g2(x),- ∞blow-up of solutions,and we present the growth rates at blow-up.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2011-02-05

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

  20. A comprehensive numerical analysis of the hydraulic behavior of a permeable pavement

    Science.gov (United States)

    Brunetti, Giuseppe; Šimůnek, Jiří; Piro, Patrizia

    2016-09-01

    The increasing frequency of flooding events in urban catchments related to an increase in impervious surfaces highlights the inadequacy of traditional urban drainage systems. Low Impact Development (LID) techniques have proven to be a viable and effective alternative by reducing stormwater runoff and increasing the infiltration and evapotranspiration capacity of urban areas. However, the lack of adequate modeling tools represents a barrier in designing and constructing such systems. This paper investigates the suitability of a mechanistic model, HYDRUS-1D, to correctly describe the hydraulic behavior of permeable pavement installed at the University of Calabria. Two different scenarios of describing the hydraulic behavior of the permeable pavement system were analyzed: the first one uses a single-porosity model for all layers of the permeable pavement; the second one uses a dual-porosity model for the base and sub-base layers. Measured and modeled month-long hydrographs were compared using the Nash-Sutcliffe efficiency (NSE) index. A Global Sensitivity Analysis (GSA) followed by a Monte Carlo filtering highlighted the influence of the wear layer on the hydraulic behavior of the pavement and identified the ranges of parameters generating behavioral solutions. Reduced ranges were then used in the calibration procedure conducted with the metaheuristic Particle swarm optimization (PSO) algorithm for the estimation of hydraulic parameters. The best fit value for the first scenario was NSE = 0.43; for the second scenario, it was NSE = 0.81, indicating that the dual-porosity approach is more appropriate for describing the variably-saturated flow in the base and sub-base layers. Estimated parameters were validated using an independent, month-long set of measurements, resulting in NSE values of 0.43 and 0.86 for the first and second scenarios, respectively. The improvement in correspondence between measured and modeled hydrographs confirmed the reliability of the

  1. Integration of a prototype wireless communication system with micro-electromechanical temperature and humidity sensor for concrete pavement health monitoring

    Directory of Open Access Journals (Sweden)

    Shuo Yang

    2015-12-01

    Full Text Available In recent years, structural health monitoring and management (SHMM has become a popular approach and is considered essential for achieving well-performing, long-lasting, sustainable transportation infrastructure systems. Key requirements in ideal SHMM of road infrastructure include long-term, continuous, and real-time monitoring of pavement response and performance under various pavement geometry-materials-loading configurations and environmental conditions. With advancements in wireless technologies, integration of wireless communications into sensing device is considered an alternate and superior solution to existing time- and labor-intensive wired sensing systems in meeting the requirements of an ideal SHMM. This study explored the development and integration of a wireless communications sub-system into a commercial off-the-shelf micro-electromechanical sensor-based concrete pavement monitoring system. A success-rate test was performed after the wireless transmission system was buried in the concrete slab, and the test results indicated that the system was able to provide reliable communications at a distance of more than 46 m (150 feet. This will be a useful feature for highway engineers performing routine pavement scans from the pavement shoulder without the need for traffic control or road closure.

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

    Science.gov (United States)

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

    2012-03-20

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

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

    Science.gov (United States)

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

    2012-01-01

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

  4. Comparison Between 2-D and 3-D Stiffness Matrix Model Simulation of Sasw Inversion for Pavement Structure

    Directory of Open Access Journals (Sweden)

    Sri Atmaja P. Rosidi

    2007-01-01

    Full Text Available The Spectral Analysis of Surface Wave (SASW method is a non-destructive in situ seismic technique used to assess and evaluate the material stiffness (dynamic elastic modulus and thickness of pavement layers at low strains. These values can be used analytically to calculate load capacities in order to predict the performance of pavement system. The SASW method is based on the dispersion phenomena of Rayleigh waves in layered media. In order to get the actual shear wave velocities, 2-D and 3-D models are used in the simulation of the inversion process for best fitting between theoretical and empirical dispersion curves. The objective of this study is to simulate and compare the 2-D and 3-D model of SASW analysis in the construction of the theoretical dispersion curve for pavement structure evaluation. The result showed that the dispersion curve from the 3-D model was similar with the dispersion curve of the actual pavement profile compared to the 2-D model. The wave velocity profiles also showed that the 3-D model used in the SASW analysis is able to detect all the distinct layers of flexible pavement units.

  5. The Quality Control of Asphalt Pavement Construction%沥青路面施工质量控制

    Institute of Scientific and Technical Information of China (English)

    2013-01-01

    The quality control of asphalt pavement constru-ction is an important link in the construction of highway proj-ect, is the key to the construction engineering quality. The aut-hor had more time in ten years to engage in the work of the qu-ality control of asphalt pavement construction, realized our cu-rrent level of quality control in asphalt pavement construction is also difficult to adapt to requirements of the design of asph-alt pavement structure, stil need to be improved. Through this article the author discusses how to improve the construction q-uality control of asphalt pavement.%  沥青路面施工质量控制是公路工程施工中的一个重要环节,是决定工程建设质量的关键。笔者十多年来有较多时间从事沥青路面施工质量控制工作,体会到我们目前沥青路面施工的质量控制水平还难以适应沥青路面结构设计要求,还有待提高。笔者通过本文浅谈如何提高沥青路面的施工质量控制工作。

  6. Three-dimensional Finite Element Analysis on the Layer Steel Fiber Reinforced Concrete Pavement:A New Type of Pavement Material

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    An investigation was conducted on the design of layer steel fiber reinforced concrete (LSFRC) pavement.Finite element method was applied to the analysis on the stress distribution in order to determine the thickness and segregation distance of LSFRC pavement slabs.

  7. 高速公路路面材料与设计探讨%Discussion on Materials and Design of Expressway Pavement

    Institute of Scientific and Technical Information of China (English)

    尹祯昌; 曹博成

    2014-01-01

    本文主要介绍了高速公路路面材料的分类及性能,并分析了高速公路路面材料和设计的关系。%This paper mainly introduces the classification and performance of expressway pavement materials, and analyzes the relationship of highway pavement materials and design.

  8. 城市人行天桥桥面铺装方案研究%The bridge deck pavement scheme research on city pedestrian bridge

    Institute of Scientific and Technical Information of China (English)

    陈娟婷; 田原

    2014-01-01

    Taking the pavement engineering of pedestrian bridge as research object, this paper introduced the pedestrian bridge pavement func-tion and common pavement classification, combining with the actual investigation researched the characteristics and applicability scope of various pavement schemes, and listed and compared, in order to provide some valuable reference for designers in pavement scheme selection.%以人行天桥的铺装工程为研究对象,介绍了天桥铺装的功能与常见的铺装分类,结合实际,调查研究了各种铺装方案的特点和适用范围,并列表加以对比分析,旨在为设计人员在铺装方案的选择上提供一些有价值的参考。

  9. Research on Rutting Resistance of Asphalt Pavement Structure%沥青路面结构抗车辙的研究

    Institute of Scientific and Technical Information of China (English)

    高立波

    2011-01-01

    结合对某高速公路路面车擞近十年的跟踪检测和试验,从新的角度认识路面结构因素对路面车辙的影响,提出了路面结构组合设计原则和联结层设计理念及结构抗车辙措施。%Combined with the almost ten years of tracing inspection and test about an expressway pavement rutting, the influence of pavement structure on pavement rutting is recognized from a new angle. The design principle of pavement structure of pavement combination, design concept of binder course and rutting resistance measures are proposed.

  10. 沥青砼路面裂缝预防措施%Prevention Measures on the Asphalt Concrete Pavement Crevices

    Institute of Scientific and Technical Information of China (English)

    贾陇春

    2014-01-01

    文章简单介绍了沥青砼路面裂缝的集中类型,对沥青砼路面产生裂缝的原因进行了分析,着重提出了相应的沥青砼路面裂缝预防措施。希望能进一步延长沥青砼路面的使用寿命,提升路面服务质量,为工程技术人员提供一定的参考和借鉴。%This paper briefly introduces the main types of asphalt concrete pavement crevices and analyzed the causes of crevices, focusing on corresponding prevention measures. By this, the author hoped to further extend the service life of asphalt concrete pavement and improved the pavement quality, providing a reference for engineering and technical personnel.

  11. MaNIAC-UAV - a methodology for automatic pavement defects detection using images obtained by Unmanned Aerial Vehicles

    Science.gov (United States)

    Henrique Castelo Branco, Luiz; César Lima Segantine, Paulo

    2015-09-01

    Intelligent Transportation Systems - ITS is a set of integrated technologies (Remote Sensing, Image Processing, Communications Systems and others) that aim to offer services and advanced traffic management for the several transportation modes (road, air and rail). Collect data on the characteristics and conditions of the road surface and keep them update is an important and difficult task that needs to be currently managed in order to reduce accidents and vehicle maintenance costs. Nowadays several roads and highways are paved, but usually there is insufficient updated data about current condition and status. There are different types of pavement defects on the roads and to keep them in good condition they should be constantly monitored and maintained according to pavement management strategy. This paper presents a methodology to obtain, automatically, information about the conditions of the highway asphalt pavement. Data collection was done through remote sensing using an UAV (Unmanned Aerial Vehicle) and the image processing and pattern recognition techniques through Geographic Information System.

  12. Analysis of Highway Subgrade Pavement Drainage Design%浅析公路路基路面排水设计

    Institute of Scientific and Technical Information of China (English)

    袁丹

    2014-01-01

    在公路设计中,路基、路面的排水设计对公路的质量及寿命有重大影响。本文首先阐述了地下水及地表水对公路路基、路面的影响和危害,分析了公路路基和路面排水设计的准则,进而探讨了公路路基路面的排水设计。%In the highway design, the drainage design of highway roadbed and pavement has a significant impact on the quality and life. This paper first elaborates the groundwater and surface water influence and harmful of highway roadbed and road pavement, analyzes the criterion of highway subgrade and pavement drainage design, and then discusses the design of highway roadbed drainage.

  13. 高速公路沥青路面病害分析%Analysis on highway asphalt pavement disease

    Institute of Scientific and Technical Information of China (English)

    李宏伟

    2012-01-01

    针对高速公路沥青路面中常见的沉陷、水毁、裂缝等病害进行了分析,阐述了各种病害产生的原因,指出沥青路面产生病害既有设计方面的原因,也有施工方面的原因,所以应优化设计,并加强施工管理,以提高沥青路面使用性能。%This article analyzes the settlement,water damage,and cracks and other diseases on highway asphalt pavement,describes causes of diseases,and points out the causes of asphalt pavement diseases in both design and construction aspect.So the design should be optimized,and the construction management should be enhanced,so as to improve the asphalt pavement performance.

  14. Global Cooling: Policies to Cool the World and Offset Global Warming from CO2 Using Reflective Roofs and Pavements

    Energy Technology Data Exchange (ETDEWEB)

    Akbari, Hashem; Levinson, Ronnen; Rosenfeld, Arthur; Elliot, Matthew

    2009-08-28

    Increasing the solar reflectance of the urban surface reduce its solar heat gain, lowers its temperatures, and decreases its outflow of thermal infrared radiation into the atmosphere. This process of 'negative radiative forcing' can help counter the effects of global warming. In addition, cool roofs reduce cooling-energy use in air conditioned buildings and increase comfort in unconditioned buildings; and cool roofs and cool pavements mitigate summer urban heat islands, improving outdoor air quality and comfort. Installing cool roofs and cool pavements in cities worldwide is a compelling win-win-win activity that can be undertaken immediately, outside of international negotiations to cap CO{sub 2} emissions. We propose an international campaign to use solar reflective materials when roofs and pavements are built or resurfaced in temperate and tropical regions.

  15. Properties and toxicological effects of particles from the interaction between tyres, road pavement and winter traction material

    Energy Technology Data Exchange (ETDEWEB)

    Gustafsson, Mats [Swedish National Road and Transport Research Institute (VTI), SE-581 95 Linkoeping (Sweden)], E-mail: mats.gustafsson@vti.se; Blomqvist, Goeran [Swedish National Road and Transport Research Institute (VTI), SE-581 95 Linkoeping (Sweden); Gudmundsson, Anders; Dahl, Andreas [Division of Ergonomics and Aerosol Technology, Department of Design Sciences, Lund University, P.O. Box 118, SE-221 00 Lund (Sweden); Swietlicki, Erik [Division of Nuclear Physics, Department of Physics, Lund University, P.O. Box 118, SE-221 00 Lund (Sweden); Bohgard, Mats [Division of Ergonomics and Aerosol Technology, Department of Design Sciences, Lund University, P.O. Box 118, SE-221 00 Lund (Sweden); Lindbom, John; Ljungman, Anders [Faculty of Health Sciences, Department of Molecular and Clinical Medicine, Division of Occupational and Environmental Medicine, SE-581 85 Linkoeping (Sweden)

    2008-04-15

    In regions where studded tyres and traction material are used during winter, e.g. the Nordic countries, northern part of USA, Canada, and Japan, mechanically generated particles from traffic are the main reason for high particle mass concentrations in busy street and road environments. In many Nordic municipalities the European environmental quality standard for inhalable particles (PM{sub 10}) is exceeded due to these particles. In this study, particles from the wear of studded and studless friction tyres on two pavements and traction sanding were generated using a road simulator. The particles were characterized using particle sizers, Particle Induced X-Ray Emission Analysis and electron microscopy. Cell studies were conducted on particles sampled from the tests with studded tyres and compared with street environment, diesel exhaust and subway PM{sub 10}, respectively. The results show that in the road simulator, where resuspension is minimized, studded tyres produce tens of times more particles than friction tyres. Chemical analysis of the sampled particles shows that the generated wear particles consist almost entirely of minerals from the pavement stone material, but also that Sulfur is enriched for the submicron particles and that Zink is enriched for friction tyres for all particles sizes. The chemical data can be used for source identification and apportionment in urban aerosol studies. A mode of ultra-fine particles was also present and is hypothesised to originate in the tyres. Further, traction material properties affect PM{sub 10} emission. The inflammatory potential of the particles from wear of pavements seems to depend on type of pavement and can be at least as potent as diesel exhaust particles. The results imply that there is a need and a good potential to reduce particle emission from pavement wear and winter time road and street operation by adjusting both studded tyre use as well as pavement and traction material properties.

  16. On the Conservation and Recycled Asphalt Pavement%论沥青路面的养护与再生

    Institute of Scientific and Technical Information of China (English)

    韩建忠

    2014-01-01

    简要论述了沥青路面养护和再生的方法,并介绍了国内外沥青路面的养护和再生情况,以期为相关单位提供较为全面的参考。%This paper discusses the asphalt pavement maintenance and regeneration methods, and describes the conservation and regeneration of asphalt pavement at home and abroad, in order to provide a more comprehensive reference for relevant units.

  17. Cause Analysis of Asphalt Concrete Pavement Disease%沥青路面病害的成因分析

    Institute of Scientific and Technical Information of China (English)

    高雪

    2013-01-01

    From raw materials selection, structure design and construction of asphalt concrete pavement, the article made a detailed description on disease types, causes and prevention measures of the asphalt concrete pavement.%  文章从沥青混凝土路面的原材料选择、结构设计、施工等方面入手,对沥青混凝土路面病害的类型、发生原因及防治措施进行详细说明。

  18. Full-Depth Pavement Reclamation with Foamed Asphalt: First-Level Analysis Report on HVS Testing on State Route 89

    OpenAIRE

    Theyse, Hecter; Long, Fenella; Jones, David; Harvey, John T

    2006-01-01

    This report focuses on the HVS testing of a foamed asphalt treated, reclaimed asphalt pavement (RAP) on State Route 89 near Sierraville. The report discusses the expected behavior of the HVS test sections, presents the results from field surveys done during June 2003, October 2003 and May 2004 as well as the 1st level analysis of HVS results from the test site. Results from field surveys done prior to, during and after HVS testing show that the pavement structure of the HVS test sections on S...

  19. The Technology of Bare Concrete Pavement%清水混凝土人行道工艺

    Institute of Scientific and Technical Information of China (English)

    陈靖

    2014-01-01

    本文概述了道路清水混凝土人行道面层的设计及施工控制要点,阐述了如何完成美观与强度、耐久性兼容的混凝土面层。%This article summarizes the design and the key points of construction control to the surface of bare concrete pavement, and expounds how to achieve concrete pavement compatible with beauty, strength and durability.

  20. Modelling of pavement materials on steel decks using the fivepoint bending test: thermo mechanical evolution and fatigue damage

    OpenAIRE

    Arnaud, Laurent; Houel, Adrien

    2010-01-01

    This paper deals with the modelling of wearing courses on steel orthotropic decks such as the Millau viaduct in France. This is of great importance when dealing with durability: due to the softness of such a support, the pavement is subjected to considerable strains that may generate top-down cracks in the layer at right angles of the orthotropic plate stiffeners and shear cracks at the interface between pavement and steel. Therefore, a five-point bending fatigue test was developed and improv...

  1. Condition assessment of concrete pavements using both ground penetrating radar and stress-wave based techniques

    Science.gov (United States)

    Li, Mengxing; Anderson, Neil; Sneed, Lesley; Torgashov, Evgeniy

    2016-12-01

    Two stress-wave based techniques, ultrasonic surface wave (USW) and impact echo (IE), as well as ground penetrating radar (GPR) were used to assess the condition of a segment of concrete pavement that includes a layer of concrete, a granular base and their interface. Core specimens retrieved at multiple locations were used to confirm the accuracy and reliability of each non-destructive testing (NDT) result. Results from this study demonstrate that the GPR method is accurate for estimating the pavement thickness and locating separations (air voids) between the concrete and granular base layers. The USW method is a rapid way to estimate the in-situ elastic modulus (dynamic elastic modulus) of the concrete, however, the existence of air voids at the interface could potentially affect the accuracy and reliability of the USW test results. The estimation of the dynamic modulus and the P-wave velocity of concrete was improved when a shorter wavelength range (3 in. to 8.5 in.) corresponding to the concrete layer thickness was applied instead of the full wavelength rage (3 in. to 11 in.) based on the standard spacing of the receiver transducers. The IE method is proved to be fairly accurate in estimating the thickness of concrete pavements. However, the flexural mode vibration could affect the accuracy and reliability of the test results. Furthermore, the existence of air voids between the concrete and granular base layers could affect the estimation of the compression wave velocity of concrete when the full wavelength range was applied (3 in. to 11 in.). Future work is needed in order to improve the accuracy and reliability of both USW and IE test results.

  2. Artificial intelligence modeling to evaluate field performance of photocatalytic asphalt pavement for ambient air purification.

    Science.gov (United States)

    Asadi, Somayeh; Hassan, Marwa; Nadiri, Ataallah; Dylla, Heather

    2014-01-01

    In recent years, the application of titanium dioxide (TiO₂) as a photocatalyst in asphalt pavement has received considerable attention for purifying ambient air from traffic-emitted pollutants via photocatalytic processes. In order to control the increasing deterioration of ambient air quality, urgent and proper risk assessment tools are deemed necessary. However, in practice, monitoring all process parameters for various operating conditions is difficult due to the complex and non-linear nature of air pollution-based problems. Therefore, the development of models to predict air pollutant concentrations is very useful because it can provide early warnings to the population and also reduce the number of measuring sites. This study used artificial neural network (ANN) and neuro-fuzzy (NF) models to predict NOx concentration in the air as a function of traffic count (Tr) and climatic conditions including humidity (H), temperature (T), solar radiation (S), and wind speed (W) before and after the application of TiO₂ on the pavement surface. These models are useful for modeling because of their ability to be trained using historical data and because of their capability for modeling highly non-linear relationships. To build these models, data were collected from a field study where an aqueous nano TiO₂ solution was sprayed on a 0.2-mile of asphalt pavement in Baton Rouge, LA. Results of this study showed that the NF model provided a better fitting to NOx measurements than the ANN model in the training, validation, and test steps. Results of a parametric study indicated that traffic level, relative humidity, and solar radiation had the most influence on photocatalytic efficiency.

  3. The effect of Cryogenic Crumb Rubber in cold recycled mixes for road pavements

    DEFF Research Database (Denmark)

    Pettinari, Matteo; Dondi, Giulio; Sangiorgi, Cesare

    2014-01-01

    of cold recycled mixes for road bases is considerable. Furthermore, new products are continuously being introduced or developed for recycling purposes. The objective of this research project was to test the effects, both mechanically and environmentally, of crumb rubber included in 100% Reclaimed Asphalt...... Pavement cold mixes for road bases, bound with bitumen emulsion and cement. The crumb rubber is produced cryogenically with granulometric selection, which together with the bitumen, the cement and the fine fractions of the mix forms a resilient mastic capable of imparting significant fatigue resistance...

  4. Theoretical Solution for Temperature Profile in Multi-layered Pavement Systems Subjected to Transient Thermal Loads

    Science.gov (United States)

    2011-01-01

    kcal/mm s ◦C) Geopolymer paste 2.0x10−7 PCC slab 5.1x10−7 Thermal diffusivity, α (mm2/s) Geopolymer 0.2 PCC slab 1.3 for the surface layer of airfield...concrete pavements. Geopolymer materials have desirable properties for serving as an alternative binder to traditional Portland cement in producing...high thermal stability. Thus it is possible to construct paving concrete made from a geopolymer binder on top of the ordinary concrete slab to limit

  5. Respirable crystalline silica exposures during asphalt pavement milling at eleven highway construction sites.

    Science.gov (United States)

    Hammond, Duane R; Shulman, Stanley A; Echt, Alan S

    2016-07-01

    Asphalt pavement milling machines use a rotating cutter drum to remove the deteriorated road surface for recycling. The removal of the road surface has the potential to release respirable crystalline silica, to which workers can be exposed. This article describes an evaluation of respirable crystalline silica exposures to the operator and ground worker from two different half-lane and larger asphalt pavement milling machines that had ventilation dust controls and water-sprays designed and installed by the manufacturers. Manufacturer A completed milling for 11 days at 4 highway construction sites in Wisconsin, and Manufacturer B completed milling for 10 days at 7 highway construction sites in Indiana. To evaluate the dust controls, full-shift personal breathing zone air samples were collected from an operator and ground worker during the course of normal employee work activities of asphalt pavement milling at 11 different sites. Forty-two personal breathing zone air samples were collected over 21 days (sampling on an operator and ground worker each day). All samples were below 50 µg/m(3) for respirable crystalline silica, the National Institute for Occupational Safety and Health recommended exposure limit. The geometric mean personal breathing zone air sample was 6.2 µg/m(3) for the operator and 6.1 µg/m(3) for the ground worker for the Manufacturer A milling machine. The geometric mean personal breathing zone air sample was 4.2 µg/m(3) for the operator and 9.0 µg/m(3) for the ground worker for the Manufacturer B milling machine. In addition, upper 95% confidence limits for the mean exposure for each occupation were well below 50 µg/m(3) for both studies. The silica content in the bulk asphalt material being milled ranged from 7-23% silica for roads milled by Manufacturer A and from 5-12% silica for roads milled by Manufacturer B. The results indicate that engineering controls consisting of ventilation controls in combination with water-sprays are

  6. HOW TO OBTAIN ECONOMICALLY EFFICIENT ASPHALT CONCRETE MIXTURES FOR CONSTRUCTIVE AUTOMOBILE ROAD AND STREET PAVEMENTS

    Directory of Open Access Journals (Sweden)

    V. A. Verenko

    2009-01-01

    Full Text Available The paper describes a methodology for evaluation of technical and economic efficiency of asphalt concrete mixture components. The method allows to perform a directed search for new materials which are used for mixture preparation and it also provides an efficient use of monetary funds. Firstly, it is possible to obtain this result due to optimum price-quality ratio of asphalt mixture which is determined by its service life in a pavement; secondly, it is possible to obtain this result due to  exclusion of errors while selecting components of the asphalt mixture out of the whole range applied presently in the world practice.

  7. Passive pavement-mounted acoustical linguistic drive alert system and method

    Science.gov (United States)

    Kisner, Roger A.; Anderson, Richard L.; Carnal, Charles L.; Hylton, James O.; Stevens, Samuel S.

    2001-01-01

    Systems and methods are described for passive pavement-mounted acoustical alert of the occupants of a vehicle. A method of notifying a vehicle occupant includes providing a driving medium upon which a vehicle is to be driven; and texturing a portion of the driving medium such that the textured portion interacts with the vehicle to produce audible signals, the textured portion pattern such that a linguistic message is encoded into the audible signals. The systems and methods provide advantages because information can be conveyed to the occupants of the vehicle based on the location of the vehicle relative to the textured surface.

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

    DEFF Research Database (Denmark)

    Lee, Hosin; Kim, Yongjoo; Geisler, Nivi

    2009-01-01

    heavy traffic and severe weather conditions in Greenland. Based on the initial set of strain data collected under the slow-moving loader right after construction, the highest strain value was observed from the test section with the highest amount of SBS-based compound. The increased amount of SBS......-based compound seemed to affect the asphalt mix to become more flexible under the heavy loads. By adding SBS-based compound to asphalt mixtures using a “dry” process, it is expected that the pavement would become more resistant to rutting than a typical asphalt mixture used in Greenland while enduring its arctic...... weather....

  9. The Construction Technology of Asphalt Concrete Pavement Joints%浅议沥青混凝土路面接缝施工技术

    Institute of Scientific and Technical Information of China (English)

    2013-01-01

    Along with the pavement construction technology continues to improve, asphalt concrete pavement has become the current preferred highway bridge pavement. And the pave-ment joint is an important link in the construction of asphalt pavement, and its construction quality directly affects the app-earance and performance of pavement. This paper briefly desc-rybes and analyzes the joint construction technique in asphalt pavement construction.%  随着路面施工技术的不断提高,沥青混凝土路面已成为当前公路道桥工程路面的首选。而路面接缝是沥青路面施工中的重要环节,其施工质量的好坏直接影响着路面的外观及其工作性能。本文针对沥青路面施工中的接缝施工技术方法进行了简要阐述和分析。

  10. ROP GTPase-mediated auxin signaling regulates pavement cell interdigitation in Arabidopsis thaliana

    Institute of Scientific and Technical Information of China (English)

    Deshu Lin; Huibo Ren; Ying Fu

    2015-01-01

    In multicel ular plant organs, cel shape formation depends on molecular switches to transduce developmental or environmental signals and to coordinate cel‐to‐cel communi-cation. Plants have a specific subfamily of the Rho GTPase family, usual y cal ed Rho of Plants (ROP), which serve as a critical signal transducer involved in many cel ular processes. In the last decade, important advances in the ROP‐mediated regulation of plant cel morphogenesis have been made by using Arabidopsis thaliana leaf and cotyledon pavement cel s. Especial y, the auxin‐ROP signaling networks have been demonstrated to control interdigitated growth of pavement cel s to form jigsaw‐puzzle shapes. Here, we review findings related to the discovery of this novel auxin‐signaling mecha-nism at the cel surface. This signaling pathway is to a large extent independent of the wel‐known Transport Inhibitor Response (TIR)–Auxin Signaling F‐Box (AFB) pathway, and instead requires Auxin Binding Protein 1 (ABP1) interaction with the plasma membrane‐localized, transmembrane kinase (TMK) receptor‐like kinase to regulate ROP proteins. Once activated, ROP influences cytoskeletal organization and inhibits endocytosis of the auxin transporter PIN1. The present review focuses on ROP signaling and its self‐organizing feature al owing ROP proteins to serve as a bustling signal decoder and integrator for plant cel morphogenesis.

  11. Development of Deflection Prediction Model for Concrete Block Pavement Considering the Block Shapes and Construction Patterns

    Directory of Open Access Journals (Sweden)

    Wuguang Lin

    2016-01-01

    Full Text Available Concrete block pavement (CBP is distinct from typical concrete or asphalt pavements. It is built by using individual blocks with unique construction patterns forming a discrete surface layer to bear traffic loadings. The surface structure of CBP varies depending on the block shapes and construction patterns, so it is hard to apply a general equivalent elastic modulus estimation method to define the surface structural strength. In this study, FEM analysis and dynamic loading test were carried out to develop a deflection prediction model for CBP considering the block shapes and construction patterns. Based on the analysis results, it was found that block shapes did not have much effect on load distribution, whereas construction patterns did. By applying the deflection prediction model to the rutting model for CBP proposed by Sun, the herringbone bond pattern showed the best performance comparing with stretcher bond or basket weave bond pattern. As the load repetition increased to 1.2 million, the rutting depth of CBP constructed by herringbone bond pattern was 2 mm smaller than those constructed by the other two patterns.

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

    Science.gov (United States)

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

    2014-01-01

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

  13. Diurnal Thermal Behavior of Pavements, Vegetation, and Water Pond in a Hot-Humid City

    Directory of Open Access Journals (Sweden)

    Xiaoshan Yang

    2015-12-01

    Full Text Available This study investigated the diurnal thermal behavior of several urban surfaces and landscape components, including pavements, vegetation, and a water pond. The field experiment was conducted in a university campus of Guangzhou, South China, which is characterized by a hot and humid summer. The temperature of ground surface and grass leaves and the air temperature and humidity from 0.1 to 1.5 m heights were measured for a period of 24 h under hot summer conditions. The results showed that the concrete and granite slab pavements elevated the temperature of the air above them throughout the day. In contrast, the trees and the pond lowered the air temperature near ground during the daytime but produced a slight warming effect during the nighttime. The influence of vegetation on air temperature and humidity is affected by the configurations of greenery. Compared to the open lawn, the grass shaded by trees was more effective in cooling and the mixture of shrub and grass created a stronger cooling effect during the nighttime. The knowledge of thermal behavior of various urban surfaces and landscape components is an important tool for planners and designers. If utilized properly, it can lead to climatic rehabilitation in urban areas and an improvement of the outdoor thermal environment.

  14. Dynamic Properties of Footbridges: Influence of Asphalt Pavement and Support Conditions

    Directory of Open Access Journals (Sweden)

    Weber Benedikt

    2015-01-01

    Full Text Available Natural frequencies and damping ratios are important parameters in the design of footbridges against vibrations. Although not normally considered in calculations, non-structural elements such as the asphalt pavement and the supports can have a significant influence on the dynamic properties. In this article we present results from vibration tests conducted on four footbridges over the last few years covering a wide range of asphalt temperatures. The experiments show that both the natural frequencies and the damping ratios can change significantly with temperature. In one particular case, a variation in natural frequency of 25% has been observed between high and low asphalt temperatures. An additional damping of around 1% due to the asphalt pavement has been detected. To more clearly understand the experimental results, the bridges were also analysed numerically using a visco-elastic material for the asphalt. The analysis of the experimental results also revealed that other non-structural elements can have a large influence on dynamic properties of bridges. In two cases, the supports did not perform as expected and lead to surprising results.

  15. Acute toxicity of runoff from sealcoated pavement to Ceriodaphnia dubia and Pimephales promelas

    Science.gov (United States)

    Mahler, Barbara J.; Ingersoll, Christopher G.; Van Metre, Peter C.; Kunz, James L.; Little, Edward E.

    2015-01-01

    Runoff from coal-tar-based (CT) sealcoated pavement is a source of polycyclic aromatic hydrocarbons (PAHs) and N-heterocycles to surface waters. We investigated acute toxicity of simulated runoff collected from 5 h to 111 days after application of CT sealcoat and from 4 h to 36 days after application of asphalt-based sealcoat containing about 7% CT sealcoat (AS/CT-blend). Ceriodaphnia dubia (cladocerans) and Pimephales promelas (fathead minnows) were exposed in the laboratory to undiluted and 1:10 diluted runoff for 48 h, then transferred to control water and exposed to 4 h of ultraviolet radiation (UVR). Mortality following exposure to undiluted runoff from unsealed asphalt pavement and UVR was ≤10% in all treatments. Test organisms exposed to undiluted CT runoff samples collected during the 3 days (C. dubia) or 36 days (P. promelas) following sealcoat application experienced 100% mortality prior to UVR exposure; with UVR exposure, mortality was 100% for runoff collected across the entire sampling period. Phototoxic-equivalent PAH concentrations and mortality demonstrated an exposure-response relation. The results indicate that runoff remains acutely toxic for weeks to months after CT sealcoat application.

  16. Effects of rejuvenator seal and fog seal on performance of open-graded friction course pavement

    Directory of Open Access Journals (Sweden)

    Nadeem A. Qureshi

    2013-05-01

    Full Text Available An open-graded friction course (OGFC is a special-purpose surface layer of hot-mix asphalt (HMA pavement that is increasingly being used around the world. Owing to its numerous benefits, OGFC is being regularly used as a final riding surface on interstate and high-traffic expressways by different highway agencies in the United States. However, some OGFC sections have experienced premature failure due to ravelling only after 6-8 years of service life. To maintain an effective, longer service life and enhanced performance of OGFC, preventive maintenance has been considered essential. There are several approaches to maintaining OGFC, one of which is the application of a fog seal and rejuvenator seal. A fog seal can reduce ravelling and extend the service life of OGFC while a rejuvenator seal can revitalise the existing aged asphalt binder in the top OGFC layer. This research focuses on optimising the fog and rejuvenator seal application rates by evaluating their effectiveness in terms of surface friction and durability. Three types of seal material were evaluated: Pavegaard (PG and Pavepreserve (PP asphalt rejuvenators and a cationic slow-setting asphalt emulsion (CSS-1H as a fog seal. Improvement in abrasion resistance of OGFC pavement was observed on application of fog and rejuvenator seals but surface friction was reduced to some extent. Hamburg test clearly shows a trend that the medium application rate of 0.10 gallon/square yard is better in enhancing resistance to rutting/moisture susceptibility of OGFC.

  17. Energy harvesting from pavements via PVDF: hybrid piezo-pyroelectric effects

    Science.gov (United States)

    Tao, Junliang; Hu, Jie; Wu, Guangxi

    2016-04-01

    In the U.S., there are over 4 million miles (6 million km) of roadways and more than 250 million registered vehicles. The energy lost in the pavement system due to traffic-induced vibration and deformation is enormous. If effectively harvested, such energy can serve as an alternative sustainable energy source that can be easily integrated to the transportation system. The potential of PVDF, which is a piezoelectric polymer material, is investigated as a potential energy harvester integrated in pavement systems. The uniqueness of this study lies in that the electrical response of PVDF under coupled mechanical and thermal stimulations are studied. It is well known that most piezoelectric materials are also pyroelectric materials, which convert temperature change into electricity. However, the potential of PVDF as a hybrid piezo-pyroelectric energy harvester has been seldom studied. Through series of well controlled experiments, it is found that there exists interesting coupling phenomenon between piezoelectric and pyroelectric effects of PVDF: the voltage generated by simultaneous mechanical and thermal stimulations is the sum of voltages generated by separate stimulations. In addition, an estimation of power generation through piezoelectric and pyroelectric effect is conducted. Finally, the overall effects of temperature on hybrid piezo-pyroelectric energy harvesting are discussed.

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

    Science.gov (United States)

    Wang, Huaping; Xiang, Ping

    2016-07-01

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

  19. Cancer risk from incidental ingestion exposures to PAHs associated with coal-tar-sealed pavement

    Science.gov (United States)

    Williams, E. Spencer; Mahler, Barbara J.; Van Metre, Peter C.

    2012-01-01

    Recent (2009-10) studies documented significantly higher concentrations of polycyclic aromatic hydrocarbons (PAHs) in settled house dust in living spaces and soil adjacent to parking lots sealed with coal-tar-based products. To date, no studies have examined the potential human health effects of PAHs from these products in dust and soil. Here we present the results of an analysis of potential cancer risk associated with incidental ingestion exposures to PAHs in settings near coal-tar-sealed pavement. Exposures to benzo[a]pyrene equivalents were characterized across five scenarios. The central tendency estimate of excess cancer risk resulting from lifetime exposures to soil and dust from nondietary ingestion in these settings exceeded 1 × 10–4, as determined using deterministic and probabilistic methods. Soil was the primary driver of risk, but according to probabilistic calculations, reasonable maximum exposure to affected house dust in the first 6 years of life was sufficient to generate an estimated excess lifetime cancer risk of 6 × 10–5. Our results indicate that the presence of coal-tar-based pavement sealants is associated with significant increases in estimated excess lifetime cancer risk for nearby residents. Much of this calculated excess risk arises from exposures to PAHs in early childhood (i.e., 0–6 years of age).

  20. Assessment of the aging level of rejuvenated hot mixed asphalt concrete pavements

    Science.gov (United States)

    McGovern, Megan; Buttlar, William G.; Reis, Henrique

    2016-04-01

    The efficacy of asphalt rejuvenator on restoring the properties of oxidatively aged asphalt was tested via a non-collinear ultrasonic subsurface wave mixing technique modified for field use. Longitudinal transducers were mounted on angle wedges to generate subsurface dilatational waves to allow for pavement evaluation when there is only access to one side. Because in the field the asphalt concrete (AC) pavement properties (i.e., ultrasonic velocities and attenuations) are unknown, a pre-determined fixed incident angle (based on the AC mixture type) was used, which allows for practical implementation in the field. Oxidative aged AC specimens were coated with rejuvenator (10% by weight of the binder) and left to dwell for varying amounts of time. Once the dwell time reached the desired amount, the specimen was immediately ultrasonically tested. The frequency ratio, f2/f1, at which the interaction took place and the normalized nonlinear wave generation parameter, β/β0, were recorded and compared against a reference plot. It was observed that the rejuvenator had the effect of restoring the nonlinear properties to those corresponding to a virgin sample after a sufficient amount of dwell time. The ability of the rejuvenator to fully penetrate and act on the binder was observed to be dependent on the porosity and aggregate structure, and thus varied for each specimen. As a result, some portions of the binder were restored to a greater extent than others. This non-uniform nature was captured via the nonlinear ultrasonic technique.

  1. Effects of Asphalt Mix Design Properties on Pavement Performance: A Mechanistic Approach

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    Ahmad M. Abu Abdo

    2016-01-01

    Full Text Available The main objective of this study was to investigate the effects of hot mix asphalt material properties on the performance of flexible pavements via mechanistic approach. 3D Move Analysis software was utilized to determine rutting and cracking distresses in an asphalt concrete (AC layer. Fourteen different Superpave mixes were evaluated by utilizing results of the Dynamic Modulus (|E⁎| Test and the Dynamic Shear Modulus (|G⁎| Test. Results showed that with the increase of binder content, the tendency of rutting in AC layer increased. However, with the increase of binder content, the cracking of AC layer lessened. Furthermore, when different binder grades were evaluated, results showed that with the increase of the upper binder grade number, rutting decreased, and with the increase of the lower binder grade number, rutting increased. Furthermore, analysis showed that with the increase of the lower binder grade number, higher percent of bottom up cracks would result. As a result of the analysis, binder grade should not be solely considered for cracking in AC layer; binder content and aggregate structure play a big role. Finally, results illustrated that the mechanistic approach is a better tool to determine the performance of asphalt pavement than commonly used methods.

  2. Study on Surface Heat Budget of Various Pavements for Urban Heat Island Mitigation

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    Hideki Takebayashi

    2012-01-01

    Full Text Available The surface heat budgets of various pavement surfaces are studied with the aim of mitigating the urban heat island effect. In this study, the thermal characteristics of pavements are examined using data from observations. The net radiation, surface temperature, temperature under the surface, conduction heat flux, and core weight for each experimental surface are recorded, together with the weather conditions at the time of observation. The latent heat flux is estimated from the observed weight of the cores. The surface heat budget under the same weather conditions is examined, and the sensible heat flux from each target surface is calculated. The parameters that influence the surface heat budget, for example, solar reflectance (albedo, evaporative efficiency, heat conductivity, and heat capacity, are examined. On a typical summer day, the maximum reduction in the sensible heat flux from that on a normal asphalt surface is about 150 W/m2 for an asphalt surface with water-retaining material and about 100 W/m2 for a cement concrete surface with water-retaining material, depending on the albedo of each surface.

  3. Safety effectiveness of pavement design treatment at intersections: Left turning vehicles and pedestrians on crosswalks

    Directory of Open Access Journals (Sweden)

    Hasina Iasmin

    2016-07-01

    Full Text Available Pedestrians are the most vulnerable road users as they are more exposed than other road users. Pedestrian safety at road intersections still remains the most vital and yet unsolved issue. One of the critical points in pedestrian safety is the occurrence of accidents between left-turning vehicle and pedestrians on crosswalks at signalized intersections. A crosswalk is a place designated for pedestrians and cyclists to cross vehicular roads safely. Drivers are expected to give priority to pedestrians or cyclists during interactions between them on the crosswalk. If a driver exhibits non-yielding behavior, the interaction will turn into a collision. This study examined the safety effect of three crosswalks designed with different materials such as red-colored material or brick pavement based on a safety performance study. The safety performance study considered left-turning driver's gap acceptance behavior and the severity of traffic conflict events between left-turning vehicles and pedestrians. The results of the study indicates that using brick pavement on a crosswalk increases the safety level of the crosswalk. Drivers at such crosswalks are more acquiescent to the priority rule.

  4. Pavement crack detection combining non-negative feature with fast LoG in complex scene

    Science.gov (United States)

    Wang, Wanli; Zhang, Xiuhua; Hong, Hanyu

    2015-12-01

    Pavement crack detection is affected by much interference in the realistic situation, such as the shadow, road sign, oil stain, salt and pepper noise etc. Due to these unfavorable factors, the exist crack detection methods are difficult to distinguish the crack from background correctly. How to extract crack information effectively is the key problem to the road crack detection system. To solve this problem, a novel method for pavement crack detection based on combining non-negative feature with fast LoG is proposed. The two key novelties and benefits of this new approach are that 1) using image pixel gray value compensation to acquisit uniform image, and 2) combining non-negative feature with fast LoG to extract crack information. The image preprocessing results demonstrate that the method is indeed able to homogenize the crack image with more accurately compared to existing methods. A large number of experimental results demonstrate the proposed approach can detect the crack regions more correctly compared with traditional methods.

  5. Modification of local asphalt with epoxy resin to be used in pavement

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    A.M.M. Abd El Rahman

    2012-12-01

    Full Text Available The durability of asphalt pavement is greatly influenced by the environmental changes during the year. In this paper, we prepared asphalt modified by mixing asphalt 60/70 with epoxidized natural rubber (ENR in different percentages (5, 10 and 15%, which was achieved using preformed peracetic acid (aqueous solution 59% at 60–80 °C, then molten cross-linker maleic anhydride (MA was added to modified asphalt until homogenous blends are achieved. Marshall test was used to evaluate the asphalt pavement performance depending on the curing time and hardener concentration. To measure marshall test, the pervious mixture was stirred with aggregate jop formula mix (JMF and 40% MA at 150–170 °C for 20 h and 1600 rpm. From the obtained data, it was found that asphalt mixed with 15% of ENR + 40% MA achieves a high stability (16,632 Newton, air voids of 2.5%, flow of 2.9 mm and mineral voids of 14.6%. While, the stability of the unmodified asphalt was (11,500 Newton, the flow 3.2 mm, the suitable air void value was 3.7% at 5.5% with the same conditions.

  6. Feasibility of using 100% Recycled Asphalt Pavement mixtures for road construction

    Science.gov (United States)

    Carlson, Russell Edgar, IV

    Recycled Asphalt Pavement (RAP) is the largest recycled good in the United States and 80 million tons are recycled yearly, saving taxpayers about $1.5 billion dollars. This paper explores the possibility of utilizing 100% RAP materials in asphalt pavement. Asphalt mixtures are produced at 135°C in a typical asphalt plant. However, at 135°C, not all binder from RAP materials may not become effective for coating aggregates. The main objective of the study is to determine the amount of effective binder available from RAP in the asphalt plant. The 100% RAP mixes have aged binder that can alter mix designs and interaction with virgin binder. In this study, to determine low temperature cracking resistance and fatigue performance, samples were prepared using a 100% RAP mix with no virgin binder and a 100% RAP mix with virgin asphalt binder to achieve the optimum binder content of the mix. Second, to determine the effectiveness of binder from RAP materials, compaction tests were performed by heating RAP materials at various temperatures. It was found that 100% RAP mixes cannot be feasible for field use if additional virgin binder is added to reach the optimum asphalt content. Based on limited test results, the low temperature grade was not within proper limits but the beam fatigue testing results were acceptable. Based on compaction test results, additional heating is needed to increase the effectiveness of asphalt binder from RAP materials.

  7. Three Permeable Pavements Performances for Priority Metal Pollutants and Metals associated with Deicing Chemicals from Edison Parking Lot, NJ - abstract

    Science.gov (United States)

    The U.S. Environmental Protection Agency constructed a 4000-m2 parking lot in Edison, New Jersey in 2009. The parking lot is surfaced with three permeable pavements [permeable interlocking concrete pavers (PICP), pervious concrete (PC), and porous asphalt (PA)]. Samples of each p...

  8. Three Permeable Pavements Performances for Priority Metal Pollutants and Metals Associated with Deicing Chemicals from Edison Parking Lot, NJ

    Science.gov (United States)

    The U.S. Environmental Protection Agency constructed a 4000-m2 parking lot in Edison, New Jersey in 2009. The parking lot is surfaced with three permeable pavements [permeable interlocking concrete pavers (PICP), pervious concrete (PC), and porous asphalt (PA)]. Samples of each p...

  9. Concentrations of polycyclic aromatic hydrocarbons (PAHs) and azaarenes in runoff from coal-tar- and asphalt-sealcoated pavement

    Science.gov (United States)

    Mahler, Barbara J.; Van Metre, Peter C.; Foreman, William T.

    2014-01-01

    Coal-tar-based sealcoat, used extensively on parking lots and driveways in North America, is a potent source of PAHs. We investigated how concentrations and assemblages of PAHs and azaarenes in runoff from pavement newly sealed with coal-tar-based (CT) or asphalt-based (AS) sealcoat changed over time. Samples of simulated runoff were collected from pavement 5 h to 111 d following application of AS or CT sealcoat. Concentrations of the sum of 16 PAHs (median concentrations of 328 and 35 μg/L for CT and AS runoff, respectively) in runoff varied relatively little, but rapid decreases in concentrations of azaarenes and low molecular weight PAHs were offset by increases in high molecular weight PAHs. The results demonstrate that runoff from CT-sealcoated pavement, in particular, continues to contain elevated concentrations of PAHs long after a 24-h curing time, with implications for the fate, transport, and ecotoxicological effects of contaminants in runoff from CT-sealcoated pavement.

  10. Concentrations of polycyclic aromatic hydrocarbons (PAHs) and azaarenes in runoff from coal-tar- and asphalt-sealcoated pavement.

    Science.gov (United States)

    Mahler, Barbara J; Van Metre, Peter C; Foreman, William T

    2014-05-01

    Coal-tar-based sealcoat, used extensively on parking lots and driveways in North America, is a potent source of PAHs. We investigated how concentrations and assemblages of PAHs and azaarenes in runoff from pavement newly sealed with coal-tar-based (CT) or asphalt-based (AS) sealcoat changed over time. Samples of simulated runoff were collected from pavement 5 h to 111 d following application of AS or CT sealcoat. Concentrations of the sum of 16 PAHs (median concentrations of 328 and 35 μg/L for CT and AS runoff, respectively) in runoff varied relatively little, but rapid decreases in concentrations of azaarenes and low molecular weight PAHs were offset by increases in high molecular weight PAHs. The results demonstrate that runoff from CT-sealcoated pavement, in particular, continues to contain elevated concentrations of PAHs long after a 24-h curing time, with implications for the fate, transport, and ecotoxicological effects of contaminants in runoff from CT-sealcoated pavement.

  11. Cost-benefit analysis of the construction of different flexible pavement structures considering the axle load and type of binder

    Directory of Open Access Journals (Sweden)

    Lucas Dotto Bueno

    2016-08-01

    Full Text Available The status of Brazilian highways reflects a deficient pavement performance when they are subjected to loadings imposed by heavy traffic. Current legislation, as enacted by Contran (National Traffic Council, has increased the axle weight limit for cargo vehicles by up to 10%. Therefore, the aim of this study was to determine a cost-benefit ratio by using different types of structures, asphalt binders and load intensities. Typical pavements were determined and then analyzed by the software AEMC (SisPav to obtain the horizontal tensile strain (εt values at the bottom of the asphalt concrete layer and, later, the NFATIGUE value. It was found that the increase in weight, within values covered by legislation, might result in a reduction of approximately 50% in the NFATIGUE value for the pavement structures analyzed. As for economic impact, the same weight increase caused a mean increase of 120% in the cost of repeated loading on pavement structures (R$ NFATIGUE-1. It was also observed that structures with more robust asphalt concrete layers can provide the best R$ NFATIGUE-1 ratios. The best results for granular materials were found with thinner layers, associated with a thicker coating. The benefits of modified binders were shown by the analyses of the best structural options: both the polymer-modified binder and the rubber asphalt binder offer significant structural and economic improvements to the structure.

  12. Measurements of the Stiffness and Thickness of the Pavement Asphalt Layer Using the Enhanced Resonance Search Method

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    Nur Mustakiza Zakaria

    2014-01-01

    Full Text Available Enhanced resonance search (ERS is a nondestructive testing method that has been created to evaluate the quality of a pavement by means of a special instrument called the pavement integrity scanner (PiScanner. This technique can be used to assess the thickness of the road pavement structure and the profile of shear wave velocity by using the principle of surface wave and body wave propagation. In this study, the ERS technique was used to determine the actual thickness of the asphaltic pavement surface layer, while the shear wave velocities obtained were used to determine its dynamic elastic modulus. A total of fifteen locations were identified and the results were then compared with the specifications of the Malaysian PWD, MDD UKM, and IKRAM. It was found that the value of the elastic modulus of materials is between 3929 MPa and 17726 MPa. A comparison of the average thickness of the samples with the design thickness of MDD UKM showed a difference of 20 to 60%. Thickness of the asphalt surface layer followed the specifications of Malaysian PWD and MDD UKM, while some of the values of stiffness obtained are higher than the standard.

  13. Exposure to wear particles generated from studded tires and pavement induces inflammatory cytokine release from human macrophages.

    Science.gov (United States)

    Lindbom, John; Gustafsson, Mats; Blomqvist, Göran; Dahl, Andreas; Gudmundsson, Anders; Swietlicki, Erik; Ljungman, Anders G

    2006-04-01

    Health risks associated with exposure to airborne particulate matter (PM) have been shown epidemiologically as well as experimentally, pointing to both respiratory and cardiovascular effects. Lately, wear particles generated from traffic have been recognized to be a major contributing source to the overall particle load, especially in the Nordic countries were studded tires are used. In this work, we investigated the inflammatory effect of PM10 generated from the wear of studded tires on two different types of pavement. As comparison, we also investigated PM10 from a traffic-intensive street, a subway station, and diesel exhaust particles (DEP). Human monocyte-derived macrophages, nasal epithelial cells (RPMI 2650), and bronchial epithelial cells (BEAS-2B) were exposed to the different types of particles, and the secretion of IL-6, IL-8, IL-10, and TNF-alpha into the culture medium was measured. The results show a significant release of cytokines from macrophages after exposure for all types of particles. When particles generated from asphalt/granite pavement were compared to asphalt/quartzite pavement, the granite pavement had a significantly higher capacity to induce the release of cytokines. The granite pavement particles induced cytokine release at the same magnitude as the street particles did, which was higher than what particles from both a subway station and DEP did. Exposure of epithelial cells to PM10 resulted in a significant increase of TNF-alpha secreted from BEAS-2B cells for all types of particles used (DEP was not tested), and the highest levels were induced by subway particles. None of the particle types were able to evoke detectable cytokine release from RPMI 2650 cells. The results indicate that PM10 generated by the wear of studded tires on the street surface is a large contributor to the cytokine-releasing ability of particles in traffic-intensive areas and that the type of pavement used is important for the level of this contribution

  14. Evaluation of the Pavement Quality Indicator (PQI for the on-site density measurement of asphalt emulsion mixes

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    Martínez-Echevarría, M. J.

    2013-03-01

    Full Text Available The Pavement Quality Indicator (PQI is a non-nuclear gauge used for the on-site density measurement of asphalt pavements without the need to extract core samples. Previous studies of hot asphalt mixes found that PQI density readings were very similar to laboratory density measurements of pavement cores. This paper describes the first stage of a research project whose objective is to analyze PQI density measurements of mixes manufactured with an asphalt emulsion binder. The PQI density variability for such mixes was verified and compared with the results obtained with other on-site methods for measuring pavement density.

    El equipo Pavement Quality Indicator es un dispositivo para la determinación de densidad in situ en pavimentos asfálticos sin extracción de testigos. Las experiencias con este equipo en mezclas bituminosas en caliente, recogidas en diferentes fuentes bibliográficas, muestran que las densidades medidas in situ con el PQI son muy similares a las obtenidas mediante la extracción de testigos. En este artículo se expone la primera etapa de un proyecto de investigación que tiene por objeto analizar los resultados de mediciones efectuadas con PQI en mezclas bituminosas donde se utiliza emulsión asfáltica como ligante. Se comprueba la variabilidad de la densidad obtenida con el equipo para este tipo de mezclas, y se comparan los resultados con otros métodos de medida de densidad in situ.

  15. Evaluating exposure of pedestrians to airborne contaminants associated with non-potable water use for pavement cleaning.

    Science.gov (United States)

    Seidl, M; Da, G; Ausset, P; Haenn, S; Géhin, E; Moulin, L

    2016-04-01

    Climate change and increasing demography press local authorities to look after affordable water resources and replacement of drinking water for city necessities like street and pavement cleaning by more available raw water. Though, the substitution of drinking by non-drinking resources demands the evaluation of sanitary hazards. This article aims therefore to evaluate the contribution of cleaning water to the overall exposure of city dwellers in case of wet pavement cleaning using crossed physical, chemical and biological approaches. The result of tracer experiments with fluorescein show that liquid water content of the cleaning aerosol produced is about 0.24 g m(-3), rending possible a fast estimation of exposure levels. In situ analysis of the aerosol particles indicates a significant increase in particle number concentration and particle diameter, though without change in particle composition. The conventional bacterial analysis using total coliforms as tracer suggests that an important part of the contamination is issued from the pavement. The qPCR results show a more than 20-fold increase of background genome concentration for Escherichia coli and 10-fold increase for Enterococcus but a negligible contribution of the cleaning water. The fluorescence analysis of the cleaning aerosol confirms the above findings identifying pavement surface as the major contributor to aerosol organic load. The physical, chemical and microbiological approaches used make it possible to describe accurately the cleaning bioaerosol and to identify the existence of significantly higher levels of all parameters studied during the wet pavement cleaning. Though, the low level of contamination and the very short time of passage of pedestrian in the zone do not suggest a significant risk for the city dwellers. As the cleaning workers remain much longer in the impacted area, more attention should be paid to their chronic exposure.

  16. Evaluating Cool Impervious Surfaces: Application to an Energy-Efficient Residential Roof and to City Pavements

    Science.gov (United States)

    Rosado, Pablo Javier

    Summer urban heat island (UHI) refers to the phenomenon of having higher urban temperatures compared to the those in surrounding suburban and rural areas. Higher urban air temperatures lead to increased cooling demand, accelerates the formation of smog, and contributes to the generation of greenhouse gas emissions. Dark-colored impervious surfaces cover a significant fraction of an urban fabric, and as hot and dry surfaces, are a major contributor to the UHI effect. Adopting solar-reflective ("cool") roofs and cool pavements, and increasing the urban vegetation, are strategies proven to mitigate urban heat islands. These strategies often have an "indirect" effect (ambient cooling) and "direct" effect (change in solar energy flux entering the conditioned space) on the energy use of buildings. This work investigates some elements of the UHI mitigation strategies, specifically the annual direct effect of a cool roof, and the direct and indirect effects of cool pavements. The first topic researched in this paper consists in an experimental assessment of the direct effects from replacing a conventional dark roof with a highly energy-efficient cool roof. The study measures and calculates the annual benefits of the cool roof on the cooling and heating energy uses, and the associated emission reductions. The energy savings attributed to the cool roof are validated by measuring the difference between the homes in the heat loads that entered the conditioned space through the ceiling and HVAC ducts. Fractional annual cooling energy savings (26%) were 2.6 times the 10% daily cooling energy savings measured in a previous study that used a white coating to increase the albedo of an asphalt shingle roof by the same amount (0.44). The improved cooling energy savings (26% vs. 10%) may be attributed to the cool tile's above-sheathing ventilation, rather than to its high thermal mass. The roof also provided energy savings during the heating season, yielding fractional annual gas

  17. Assessment of an Impulse GPR Antenna Abilities in Investigation of Transversal Cracks of the Bituminous Pavement

    Science.gov (United States)

    Krysiński, L.; Sudyka, J.

    2012-04-01

    Ground Penetrating Radar (GPR) technique is commonly used for detection of internal singularities of construction structure. The method is particularly efficient in the case of linear horizontal objects when profile scanning is being performed in the direction perpendicular to object elongation and polarization of the electric field is parallel to the elongation. Then the singular object manifests itself in the echogram as a scattering hyperbola. Similar response is generated by an object having shape close to a vertical half plane with horizontal edge, when the edge acts like the scattering linear object. The use of GPR technique for investigation of transversal cracks in the bituminous pavement would seem to be promising, but numerous paradoxes occur just at the beginning tests. Even well visible cracks of more than ten millimeters thickness doesn't generate noticeable GPR response, while thinner ones sometimes can produce strong response but in the deeper interior of the pavement. Thus arise a more general question: what the GPR technique can tell us about the cracks? Trying to study this problem some laboratory tests were performed to estimate efficiency of signal generation by structures simulating idealized cracks' shapes. Next long-term (several years) visual observation and repeated GPR scanning was performed on the three road sections (each one of several hundred meters length) with heavy traffic, where ongoing cracking process occurs. The preliminary measurements were directed to obtain the proper way of scanning. The main aim of the analysis was to find GPR characteristics of cracks that can be noticed on echograms. It was performed by detailed correlation of the visually observed cracks position with echograms using decimeter precision. These efforts provided a list of diagnostic GPR characteristics of cracks and some provisional scale of their intensity. In several cases the cracks were probed by drillings to recognize structures responsible for signal

  18. GPR Image and Signal Processing for Pavement and Road Monitoring on Android Smartphones and Tablets

    Science.gov (United States)

    Benedetto, Francesco; Benedetto, Andrea; Tedeschi, Antonio

    2014-05-01

    Ground Penetrating Radar (GPR) is a geophysical method that uses radar pulses to image the subsurface. This non-destructive method uses electromagnetic radiation and detects the reflected signals from subsurface structures. It can detect objects, changes in material, and voids and cracks. GPR has many applications in a number of fields. In the field of civil engineering one of the most advanced technologies used for road pavement monitoring is based on the deployment of advanced GPR systems. One of the most relevant causes of road pavement damage is often referable to water intrusion in structural layers. In this context, GPR has been recently proposed as a method to estimate moisture content in a porous medium without preventive calibration. Hence, the development of methods to obtain an estimate of the moisture content is a crucial research field involving economic, social and strategic aspects in road safety for a great number of public and private Agencies. In particular, a recent new approach was proposed to estimate moisture content in a porous medium basing on the theory of Rayleigh scattering, showing a shift of the frequency peak of the GPR spectrum towards lower frequencies as the moisture content increases in the soil. Addressing some of these issues, this work proposes a mobile application, for smartphones and tablets, for GPR image and signal processing. Our application has been designed for the Android mobile operating system, since it is open source and android mobile platforms are selling the most smartphones in the world (2013). The GPR map can be displayed in black/white or color and the user can zoom and navigate into the image. The map can be loaded in two different ways: from the local memory of the portable device or from a remote server. This latter possibility can be very useful for real-time and mobile monitoring of road and pavement inspection. In addition, the application allows analyzing the GPR data also in the frequency domain. It is

  19. PAH volatilization following application of coal-tar-based pavement sealant

    Science.gov (United States)

    Van Metre, Peter C.; Majewski, Michael S.; Mahler, Barbara J.; Foreman, William T.; Braun, Christopher L.; Wilson, Jennifer T.; Burbank, Teresa L.

    2012-01-01

    Coal-tar-based pavement sealants, a major source of PAHs to urban water bodies, have recently been identified as a source of volatile PAHs to the atmosphere. We tracked the volatilization of PAHs for 1 year after application of a coal-tar-based pavement sealant by measuring gas-phase PAH concentrations above the pavement surface and solid-phase PAH concentrations in sealant scraped from the surface. Gas-phase concentrations at two heights (0.03 and 1.28 m) and wind speed were used to estimate volatilization flux. The sum of the concentrations of eight frequently detected PAHs (ΣPAH8) in the 0.03-m sample 1.6 h after application (297,000 ng m-3) was about 5000 times greater than that previously reported for the same height above unsealed parking lots (66 ng m-3). Flux at 1.6 h after application was estimated at 45,000 μg m-2 h-1 and decreased rapidly during the 45 days after application to 160 μg m-2 h-1. Loss of PAHs from the adhered sealant also was rapid, with about a 50% decrease in solid-phase ΣPAH8 concentration over the 45 days after application. There was general agreement, given the uncertainties, in the estimated mass of ΣPAH8 lost to the atmosphere on the basis of air sampling (2–3 g m-2) and adhered sealant sampling (6 g m-2) during the first 16 days after application, translating to a loss to the atmosphere of one-quarter to one-half of the PAHs in the sealcoat product. Combining the estimated mass of ΣPAH8 released to the atmosphere with a national-use estimate of coal-tar-based sealant suggests that PAH emissions from new coal-tar-based sealcoat applications each year (~1000 Mg) are larger than annual vehicle emissions of PAHs for the United States.

  20. Road Edge of Pavement, Part of Impervious, Published in 1999, 1:600 (1in=50ft) scale, Town of Cary NC.

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — This Road Edge of Pavement dataset, published at 1:600 (1in=50ft) scale, was produced all or in part from Orthoimagery information as of 1999. It is described as...