WorldWideScience

Sample records for brick pavements

  1. Recycling of radioactive oil sludge waste into pavement brick

    International Nuclear Information System (INIS)

    Malaysia produces about 1450 tons of radioactive oil sludge waste per year and there is an urgent need to find a permanent solution to the storage and disposal of this radioactive waste problem. Several treatment methods such bacteria farming, ultracentrifuge, steam reforming and incineration are currently being used but the core issue of the radioactive material in the oil sludge had not been solved. The paper relates a study on utilizing the radioactive component of the oil sludge and turning them into pavement brick. Characteristic study of this radioactive component by XRD and XRF show that it mainly comprised of quartz and anorthite minerals. While the radioactivity analysis by gamma technique shows that more than 90 % of this radioactivity comes from this soil component with Ra-226 and Ra-228 as the main radionuclides. A vitrified brick was then produced from this sediment by mixing it with low radioactive local red clay. The result also shows that the formation of the vitrified layer may be due high content of K in the red clay. Tensile test on the brick shows that it has more than four times the strength of commercial clay brick. Long duration leaching test on the brick also shows that there is no dissolution of radionuclide from the brick. (author)

  2. 活性粉末混凝土路面砖的经济性分析%The Economic Analysis of Reactive Powder Concrete Pavement Brick

    Institute of Scientific and Technical Information of China (English)

    杨丹; 王亚洲

    2015-01-01

    This paper mainly introduces the features and advantages of reactive powder concrete (RPC) pavement brick, and in the material composition of reactive powder concrete as the economy of the urban road brick are analyzed. Using of the reactive powder concrete pavement brick in Municipal Engineering can significantly increase the road service performance and durability, and play an important role in the future development of the road.%本文主要介绍了活性粉末混凝土(RPC)路面砖的特点和优势,并从材料组成上对活性粉末混凝土用作城市路面砖的经济性进行了分析。市政工程中采用活性粉末混凝土做路面砖,可以显著提高道路使用性能及耐久性,在未来道路发展中占有重要作用。

  3. 基于入渗产流分析的透水砖地面铺装结构试验%Experimental study on pavement structure of pervious bricks based on infiltration and nmoff generation analysis

    Institute of Scientific and Technical Information of China (English)

    张书函; 陈建刚; 赵飞; 侯立柱

    2011-01-01

    In order to find pervious pavement structures in favor of rainfall infiltration and runoff reduction, the characteristics of the rainfall infiltration and runoff generation in the pervious pavements with different structures were studied by means of artificial rainfall experiments. According to the comparison of performances of runoff reduction, infiltration increase and runoff generation lagging among 8 kinds of pavement structures, the optimal pavement structure should be the mode of " pervious brick and concrete without sand and single gradation gravel" from top to bottom.%为了找出有利于降雨入渗、削减径流的透水地面铺装结构,通过人工降雨试验,研究不同铺装垫层结构透水地面的降雨入渗与产流特性.根据8种铺装结构在径流削减、入渗量增加、开始产流时间滞后等方面的效果比较,推荐透水砖地面自上而下的铺装结构为“透水砖面层+无砂混凝土+单级配碎石”形式.

  4. Nozzle Bricks and Well Bricks

    Institute of Scientific and Technical Information of China (English)

    Zhang Xiaohui; Peng Xigao

    2011-01-01

    1 Scope This standard specifies the classification,brand,technical requirements,test methods,inspection rules,marking,packing,transportation,storage,and quality certificate of nozzle bricks and well bricks.This standard is applicable to unfired and fired products.

  5. Laboratory evaluation of cement treated aggregate containing crushed clay brick

    Directory of Open Access Journals (Sweden)

    Liqun Hu

    2014-10-01

    Full Text Available The waste clay bricks from debris of buildings were evaluated through lab tests as environmental friendly materials for pavement sub-base in the research. Five sets of coarse aggregates which contained 0, 25%, 50%, 75% and 100% crushed bricks, respectively, were blended with sand and treated by 5% cement. The test results indicated that cement treated aggregate which contains crushed clay brick aggregate had a lower maximum dry density (MDD and a higher optimum moisture content (OMC. Moreover, the unconfined compressive strength (UCS, resilience modulus, splitting strength, and frost resistance performance of the specimens decreased with increase of the amount of crushed clay brick aggregate. On the other hand, it can be observed that the use of crushed clay brick in the mixture decreased the dry shrinkage strain of the specimens. Compared with the asphalt pavement design specifications of China, the results imply that the substitution rate of natural aggregate with crushed clay brick aggregate in the cement treated aggregate sub-base material should be less than 50% (5% cement content in the mixture. Furthermore, it needs to be noted that the cement treated aggregate which contains crushed clay bricks should be cautiously used in the cold region due to its insufficient frost resistance performance.

  6. 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...

  7. Pavement evaluation and rehabilitation

    Energy Technology Data Exchange (ETDEWEB)

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

    1987-01-01

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

  8. 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...

  9. 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…

  10. Silica Refractory Bricks

    Institute of Scientific and Technical Information of China (English)

    Yu Lingyan; Peng Xigao

    2011-01-01

    @@ 1.Scope This standard specifies the classification,technical requirements,test methods,quality appraisal procedures,packing,marking,transportation,storage,and quality certificate of silica refractory bricks.This standard is applicable to silica refractory bricks with single weight≤40 kg.

  11. Arithmetic theory of brick tilings

    International Nuclear Information System (INIS)

    A new, 'arithmetic', approach to the algebraic theory of brick tilings is developed. This approach enables one to construct a simple classification of brick tilings in Zd and to find new proofs of several classical results on brick packing and tilings in Zd. In addition, possible generalizations of results on integer brick packing to the Euclidean plane R2 are investigated

  12. Engineering BioBrick vectors from BioBrick parts

    Directory of Open Access Journals (Sweden)

    Knight Thomas F

    2008-04-01

    Full Text Available Abstract Background The underlying goal of synthetic biology is to make the process of engineering biological systems easier. Recent work has focused on defining and developing standard biological parts. The technical standard that has gained the most traction in the synthetic biology community is the BioBrick standard for physical composition of genetic parts. Parts that conform to the BioBrick assembly standard are BioBrick standard biological parts. To date, over 2,000 BioBrick parts have been contributed to, and are available from, the Registry of Standard Biological Parts. Results Here we extended the same advantages of BioBrick standard biological parts to the plasmid-based vectors that are used to provide and propagate BioBrick parts. We developed a process for engineering BioBrick vectors from BioBrick parts. We designed a new set of BioBrick parts that encode many useful vector functions. We combined the new parts to make a BioBrick base vector that facilitates BioBrick vector construction. We demonstrated the utility of the process by constructing seven new BioBrick vectors. We also successfully used the resulting vectors to assemble and propagate other BioBrick standard biological parts. Conclusion We extended the principles of part reuse and standardization to BioBrick vectors. As a result, myriad new BioBrick vectors can be readily produced from all existing and newly designed BioBrick parts. We invite the synthetic biology community to (1 use the process to make and share new BioBrick vectors; (2 expand the current collection of BioBrick vector parts; and (3 characterize and improve the available collection of BioBrick vector parts.

  13. Asphalt pavement temperature prediction

    OpenAIRE

    Minhoto, Manuel; Pais, Jorge; Pereira, Paulo

    2006-01-01

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

  14. Permeable Pavements at Purdue

    OpenAIRE

    Knapp, Jim

    2013-01-01

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

  15. Pervious Pavement System Evaluation

    Science.gov (United States)

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

  16. Radiation shielding bricks

    International Nuclear Information System (INIS)

    A radiation shielding brick for use in building dry walls to form radiation proof enclosures and other structures is described. It is square in shape and comprises a sandwich of an inner layer of lead or similar shielding material between outer layers of plastics material, for structural stability. The ability to mechanically interlock adjacent bricks is provided by shaping the edges as cooperating external and internal V-sections. Relatively leak-free joints are ensured by enlarging the width of the inner layer in the edge region. (author)

  17. Mud Brick Resilience

    DEFF Research Database (Denmark)

    Johannessen, Runa

    2012-01-01

    In the seemingly endless circle of demolition and illegal rebuilding hand-made mud bricks produced from the soil of contested territory become an act of resistance. In June 2011, the Palestinian village Fasayel encountered the Israeli military’s demolition of 21 of the village’s built structures....

  18. Industrial wastes for firing Bricks

    Institute of Scientific and Technical Information of China (English)

    ZhanXuanye; LuGuansheng; Gaojun

    2005-01-01

    The paper discusses the feasibility on utilizing high-calcium industrial wastes in firing brick. In China, industrial wastes with over 10% calcium oxide is not regarded as raw materials for producing brick, so it is limited to use industrial wastes. The paper gives out the ideas that high-calcium industrial wastes can be used to produce fired brick by good raw material preparation process and proper methods.

  19. Brick handling: a case study.

    Science.gov (United States)

    Webb, R D; Handyside, J

    1982-09-01

    A small change in brick dimensions resulted in an increase in the perceived work-load of men loading and unloading pallets of bricks by hand. A laboratory study indicated that the change in brick dimensions required changes in grip pattern in order to unload bricks at the same rate, moving the same number at a time. These changed grip patterns resulted in increased upper body movement, increased chest-muscle activity and higher heart rates. These differences were reflected in higher subjective ratings of fatigue. PMID:15676442

  20. 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 ...

  1. More than Bricks and Mortar

    Science.gov (United States)

    Stanistreet, Paul

    2009-01-01

    Gaythorne Row, a terrace of Victorian back-to-back houses in Great Horton, was earmarked for demolition when, in 1986, Bradford Industrial Museum took possession of the three cottages and transported them, brick by brick, to the museum site four miles away. The houses were built in 1876, a year later than the old worsted spinning mill in which the…

  2. Pavement management using hyperspectral imagery

    Science.gov (United States)

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

    2003-08-01

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

  3. Pervious Pavement System Evaluation- Abstract

    Science.gov (United States)

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

  4. Properties of Magnesia-Hercynite Brick

    Institute of Scientific and Technical Information of China (English)

    LIU Huilin

    2008-01-01

    Properties of magnesia-hercynite brick were studied. The coatability, thermal shock resistance, corrosion resistance to cement clinker and thermal conductivity were compared with those of magnesia-chrome brick and magnesia-spinel brick used widely in sintering zone of cement rotary kiln. The result shows that magnesia-hercynite brick is better than magnesia-chrome brick in thermal chock resistance and Corrosi on resistance to cement clinker, is similar to magnesia-chrome brick and is better than magnesia-spinel brick in coatability and thermal conductivity.

  5. 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

  6. Pervious Pavement System Evaluation-Poster

    Science.gov (United States)

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

  7. High Performance Concrete Pavement in Indiana

    OpenAIRE

    Nantung, Tommy E

    2011-01-01

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

  8. Recycling of asphalt pavements with asphalt rubber

    OpenAIRE

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

    2008-01-01

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

  9. Silica Brick for Coke Oven

    Institute of Scientific and Technical Information of China (English)

    Wang Jing

    2007-01-01

    @@ 1 Scope This standard specifies the classification,specification,test method,quality appraisal procedure,labeling,packing,transportation,storage and quality certification of silica brick for coke oven.

  10. Reducing Your Cost for Asphalt Pavements

    OpenAIRE

    Evans, Alvin

    2012-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Andrzej Plewa

    2015-07-01

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

  12. Pavement thickness evaluation using ground penetrating radar

    Science.gov (United States)

    Harris, Dwayne Arthur

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

  13. EFFECTS OF PAVEMENT SURFACE TEMPERATURE ON THE MODIFICATION OF URBAN THERMAL ENVIRONMENT

    Directory of Open Access Journals (Sweden)

    SARAT, Adebayo-Aminu

    2012-01-01

    Full Text Available Urban centres continue to experience escalating average summer temperature over the last fifty years. Temperature in the urban core cites have been rising due to rapid growth of urbanization in the latter half of the twentieth century (Akbari et al., 1989. Outdoor experiments were conducted to investigate the effects of different movement of materials on the urban thermal environment. Meteorological conditions such as air temperature, pavement surface temperature, Relative humidity and wind velocity were recorded to determine temperature differences among Asphalt/concrete, interlocking bricks and grass surfaces.

  14. 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…

  15. Tuning in to pavement radio

    NARCIS (Netherlands)

    Ellis, S.D.K.

    1989-01-01

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

  16. Kaolinite Refractory Bricks for Blast Furnaces

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    @@ This standard is suitable to the fireclay bricks for blast furnace. 1 Classification, Shape and Dimension 1 According to physical and chemical indexes, the brick can be divided into two trademarks: ZGN-42 and GN-42.

  17. The integrity of CAGR moderator bricks

    International Nuclear Information System (INIS)

    The procedures for assessing the integrity of moderator bricks in Advanced Gas Cooled Reactors is described together with experiments proposed to improve the graphite input data and verify the condition of bricks at the end of life. (author)

  18. Can an Electron Rotate a Brick?

    Science.gov (United States)

    Bohren, Craig F.

    2009-01-01

    In "The Theory of Almost Everything", Robert Oerter asserts the following: "Take a beam of electrons that are all spinning in the same direction and fire it at, say, a brick. If you could keep this up for long enough, and if there were no other forces acting on the brick, the electrons would transfer their rotation to the brick, and it would begin…

  19. Chinese Standards on Refractories Fireclay Brick and Semi-silica Brick for Coke Oven

    Institute of Scientific and Technical Information of China (English)

    Wang Jing

    2009-01-01

    @@ 1 Scope This standard specifies the technical requirements,test methods,quality appraisal procedure,packing,transportation,storage,and quality certificate of fireclay brick and semi-silica brick for coke oven. This standard is applicable to the fireclay brick and semi-silica brick for coke oven,and the bricks for inner linings of carbon furnace,gas generator and shaft furnace.

  20. Removable Urban Pavements: An innovative, sustainable technology

    OpenAIRE

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

    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...

  1. Landfill gas powers brick production

    International Nuclear Information System (INIS)

    Marshalls plc produce high-quality facing bricks using tunnel kilns at the company's Stairfoot Brickworks site, in the UK. The company extracts clay from the adjacent quarries, which are subsequently filled with domestic waste. In 1981 Marshalls decided to exploit the landfill gas (LFG) resource 'on its doorstep'. (author)

  2. 3D Printing for Bricks

    OpenAIRE

    ECT Team, Purdue

    2015-01-01

    Building Bytes, by Brian Peters, is a project that uses desktop 3D printers to print bricks for architecture. Instead of using an expensive custom-made printer, it uses a normal standard 3D printer which is available for everyone and makes it more accessible and also easier for fabrication.

  3. Structural Evaluation for Maputo Airport Pavement

    Institute of Scientific and Technical Information of China (English)

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

    2007-01-01

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

  4. Mechanical Response Analysis of Asphalt Pavement Structure

    Directory of Open Access Journals (Sweden)

    Yu Zhenqing

    2015-11-01

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

  5. Long Life Pavements; Firmes de larga duracion

    Energy Technology Data Exchange (ETDEWEB)

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

    2009-07-01

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

  6. HMA Pavement Performance and Durability

    OpenAIRE

    del Pilar Vivar, Eliana; Haddock, John E.

    2006-01-01

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

  7. Modelling Flexible Pavement Response and Performance

    DEFF Research Database (Denmark)

    Ullidtz, Per

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

  8. 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

  9. Pervious Pavement System Evaluation-Paper

    Science.gov (United States)

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

  10. Analysis and design optimization of flexible pavement

    Energy Technology Data Exchange (ETDEWEB)

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

    2000-04-01

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

  11. Brick walls on the brane

    International Nuclear Information System (INIS)

    The so-called 'brick-wall model' is a semiclassical approach that has been used to explain black hole entropy in terms of thermal matter fields. Here, we apply the brick-wall formalism to thermal bulk fields in a Randall-Sundrum brane world scenario. In this case, the black hole entity is really a string-like object in the anti-de Sitter bulk, while appearing as a Schwarzchild black hole to observers living on the brane. In spite of these exotic circumstances, we establish that the Bekenstein-Hawking entropy law is preserved. Although a similar calculation was recently considered in the literature, this prior study invoked a simplifying assumption (which we avoid) that cannot be adequately justified

  12. Pavement Crack Detection Using Spectral Clustering Method

    Directory of Open Access Journals (Sweden)

    Jin Huazhong

    2015-01-01

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

  13. Non-autoclave silicate brick

    OpenAIRE

    V. N. Yaglov; Ya. N. Kovalev; V. N. Romaniuk; G. A. Burak

    2015-01-01

    The paper proposes a technology for obtaining bricks on the basis of lime-silica mixtures where chemical interactions are practically completely realized in dispersive state at the stage of preparation of binding contact maturing and raw mixture as a whole. The role of forming operation (moulding) is changed in principle because in this case conversion of dispersive system into a rock-like solid occurs and due to this the solid obtains complete water-resistance in contact with water immediate...

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

    Directory of Open Access Journals (Sweden)

    Sina Mirzapour Mounes

    2014-01-01

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

  15. 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.

  16. The production process for water penetrated brick

    Institute of Scientific and Technical Information of China (English)

    SunGuofeng

    2005-01-01

    Waste penetrated brick, which is a green building material with good water penetration, high strength, lower firing temperature, lower production cost, good appearance and good structure, can holding ground water lever. This article analysis the production process and related factor for water penetrated brick:proper particle size distribution, proper shaping method, proper press and proper firing can ensure to produce good quality water penetrated brick.

  17. Effects of temperature and water on pavement performance

    Energy Technology Data Exchange (ETDEWEB)

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

    1987-01-01

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

  18. Aircraf landing gear design in respect of pavement design

    OpenAIRE

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

    2009-01-01

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

  19. "Method, system and storage medium for generating virtual brick models"

    DEFF Research Database (Denmark)

    2009-01-01

    An exemplary embodiment is a method for generating a virtual brick model. The virtual brick models are generated by users and uploaded to a centralized host system. Users can build virtual models themselves or download and edit another user's virtual brick models while retaining the identity of the...... original virtual brick model. Routines are provided for both storing user created building steps in and generating automated building instructions for virtual brick models, generating a bill of materials for a virtual brick model and ordering physical bricks corresponding to a virtual brick model....

  20. Assessment of highway pavements using GPR

    Science.gov (United States)

    Plati, Christina; Loizos, Andreas

    2015-04-01

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

  1. Bauxite Based Bricks for Steel Ladle

    Institute of Scientific and Technical Information of China (English)

    Yu Lingyan; Peng Xigao

    2011-01-01

    @@ 1.Scope This standard specifies the classification,technical requirements,test methods,inspection rules,packing,marking,transportation,storage,and quality certificate of bauxite based bricks for steel ladle linings.This standard is applicable to bauxite based bricks for working layer of steel ladle.

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

    Directory of Open Access Journals (Sweden)

    Shaohua Li

    2013-09-01

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

  3. Permeable Pavement Research - Edison, New Jersey

    Science.gov (United States)

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

  4. Pervious Pavement System Evaluation- Abstract 1

    Science.gov (United States)

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

  5. Children, urban care, and everyday pavements

    OpenAIRE

    Kim Kullman

    2014-01-01

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

  6. Fusing complementary images for pavement cracking measurements

    International Nuclear Information System (INIS)

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

  7. Investigation of original bricks from Ventspils castle for the purpose of restorations of medieval brick masonry

    International Nuclear Information System (INIS)

    This paper mainly tries to characterize Middle Age brick taken from Ventspils Castle (13-17th century). To this aim, the following techniques were applied: visual inspection, X-ray diffraction, mercury porosimetry, physical laboratory tests (water absorption, density, open porosity, saturation coefficient, Mage's index) and chemical analysis. The medieval bricks are still in good condition, any visible damages were not recognized in the course of visual inspection. According to the results of chemical analysis, three types of bricks made from different clays in different centuries were used. According to X-ray diffraction analysis data no one type of medieval bricks contains illite. So sintering temperature of the medieval bricks studied was higher than 900 deg C. The secondary calcite was formed in the structure of bricks from lime mortars under influence of water migration during several centuries. All medieval bricks studied are porous - open porosity of them amounts to 26-30 %. 14-15th century bricks have inclusions of chamotte additive, which makes the bricks less durable to soluble salts and frost, and of organic additive, that imparts the higher porosity. Mage's index for all medieval is less than 0.55, but saturation coefficient is close to 0,78 and it means that these bricks are not enough durable to soluble salts and frost

  8. 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. PMID:24027444

  9. 21 CFR 133.109 - Brick cheese for manufacturing.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 2 2010-04-01 2010-04-01 false Brick cheese for manufacturing. 133.109 Section... Standardized Cheese and Related Products § 133.109 Brick cheese for manufacturing. Brick cheese for manufacturing conforms to the definition and standard of identity for brick cheese prescribed by §...

  10. 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.

  11. Bridge and brick motifs in complex networks

    Science.gov (United States)

    Huang, Chung-Yuan; Sun, Chuen-Tsai; Cheng, Chia-Ying; Hsieh, Ji-Lung

    2007-04-01

    Acknowledging the expanding role of complex networks in numerous scientific contexts, we examine significant functional and topological differences between bridge and brick motifs for predicting network behaviors and functions. After observing similarities between social networks and their genetic, ecological, and engineering counterparts, we identify a larger number of brick motifs in social networks and bridge motifs in the other three types. We conclude that bridge and brick motif content analysis can assist researchers in understanding the small-world and clustering properties of network structures when investigating network functions and behaviors.

  12. Drying brick masonry by electro-osmosis

    DEFF Research Database (Denmark)

    Ottosen, Lisbeth M.; Rörig-Dalgaard, Inge

    2006-01-01

    When a fine grained, porous medium is applied an electric DC field, transport of matter occurs, and the transport mechanism in focus of the present study is electro-osmosis, which is transport of water. In laboratory it was shown possible to transport water inside a brick and brick/mortar system ...... a clear movement of water towards the cathode was seen. Thus the basis for utilizing the electro-osmotic effect for drying brick masonry is present, but proper electrodes still needs to be developed....

  13. NON-AUTOCLAVE SILICATE BRICK

    Directory of Open Access Journals (Sweden)

    V. N. Yaglov

    2015-01-01

    Full Text Available The paper proposes a technology for obtaining bricks on the basis of lime-silica mixtures where chemical interactions are practically completely realized in dispersive state at the stage of preparation of binding contact maturing and raw mixture as a whole. The role of forming operation (moulding is changed in principle because in this case conversion of dispersive system into a rock-like solid occurs and due to this the solid obtains complete water-resistance in contact with water immediately after forming operation. Theoretical basis for the developed technology is capability of silicate dispersive substances (hydrated calcium silicate to transit in non-stable state, to form a rock-like water-resistant solid in the moment of mechanical load application during forming process. Specific feature of the proposed method is an exclusion of additional operations for autoclaving of products from the process of obtaining a silicate brick.Synthetic hydrated calcium silicate in contrast to natural ones are more uniform in composition and structure, they contain less impurities and they are characterized by dispersive composition and due to the mentioned advantages they find wider practical application. Contact-condensation binders permit to manipulate product properties on their basis and ensure maximum correspondence to the requirements of the concrete application. Raw material sources for obtaining synthetic hydrated calcium silicates are practically un-limited because calcium-silicon containing substances are found as in various technogenic wastes so in natural compounds as well. So the problem for obtaining hydrated calcium silicates having contact-condensation ability for structure formation becomes more and more actual one. This transition is considered as dependent principally on arrangement rate of substance particles which determined the level of its instability.

  14. POROUS PAVEMENT. PHASE I. DESIGN AND OPERATIONAL CRITERIA

    Science.gov (United States)

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

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

    OpenAIRE

    Pierre Guy Atangana Njock; Li Yueguang

    2015-01-01

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

  16. 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.

  17. 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...

  18. Moisture movements in render on brick wall

    DEFF Research Database (Denmark)

    Hansen, Kurt Kielsgaard; Munch, Thomas Astrup; Thorsen, Peter Schjørmann; Villumsen, Casper Rosengaard; Bentzon, Lars Chr.

    2003-01-01

    A three-layer render on brick wall used for building facades is studied in the laboratory. The vertical render surface is held in contact with water for 24 hours simulating driving rain while it is measured with non-destructive X-ray equipment every hour in order to follow the moisture front...... through the render and into the brick. The test specimen is placed between the source and the detector. The test specimens are all scanned before they are exposed to water. In that way the loss of counts from the dry scan to the wet scan qualitatively shows the presence of water. The results show nearly...... no penetration of water through the render and into the brick, and the results are independent of the start condition of the test specimens. Also drying experiments are performed. The results show a small difference in the rate of drying, in favour of the bricks without render....

  19. Shielding walls against ionizing radiation. Lead bricks

    International Nuclear Information System (INIS)

    The standard contains specifications for the shape and requirements set for lead bricks such that they can be used to construct radiation-shielding walls according to the building kit system. The dimensions of the bricks are selected in such a way as to permit any modification of the length, height and thickness of said shielding walls in units of 50 mm. The narrow side of the lead bricks juxtaposed to one another in a wall construction to shield against radiation have to form prismatic grooves and tongues: in this way, direct penetration by radiation is prevented. Only cuboid bricks (serial nos. 55-60 according to Table 10) do not have prismatic tongues and grooves. (orig.)

  20. Burned Microporous Alumina-Graphite Brick

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    @@ 1 Scope This standard specifies the definition,classifica-tion,technical requirements,test methods,inspection rules,marking,packing,transportation and quality certificate of burned microporous alumina-graphite brick.

  1. Silica Brick for Hot Blast Stove

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    @@ 1 Scope This standard specifies the glossary and definition, marking, shape and dimension, technical requirements, test method, quality appraisal procedure, packing, label, transportation, storage and quality certification of silica brick for hot blast stove.

  2. Specification for lead bricks for radiation shielding

    International Nuclear Information System (INIS)

    Specification with metric dimensions for two systems of interlocking lead bricks for building permanent or temporary shielding walls including numbering system with illustrations, and schedule for ordering purposes. (author)

  3. Spills on Flat Inclined Pavements

    Energy Technology Data Exchange (ETDEWEB)

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

    2004-03-01

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

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

    NARCIS (Netherlands)

    Boogaard, Floris; Lucke, Terry; Beecham, Simon

    2013-01-01

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

  5. Water vapour permeability of clay bricks

    OpenAIRE

    Dondi, M.; Principi, P.; Raimondo, M.; Zanarini, G.

    2003-01-01

    The water vapour permeability of clay bricks has been experimentally measured in order to draw a representative outline of industrial products without pore-forming additives. The correlations between water vapour permeability and the main compositional and microstructural parameters of both bricks and clay bodies have been investigated. A statistical model was set up in order to predict with reasonable precision and reliability, the water vapour permeability on the basis of open porosity, bul...

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

    OpenAIRE

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

    2005-01-01

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

  7. Decontaminating lead bricks and shielding

    International Nuclear Information System (INIS)

    Lead used for shielding is often surface contaminated with radionuclides and is therefore a Resource Conservation and Recovery Act (RCRA) D008 mixed waste. The technology-based standard for treatment is macroencapsulation. However, decontaminating and recycling the clean lead is a more attractive solution. Los Alamos National Lab. decontaminates material and equipment contaminated with radioisotopes. Decontaminating lead poses special problems because of the RCRA hazard classification and the size of the inventory, now about 100 metric tons and likely to grow substantially because of planned decommissioning operations. This lead, in the form of bricks and other shield shapes, is surface contaminated with fission products. One of the best methods for decontaminating lead is removing the thin superficial layer of contamination with an abrasive medium under pressure. For lead, a mixture of alumina with water and air at about 280 kPa (40 psig) rapidly and effectively decontaminates the lead. The abrasive medium is sprayed onto the lead in a sealed-off area. The slurry of abrasive and particles of lead falls through a floor grating and is collected in a pump. A pump sends the slurry mixture back to the spray gun, creating a continuous process

  8. 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.

  9. "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...

  10. 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 in a...

  11. 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...

  12. Permeable pavement research – Edison, New Jersey

    Science.gov (United States)

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

  13. Radiological significance of building bricks in Pakistan

    International Nuclear Information System (INIS)

    Baked clay bricks samples were collected from both urban and rural areas of the North West Frontier Province of Pakistan and natural radioactivity due to 40K, 226Ra and 232Th has been measured in these samples. The specific absorbed dose rates due to natural radioactivity emanating from the walls, floors and ceilings of the typical model rooms made of these building bricks have been calculated applying the mesh size adaptive volume integral methodology. The occupancy factor, representing the weighted average of all the population in the country, was taken to be 0.3 and 0.35 mSv.y-1 for the two types of model rooms. These values are smaller than those predicted by UNSCEAR for normal background areas. Thus the building bricks analysed in this study do not pose any significant health problem to the population. (author)

  14. Frost resistance of concrete with crushed brick as aggregate

    OpenAIRE

    Janković Ksenija; Bojović Dragan; Nikolić Dragan; Lončar Ljiljana; Romakov Zoran

    2010-01-01

    The investigation included concrete made by using recycled brick as aggregate. Experimental work included several types of concrete made with the same cement content (385 kg/m3), and same consistency (slump about 1 cm). Recycled brick and combination of natural river aggregate and recycled brick were used as aggregates. The influence of percentage and grain size of crushed brick aggregate on concrete compressive strength, water absorption and frost resistance were observed. On the basis of th...

  15. Measurement of natural radionuclides in bricks and brick-making clays from Cuddalore district, Tamilnadu, India

    International Nuclear Information System (INIS)

    In India, bricks as building materials are mainly prepared by clay using the deposited sediments of rivers, and the radionuclide contents in bricks and brick-making clays should vary with origin and geological condition. In this paper, the radionuclide contents of these materials from river bank areas of Cuddalore district, Tamilnadu India are measured by gamma ray spectrometer using NaI (Tl) detector, and compared with those of other countries. The radiation hazard indices, which are evaluated by radium-equivalent (Raeq) activity, are lower than that of NEA-OECD. (authors)

  16. Brick Walls for Nonstationary Black Holes

    Institute of Scientific and Technical Information of China (English)

    黎忠恒; 米丽琴; 赵峥

    2002-01-01

    The validity condition of the brick-wall model is analysed in nonstationary space time. It is shown that the model holds only in thin regions, only by using tortoise coordinates, near the event horizon of a slowly varying (quasi-stationary) black hole. The reason for the use of tortoise coordinates is that the stationary state solutions of quantum field equations in other coordinates do not exist for any region in nonstationary space-time. Meanwhile,the quantum corrections to the entropy of the Vaidya-Bonner black hole due to the spin fields are calculated in terms of the brick-wall model.

  17. MODELING PAVEMENT DETERIORATION PROCESSES BY POISSON HIDDEN MARKOV MODELS

    Science.gov (United States)

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

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

  18. Investigation on Production and Markets of Silica Bricks in China

    Institute of Scientific and Technical Information of China (English)

    ZHANG Zhongqi; CHU Guosheng; WANG Tiezheng; PAN Shangxin

    2003-01-01

    The annual output of China' s silica brick amounts up to over 300 thousand tons, which accounts for more than 70% of the total output of silica bricks in the world.Besides satisfying domestic markets, China's silica bricks have been exported to many countries and regions such as Japan, USA etc. In this paper, the situation of silica bricks production, technology, sales and exporting have been described. Also suggestions on improvement of silica bricks quality and exporting, corporation with foreign partners have been put forward in order to win larger market share both at home and abroad.

  19. Investigation on Production and Markets of Silica Bricks in China

    Institute of Scientific and Technical Information of China (English)

    ZHANGZhongqi; CHUGuosheng; WANGTiezheng; PANShangxin

    2003-01-01

    The annual output of China's silica brick amounts up to over 300 thousand tons, which accounts for more than 70% of the total oupout of silica bricks in the world. Besides satisfying domestic markets, China's silica bricks have been exported to many countries and retions such as Japan, USA etc. In this paper, the situation of silica bricks production, technology, sales and exporting have been described. Also suggestions on improvement of silica bricks quality and exporting, corporation with foreign partners have been put forward in order to win larger market share both aat home and abroad.

  20. Adherence Characteristics of Cement Clinker on Basic Bricks

    Institute of Scientific and Technical Information of China (English)

    GUO Zongqi; Michel Rigaud

    2002-01-01

    Based on the sandwich test, adherence mechanisms of cement clinker on various basic bricks were tackled by microstructural observations with help of cathodoluminescence technique. Doloma based bricks offer sufficient lime to react with clinker, forming C3 S rich layer and initializing superior adherence. However, clinker with low silica ratio leads to MgO agglomeration at the interface of doloma bricks, which reduces adherence strength. On magnesia spinel bricks, fine, crystalline spinel easily reacts with lime containing phases from clinker to form lowmelting phases and belite zone, which shows high adherence performance. Lack of fine spinel in magnesia spinel bricks results in poor adherence.

  1. Urban waste as a potential source for brick plants

    Science.gov (United States)

    Daugherty, K. E.; Eberendu, A.; Griffin, J.; Gegbe, H.; Ike, C.; Aboo, A.

    1982-02-01

    A joint government/industry/university project was formulated to address the technical feasibility of utilizing municipal solid waste (MSW) as a commercial fuel for the brick industry. Specifically, refuse derived fuel (RDF) from MSW was investigated for three potential applications in the brick industry: (1) rotary brick kilns; (2) tunnel brick kilns; and (3) moisture dryers. The successful development of such a procedure would be a dramatic achievement with widespread applicability, transferability, and commercial merit for energy displacement. The sampling, collection, and analysis of MSW, the analysis of RDF, and the potential utilization of RDF as an alternate source of fuel for the brick industry are described.

  2. An Airport Pavement Traffic Simulation Based on CPN

    OpenAIRE

    Heng Hong-jun; Yang Jue

    2014-01-01

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

  3. International Symposium on Pavement Life Cycle Assessment 2014

    OpenAIRE

    JULLIEN, Agnès; Harvey, John

    2014-01-01

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

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

    OpenAIRE

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

    2008-01-01

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

  5. Integrated transportation monitoring system for both pavement and traffic

    OpenAIRE

    Xue, Wenjing

    2013-01-01

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

  6. Recent Developments in Pavement Management on Irish National Roads

    OpenAIRE

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

    2015-01-01

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

  7. Long-Term Field Performance of Pervious Concrete Pavement

    OpenAIRE

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

    2012-01-01

    The work described in this paper provides an evaluation of an aged pervious concrete pavement in the Northeastern United States to provide a better understanding of the long-lasting effects of placement techniques as well as the long-term field performance of porous pavement, specifically in areas susceptible to freezing and thawing. Multiple samples were taken from the existing pavement and were examined in terms of porosity and unit weight, compressive and splitting tensile strength, and th...

  8. Pavement Response to Variable Tyre Pressure of Heavy Vehicles

    OpenAIRE

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

    2016-01-01

    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...

  9. In-Situ Behavior of Geosynthetically Stabilized Flexible Pavement

    OpenAIRE

    Appea, Alexander Kwasi

    1997-01-01

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

  10. 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.

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

    OpenAIRE

    Isamu Yoshitake; Takeo Ishida; Sunao Fukumoto

    2015-01-01

    Recyclable concrete pavement was made from fly ash and crushed limestone sand and gravel as aggregates so that the concrete pavement could be recycled to raw materials for cement production. With the aim to use as much fly ash as possible for the sustainable development of society, while achieving adequate strength development, pavement concrete having a cement-replacement ratio of 40% by mass was experimentally investigated, focusing on the strength development at an early age. Limestone pow...

  12. Remarks on 't Hooft's brick wall model

    International Nuclear Information System (INIS)

    A semi-classical reasoning leads to the non-commutativity of the space and time coordinates near the horizon of Schwarzschild black hole. This non-commutativity in turn provides a mechanism to interpret the brick wall thickness hypothesis in 't Hooft's brick wall model as well as the boundary condition imposed for the field considered. For concreteness, we consider a noncommutative scalar field model near the horizon and derive the effective metric via the equation of motion of noncommutative scalar field. This metric displays a new horizon in addition to the original one associated with the Schwarzschild black hole. The infinite red-shifting of the scalar field on the new horizon determines the range of the noncommutative space and explains the relevant boundary condition for the field. This range enables us to calculate the entropy of black hole as proportional to the area of its original horizon along the same line as in 't Hooft's model , and the thickness of the brick wall is found to be proportional to the thermal average of the noncommutative space-time range. The Hawking temperature has been derived in this formalism. The study here represents an attempt to reveal some physics beyond the brick wall model. (author)

  13. Architectural Thermal Forms II: Brick Envelope

    DEFF Research Database (Denmark)

    Foged, Isak Worre

    The paper presents an architectural concept and design method that investigates the use of dynamic factors in evolutionary form finding processes. The architectural construct, phenotype, is based on a brick assembly and how this can be organized based upon material properties and environmental...

  14. Using rice straw to manufacture ceramic bricks

    Directory of Open Access Journals (Sweden)

    Gorbunov German Ivanovich

    2014-12-01

    Full Text Available In the article, the co-authors offer their advanced and efficient methodologies for the recycling of the rice straw, as well as the novel approaches to the ceramic brick quality improvement through the application of the rice straw as the combustible additive and through the formation of amorphous silica in the course of the rice straw combustion. The co-authors provide characteristics of the raw materials, production techniques used to manufacture ceramic bricks, and their basic properties in the article. The co-authors describe the simulated process of formation of amorphous silica. The process in question has two independent steps (or options: 1 rice straw combustion and ash formation outside the oven (in the oxidizing medium, and further application of ash as the additive in the process of burning clay mixtures; 2 adding pre-treated rice straw as the combustible additive into the clay mixture, and its further burning in compliance with the pre-set temperature mode. The findings have proven that the most rational pre-requisite of the rice straw application in the manufacturing of ceramic bricks consists in feeding milled straw into the clay mixture to be followed by molding, drying and burning. Brick samples are highly porous, and they also demonstrate sufficient compressive strength. The co-authors have also identified optimal values of rice straw and ash content in the mixtures under research.

  15. Strengthening brick masonry columns using ferrocement

    International Nuclear Information System (INIS)

    Prior to concrete becoming a widely used building material, brick masonry walls and columns were mainly provided in buildings in most parts of the Indo-Pak Sub-Continent. Quite a large number of these old brick masonry buildings have lost strength, which needs to be restored. A research work was carried out to enhance the strength of brick masonry columns through confinement with ferrocement so as to act as a retrofit arrangement in restoring strength of old brick masonry columns. Composite behavior of masonry columns coated with/without ferrocement having 1, 2 and 3 layers of wire meshes were prepared and tested. Bonding agent was also used for some cases. Test results revealed that the application of ferrocement coating on bare masonry columns enhances the compressive strength quite significantly. Ferrocement specimens having 1 layer of wire mesh wrapped inside showed an increase in failure load up to 134% as compared to control specimen. The cracking resistance and stable crack growth mechanism is also improved. The use of bonding agent does not help in improving load carrying capacity however it is effective in controlling the spalling of concrete cover. (author)

  16. Incorporation feasibility of leather residues in bricks

    Energy Technology Data Exchange (ETDEWEB)

    Aguiar, J.B. [Minho Univ. (Portugal). Civil Engineering Dept.; Valente, A.; Pires, M.J. [Inst. of Development and Innovation Technology of Minho, Braga (Portugal); Tavares, T. [Biological Engineering Dept., Univ. of Minho, Braga (Portugal)

    2002-07-01

    The footwear industry has strips of leather as one of its by-products. These leather residues, due to their high chromium content, can be regarded as a threat to the environment, particularly if no care is taken with their disposal. With the incorporation of the residues in ceramic products, after trituration, is possible to neutralise the eventual toxicity of chromium. In a laboratory study we produced prismatic bricks using clay from the region and incorporating 1, 3 and 5% (by mass) of leather residues. This corresponds at about 20, 60 and 100% (by apparent volume). The moulds were filled up with paste and, in order to have some compactness, the ceramic paste was compressed with a spatula. After that, it began the process of drying and burning the bricks. They were tested to flexure, compression and leaching. The results showed that the toxicity of chromium disappeared in the bricks. The mechanical tests showed a decrease in strength for the specimens with leather residue. The compressive strength decreases about 22% for 1% of incorporation of leather residue. However, as bricks were lighter and more porous, we can expect that they are better for thermal isolation. (orig.)

  17. Pressure equalisation of brick masonry cavity walls

    NARCIS (Netherlands)

    Geurts, C.P.W.; Bouma, P.W.; Aghaei, A.

    2005-01-01

    This paper describes two full-scale experiments in which the pressure distribution over the layers of brick masonry cavity walls is studied. The first experiment focuses on the specification of the wind loads on both outer and inner leafs of these walls. The second experiment is set-up to find a mod

  18. Outside corner and method of making in the making lead brick (plain brick) using rotary table

    International Nuclear Information System (INIS)

    It has been developed a tool that can be used for defining angles on the fabrication of lead bricks. The angles are both outside of the lead bricks that correspond to male and female shape respectively. The lead bricks should be in accordance to ISO 7212-1986 standard which has angle tolerance 90° 0+15 for male and 90° 0-15 for female. The accuracy of these angles is very important to maintain the equilibrium position of the bricks so that their arrangement will not lining or collapse. A rotary table is used for the fabrication to make easier in setting up any related working apparatus and to have precision measurement result. However, a lot of operator do not know yet how to operate such a rotary table to produce angle with such an eligible tolerance. Therefore, a method of measurement in machining lead brick process using a rotary table is necessarily required. This method will be used as a reference to have angle accuracy of 0,03° in producing outside and inside angles or male and female lead bricks. (author)

  19. Hybrid green permeable pave with hexagonal modular pavement systems

    International Nuclear Information System (INIS)

    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.

  20. 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.

  1. Compressive strength of brick masonry made with weak mortars

    DEFF Research Database (Denmark)

    Pedersen, Erik Steen; Hansen, Klavs Feilberg

    2013-01-01

    strength of masonry depends only on the strength of the bricks. A compression failure in masonry made with weak mortars occurs as a tension failure in the bricks, as they seek to prevent the mortar from being pressed out of the joints. The expression is derived by assuming hydrostatic pressure in the...... mortar joints, which is the most unfavourable stress distribution with respect to tensile stresses in bricks. The expression is compared with the results of compression tests of masonry made with weak mortars. It can take into account bricks with arbitrary dimensions as well as perforated bricks. For a...... stronger mortar (fm≈6 N/mm2) compression tests of masonry with perforated bricks show that the EC6 expression is not always safe for Danish masonry. This is probably because the tensile strength of the bricks also has an effect on the compressive strength of masonry when the mortar is stronger than weak...

  2. Towards noise classification of road pavements

    OpenAIRE

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

    2008-01-01

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

  3. Smart pavement sensor based on thermoelectricity power

    Science.gov (United States)

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

    2010-04-01

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

  4. Life cycle assessment of regional brick manufacture

    Directory of Open Access Journals (Sweden)

    López-Aguilar, H. A.

    2016-06-01

    Full Text Available This document presents a Life Cycle Assessment (LCA study to quantify the environmental cradle-to-gate impact of the manufacture of brick for the construction industry, produced with material of igneous source. Its mineral composition and thermal isolation properties were characterized for use in real estate construction. The LCA results for brick manufacture using this material identified the greatest environmental impact to be associated with material extraction and its proportional cement content. Additionally, this document presents an evaluation of the environmental impact of the manufacturing process by comparing traditional fired clay brick and brick of the material under study. In conclusion, the studied material shows thermal insulation qualities and suitability for the manufacture of bricks with low incorporated energy.Este trabajo presenta un estudio de Análisis de Ciclo de Vida (ACV para cuantificar los impactos ambientales de la cuna a la puerta de la manufactura de ladrillos para la industria de la construcción, fabricados de un material de origen ígneo. Se caracterizó su composición mineralógica y propiedades de aislamiento térmico para ser usado en la construcción de inmuebles. Los resultados ACV de la fabricación de ladrillos de este material, identificaron la mayor contribución a los impactos ambientales asociados a la extracción del material y la cantidad proporcional de cemento. Adicionalmente, se presenta una evaluación comparativa del impacto ambiental entre la manufactura de un ladrillo tradicional de arcilla cocido y de un ladrillo del material en estudio. En conclusión el material estudiado muestra cualidades de aislamiento térmico y es adecuado para la fabricación de ladrillos con baja energía incorporada.

  5. A study of natural radioactivity in different types of bricks

    International Nuclear Information System (INIS)

    This study reports radioactivity in bricks measured using gamma spectroscopy. Sixteen samples of clay bricks and four samples of cement bricks were analysed. The mean activity concentrations of Th sup 232, Ra sup 226 and K sup 40 in clay bricks were 63,33 and 530 Bq per kg respectively. In cement brick samples these mean activity concentrations were 17, 42 and 524 Bq per kg respectively. Radium equivalent values obtained for clay bricks and cement bricks ranged from 16-348 and 89-142 Bq per kg respectively. Ra sub eq is a measure to ascertain whether these masonry materials have a radiation hazard. The mean value for Ra sub eq for typical masonry in the world is 370 Bq per kg and as such the values obtained in this study indicate that these masonry materials are not radioactively hazardous. The criterion limit which is also a measure to consider whether it is radioactively hazardous to use these materials in dwellings show that the values obtained are 0.22 and 0.16 for clay and cement bricks respectively. Thus the value obtained from this criterion limit further strengthens the fact that the bricks do not pose a radiation hazard. The mean annual dose from clay and cement bricks were also calculated.(AU)

  6. Experimental characterisation of Polyethylene Terephthalate (PET) bottle Eco-bricks

    International Nuclear Information System (INIS)

    Highlights: • Characterisation of a novel “Eco-brick” by recycling PET bottles and plastic waste. • Eco-bricks have properties for possible uses in construction. • Consistent manufacturing of Eco-bricks demonstrated to be possible. • Weight of Eco-bricks has a nearly linear relationship with mechanical strength. • Light passage and sound reduction potential of Eco-bricks shown to be good. - Abstract: This paper addresses the issue of recycling waste plastic by considering the feasibility of use of Eco-bricks for constructional purposes. The Eco-bricks are formed by packing plastic within Polyethylene Terephthalate (PET) bottles. Guidelines were provided for the construction of Eco-bricks. Experiments were carried out to characterise some of the properties of these bricks. Compression test, sound insulation assessment and light transmission were considered in this regard and compared with traditional construction materials and conditions. Possible applications of Eco-bricks were discussed. The paper presents the first attempt to characterise these bricks and the results encourage future use of them to a significantly wider extent and for various purposes

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

    International Nuclear Information System (INIS)

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

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

    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,…

  9. Electrokinetic removal of salt from brick masonry

    DEFF Research Database (Denmark)

    Ottosen, Lisbeth M.; Pedersen, Anne Juul; Rörig-Dalgaard, Inge

    2006-01-01

    A method to effectively remove salts from masonry is lacking. The present study aims at determining the removal efficiency of salts from bricks in an applied low current electric DC field. At first an investigation on removal of NaCl and Na(NO3)2 from spiked bricks in laboratory scale was conducted...... electrodes, a cathode and an anode, that were placed on a masonry wall of an old stable. The masonry had a high concentration of nitrates and problems with hygroscopic moisture. The electrodes consisted of reinforcement steel in carbonate-rich clay. The clay was chosen mainly to improve electric contact...... between metal and masonry and to hinder the acid produced at the anode in reaching the masonry. In the first set of electrodes the clay was too dry, and electric current was only applied for 7 days. Still the highest concentrations of nitrates and chlorides in the clay measured after these 7 days was...

  10. Monitoring asphalt pavement damages using remote sensing techniques

    Science.gov (United States)

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

    2015-06-01

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

  11. Shear behaviour of crushed concrete and bricks

    OpenAIRE

    Chidiroglou, Iordanis; O'Flaherty, Fin; Goodwin, Andrew

    2009-01-01

    Demolition waste materials mainly consist of concrete and bricks and arise from the demolition of existing structures and buildings. Environmental and economical reasons make their recycling necessary, but to date, their use is curtailed due to the lack of research in determining their properties. This paper reports on the efforts to understand the behavioural characteristics of three types of recycled material to determine their potential for engineering fill applicat...

  12. Brane Brick Models in the Mirror

    CERN Document Server

    Franco, Sebastian; Seong, Rak-Kyeong; Vafa, Cumrun

    2016-01-01

    Brane brick models are Type IIA brane configurations that encode the $2d$ $\\mathcal{N}=(0,2)$ gauge theories on the worldvolume of D1-branes probing toric Calabi-Yau 4-folds. We use mirror symmetry to improve our understanding of this correspondence and to provide a systematic approach for constructing brane brick models starting from geometry. The mirror configuration consists of D5-branes wrapping 4-spheres and the gauge theory is determined by how they intersect. We also explain how $2d$ $(0,2)$ triality is realized in terms of geometric transitions in the mirror geometry. Mirror symmetry leads to a geometric unification of dualities in different dimensions, where the order of duality is $n-1$ for a Calabi-Yau $n$-fold. This makes us conjecture the existence of a quadrality symmetry in $0d$. Finally, we comment on how the M-theory lift of brane brick models connects to the classification of $2d$ $(0,2)$ theories in terms of 4-manifolds.

  13. Urban-environmental study from the Juarez municipality brick factories

    Directory of Open Access Journals (Sweden)

    María de Lourdes Romo Aguilar

    2004-01-01

    Full Text Available This paper seeks to evaluate the current situation of the traditional and ecological brick kilns in Juarez. The evaluation is addressed in both the environmental and socio-economic context. The brick production belongs to the informal economic sector without any regulatory scheme and without taxation. Its very low technology has serious impacts on the binational environment of the Paso del Norte region, through the highly polluted emissions to the atmosphere. However, the social and economic context of people working in this industry does not allow important changes, thus, making difficult any initiative for the brick kilns improvements and relocation. The main information source was a very concise survey applied to whole universe of brick makers. Data survey was registered in a Geographic Information System (GIS environment allowing us the analysis of the brick kilns in a spatial context. Finally, this document presents a descriptive profile of the brick kilns production and for the brickmakers.

  14. Experimental bond behavior of FRP sheets glued on brick masonry

    OpenAIRE

    Oliveira, Daniel V.; Basílio, Ismael; Lourenço, Paulo B.

    2011-01-01

    This paper deals with the experimental characterization of the mechanical tensile and shear bond behavior of fiber reinforced polymer (FRP) sheets externally glued on masonry prisms, in terms of load capacity and stress distribution along the bonded length. The brick masonry adopted tries to replicate ancient brick masonry, by using handmade low strength solids bricks and low strength lime based mortar. Key parameters relative to the FRP-masonry interface response, particularly bo...

  15. 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.

  16. Frost resistance of concrete with crushed brick as aggregate

    Directory of Open Access Journals (Sweden)

    Janković Ksenija

    2010-01-01

    Full Text Available The investigation included concrete made by using recycled brick as aggregate. Experimental work included several types of concrete made with the same cement content (385 kg/m3, and same consistency (slump about 1 cm. Recycled brick and combination of natural river aggregate and recycled brick were used as aggregates. The influence of percentage and grain size of crushed brick aggregate on concrete compressive strength, water absorption and frost resistance were observed. On the basis of the results obtained during experimental research, a general conclusion can be drawn that the application of recycled concrete as aggregate can lead to new composites with satisfactory physical-mechanical properties.

  17. Modelling of radiolytically corroded commercial AGR graphite fuel bricks

    International Nuclear Information System (INIS)

    Profiling of cross-sectional slices taken from a commercial AGR(CAGR) moderator fuel brick provides a method for modelling graphite property changes associated with radiolytic corrosion. A measure of the change in overall brick strength can be obtained by loading to failure the profiled slice under simulated loaded-core conditions. The application of this technique to predict the behaviour of radiolytically corroded CAGR fuel bricks is described. The effect on brick strength of different corrosion profiles, which result from exposure in different coolant gas mixtures, is examined and a simple relationship between strength and an expression describing the corrosion profile derived. (author)

  18. Production and Development of LRCO‘s Silica Bricks

    Institute of Scientific and Technical Information of China (English)

    MAXianghong; LIZhenmin; 等

    1998-01-01

    This paper reviews the history of development and production of silica bricks at Luoyang Refrac-tories(Group) Co.,Ltd,(Former Luoyang Refrac-tories Factory). Through the improvement and in-troducing technology from abroad the company's management and quality standard on silica bricks production has reached a higher level.The physical and chemical specifications,as well as the appear-ance of silica bricks for coke ovens,hot blast stoves and glass kilns have reached the advanced interna-tional level.Now the company has become producing base and main exporting base various kinds of silica bricks in China.

  19. Bricks as indicators for an urban soil genesis

    Science.gov (United States)

    Nehls, Thomas; Rokia, Sarah; Schwartz, Christophe; Wessolek, Gerd

    2013-04-01

    Bricks can be considered as anthropogenic markers since they are regularly found in urban soils worldwide. They are among the most resistent residues of building materials, therefore are called technogenic substrates. They have been dumped to urban soils since more than 4000 years and can be dated back to their burning using thermoluminescence. In Berlin, bricks have been piled up to more than 37 rubble mountains in the city after WW II. The devils mountain, the most prominent of them is higher than 60m. However, bricks are known not to be isolated in the soil but to fulfill soil functions due to their porosity. Therefore, they are nice research objects for soil scientists. The purpose of this study is to investigate abundance and functions of bricks in urban soils, focusing on plant nutrition and contamination aspects. Three different Berlin urban soils have been studied for their brick contents in the coarse and fine earth fractions by endless hand sorting. Light and scanning electron microscopy was then employed to investigate the bricks for proofs of plant roots. Third, CEC, pH, EC, Corg, nutrient storage (XRF) and availability (2:1 extract, ion chromatography, AAS) of bricks and fine earth fractions of the corresponding soil horizons have been investigated. The fine earth fractions of the investigated soils contain 3 to 5% of bricks, while the coarse fractions contain up to 50%. We found roots entering brick pores or at least attached to brick surfaces. Therefore, plants can use the water and nutrients stored in bricks. The CEC of bricks is grain size dependent and reaches a maximum of 6 cmolc kg-1 for particles smaller than 0.063 mm. This dependency is not explained by a low pore connectivity. Rather, it is the result of the restricted diffusion into the brick pore system due to the short shaking time in the CEC analysis protocol. From the nutrient storage and availabilities we conclude that bricks can better supply plants with K, Mg, Ca and S than the bulk

  20. Durability of compressed soil-cement bricks

    Directory of Open Access Journals (Sweden)

    Acosta Valle, A.

    2001-06-01

    Full Text Available This papers shows the evaluation process of the durability of compressed soil-cement bricks. A great number of tests were made to determine the behavior of bricks when they are compression loaded and under the influence of moisture. Two different types of soils were used to produce the bricks, a lime-clay soil and a sand one. The sand soil is very resistant. The other one has a limited use. An experimental design was used to test the bricks. It is a rotational and quadratic method with a hexagonal figure which contains replicas at the central point. This method ensures the reliability of test results. Otherwise, it would reduce the amount of specimens necessary for the tests. The optimun moisture content is obtained by using a press machine. It is more rational than the standard Proctor compactation test, because it applies the same type and amount of energy used to produce the bricks. The obtained results show the behavior differences between the two compressed soil-cement bricks subjected to the compression test, water absorption and wetting and drying tests. The durability tests results are very important in the possible use of the bricks produced.

    En el trabajo se evalúa la durabilidad de elementos aglomerados de suelo estabilizado. Se realiza un amplio número de ensayos encaminados a determinar el comportamiento frente a la acción de las cargas y la humedad de dos suelos con características diferentes: uno limo-arcilloso y el otro arenoso. Este último presenta resultados muy favorables en ambas direcciones. El otro, con un posible uso más limitado. Se emplea un método de diseño experimental del tipo rotacional cuadrático en hexágono, con réplicas en el punto central, el que garantiza la confiabilidad de los resultados de los ensayos, a la vez que disminuye la cantidad de especímenes a ensayar. Se determina la humedad óptima a utilizar en las diferentes dosificaciones empleando la máquina compactadora, que resulta m

  1. Climate change, energy, sustainability and pavements

    International Nuclear Information System (INIS)

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

  2. 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.

  3. Evaluation of base widening methods on flexible pavements in Wyoming

    Science.gov (United States)

    Offei, Edward

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

  4. 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.

  5. 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.

  6. 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.

  7. Research on pavement roughness based on the laser triangulation

    Science.gov (United States)

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

    2016-06-01

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

  8. 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...

  9. Validation of theoretical models through measured pavement response

    DEFF Research Database (Denmark)

    Ullidtz, Per

    1999-01-01

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

  10. New approach for calculating permanent deformation in asphalt pavement

    Institute of Scientific and Technical Information of China (English)

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

    2010-01-01

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

  11. 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.

  12. Study of radon diffusion through clay bricks

    International Nuclear Information System (INIS)

    Radon is a naturally occurring radioactive gas that is generated in the earth's crust and is free to migrate through soil and be released to the indoor and outdoor atmosphere. Much attention has been given to the radiological health hazard posed by increased radon concentrations in the living and working environment. In order to study radon profiles for geophysical purposes and to predict its entry indoors, it is necessary to study its transport through building materials. The most common way of modeling radon flow through building materials is the advective transport by pressure-driven air flow from the source. The transport phenomenon of radon through diffusion is a significant contributor to indoor radon entry. The diffusion coefficient of radon gas in building materials is often used as an indication for radon transportability through a porous medium and, furthermore, as an essential tool for quantitative predictions of radon concentrations in dwellings by estimating the exhalation rates of the wall surfaces. Radon diffusion coefficients in bricks were determined by employing the two compartment method in which one compartment is kept at a high radon concentration while the other is initially at low concentration. The radon diffusion coefficient is then deduced by monitoring the radon in the second compartment by measuring the steady state radon flux into the compartment. In this case, a steady-state solution was used to calculate the diffusion coefficient. The radon diffusion coefficients were found to vary from 0.32x10-6 m2/s to 0.48 x10-6 m2/s and the diffusion length were from 36x10-2 m to 42 x102 m in bricks. The results indicate that the bricks analyzed are fairly radon tight. (author)

  13. Brick walls and AdS/CFT

    Science.gov (United States)

    Kay, Bernard S.; Ortíz, L.

    2014-05-01

    We discuss the relationship between the bulk-boundary correspondence in Rehren's algebraic holography (and in other `fixed-background', QFT-based, approaches to holography) and in mainstream string-theoretic `Maldacena AdS/CFT'. Especially, we contrast the understanding of black-hole entropy from the point of view of QFT in curved spacetime—in the framework of 't Hooft's `brick wall' model—with the understanding based on Maldacena AdS/CFT. We show that the brick-wall modification of a Klein-Gordon field in the Hartle-Hawking-Israel state on dimensional Schwarzschild AdS has a well-defined boundary limit with the same temperature and entropy as the brick-wall-modified bulk theory. One of our main purposes is to point out a close connection, for general AdS/CFT situations, between the puzzle raised by Arnsdorf and Smolin regarding the relationship between Rehren's algebraic holography and mainstream AdS/CFT and the puzzle embodied in the `complementarity principle' proposed by Mukohyama and Israel in their work on the brick-wall approach to black hole entropy. Working on the assumption that similar results will hold for bulk QFT other than the Klein-Gordon field and for Schwarzschild AdS in other dimensions, and recalling the first author's proposed resolution to the Mukohyama-Israel puzzle based on his `matter-gravity entanglement hypothesis', we argue that, in Maldacena AdS/CFT, the algebra of the boundary CFT is isomorphic only to a proper subalgebra of the bulk algebra, albeit (at non-zero temperature) the (GNS) Hilbert spaces of bulk and boundary theories are still the `same'—the total bulk state being pure, while the boundary state is mixed (thermal). We also argue from the finiteness of its boundary (and hence, on our assumptions, also bulk) entropy at finite temperature, that the Rehren dual of the Maldacena boundary CFT cannot itself be a QFT and must, instead, presumably be something like a string theory.

  14. Electrochemical desalination of bricks - Experimental and modeling

    DEFF Research Database (Denmark)

    Skibsted, Gry; Ottosen, Lisbeth M.; Jensen, Pernille Erland;

    2015-01-01

    Chlorides, nitrates and sulfates play an important role in the salt-decay of porous materials in buildings and monuments. Electrochemical desalination is a technology able to remove salts from such porous materials in order to stop or prevent the decay. In this paper, experimental and numerical......-contaminated bricks with respect to the monovalent ions is discussed. Comparison between the experimental and the simulation results showed that the proposed numerical model is able to predict electrochemical desalination treatments with remarkable accuracy, and it can be used as a predictive tool for the...

  15. Incorporation feasibility of leather residues in bricks

    OpenAIRE

    Aguiar, J. L. Barroso de; Valente, A; Pires, M.J.; Tavares, M. T.

    2001-01-01

    The footwear industry has strips of leather as one of its by-products. These leather residues, due to their high chromium content, can be regarded as a threat to the environment, particularly if no care is taken with their disposal. With the incorporation of the residues in ceramic products, after trituration, is possible to neutralise the eventual toxicity of chromium. In a laboratory study we produced prismatic bricks using clay from the region and incorporating 1, 3 and 5% (by mass) of lea...

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

    OpenAIRE

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

    2015-01-01

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

  17. An Exploration of the Nanoworld with LEGO Bricks

    Science.gov (United States)

    Campbell, Dean J.; Miller, Josiah D.; Bannon, Stephen J.; Obermaier, Lauren M.

    2011-01-01

    LEGO bricks can be used for a number of demonstrations of chemical structures and properties, especially at the nanoscale level. These bricks can also be used to model instrumentation that probes these structures and properties. Detailed resources about many of these demonstrations are located on the extensive Web site "Exploring the Nanoworld…

  18. Investigation for picking up a brick from the melter

    International Nuclear Information System (INIS)

    The tool to pick up the roof brick on the bottom of the melter was designed and manufactured after investigation of fundamental design of the tool, investigation of material of the tool, and some mock up tests. After that, picking up the brick in the melter was done, and it was successful after the second modification of the tool. (author)

  19. Lead brick with a resistant coating and the coating process

    International Nuclear Information System (INIS)

    The invention concerns a lead brick with a resistant coating made from an elastomer material such silicone type, giving a smooth surface able to be decontaminated. The brick allows to build biological protection barriers to protect users against injurious radiations, specially, x radiations or gamma radiations. (N.C.). 6 refs., 4 figs

  20. 78 FR 3449 - Silica Bricks and Shapes From China

    Science.gov (United States)

    2013-01-16

    ... 23, 2012 (77 FR 70185). The conference was held in Washington, DC, on December 6, 2012, and all... COMMISSION Silica Bricks and Shapes From China Determination On the basis of the record \\1\\ developed in the... China of silica bricks and shapes, provided for in subheading 6902.20.10 of the Harmonized...

  1. Inside the Sex Ed Studio: An Interview with Peggy Brick

    Science.gov (United States)

    Taverner, William J.

    2008-01-01

    "Inside the Sex Ed Studio" profiles leaders in the field of sexuality education. Peggy Brick, former director of Planned Parenthood of Greater Northern New Jersey's Center for Family Life Education (CFLE) and author of numerous sexuality education resources used worldwide, is the subject of this interview. Ms. Brick was interviewed by William J.…

  2. Utilization of Household Sewage Sludge in Brick making

    Institute of Scientific and Technical Information of China (English)

    SunGuofeng

    2005-01-01

    Household sewage sludge is a kind of solid waste produced in sewage purifying at sewage farm. in procedure of water purifying, which can be used as raw material for producing fired brick. This article compares the chemical composition between household sewage sludge and clay, and explores two kinds of production process for making brick with Household sewage sludge.

  3. A fly ash and shale fired brick production line

    Institute of Scientific and Technical Information of China (English)

    ZhuYali

    2005-01-01

    The article describes the fly ash and shale fired brick production line with annual output of 1250 million bricks, designed by Xi'an Research and Design Institute of Wall and Roof Material, commissioned by QinDian Building Material Subcompany, and set an example for using fly ash and shale in China.

  4. Spalling Resistant Bauxite Based Bricks for Cement Kiln

    Institute of Scientific and Technical Information of China (English)

    Zhang Xiaohui; Peng Xigao

    2011-01-01

    @@ 1.Scope This standard specifies the term,definition,classification,labeling,technical requirements,test methods,inspection rules,packing,marking,transportation,storage,and quality certificate of spalling resistant bauxite based bricks for cement kiln.This standard is applicable to the spalling resistant bauxite based bricks for cement kiln.

  5. Possible weathering of the brick matrix when exposed to water

    DEFF Research Database (Denmark)

    Rörig-Dalgaard, Inge

    2014-01-01

    The main reasons for deterioration of bricks are frost, crystallization pressure and chemical exposure. Despite of this the effect of chemical exposure is limited clarified. Depending on the brick type the original pH of bricks are 9-10. Though bricks can to subjected to water in shape of acid rain...... with a pH as low as 3. The exposure of acid rain and rain water to bricks is expected to have an influence on the brick matrix dependent on the specific exposure but to which extend? The present work is a systematic test of the influence of the pH on the brick matrix where the effect of water...... with different well-defined pH values are examined to investigate the long term effect of acid rain or other reasons causing pH changes to bricks (as e.g. electrokinetic treatment). Through capillary suction, macro pictures from the exposed surfaces, measurement of the pH and electrical conductivity it seemed...

  6. 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

  7. Long-Term Field Performance of Pervious Concrete Pavement

    Directory of Open Access Journals (Sweden)

    Aleksandra Radlińska

    2012-01-01

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

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

    OpenAIRE

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

    2011-01-01

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

  9. Visualizing Pavement Management Data at the Project Level

    OpenAIRE

    Rydholm, Timothy C.; Luhr, David R.

    2015-01-01

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

  10. The reflective cracking in the pavement overlay design

    OpenAIRE

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

    2003-01-01

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

  11. Optical fiber feasibility study in Accelerated Pavement Testing facility

    OpenAIRE

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

    2009-01-01

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

  12. 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.

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

    OpenAIRE

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

    2006-01-01

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

  14. Reliability-based Design Procedure for Flexible Pavements

    OpenAIRE

    Dinegdae, Yared Hailegiorgis

    2015-01-01

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

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

    Science.gov (United States)

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

    2016-07-01

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

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

    Directory of Open Access Journals (Sweden)

    Jens Skarabis

    2015-04-01

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

  17. 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.

  18. 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.

  19. Thermal Performance of the Storage Brick Containing Microencapsulated PCM

    International Nuclear Information System (INIS)

    The utilization of microencapsulated phase change materials(PCMs) provides several advantages over conventional PCM application. The heat storage system, as well as heat recovery system, can be built to a smaller size than the normal systems for a given thermal cycling capacity. This microencapsulated PCM technique has not yet been commercialized, however. In this work sodium acetate trihydrate(CH3COONa · 3H2O) was selected for the PCM and was encapsulated. This microencapsulated PCM was mixed with cement mortar for utilization as a floor heating system. In this experiment performed here the main purpose was to investigate the thermal performance of a storage brick with microencapsulated PCM concentration. The thermal performance of this storage brick is dependent on PCM concentration, flow rate and cooling temperature of the heat transfer fluid, etc. The results showed that cycle time was shortened as the PCM content was increased and as the mass flow rate was increased. The same effect was obtained when the cooling temperature was decreased. For each thermal storage brick the overall heat transfer coefficient(U-value) was constant for a 0% brick, but was increased with time for the bricks containing microencapsulated PCM. For the same mass flow rate, as the cooling temperature decreased, the amount of heat withdrawn increased, and in particular a critical cooling temperature was found for each thermal storage brick. The average effectiveness of each thermal storage brick was found to be approximately 48%, 51% and 58% respectively

  20. Natural radioactivity in bricks used in Sri Lanka

    International Nuclear Information System (INIS)

    The objective of the present study was to determine the specific radioactivity concentrations of Ra sup 226, Th sup 232 and K sup 40 in brick samples collected from different areas and compare with the corresponding results for bricks of different countries.Sixteen clay and four cement brick samples were collected from kilns in different areas in Sri Lanka. The gamma ray spectra of the prepared samples were measured using a typical high resolution gamma spectrometer based on a shielded HpGe detector.The spectrometer was calibrated for energy and efficiency over the experimental energy range 186-2700 keV using IAEA reference material RGU-1, RGTH-1 and RGK-1.GANAAS software was used to analyse the photopeaks. The measured average specific radioactivity concentrations of Ra sup 226, Th sup 232, K sup 40 in the clay bricks were 35, 69 and 604 Bq per kg respectively. For cement bricks these values were 17, 42, 525 Bq per kg. The corresponding world average values are 50,50 and 500 Bq per kg for the said radionuclides.All three radionuclides were greater than the world average in clay bricks measured from Mahiyangana. Clay bricks from Ampitiya, Anuradhapura and Nikaweratiya measured values are less than the world average for all three radionuclides. Data on concentrations of natural radionuclides can be used to determine dose rates in relation to building materials

  1. Surface dating of bricks, an application of luminescence techniques

    Science.gov (United States)

    Galli, Anna; Martini, Marco; Maspero, Francesco; Panzeri, Laura; Sibilia, Emanuela

    2014-05-01

    Luminescence techniques are a powerful tool to date archaeological ceramic materials and geological sediments. Thermoluminescence (TL) is widely used for bricks dating to reconstruct the chronology of urban complexes and the development of human cultures. However, it can sometimes be inconclusive, since TL assesses the firing period of bricks, which can be reused, even several centuries later. This problem can be circumvented using a dating technique based on a resetting event different from the last heating. OSL (Optically Stimulated Luminescence) exploits the last light exposition of the brick surface, which resets the light-sensitive electron traps until the surface is definitely shielded by mortar and superimposed bricks. This advanced application (surface dating) has been successfully attempted on rocks, marble and stone artifacts, but not yet on bricks. A recent conservation campaign at the Certosa di Pavia gave the opportunity to sample some bricks belonging to a XVII century collapsed wall, still tied to their mortars. This was an advantageous condition to test this technique, comparing the dating results with precise historical data. This attempt gave satisfactory results, allowing to identify bricks surely reused and to fully confirm that the edification of the perimetral wall occurred at the end of XVII century.

  2. Natural radioactivity in the bricks fabricated around Kasur (Pakistan)

    International Nuclear Information System (INIS)

    Natural gamma ray activity has been measured in the bricks fabricated in the area around Kasur. The deviations of maximum and minimum values from average values in the measured gamma ray activities due to 40K, /sup 226/Ra and /sup 232/Th are less than 20%. Comparison with the bricks fabricated in Rawalpindi and Islamabad showed that the bricks of Kasur area have about 25% higher gamma-ray activity for the nuclides 40K, /sup 226/Ra and /sup 232 Th/ as well as for the total activity. (author)

  3. Construction sustainability with adobe bricks type elements

    Directory of Open Access Journals (Sweden)

    Andreea Hegyi

    2016-06-01

    Full Text Available Sustainability is a criterion defined in the 80, which is essential in all fields of current activity. At the moment, it can not talk about development without being taken into account sustainability criteria. It presents the ensuring for an harmonious development, in line with current needs, without to endanger the possibility to develop and satisfy the needs of future generations. The buildings of adobe bricks-type elements ensure successfully the conditions imposed by this criterion. This type of construction ensures the responsible use of renewable natural resources, the possibility of reuse and recycling of materials, contributes to environmental protection and to pollution reduction, to energy saving and it provides a cleaner and healthier living environment. Not least, the buildings of this type are accessible in terms of cost and can contribute to the development of other fields such as eco-tourism.

  4. Moisture properties of the lightweight brick body

    Science.gov (United States)

    Čáchová, Monika; Koňáková, Dana; Vejmelková, Eva; Keppert, Martin; Černý, Robert

    2016-06-01

    Brick have been used for thousands years and during that time they went throw the long development. One of the possibilities how to changed properties of ceramic products is to change material compositions. This article is focused on utilization of lightening additives. Commonly used sawdust is compared with straw. The matter of measurement was to determine its influence on moisture properties. Basic physical properties were measured as well, since mainly open porosity has influence on water transport. Achieved results proved that utilization of straw leads to open porosity decrease. Particularly the amount of small pores (diameter under 1µm) went down. Regarding the moisture properties water vapor transport ability was decreased by adding straw in to the ceramic, while ability of water liquid transport remained unaffected.

  5. Surface Water Quality Assessment of the Jirania Brick Cluster – A Case Study

    OpenAIRE

    Amarendra Jamatia; Sukanta Chakraborty

    2014-01-01

    Along with the infrastructural development works, the demand for construction materials is increasing rapidly, which in turns lead to the rapid growth of brick manufacturing industries. Large demand of bricks in development and construction sectors has resulted in mushrooming of brick industries clusters at the outskirt of Agartala City. Jirania brick industries cluster is one of largest cluster of the Tripura State (India). Approximately 45% of total bricks of the State are b...

  6. POROUS PAVEMENT PHASE I DESIGN AND OPERATIONAL CRITERIA (EPA/600/2-80/135)

    Science.gov (United States)

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

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

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

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

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

    OpenAIRE

    Davis, Robin Michelle

    2001-01-01

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

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

    OpenAIRE

    Yingwei Ren; Jingsong Shan

    2014-01-01

    It is important that decision of asphalt pavement structure requires overall considerations of the performance and financial investment. To have asphalt pavement structure fulfilling good reliability, the asphalt pavement structure decision was researched based on value engineering theory. According to the national and provincial highway investigation data in Shandong Province during the last decade, the asphalt pavement performance attenuation rules of traffic levels and asphalt layer thickn...

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

    OpenAIRE

    Salour, Farhad

    2015-01-01

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

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

    OpenAIRE

    Bekele, Abiy

    2011-01-01

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

  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. PMID:24681366

  13. Properties of bricks produced from Greenlandic marine sediments

    DEFF Research Database (Denmark)

    Bertelsen, Ida Maria Gieysztor; Belmonte, Louise Josefine; Chen, Wan;

    2015-01-01

    ). Miniature bricks werethen prepared according to the optimal conditions and formed at a pressure of 20 MPa, fired at 1020 Cfor 3:5 days at the brickwork Wienerberger Tegl in Helsinge, Denmark. The durability properties suchas porosity, water absorption, bulk density, linear shrinkage, and compressive...... submersion in cold water to fulfilthe requirements for severe weathering according to ASTM-C62 (2013). It was concluded that the firingtemperature needed to be increased in order to obtain a more durable brick-type, suitable for the Arcticclimate.......This study investigated the possibility of a local brick production from fine grained marine sediments (MS) near Sisimiut, Greenland. The assessment is based on the physical and mechanical properties of clay bricks concerning the resistance to the harsh, Arctic weather conditions, together with an...

  14. High Alumina Refractory Bricks for Electric Arc Furnace Roofs

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    @@ 1 Scope This standard specifies the sort, technical requirement, test method, inspection rules, marking, packing, transportation, storage and quality certification of high alumina refractory bricks for electric arc furnace roofs.

  15. Brane Brick Models and 2d (0,2) Triality

    CERN Document Server

    Franco, Sebastian; Seong, Rak-Kyeong

    2016-01-01

    We provide a brane realization of 2d (0,2) Gadde-Gukov-Putrov triality in terms of brane brick models. These are Type IIA brane configurations that are T-dual to D1-branes over singular toric Calabi-Yau 4-folds. Triality translates into a local transformation of brane brick models, whose simplest representative is a cube move. We present explicit examples and construct their triality networks. We also argue that the classical mesonic moduli space of brane brick model theories, which corresponds to the probed Calabi-Yau 4-fold, is invariant under triality. Finally, we discuss triality in terms of phase boundaries, which play a central role in connecting Calabi-Yau 4-folds to brane brick models.

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

    International Nuclear Information System (INIS)

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

  17. The production technology of shale fly ash fired brick

    Institute of Scientific and Technical Information of China (English)

    JiaoYuhua

    2005-01-01

    When we construct the shale fly-ash fired brick production line, the first of all is that we must explored mineral raw material in detailed, and prove up the exploitable storage,so that the storage of raw material can supply the production line adequately when the factory has been set up.The second is that we must analyze the raw material completely. According to the raw material basic properties,we can decide process of the brick making.

  18. INVESTIGATION OF THERMAL SHOCK BEHAVIOUR IN ALUMINA BASED REFRACTORY BRICKS

    OpenAIRE

    N. Sinan KÖKSAL; B. Sadık ÜNLÜ; Cevdet MERİÇ

    2003-01-01

    cUnderstanding of mechanical and thermal properties of refractory bricks used in industry is an important aspect to determine appropriate operating conditions. In this study, commercial refractory materials used in the sector of iron steel 45 % and 80 % alumina (Al2O3) of content refractory bricks were investigated. To determinate thermal shock behavior and mechanical properties of samples, thermal shock tests were applied by quenching in the water at the temperature differences of 500, 70...

  19. Effect of Peat on Physicomechanical Properties of Cemented Brick

    OpenAIRE

    Syed Mofachirul Islam; Roslan Hashim; A. B. M. Saiful Islam; Ryan Kurnia

    2014-01-01

    The popularity of low cost, lightweight, and environmentally affable masonry unit in building industry carries the need to investigate more flexible and adaptable brick component as well as to retain the requirements confirmed in building standards. In this study, potential use of local materials used as lightweight building materials in solving the economic problems of housing has been investigated. Experimental studies on peat added bricks have been carried out. It demonstrates the physicom...

  20. Polymetric brick wall patterns and two-dimensional substitutions

    CERN Document Server

    Dekking, Michel

    2012-01-01

    Polymetric walls are walls built from bricks in more than one size. Architects and builders want to built polymetric walls that satisfy certain structural and aesthetical constraints. In a recent paper by de Jong, Vinduska, Hans and Post these problems are solved by integer programming techniques, which can be very time consuming for patterns consisting of more than 40 bricks. Here we give an extremely fast method, generating patterns of arbitrary size.

  1. High Temperature Property Development of Bauxite Based Bricks

    Institute of Scientific and Technical Information of China (English)

    A. Molin; K. Ghanbari Ahari; B. Josiek; J. Molin

    2003-01-01

    Physical properties and microstructural evolution on firing of 3 types of bauxite based refractory bricks were carried out using techniques such as porosimetry, XRD and SEM. The groups differed from each other by progressive refining of the matrix or bond phase. It is revealed that such a refinement of the matrix can improve the high temperature properties of the bricks made from poor grade materials.

  2. Cellular Concrete Bricks with Recycled Expanded Polystyrene Aggregate

    OpenAIRE

    Juan Bosco Hernández-Zaragoza; Teresa López-Lara; Jaime Horta-Rangel; Carlos López-Cajún; Eduardo Rojas-González; F. J. García-Rodríguez; Jorge Adue

    2013-01-01

    Cellular concrete bricks were obtained by using a lightweight mortar with recycled expanded polystyrene aggregate instead of sandy materials. After determining the block properties (absorption, compressive strength, and tensile stresses), it was found that this brick meets the requirements of the masonry standards used in Mexico. The obtained material is lighter than the commercial ones, which facilitates their rapid elaboration, quality control, and transportation. It is less permeable, whic...

  3. Reutilization of leather residue by incorporation in bricks

    OpenAIRE

    Aguiar, J. L. Barroso de; Valente, A. R.; Pires, M.J.; Tavares, M. T.

    2002-01-01

    Leather strips is one by-product of the footwear industry. Due to high chromium content, this leather residue can be regarded as a threat to the environment, particularly if no care is taken with its disposal. With the incorporation of this residue into ceramic products, it is possible to neutralise the chromium toxicity. In a laboratory study, the authors produced prismatic bricks using clay from the region, incorporating 1, 3 and 5 mass-% of leather residues. The bricks were tested regardin...

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

    Directory of Open Access Journals (Sweden)

    B. Matić

    2012-07-01

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

  5. A study of fly ash-lime granule unfired brick

    Energy Technology Data Exchange (ETDEWEB)

    P. Chindaprasirt; K. Pimraksa [Khon Kaen University (Thailand). Department of Civil Engineering

    2008-02-15

    In this paper, the properties of fly ash-lime granule unfired bricks are studied. Granules were prepared from mixtures of fly ash and lime at fly ash to hydrated lime ratios of 100:0 (Ca/Si = 0.2), 95:5 (Ca/Si = 0.35) and 90:10 (Ca/Si = 0.5). After a period of moist curing, the microstructure and mineralogy of the granules were studied. Microstructure examination reveals that new phases in the form of needle-like particles are formed at the surface of granule. The granules were used to make unfired bricks using hydrothermal treatment at temperature of 130 {+-} 5{sup o}C and pressure of 0.14 MPa. The microstructures, mineralogical compositions, mechanical properties and environmental impact of bricks were determined. The results reveal that the strengths of unfired bricks are dependent on the fineness of fly ash. The strength is higher with an increase in fly ash fineness. The strengths of the fly ash-lime granule unfired brick are excellent at 47.0-62.5 MPa. The high strength is due to the formation of new products consisting mainly of hibschite and Al-substituted 11 {angstrom} tobermorite. The main advantage of utilization of granule is the ability to increase the pozzolanic reaction of fly ash through moisture retained in the granule. In addition, the heavy elements, in particular Cd, Ni, Pb and Zn are efficiently retained in the fly ash-lime granule unfired brick.

  6. Low cost pavement marking materials based on plasticized sulfur

    Science.gov (United States)

    Dale, J. M.

    1982-04-01

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

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

    DEFF Research Database (Denmark)

    Ullidtz, Per; Ertman Larsen, Hans Jørgen

    1997-01-01

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

  8. Design prediction of pavement skid resistance from laboratory tests

    Science.gov (United States)

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

    1980-08-01

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

  9. 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.

  10. 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.

  11. 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

  12. 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.

  13. 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.

  14. 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

  15. 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)

  16. ESR dosimetry using quartz grains in bricks

    International Nuclear Information System (INIS)

    Present studies indicate that ESR dosimetry of A-bomb can be done using the signal at g=2.0008 for quartz grains in bricks collected at distances of about less than 1 - 2 km from the epicenter of Hiroshima and Nagasaki. One can estimate that ESR dating of archaeological samples of a few thousands years before present is also possible using quartz grains of ancient ceramics. As the sensitivity of ESR spectrometer is improved, the minimum number of the detectable spins will be further reduced. The minimum detectable dose of 1.6 ± 0.6 Gy and the detectable age of a few thousand years would be reduced by one or two orders of the magnitude. This indicates that ESR dosimetry can replace TLD because of the advantage of repeated measurements of a sample. If a few dose can be measured, ESR dating based on dosimetry will go into the field from geology to archaeology and probably into history and forensic science. (author)

  17. Properties of Nanocrystals-formulated Aluminosilicate Bricks

    Directory of Open Access Journals (Sweden)

    Francesca Conciauro

    2015-10-01

    insulating and/or mechanical properties. The nanocrystals- modified refractories showed variations in properties, with respect to the untreated aluminosilicate reference in heat- insulating performances (thermal diffusivities were measured by the “hot disk” technique. In general, they also showed improvements in mechanical compression resist‐ ance for all of the samples at 2 wt. %. The best heat insula‐ tion was obtained with the addition of nano-aluminium hydroxide at 2 wt. %, while the highest mechanical compres‐ sion breaking resistance was found with nano-CaCO3 at 2 wt. %. These outcomes were investigated with complemen‐ tary techniques, like mercury porosimetry for porosity, and Archimedes methods to measure physical properties like the bulk and apparent densities, apparent porosities and water absorption. The results show that the nano-alumini‐ um hydroxide modified bricks were the most porous, which could explain the best heat-insulating performances. There is a less straightforward explanation for the mechanical resistance results, as they may have relations with the characteristics of the pores. Furthermore, the nanoparti‐ cles may have possible reactions with the matrix during the heat treatments.

  18. Ceramic bricks made from municipal solid waste incineration-derived clay and ashes: a quality study

    Directory of Open Access Journals (Sweden)

    César Augusto García Ubaque

    2012-10-01

    Full Text Available This paper presents analytical data from tests on bricks made from different clay/ash mixtures. The ashes used were obtained from a Hoffmann-type brick-making furnace equipped for coal and municipal solid waste co-firing. The bricks were physically and chemically characterised and their quality was determined by porosimetry, water absorption, breaking load and tensile strength tests. Brick loading capacity increased by up to 10% with ash mixtures and decreased at higher percentages, whereas water absorption increased brick loading capacity for all mixtures. This study showed that clay/ash bricks complied with all the quality standards required in Colombia.

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

    Science.gov (United States)

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

    2015-04-01

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

  20. 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.

  1. Enhancing the Mechanical Properties of Lateritic Brick for Better Performance

    Directory of Open Access Journals (Sweden)

    O.A. Olowu

    2014-11-01

    Full Text Available The research considered the production of improved stabilized lateritic Bricks (ISLB with enhanced mechanical properties. The research data were derived from laboratory experiments which include capillary test, erosion test, abrasion test, density test and compressive strength test. Three batches of 290mm x 140mm x 100mm brick samples were produced which are: the Adobe Unstabilized Lateritic Bricks (AULB, Improved Stabilized Lateritic Brick (ISLB and the Control Stabilized Lateritic Bricks (CSLB. Brick stabilization was maintained at 5% by weight of cement. Compaction of the bricks were carried out manually; the moulded bricks were carefully extruded in good shape and placed on clean, hard flat surface to allowed to dry under normal atmospheric temperature and pressure . The ISLB was divided into four groups of 12 bricks samples immersed in solution of zycosil and water in the following proportion by volume: (1:100,(1:200,(1:300 and (1:400 for 30 minutes and dried under normal atmospheric temperature and pressure before curing commenced. The result of the capillary test on bricks samples after 24 hours showed that AULB and CSLB has (0.35 and 0.15kg weight difference equivalent of (0.00599 and 0.00256 kg/m2 /min suction rate while the ISLB have 0.05kg weight difference equivalent to 0.000855kg/m2 /min suction rate. The result of erosion test for brick durability ranked between very firm for ISLB of 1:100, 1:200 and 1:300 Zycosil Water Solution (ZWS, firm for ISLB of 1:400 ZWS; firm for CSLB and loose for AULB. The abrasion test result showed that the ISLB have abrasion value of (1,2,2 and 2% while the CSLB and AULB have (3 and 12% abrasion value. The density of ISLB are (1933.50, 1921.18, 1916.26 and 1908.87 kgm-3 at 28 days while the density of CSLB and AULB were (1926.11 and 1800.49 kgm-3 . Density results conform to minimum specification requirement for lateritic bricks of bulk density of 1810kgm-3 as recommended by the Nigeria Building and

  2. Effect of Peat on Physicomechanical Properties of Cemented Brick

    Directory of Open Access Journals (Sweden)

    Syed Mofachirul Islam

    2014-01-01

    Full Text Available The popularity of low cost, lightweight, and environmentally affable masonry unit in building industry carries the need to investigate more flexible and adaptable brick component as well as to retain the requirements confirmed in building standards. In this study, potential use of local materials used as lightweight building materials in solving the economic problems of housing has been investigated. Experimental studies on peat added bricks have been carried out. It demonstrates the physicomechanical properties of bricks and investigates the influence of peat, sand, and cement solid bricks to the role of various types of constructional applications. The achieved compressive strength, spitting strength, flexural strength, unit weight, and ultrasonic pulse velocity are significantly reduced and the water absorption is increased with percentage wise replacement of peat as aggregate in the samples. The maximum 20% of (% mass peat content meets the requirements of relevant well-known international standards. The experimental values illustrate that, the 44% volumetric replacement with peat did not exhibit any sudden brittle fracture even beyond the ultimate loads and a comparatively smooth surface is found. The application of peat as efficient brick substance shows a potential to be used for wall and a viable solution in the economic buildings design.

  3. Effect of peat on physicomechanical properties of cemented brick.

    Science.gov (United States)

    Islam, Syed Mofachirul; Hashim, Roslan; Islam, A B M Saiful; Kurnia, Ryan

    2014-01-01

    The popularity of low cost, lightweight, and environmentally affable masonry unit in building industry carries the need to investigate more flexible and adaptable brick component as well as to retain the requirements confirmed in building standards. In this study, potential use of local materials used as lightweight building materials in solving the economic problems of housing has been investigated. Experimental studies on peat added bricks have been carried out. It demonstrates the physicomechanical properties of bricks and investigates the influence of peat, sand, and cement solid bricks to the role of various types of constructional applications. The achieved compressive strength, spitting strength, flexural strength, unit weight, and ultrasonic pulse velocity are significantly reduced and the water absorption is increased with percentage wise replacement of peat as aggregate in the samples. The maximum 20% of (% mass) peat content meets the requirements of relevant well-known international standards. The experimental values illustrate that, the 44% volumetric replacement with peat did not exhibit any sudden brittle fracture even beyond the ultimate loads and a comparatively smooth surface is found. The application of peat as efficient brick substance shows a potential to be used for wall and a viable solution in the economic buildings design. PMID:24982941

  4. 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.

  5. Monitoring Strategies in Permeable Pavement Systems to Optimize Maintenance Scheduling

    Science.gov (United States)

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2010-05-15

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

  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. 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

  9. 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.

  10. 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...

  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. 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

  13. Performance Evaluation of Flexible Pavements: A Case Study

    Directory of Open Access Journals (Sweden)

    V.K Chakravarthi1 ,

    2015-10-01

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

  14. 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.

  15. Measuring Clogging with Pressure Transducers in Permeable Pavement Strips

    Science.gov (United States)

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

  16. 75 FR 20813 - Certain Magnesia Carbon Bricks from the People's Republic of China: Amended Preliminary...

    Science.gov (United States)

    2010-04-21

    ... Determination, 75 FR 11847 (March 12, 2010) (``Preliminary Determination''). We are amending our Preliminary... International Trade Administration Certain Magnesia Carbon Bricks from the People's Republic of China: Amended... value (``LTFV'') in the antidumping duty investigation of certain magnesia carbon bricks...

  17. esearch and Application of Burned Microporous High Alumian—Graphite(Al/C) Brick in Blast Furnace

    Institute of Scientific and Technical Information of China (English)

    ZHANXiaoming; SONGMusen

    1999-01-01

    This paper inroduces the research background,technology,product property and application of burned microporous high alumina-graphite brick (Al2O3-C brick) used in blast furnace,The difference of property between Al2O3-C brick and other blast furnace refractories is discussed .The results of simulative tests show that ,Al2O3-C brick has good alkali resistance,slag resistance,thermal shock resistance,oxidation resistance,high thermal conductivity,low permeability and low solubility in molten iron,The brick with micropores of average radius less than 1μm has been successively applied to fourteen blast furnaces, the lining life of the brick is almost as long as that of Si3N4 bonded SiC brick Al2O3-C brick will be widely used in lower stack ,belly,bosh and hearth in the future.

  18. 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.

  19. 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.

  20. Cellular Concrete Bricks with Recycled Expanded Polystyrene Aggregate

    Directory of Open Access Journals (Sweden)

    Juan Bosco Hernández-Zaragoza

    2013-01-01

    Full Text Available Cellular concrete bricks were obtained by using a lightweight mortar with recycled expanded polystyrene aggregate instead of sandy materials. After determining the block properties (absorption, compressive strength, and tensile stresses, it was found that this brick meets the requirements of the masonry standards used in Mexico. The obtained material is lighter than the commercial ones, which facilitates their rapid elaboration, quality control, and transportation. It is less permeable, which helps prevent moisture formation retaining its strength due to the greater adherence shown with dry polystyrene. It was more flexible, which makes it less vulnerable to cracking walls due to soil displacements. Furthermore, it is economical, because it uses recyclable material and has properties that prevent deterioration increasing its useful life. We recommend the use of the fully dry EP under a dry environment to obtain the best properties of brick.

  1. Production of Silica-refractory Bricks from White Sand

    Directory of Open Access Journals (Sweden)

    Gazze Almarahle

    2005-01-01

    Full Text Available At present, no refractories are produced in Jordan, but large quantities are imported for use in the lining of furnaces and kilns in the metallurgical industries.The aim of this study is to initiate a program of research for production of silica-refractory bricks from local materials.The raw material, which has been used in this study was white sand. This sand contains less than 0.5% Fe2O3 and is therefore suitable for production of glass. The sand used for production of glass is also suitable for production of silica refractory bricks. The method for production of this bricks consists of mixing the white sand with 2.5 CaO (milklime which acts as a binder and mineraliser in order to convert the free quartz to tridymite and crystobalite.

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

    Science.gov (United States)

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

    2007-12-01

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

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

    Science.gov (United States)

    Pardillo Mayora, José M; Jurado Piña, Rafael

    2009-07-01

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

  4. An accelerated test method for efflorescence in clay bricks

    International Nuclear Information System (INIS)

    An investigation into the creation of accelerated efflorescence in clay bricks was undertaken with a view to creating a viable test procedure for determining efflorescence potential. The testing programme incorporated ambient conditions similar to those which promote efflorescence growth in bricks in use. Theoretical investigations into the physical mechanism underlying the creation of efflorescence directed the attempts to accelerate the process. It was found that calcium sulphate efflorescence could not be sufficiently accelerated such that a useful efflorescence test procedure could be proposed. The inability to produce accelerated efflorescence in brick samples was attributed to limitations associated with time dependent salt diffusion in the efflorescence mechanism. The preliminary testing that was undertaken into the creation of efflorescence prompted the use of acid assisted methods to accelerate efflorescence. The acid assisted method that was adopted to provide a possible indication of efflorescence potential relies upon the transformation of low solubility calcium to a more soluble form. The movement of the transformed salt is then induced by cyclic temperature exposure at temperatures similar to those experienced in Spring. The appearance of the transformed calcium salt on the surface of the brick specimen provides an indication of the efflorescence potential. Brick piers constructed on an exposed site and monitored over a 12 month period provided information on the validity of the acid assisted test method. The efflorescence observed on the piers correlated well with that predicted by the acid assisted test, suggesting that the new test has the potential to accurately predict the efflorescence potential of clay bricks Relationships between other properties such as air permeability, sorptivity and tensile strength were investigated such that an alternative method of predicting efflorescence could be achieved. It was found that (within the bounds of the

  5. Experimental and numerical researches on collision of graphite bricks

    International Nuclear Information System (INIS)

    Highlights: • Collisions between two graphite bricks have been studied in the experiment. • Linear track and optics acquisition system were used to obtain collision characters. • The contact time decreases while the coefficient of restitution rises up with speed. • Specimen's rotating slightly to adjust posture is the main factor of the contact time. • The collision characters are sensitive to the posture deviation of specimens. - Abstract: Graphite bricks have important applications in high temperature gas-cooled reactors (HTGRs). The core of HTGR is a pebble-bed surrounded by graphite bricks, so vibrations and collisions between graphite bricks caused by external excitation have important influence on structural stability of the core. The experiment is aimed at studying the collisions between two bricks, using linear track test and optics acquisition system to obtain the collision characteristics of graphite bricks. Experimental results show the contact time decreases while the coefficient of restitution rises up with collision speed increasing. The results data are well-distributed and basic rules are credible. In the experiment, the impact surfaces did not make contact at the same time, as the specimens would twirl gently to adjust posture, and perfect flat collision was difficult to achieve. We simulated the collision process by a two-dimensional numerical model which had a small collision angle between the two contact surfaces. The simulation results fit well with experimental data and reveal the main influence factor of the collision characteristics. We have also discussed factors of small collision angle in the experiment, the dispersion degree of the contact time data in different speed ranges and the relationship between the coefficient of restitution and the speed. Discussion on the posture adjustment in a flat collision is an important part in the paper, and the analysis of that is meaningful for the future dynamic simulation of the core

  6. Experimental and numerical researches on collision of graphite bricks

    Energy Technology Data Exchange (ETDEWEB)

    Jin, Lie; Wang, Hongtao [Institute of Nuclear and New Energy Technology, Tsinghua University, Beijing 100084 (China); Sun, Libin, E-mail: slb@tsinghua.edu.cn [Institute of Nuclear and New Energy Technology, Tsinghua University, Beijing 100084 (China); Wang, Haitao [Institute of Nuclear and New Energy Technology, Tsinghua University, Beijing 100084 (China); Ma, Shaopeng [Department of Mechanics, School of Aerospace Engineering, Beijing Institute of Technology, Beijing 100084 (China)

    2014-08-15

    Highlights: • Collisions between two graphite bricks have been studied in the experiment. • Linear track and optics acquisition system were used to obtain collision characters. • The contact time decreases while the coefficient of restitution rises up with speed. • Specimen's rotating slightly to adjust posture is the main factor of the contact time. • The collision characters are sensitive to the posture deviation of specimens. - Abstract: Graphite bricks have important applications in high temperature gas-cooled reactors (HTGRs). The core of HTGR is a pebble-bed surrounded by graphite bricks, so vibrations and collisions between graphite bricks caused by external excitation have important influence on structural stability of the core. The experiment is aimed at studying the collisions between two bricks, using linear track test and optics acquisition system to obtain the collision characteristics of graphite bricks. Experimental results show the contact time decreases while the coefficient of restitution rises up with collision speed increasing. The results data are well-distributed and basic rules are credible. In the experiment, the impact surfaces did not make contact at the same time, as the specimens would twirl gently to adjust posture, and perfect flat collision was difficult to achieve. We simulated the collision process by a two-dimensional numerical model which had a small collision angle between the two contact surfaces. The simulation results fit well with experimental data and reveal the main influence factor of the collision characteristics. We have also discussed factors of small collision angle in the experiment, the dispersion degree of the contact time data in different speed ranges and the relationship between the coefficient of restitution and the speed. Discussion on the posture adjustment in a flat collision is an important part in the paper, and the analysis of that is meaningful for the future dynamic simulation of the core

  7. Introducing Energy-efficient Clean Technologies in the Brick Sector of Bangladesh

    OpenAIRE

    World Bank

    2011-01-01

    This study's objectives are: (i) to present the pros and cons of existing and alternative brick technologies in Bangladesh with specific focus on pollution and energy efficiency; (ii) to estimate the private and social benefits of these technologies (iii) to summarize China's experience in the development of the brick industry, as the world leader brick producer and (iv) to provide concret...

  8. ASSESSMENT OF NATURAL RADIOACTIVITY IN CONCRETE BLOCK, EXTRUDED CLAY BRICK, AND MUD BRICK TAKEN FROM OGBOMOSO, SOUTHWESTERN, NIGERIA

    OpenAIRE

    Bolaji Omogbemiga AYINMODE; FAMAKINWA, Rebecca Oluwadamilola; Jonathan Olanipekun AJAYI

    2012-01-01

    This study evaluates the natural radioactivity in concrete block, extruded clay brick, and mud brick taken from Ogbomoso city. The six samples were collected from different part of the city, and were analyzed using highly sensitive HPGe gamma spectrometer. The mean activity concentration in Bq Kg -1 of 40K , 238 U (226Ra) and 232Th were 135.10 ± 3.23, 9.58 ± 3.16 and 14.30 ± 3.32 respectively in concrete block ; 66.34 ± 6.66, 6.81 ± 2.26 and 6.78 ± 2....

  9. 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.

  10. 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...

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

    OpenAIRE

    Kiplagat Chelelgo

    2010-01-01

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

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

    OpenAIRE

    Ali Reza Ghanizadeh

    2016-01-01

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

  13. COMPUTATIONAL INVESTIGATION OF COMPOSED MULTILAYERED HALF-SPACE STRENGTH UNDER PAVEMENT

    Directory of Open Access Journals (Sweden)

    Svetlana Talakh

    2015-10-01

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

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

    OpenAIRE

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

    2014-01-01

    Pavements always play a predominant role in transportation. Health monitoring of pavements is becoming more and more significant, as frequently suffering from cracks, rutting, and slippage renders them prematurely out of service. Effective and reliable sensing elements are thus in high demand to make prognosis on the mechanical properties and occurrence of damage to pavements. Therefore, in this paper, various types of functionality enhancement of industrialized optical fiber sensors for pav...

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

    OpenAIRE

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

    2007-01-01

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

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

    OpenAIRE

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

    2010-01-01

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

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

    OpenAIRE

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

    2012-01-01

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

  18. Preparation and characterization of green bricks using pharmaceutical industrial wastes.

    Science.gov (United States)

    Yamuna Rani, M; Bhagawan, D; Himabindu, V; Venkateswara Reddy, V; Saritha, P

    2016-05-01

    This paper reports on recycling of industrial wastes (three pharmaceutical industrial sludges) into environmental friendly value-added materials. Stabilization/Solidification (S/S or bricks) process was applied to make a safer way for the utilization of pharmaceutical waste. The additives in this study include binders (cement, lime and bentonite) and strengthening material (pulverized fuel ash (PFA), silica fume and quarry dust) was used at different compositions. Bricks were cured for 28 days, and the following analysis-like compressive strength, leachability of heavy metals, mineralogical phase identity by X-ray diffraction (XRD) spectroscopy, Fourier transform infrared spectroscopy (FTIR) and thermal behaviour by thermogravimetric-differential thermal analysis (TG-DTA) had done. All the bricks were observed to achieve the standard compressive strength as required for construction according to BIS standards. Metal concentration in the leachate has reached the dischargeable limits according to Brazilian standards. Results of this study demonstrate that production of bricks is a promising and achievable productive use of pharmaceutical sludge. PMID:26286801

  19. Unfired clay bricks – retention curves and liquid diffusivities

    DEFF Research Database (Denmark)

    Hansen, Kurt Kielsgaard; Peuhkuri, Ruut Hannele; Kristensen, A.; Hansen, E.J. de Place

    This paper presents retention curves and liquid diffusivities of two different types of unfired clay bricks, both produced in Denmark on commercial basis. The retention curves are determined by use of pressure plate and pressure membrane apparatuses. The liquid diffusivity is calculated on the...

  20. 3-dimensional analysis of FELIX brick with hole

    International Nuclear Information System (INIS)

    Electromagnetic induction on FELIX brick with a hole has been analyzed with 3-Dimensional EDDYNET computer code. Incorporating loop currents on hexahedral meshes, the 3-Dimensional EDDYNET program solves eddy current problems by a network approach, and provides good accuracy even for coarse meshes. (author)

  1. Brick and Stone Masonry Series. Duty Task List.

    Science.gov (United States)

    Oklahoma State Dept. of Vocational and Technical Education, Stillwater. Curriculum and Instructional Materials Center.

    This task list is intended for use in planning and/or evaluating a competency-based course in brick and stone masonry. The tasks required for 15 different duties performed by bricklayers and 13 different duties typically performed by rocklayers are outlined. The following bricklaying duties are covered: estimating materials for and laying out a…

  2. Measurement of radionuclides in bricks made from refuse ash of sewage sludge

    International Nuclear Information System (INIS)

    Since people spend about 80% of their time in buildings, in order to estimate the radiation exposure dose of nation, it is necessary to grasp indoor dose level. It has been known that as for indoor radiation exposure dose, it is different according to the types of buildings, and generally it is low in wooden houses, and high in concrete and brick buildings. This difference is due to the shielding of environmental radiation by building material and the radiation emitted from building materials themselves. In this study, the radionuclides in the bricks made of sewage slude-incinerated ash and red bricks for the reference were investigated. The radiation emitted from the bricks was measured with a thermoluminescence dosimeter (TLD). The sampling and pretreatment, the measuring method, the measurement of the radiation dose on the bricks, and the results are reported. As for the natural radionuclides in the bricks, 7Be was detected in most sludge bricks, and the concentration varied largely according to the data of sampling. It was not detected in red bricks. 40K, 214Bi and 228Ac were detected in all the sludge and red bricks. Artificial radionuclides such as 54Mn, 60Co, 106Ru, 131I, 134Cs and 144Ce were not detected in all the sludge and red bricks. The radiation dose on the sludge and red bricks was 20.5 - 21.7 mR, and constant regardless of the data of sampling. (K.I.)

  3. A user's guide to COMULIP (a program for determining brick movements in an AGR core)

    International Nuclear Information System (INIS)

    COMULIP (COre Movements Using LInear Programming) is a set of computer programs which allows the user to find the maximum movements of bricks in a layer of 16 sided polygonal bricks and 4 sided interstitial bricks, as in the core of the Hinkley 'B' Advanced Gas Cooled Reactor. The user supplies the dimensions of the bricks and keys, the boundary constraints and specifies the brick and direction for which the maximum movement is to be found. To facilitate data input, a standard set of dimensions is entered together with individual brick dimensions which differ. The linear programming method is used to maximise an objective function, which in this case is the movement of a specified brick in a given direction, subject to a set of linear constraints, which define the geometrical condition that no brick should overlap. The elasticity of the bricks is not taken into account, the effect of this being small compared with that of the clearances. The model analysed is a two dimensional horizontal cross-section through the core. This report forms the user's guide to the computer programs and gives details of the input data required and the output produced, as well as a brief description of the solution technique. The program may be used to study the effect of dimensional changes and brick or key damage, which occur during the lifetime of the reactor, on the movement of bricks. (author)

  4. Monitoring Thermal Performance of Hollow Bricks with Different Cavity Fillers in Difference Climate Conditions

    Science.gov (United States)

    Pavlík, Zbyšek; Jerman, Miloš; Fořt, Jan; Černý, Robert

    2015-03-01

    Hollow brick blocks have found widespread use in the building industry during the last decades. The increasing requirements to the thermal insulation properties of building envelopes given by the national standards in Europe led the brick producers to reduce the production of common solid bricks. Brick blocks with more or less complex systems of internal cavities replaced the traditional bricks and became dominant on the building ceramics market. However, contrary to the solid bricks where the thermal conductivity can easily be measured by standard methods, the complex geometry of hollow brick blocks makes the application of common techniques impossible. In this paper, a steady-state technique utilizing a system of two climatic chambers separated by a connecting tunnel for sample positioning is used for the determination of the thermal conductivity, thermal resistance, and thermal transmittance ( U value) of hollow bricks with the cavities filled by air, two different types of mineral wool, polystyrene balls, and foam polyurethane. The particular brick block is provided with the necessary temperature- and heat-flux sensors and thermally insulated in the tunnel. In the climatic chambers, different temperatures are set. After steady-state conditions are established in the measuring system, the effective thermal properties of the brick block are calculated using the measured data. Experimental results show that the best results are achieved with hydrophilic mineral wool as a cavity filler; the worst performance exhibits the brick block with air-filled cavities.

  5. 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.

  6. Full scale demonstration of air-purifying pavement.

    Science.gov (United States)

    Ballari, M M; Brouwers, H J H

    2013-06-15

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

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

    Science.gov (United States)

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

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

  8. 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.

  9. 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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Lai, J.S.

    1976-12-01

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

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

    Directory of Open Access Journals (Sweden)

    Jitendra Gurjar, Pradeep Kumar Agarwal, Manoj Kumar Sharma

    2013-07-01

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

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

    OpenAIRE

    Kundan Meshram; H.S. Goliya; Akhilesh Poddar

    2013-01-01

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

  13. Study on Microstructure and Slag Corrosion Mechanism of High Chrome Bricks for Gasifier

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Research was focused on slag corrosion mechanism of high chrome bricks used for different types of gasifier by comparing the structure of high chrome bricks for petroleum coke gasifier and water-coal slurry gasifier with slag corroded testing brick and water coal slurry gasifier through Scanning Electron Microscope (SEM) examination and X-ray diffraction. Results show that for high chrome brick used for petroleum coke gasifier, corrosion is mainly caused by Cr2O3 in the brick and V2O5 in molten slag and liquid phase generation at low temperature; for high chrome brick used for water-coal slurry gasifier, corrosion is caused by dissolution of Cr2O3 in molten slag and corrosion of ZrO2. For LIRR-HK95 brick, it performs better petroleum coke corrosion resistance than the others due to the optimal composition and structure.

  14. Effects of waste glass additions on quality of textile sludge-based bricks.

    Science.gov (United States)

    Rahman, Ari; Urabe, Takeo; Kishimoto, Naoyuki; Mizuhara, Shinji

    2015-01-01

    This research investigated the utilization of textile sludge as a substitute for clay in brick production. The addition of textile sludge to a brick specimen enhanced its pores, thus reducing the quality of the product. However, the addition of waste glass to brick production materials improved the quality of the brick in terms of both compressive strength and water absorption. Maximum compressive strength was observed with the following composition of waste materials: 30% textile sludge, 60% clay and 10% waste glass. The melting of waste glass clogged up pores on the brick, which improved water absorption performance and compressive strength. Moreover, a leaching test on a sludge-based brick to which 10% waste glass did not detect significant heavy metal compounds in leachates, with the product being in conformance with standard regulations. The recycling of textile sludge for brick production, when combined with waste glass additions, may thus be promising in terms of both product quality and environmental aspects. PMID:25812619

  15. Inventorying Toronto's single detached housing stocks to examine the availability of clay brick for urban mining.

    Science.gov (United States)

    Ergun, Deniz; Gorgolewski, Mark

    2015-11-01

    This study examines the stocks of clay brick in Toronto's single detached housing, to provide parameters for city scale material reuse and recycling. Based on consensus from the literature and statistics on Toronto's single detached housing stocks, city scale reusable and recyclable stocks were estimated to provide an understanding of what volume could be saved from landfill and reintroduced into the urban fabric. On average 2523-4542 m(3) of brick was determined to be available annually for reuse, which would account for 20-36% of the volume of virgin brick consumed in new house construction in 2012. A higher volume, 6187 m(3) of brick, was determined to be available annually for recycling because more of the prevalence of cement-based mortar, which creates challenges for brick reuse in Toronto. The results demonstrated that older housing containing reusable brick were being mostly landfilled and replaced with housing that contained only recyclable brick. PMID:25912626

  16. Dynamic thermal performance of alveolar brick construction system

    International Nuclear Information System (INIS)

    Highlights: → Even though U-value does not measure thermal inertia, it is the commonly used parameter. → The thermal performance analysis of buildings must include the evaluation of transient parameters. → Transient parameters of alveolar brick constructive system show good agreement with its low energy consumption. -- Abstract: Alveolar bricks are being introduced in building sector due to the simplicity of their construction system and to the elimination of the insulation material. Nevertheless, it is not clear if this new system is energetically efficient and which is its thermal behaviour. This paper presents an experimental and theoretical study to evaluate the thermal behaviour of the alveolar brick construction system, compared with a traditional Mediterranean brick system with insulation. The experimental study consists of measuring the thermal performance of four real house-like cubicles. The thermal transmittance in steady-state, also known as U-value, is calculated theoretically and experimentally for each cubicle, presenting the insulated cubicles as the best construction system, with differences around 45% in comparison to the alveolar one. On the other hand, experimental results show significantly smaller differences on the energy consumption between the alveolar and insulated construction systems during summer period (around 13% higher for the alveolar cubicle). These values demonstrate the high thermal efficiency of the alveolar system. In addition, the lack of agreement between the measured energy consumption and the calculated U-values, guides the authors to analyze the thermal inertia of the different building components. Therefore, several transient parameters, extracted from the heat transfer matrix and from experimental data, are also evaluated. It can be concluded that the alveolar brick construction system presents higher thermal inertia than the insulated one, justifying the low measured energy consumption.

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

    OpenAIRE

    Xiu Liu; Zhaojie Sun; Decheng Feng; Yixiang Cao

    2013-01-01

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

  18. 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...

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

    OpenAIRE

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

    2011-01-01

    Problem statement: Recycled materials aggregate from the demolished concrete structures and fly ash from burning coal shows the possible application as structural and non structural components in concrete structures. This research aims to evaluate the feasibility of using concrete containing recycled concrete aggregate and fly ash in concrete pavement. Approach: Two water cement ratio (0.45 and 0.55) the compressive strength, modulus of electricity and flexural streng...

  20. 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.

  1. Use of scrap rubber in asphalt pavement surfaces

    Science.gov (United States)

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

    1991-12-01

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

  2. Use of Recycled Aggregates in Riigid Pavement Construction

    OpenAIRE

    Muscalu, Marius-Teodor; Andrei, Radu

    2011-01-01

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

  3. Identifying Fine Aggregates Prone to Polishing in PCC Pavements

    OpenAIRE

    Fowler, David W; Rached, Marc M.

    2012-01-01

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

  4. The Research on the Cracks of the Asphalt Pavement

    OpenAIRE

    OuYangZiqiang; Li Chunge

    2015-01-01

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

  5. 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

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

    OpenAIRE

    Jay N. Meegoda; Shengyan Gao

    2015-01-01

    Skid resistance is an important parameter for highway designs, construction, management, maintenance and safety. The purpose of this manuscript is to propose the correlation between skid resistance, which is measured as skid resistance trailer, and mean profile depth (MPD) or the macro surface texture, which is measured by vehicle mounted laser, so that highway agencies can predict the skid resistance of pavement without the use of expensive and time consuming skid resistance trailer, which a...

  7. 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.

  8. 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.

  9. INVESTIGATION OF ASPHALT PAVEMENT WITH ADDED CRUMB RUBBER

    OpenAIRE

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

    2014-01-01

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

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

    OpenAIRE

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

    2005-01-01

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

  11. 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...

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

    OpenAIRE

    Maher, Michael; Kazmierowski, Tom; Navarra, Michael

    2015-01-01

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

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

    OpenAIRE

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

    2014-01-01

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

  14. 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.

  15. 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.

  16. 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.

  17. 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.

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

    Science.gov (United States)

    Loizos, Andreas; Plati, Christina

    2014-05-01

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

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

    Directory of Open Access Journals (Sweden)

    Su Zhang

    2016-05-01

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

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

    OpenAIRE

    LU, ZHENG; Yao, Hailin; Zhang, JingBo

    2014-01-01

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

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

    OpenAIRE

    Hongyan Ma; Dongsheng Wang; Changjun Zhou; Decheng Feng

    2015-01-01

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

  2. Automation of TL brick dating by ADAM-1

    International Nuclear Information System (INIS)

    Thermoluminescence has become an established dating method for ceramics and more recently for bricks. Based on the experiences of the work carried out since the late 1970's at the Rathgen-Forschungslabor in Berlin on the dating of bricks from historic architecture, and after evaluating all commercially available and some individually built automated and semi-automated TL-readers, a specially adapted machine for the fine grain dating of bricks was constructed in an interdisciplinary research project, undertaken by a team recruited from three faculties of the Czech Technical University in Prague. The result is the automated TL-reader ADAM-1 (Automated Dating Apparatus for Monuments) for the dating of historic architecture. Both the specific adaptation of the technique and the necessary optimal automation have influenced the design of this TL-reader. The principle advantage of brick as opposed to ceramic TL-dating emerges from the possibility of being able to obtain both a large number of samples and an above average quantity of datable material from each sample. This, together with the specific physical and chemical conditions in a brick wall, allowed a rethinking of the traditional error calculation and thus lower error margins as those obtained when dating ceramic shards. The TL-reader must therefore be able to measure and evaluate automatically numerous samples. The annular sample holder of ADAM-1 has 60 sample positions, which allow the irradiation and evaluation of samples taken from two locations. The thirty samples from one sampling point are divided into subgroups, which are processed in various ways. Three samples serve for a rough estimate of the TL sensitivity of the brick material. Nine samples are used for the measurement of 'natural TL' of the material. A further nine samples are used for testing the sensitivity of the material to beta radiation. The last nine samples serve for the testing of the sensitivity to alpha radiation. To determine the

  3. Surface Water Quality Assessment of the Jirania Brick Cluster – A Case Study

    Directory of Open Access Journals (Sweden)

    Amarendra Jamatia

    2014-06-01

    Full Text Available Along with the infrastructural development works, the demand for construction materials is increasing rapidly, which in turns lead to the rapid growth of brick manufacturing industries. Large demand of bricks in development and construction sectors has resulted in mushrooming of brick industries clusters at the outskirt of Agartala City. Jirania brick industries cluster is one of largest cluster of the Tripura State (India. Approximately 45% of total bricks of the State are being produced from the Jirania brick industries clusters. The use of conventional technology for brick making has resulted significant contribution of pollution load to the environment. The main components of environment which are being affected by the brick industries include but not limited to air, water, soil etc. The present study is carried out to identify the potential contribution of pollution load on surface water sources of the region from the mentioned brick industries. The surface water samples collected from nine sampling station located at different places in the area are analyzed and the experimental results of various quality parameters are presented in the paper. Such a study will help to estimate the total pollution load of the brick industry in the mentioned area.

  4. Natural radioactivity content and radionuclides leachability of bricks containing industrial waste

    International Nuclear Information System (INIS)

    A study have been carried out using gamma-ray spectrometric system to determine the natural radioactivity level in bricks made from industrial waste and their associated radiation hazard. Brick-1 and brick-2 contained waste from coal power plant and granite industry, respectively. The leachability of radionuclides from these bricks was also investigated. The activity concentration values of 226Ra, 228Ra, 232Th, and 40K are 64.25, 63.15, 67.9 and 254.19 Bq kg-1, respectively in brick-1, and 193, 164.48, 164.63 and 1348.75 Bq kg-1, respectively in brick-2. The radiation hazard indexes such as radium equivalent activities (Raeq), representative level index (Iγr), external hazard index (Hex) and internal hazard index (Hin) were calculated and compared with the internationally approved values. Results indicate that brick-1 showed less radiological hazard than brick-2. This suggested that brick-1 could be used in building construction without exceeding the proposed criterion level. The leachability of 226Ra for bricks showed the activity concentration slightly exceeded the limit generally used for industrial wastewater for example 1 BqL-1. (author)

  5. FORECASTING OF DURABILITY OF ASPHALT PAVEMENT ON THE BASIS OF LEVELS OF THEIR VIBRATION LOADING

    Directory of Open Access Journals (Sweden)

    V. A. Osinovskaya

    2015-12-01

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

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

    NARCIS (Netherlands)

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

    2012-01-01

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

  7. 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…

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

    International Nuclear Information System (INIS)

    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.

  9. 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.

  10. 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... HIGHWAYS NATIONAL PARK SERVICE MANAGEMENT SYSTEMS National Park Service Management Systems § 970.208 Federal lands pavement management system (PMS). In addition to the requirements provided in § 970.204,...

  11. Brick finding efficiency in muonic decay tau neutrino events

    International Nuclear Information System (INIS)

    In this paper a new algorithm is used for the brick finding of muonic decay tau neutrino events. The new algorithm uses Hough Transform to select the most significant strips. The events are then classified in few categories depending on the nature of the neutrino interaction. A neural network based on kinematics and geometric configurations of each category is then used to select the right wall. Once the right wall is found the strips selected by the Hough Transform are used to find the X-Y position of the neutrino interaction vertex. The brick finding efficiency of this new algorithm is 72.3%. This represents a tangible improvement with respect to the performance of the previous algorithm used in OPERA [1]. (author)

  12. Fingermark recovery from riot debris: Bricks and stones.

    Science.gov (United States)

    Davis, Lisa; Fisher, Ruth

    2015-03-01

    During the UK riots in August 2011, large volumes of bricks and stones were used as weapons or projectiles in acts of violence or to gain illegal entry to properties. As a result, it has been emphasised that it is necessary to determine suitable chemical treatment(s) that will enable the development of fingermarks on such items in order to identify those involved. This study has undertaken the task of attempting to develop latent fingermarks on common house bricks, limestone and sandstone using current techniques including ninhydrin and fluorescence. Results produced have shown that, with fluorescent fingerprint powder, silver nitrate and superglue providing the best results, it is now possible to enhance fingermarks that were previously left undeveloped. In addition, Isomark T-1 Rapid Grey High Resolution Forensic Impression Material has proved extremely effective as an alternative method of recovering fingermarks developed with fluorescent fingerprint powder. PMID:25753994

  13. Low Temperature Regolith Bricks for In-Situ Structural Material

    Science.gov (United States)

    Grossman, Kevin; Sakthivel, Tamil S.; Mantovani, James; Seal, Sudipta

    2016-01-01

    Current technology for producing in-situ structural materials on future missions to Mars or the moon relies heavily on energy-intensive sintering processes to produce solid bricks from regolith. This process requires heating the material up to temperatures in excess of 1000 C and results in solid regolith pieces with compressive strengths in the range of 14000 to 28000 psi, but are heavily dependent on the porosity of the final material and are brittle. This method is currently preferred over a low temperature cementation process to prevent consumption of precious water and other non-renewable materials. A high strength structural material with low energy requirements is still needed for future colonization of other planets. To fulfill these requirements, a nano-functionalization process has been developed to produce structural bricks from regolith simulant and shows promising mechanical strength results. Functionalization of granular silicate particles into alkoxides using a simple low temperature chemical process produces a high surface area zeolite particles that are held together via inter-particle oxygen bonding. Addition of water in the resulting zeolite particles produces a sol-gel reaction called "inorganic polymerization" which gives a strong solid material after a curing process at 60 C. The aqueous solution by-product of the reaction is currently being investigated for its reusability; an essential component of any ISRU technology. For this study, two batches of regolith bricks are synthesized from JSC-1A; the first batch from fresh solvents and chemicals, the second batch made from the water solution by-product of the first batch. This is done to determine the feasibility of recycling necessary components of the synthesis process, mainly water. Characterization including BET surface area, SEM, and EDS has been done on the regolith bricks as well as the constituent particles,. The specific surface area of 17.53 sq m/g (average) of the granular regolith

  14. Mechanical properties of adobe bricks in ancient constructions

    OpenAIRE

    Silveira, Dora; VARUM Humberto; Costa, Aníbal; Martins, Tiago; Pereira, Henrique; Almeida, Joao

    2012-01-01

    A study of the mechanical properties of adobe bricks collected from houses and land dividing walls in Aveiro district, Portugal, representative of existing traditional constructions, was conducted. Cylindrical adobe specimens were subjected to simple compression and splitting tests. From these tests it was possible to evaluate the strength capacity, stiffness and deformation evolution for increasing loading. Correlations between the evaluated properties were determined, and the results obtain...

  15. Energy Efficiency Improvement Potential in Historical Brick Building

    OpenAIRE

    Žogla, Gatis; Blumberga, Andra; Zvaigznītis, Kristaps; Dzikēvičs, Miķelis; Blumberga, Dagnija; Burinskiene, Marija

    2013-01-01

    Energy efficiency in historical heritage buildings is viewed as a taboo because these buildings usually are law-protected and no energy efficiency measures that would change the appearance of building are allowed. In this paper we look at a potential of increasing energy efficiency level in historical buildings. Measurements to determine energy efficiency of a historical brick building have been done, which also give the possibility to determine the potential of energy efficiency measures in ...

  16. Modeling Influenza Antigenic Shift and Drift with LEGO Bricks

    OpenAIRE

    Boriana Marintcheva

    2016-01-01

    The concepts of antigenic shift and drift could be found in almost every microbiology and virology syllabus, usually taught in the context of Influenza virus biology. They are central to understanding viral diversity and evolution and have direct application to anti-flu vaccine design and effectiveness. To aid student understanding of the concepts, I have developed an exercise to visualize the mechanistic aspects of antigenic shift and drift using LEGO bricks. This hands-on/minds-on exercise ...

  17. Valorization and inertization of galvanic sludge waste in clay bricks

    OpenAIRE

    Pérez-Villarejo, L.; Martínez-Martínez, S; Carrasco-Hurtado, B.; Eliche-Quesada, D.; Ureña-Nieto, C.; Sánchez-Soto, Pedro José

    2015-01-01

    Galvanic sludge wastes (GSW) are produced by the physico-chemical treatments of wastewater generated by electroplating plants. These materials have a significant potential for the production of clay ceramic bricks. This paper focuses on the viability of the inertization of heavy metals from GSW mixed with clays. The original materials were obtained by mixing three types of raw clay (red, yellow and black) in equal parts with GSW. These mixtures were characterized by XRD, XRF, and chemical ele...

  18. Peak and residual strengths of brick masonry spandrels

    OpenAIRE

    Beyer, Katrin

    2012-01-01

    Unreinforced masonry (URM) walls comprise vertical piers and horizontal spandrels, which together form the lateral load resisting system. Whereas past research yielded significant advances in the understanding of the force-deformation characteristics of masonry piers, knowledge of the behaviour of masonry spandrels is lacking. This paper makes a contribution to our understanding of the seismic behaviour of brick masonry spandrel elements by describing typical behaviour modes and analysing the...

  19. TorBricks: Blocking-Resistant Tor Bridge Distribution

    OpenAIRE

    Zamani, Mahdi; Saia, Jared; Crandall, Jedidiah

    2016-01-01

    Tor is currently the most popular network for anonymous Internet access. It critically relies on volunteer nodes called bridges for relaying Internet traffic when a user's ISP blocks connections to Tor. Unfortunately, current methods for distributing bridges are vulnerable to malicious users who obtain and block bridge addresses. In this paper, we propose TorBricks, a protocol for distributing Tor bridges to n users, even when an unknown number t < n of these users are controlled by a malicio...

  20. A practical proposal for solving the world's cigarette butt problem: Recycling in fired clay bricks.

    Science.gov (United States)

    Mohajerani, Abbas; Kadir, Aeslina Abdul; Larobina, Luke

    2016-06-01

    The disposal and littering of cigarette butts (CBs) is a serious environmental problem. Trillions of cigarettes are produced every year worldwide, resulting in millions of tonnes of toxic waste being dumped into the environment in the form of cigarette butts. As CBs have poor biodegradability, it can take many years for them to break down. This paper reviews and presents some of the results of a study on the recycling of CBs into fired clay bricks. Bricks with 2.5%, 5%, 7.5%, and 10% CB content by weight were manufactured and tested, and then compared against control clay bricks with 0% CB content. The results showed that the dry density decreased by up to 30% and the compressive strength decreased by 88% in bricks with 10% CBs. The calculated compressive strength of bricks with 1% CBs was determined to be 19.53Mpa. To investigate the effect of mixing time, bricks with 7.5% CB content were manufactured with different mixing times of 5, 10, and 15min. To test the effect of heating time on the properties of CB bricks, the heating rate used during manufacturing was changed to 0.7, 2, 5, and 10°Cmin(-1). Bricks with 0% and 5% CB content were fired with these heating rates. Leachate tests were carried out for bricks with 0%, 2.5%, 5%, and 10% CB content. The emissions released during firing were tested for bricks with 0% and 5% CB content using heating rates of 0.7, 2, 5, and 10°Cmin(-1). The gases tested were carbon monoxide (CO), carbon dioxide (CO2), chlorine (Cl2), nitrogen oxide (NO), and hydrogen cyanide (HCN). Finally, estimations were made for the energy that could be saved by firing bricks incorporating CBs. Calculations showed that up to 58% of the firing energy could potentially be saved. Bricks were shown to be a viable solution for the disposal of CBs. They can reduce contamination caused by cigarette butts and provide a masonry construction material that can be either loadbearing or non-loadbearing, depending on the quantity of CBs incorporated. This

  1. PECULIAR FEATURES OF HEAT-HUMIDITY MODE PERTAINING TO POROUS LAYERS OF ASPHALT CONCRETE PAVEMENTS

    Directory of Open Access Journals (Sweden)

    V. Verenko

    2014-10-01

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

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

    International Nuclear Information System (INIS)

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

  3. Bricks and urbanism in the Indus Valley rise and decline

    CERN Document Server

    Khan, Aurangzeb

    2013-01-01

    The Indus Valley Culture (IVC), often denoted by its major city Harappa, spanned almost two millennia from 3200 to 1300 BC. Its tradition reaches back to 7000 BC: a 4000 year long expansion of villages and towns, of trading activity, and of technological advancements culminates between 2600 and 1900 BC in the built-up of large brick-built cities, writing, and political authority; the IVC emerges as one of the first great civilizations in history. During the ensuing 600 years, however, key technologies fall out of use, urban centers are depopulated, and people leave the former core areas of the IVC; although many different hypotheses have been put forward, a conclusive causal chain for this decline has not yet been established. We here combine literature estimates on brick typology, and on urban area for individual cities; in the context of the existing extensive data on Harappan artifact find sites and put in their chronological order, the combined narratives told by bricks, cities, and extent, can provide a ...

  4. Calculation and measurement of depth dose distributions in bricks

    International Nuclear Information System (INIS)

    The dose accumulated in bricks exposed to gamma radiation can be measured as a function of depth using luminescence methods. The dependence of dose on depth has the potential of providing information on the energy as well as on the angular distribution of the incident radiation, which could give indications on the configuration of the radiation sources. A prerequisite for such an analysis is a comprehensive knowledge on the dependence of dose on depth for different source energies and for specific source configurations. Depth dose distribution in brick walls have been calculated by Monte Carlo simulations for a source distribution on a wall, for a source distribution on the ground and for a parallel photon beam, for source energies ranging from 140 keV to 1600 keV. It is shown that depth dose distributions depend substantially on source configuration and energy. Depth dose distributions measured in ceramic materials irradiated in the laboratory and in a brick from a contaminated area are compared with results of Monte Carlo calculations. (Author)

  5. Wave Manipulation in Metamaterials: A LEGO® Bricks Enabled Platform

    Science.gov (United States)

    Celli, Paolo; Gonella, Stefano

    In this work, we show how simple, reconfigurable arrangements of LEGO® bricks can be turned into the building blocks of an experimental platform for the investigation of wave phenomena in metamaterial architectures. The approach involves the assembly of reconfigurable specimens consisting of patterns of bricks on a baseplate and the use of a 3D laser vibrometer to reconstruct global and local wave features. The ability to seamlessly transition between different topologies makes this an effective approach for rapid experimental verification and proof of concept in the arena of mechanical metamaterials engineering. The intuitive nature of the brick-and-baseplate assembly paradigm can also be leveraged to implement families of intuitive lab demonstrations with significant didactic and scientific outreach potential. The versatility of the platform is tested through a series of experiments that illustrate a variety of wave manipulation effects, such as waveguiding and seismic isolation, both in periodic and disordered topologies. We acknowledge the support of the National Science Foundation (Grant CMMI-1266089).

  6. Diffusion and electromigration in clay bricks influenced by differences in the pore system resulting from firing

    DEFF Research Database (Denmark)

    Rörig-Dalgaard, Inge; Ottosen, Lisbeth M.; Hansen, Kurt Kielsgaard

    2012-01-01

    effective diffusion coefficient was empirically determined for chloride and sodium through the application of an electric DC field across the bricks. The lowest effective diffusion coefficient was found for the dark colored brick, increasing for the medium and bright colored respectively. This finding...... pore system to contribute to an overall understanding of ion transport in porous materials.The pore system in bricks are influenced by the firing degree, clay mixture composition and ion content. The present paper focuses on the pore system and effects from clay mixture composition and ion content were...... neglected by using the same brick type from the same brickwork (delivered at the same pallet). The used bricks were fired in a circular kiln were uneven heating during firing occurs. Significant color differences were visible between the bricks in the pallet and for the investigation purpose they were...

  7. Utilization of concentrate of membrane filtration of bleach plant effluent in brick production

    International Nuclear Information System (INIS)

    Utilization potential of membrane filtration retentate (concentrate) of bleach plant effluent from paper industry, in bricks production, was investigated in the present study. Bricks were prepared by using retentate of membrane filtration in place of water. The physical properties measured for bricks were dimensions, density, moisture content, compressive strength, water absorption and porosity. Chemical analysis of the bricks was performed for water leachability and acid leachability, using ASTM Standard methods D 3987-06 and D 5233-92 respectively. The leachate samples were analyzed for Al, Cu, Fe, Co, Cr, Pb, Ni and Zn using AAS (atomic absorption spectrophotometer). Adsorbable organic halides (AOX) of leachate were analyzed by using AOX analyzer model ECS 1200 using column method. It was observed that the physical and chemical properties of bricks especially fire clay bricks were not adversely affected by the use of wastewater. Therefore, the organic matter of the retentate of membrane filtration creates no problems for this application.

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

    Science.gov (United States)

    Lijun, Suo; Xinwu, Wang

    The study revealed that whether it is early distresses in asphalt pavement or not depends largely on working performance of base. In the field of asphalt pavement, it is widely accepted that lean concrete base, compared with the general semi-rigid base, has better working performance, such as high strength and good eroding resistance. Problem of early distresses in asphalt pavement, which caused by more traffic loadings, can be settled effectively when lean concrete is used in asphalt pavement. Traffic loading is important parameter used in the analysis of the new pavement design. However, few studies have done extensive and intensive research on the load stress for asphalt pavement of lean concrete base. Because of that, it is necessary to study the load stress for the asphalt pavement. In the paper, first of all, three-dimension finite element model of the asphalt pavement is created for the aim of doing mechanical analysis for the asphalt pavement. And then, the two main objectives of this study are investigated. One is analysis for load stress of lean concrete base, and the other is analysis for load stress of asphalt surface. The results show that load stress of lean concrete base decreases, decrease and increase with increase of base's thickness, surface's thickness and ratio of base's modulus to foundation's modulus respectively. So far as the asphalt surface is concerned, maximum shearing stress, which is caused by load, is evident in asphalt surface which is located in transverse contraction joint of lean concrete base of asphalt pavement. Maximum shearing stress decrease, decrease, decrease and increase respectively with increase of the surface's modulus, the surface's thickness, base's thickness and ratio of base's modulus to foundation's modulus.

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

    Directory of Open Access Journals (Sweden)

    A.M. Kirillov

    2015-09-01

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

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

    Science.gov (United States)

    Injun, Song

    2015-04-01

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

  11. REBELLION: SECOND GENERATION BANGLADESHI IMMIGRANTS IN BRICK LANE BY MONICA ALI

    OpenAIRE

    A. Nejat TÖNGÜR*

    2013-01-01

    Brick Lane is one of the few novels which reflect the lives of first and second generation Bangladeshi immigrants in Britain. Although Brick Lane focuses on Nazneen as central character, the novel provides very rich information about the life styles, work patterns, family structure, and cultural, social, economic and religious dynamics of the Bangladeshi community in Brick Lane. Ali also shows that the second-generation young Bangladeshis are distinct with their frequent clashes with their pa...

  12. Determination of element composition in CoffeeBricks before and after incineration

    OpenAIRE

    Fröling, Annika

    2015-01-01

    The purpose for this study was to determine the element composition in CoffeeBricks before and after incineration. The difference between element composition in CoffeeBricks (barbecue briquettes made out of spent coffee grounds) and regular barbecue briquettes was also evaluated in this study. Aqua regia digests from the ash residues of CoffeeBricks and the ash residues of regular barbecue briquettes were analyzed with Inductively Coupled Plasma Atomic Emission Spectroscopy (ICP-AES). H2SO4/H...

  13. Prevalence of Brick Tea-Type Fluorosis in the Tibet Autonomous Region

    Directory of Open Access Journals (Sweden)

    Zhipeng Fan

    2016-02-01

    Full Text Available Background: The prevalence of brick tea-type fluorosis is high in Tibet because of the habit of drinking brick tea in this region. Brick tea-type fluorosis has become an urgent public health problem in China. Methods: A cross-sectional survey was conducted to investigate prevalence of brick tea-type fluorosis in all districts of Tibet using a stratified cluster sampling method. Dental fluorosis in children aged 8–12 years and clinical skeletal fluorosis in adults were diagnosed according to the national criteria. A total of 423 children and 1320 adults participated in the study. Samples of drinking water, brick tea, brick tea infusion (or buttered tea, and urine were collected and measured for fluoride concentrations by the fluoride ion selective electrode method. Results: The fluoride level in all but one of the brick tea samples was above the national standard. The average daily fluoride intake from drinking brick tea in all seven districts in Tibet was much higher than the national standard. The prevalence of dental fluorosis was 33.57%, and the prevalence of clinical skeletal fluorosis was 46.06%. The average daily fluoride intake from drinking brick tea (r = 0.292, P < 0.05, urine fluoride concentrations in children (r = 0.134, P < 0.05, urine fluoride concentrations in adults (r = 0.162, P < 0.05, and altitude (r = 0.276, P < 0.05 were positively correlated with the prevalence of brick tea-type fluorosis. Herdsmen had the highest fluoride exposure and the most severe skeletal fluorosis. Conclusions: Brick tea-type fluorosis in Tibet is more serious than in other parts of China. The altitude and occupational factors are important risk factors for brick tea-type fluorosis.

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

    Science.gov (United States)

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

    1980-06-01

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

  15. 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.

  16. Effect of Age and Environment on Strength of Old Baked Clay Bricks of Indus Valley Civilization

    Directory of Open Access Journals (Sweden)

    NAWAB ALI LAKHO

    2016-07-01

    Full Text Available This paper presents results of experimental investigations conducted on old baked clay bricks of Indus Valley civilization of tenth century. The object of this study is to evaluate the effect of age and environmental conditions on the strength of the baked clay bricks which are about 1000 years old. The brick samples were collected from six different archeological sites at the banks of old route of River Indus in district Sanghar, Sindh, Pakistan. These specimens were tested for apparent density, compressive strength, tensile strength, modulus of rupture and the weathering effects on them during the course of time. ASTM (American Society for Testing and Materials standard for baked clay bricks, based on compressive strength, suggests that the bricks of four sites can withstand severe weathering while the bricks of two sites are resistant to moderate weathering. These results were compared to the values of the corresponding data of bricks, of same period, obtained from the historical monuments of the world as reported in the literature. The comparison showed that the values of physical properties of old baked clay bricks of Indus valley civilization of tenth century are in agreement with that of old baked clay bricks of contemporary era. The results of this study could also be helpful for preservation of old archeological sites of Indus valley civilization.

  17. The technical research on the huge glazed brick from the relic of Nanyue Kingdom Palace

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    ‘Qin brick and Han tile’ has a great worldwide reputation in the architectural history of China. According to the former archaeological materials, the big hollow brick is usually one meter long and thirty to forty centimeters wide, while the solid brick is generally much smaller. But in 1995, large scale vestiges and structures were un- earthed at the center of Guangzhou’s old district, from the relic of Nanyue Kingdom Palace, which was built some 2000 years ago during the Western-Han Dynasty. A great number of earthen structural members were discovered, especially the solid glazed bricks in various beautiful patterns with an astonishing thickness and size. Some of them are one meter square, more than 20 centimeters thick, and weight half a ton, which are named ‘Brick No.1 in the world’ by excavators. People have shown great interest in how to make these huge glazed bricks at the ancient tech- nical conditions, because it is very difficult to manufacture such huge bricks even with the modern technology. At the request of Guangdong Nanyue Kingdom Palace Museum, Shanghai Institute of Ceramics carried out systematical measurements and analysis on these bricks and studied the physical and chemical forming mechanisms from their chemical compositions, structure, and physical character- istics. Here the technical characteristics of the bricks are also discussed.

  18. Corrosion Mechanism of MgO-CaO Brick for AOD Furnace

    Institute of Scientific and Technical Information of China (English)

    WANG Jiandong; GE Changchun; SHEN Weiping

    2006-01-01

    Residual MgO-CaO brick after being used in AOD furnace was determined by OM, SEM and EDAX. Corrosion mechanism of MgO-CaO brick as furnace lining was studied. Results show that: The corrosion of MgOCaO brick is mainly attributed to the solution and infiltration of silicate liquid phase. Transverse cracks between reacted zone and original zone are parallel to the working face, which is an important factor for deteriorating the corrosion of MgO-CaO bricks.

  19. Dredged sediments as a resource for brick production: Possibilities and barriers from a consumers’ perspective

    International Nuclear Information System (INIS)

    Highlights: • Consumers are suspicious towards bricks produced from dredged sediments. • Technical quality, safety and environmental impacts are considered key characteristics. • Public has insufficient knowledge on bricks produced from dredged sediments. • Sensitization and provision of information to customers are of primary importance. - Abstract: A possible solution for the oversupply of dredged sediments is their use as a raw material in brick production. Despite the fact that several examples (e.g., Agostini et al., 2007; Hamer and Karius, 2002; Xu et al., 2014) show that this application is feasible, some economic, technical and social limitations interfere with the development of a market of dredged materials in brick production in Flanders. While we describe the main characteristics of the supply side, we focus on the limitations and barriers from the demand side in the present study. Based on a consumers survey we analyze consumers’ risk perceptions and attitudes towards bricks produced from dredged sediments. Consumers in Flanders are rather suspicious with respect to bricks produced from dredged sediments and their risk perception is mainly determined by the possibility of a bad bargain (brick of inferior quality) and the connotation with chemical contamination. The willingness to pay for bricks made from dredged sediments is mainly influenced by the age of the respondents, as well environmental awareness, and the respondents’ belief in their ability to influence environmental problems. Sensitization and information of customers seems to be of primary importance to make dredged-sediment-derived bricks a successful product

  20. Natural radioactivity in different types of bricks fabricated and used in the Cairo region

    International Nuclear Information System (INIS)

    The specific radioactivity concentrations of 226Ra, 232Th and 40K were measured in samples of different types of bricks (clay, cement, and sand) fabricated and used in urban buildings in the Cairo region in Egypt, using a γ-ray spectrometer with a HpGe-detector. The radiation hazard of the total natural radioactivity in the studied brick was estimated by different approaches. The concentrations of the natural radionuclides and the radium-equivalent activity in the studied Egyptian brick samples are compared with the corresponding results for bricks of the different countries and are found to be significantly lower in all cases. (Author)

  1. Bauxite Based Refractory Bricks for Hot Blast Stove YB/T 5016-2000

    Institute of Scientific and Technical Information of China (English)

    Wang Jing; Chai Junlan

    2008-01-01

    @@ 1Scope This standard specifies the technical requirements, test method, inspection rules, packing, marking, transportation, storage and quality certificate of bauxite based refractory bricks for hot blast stove.

  2. Dredged sediments as a resource for brick production: Possibilities and barriers from a consumers’ perspective

    Energy Technology Data Exchange (ETDEWEB)

    Cappuyns, Valérie, E-mail: valerie.cappuyns@kuleuven.be; Deweirt, Valentine; Rousseau, Sandra

    2015-04-15

    Highlights: • Consumers are suspicious towards bricks produced from dredged sediments. • Technical quality, safety and environmental impacts are considered key characteristics. • Public has insufficient knowledge on bricks produced from dredged sediments. • Sensitization and provision of information to customers are of primary importance. - Abstract: A possible solution for the oversupply of dredged sediments is their use as a raw material in brick production. Despite the fact that several examples (e.g., Agostini et al., 2007; Hamer and Karius, 2002; Xu et al., 2014) show that this application is feasible, some economic, technical and social limitations interfere with the development of a market of dredged materials in brick production in Flanders. While we describe the main characteristics of the supply side, we focus on the limitations and barriers from the demand side in the present study. Based on a consumers survey we analyze consumers’ risk perceptions and attitudes towards bricks produced from dredged sediments. Consumers in Flanders are rather suspicious with respect to bricks produced from dredged sediments and their risk perception is mainly determined by the possibility of a bad bargain (brick of inferior quality) and the connotation with chemical contamination. The willingness to pay for bricks made from dredged sediments is mainly influenced by the age of the respondents, as well environmental awareness, and the respondents’ belief in their ability to influence environmental problems. Sensitization and information of customers seems to be of primary importance to make dredged-sediment-derived bricks a successful product.

  3. 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.

  4. 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.

  5. 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. PMID:24527626

  6. 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.

  7. An Overview Of Pavement Management System For Industrial Areas

    Science.gov (United States)

    Hokam, Vivek S.

    2012-03-01

    ACT With the current surge in national economy the industrial traffic has increased many folds in terms of quantity of load and traffic volume. This results in early deterioration of the roads. Also the serviceability reduces hampering the industry's supply of raw material and transport of finished goods. An efficient road transportation system is of vitally important for smooth operations of industrial units. Construction of new roads needs an enormous investment. However, once constructed the road network system requires huge resources to maintain serviceability and to ensure safe passage at an appropriate speed and with low VOC (Vehicle Operating Cost). Road maintenance is therefore an essential function and should be carried out on a timely basis. The cost of providing and maintaining the roads for the industrial areas at an acceptable serviceability level is quite high. It is therefore essential for a transportation engineer to attempt establishing an acceptable pavement condition level from economic, safety and environmental point of view. In today's economic environment of constrained budgets, as the existing road infrastructure has aged, a more systematic approach towards determining maintenance and rehabilitation needs is necessary. The efficient pavement management system shall provide objective information and useful analysis to ensure consistent and cost effective decisions related to preservation of existing industrial road network in healthy condition.

  8. Effectiveness of pavement-solar energy system – An experimental study

    International Nuclear Information System (INIS)

    Highlights: • We built a small-scale pilot project of pavement-solar energy utilization. • Design an automatic monitoring system to record the operating data. • The average heat absorptivity of pavement-solar energy is 37%. • The average thermal storage effectiveness of the system is 17%. - Abstract: A small-scale pilot project was built for the pavement-solar energy utilization in this paper. An automatic data acquisition system was designed to measure the effectiveness of the pavement solar energy system based on the operation data of 24 h a day in both summer and winter. Through 69 days (1656 h) of operation in summer, 2821 kW h of heat energy were stored in soil underground. In the transitional season, 4598 kW h of heat energy were taken out from soil during 104 days (2496 h) of operation in winter. The analysis showed that in summer, solar heat collection of asphalt pavement could effectively reduce 7 °C of its temperature. Under conditions of natural radiation, the average heat absorptivity of pavement was 37% and the average thermal storage effectiveness of the system was 17%. The electrical energy consumed by the system is only 11% of stored heat. During the winter, the asphalt pavement absorbs heat from underground soil which effectively increases its temperature, cutting 32% days of surface temperature below the freezing point. This not only save the energy for ice/snow removal but also mitigate associated safety risks

  9. 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

    2016-03-01

    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. PMID:27011196

  10. 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.

  11. 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.

  12. Investigation of the Permanent Deformation Characteristics of Overlaid Pavement Incorporating Stress Absorbing Membrane Interlayers

    Institute of Scientific and Technical Information of China (English)

    Olumide Moses Ogundipe[1; Nicholas H. Thom[2; Andrew C. Collop[3

    2014-01-01

    This study was carried out to evaluate the resistance of overlaid pavement incorporating stress absorbing membrane interlayers to permanent deformation. In this study, the permanent deformation of the interlayer mixtures was determined using the RLAT (repeated load axial text) carried out in the Nottingham Asphalt Tester. Also, a test pavement was constructed in the laboratory to assess the resistance to permanent deformation of overlaid pavement incorporating SAMIs (stress absorbing membrane interlayers). The test pavement was divided into two along the centre line. Each of the divisions has three sections--two having SAMIs and one without SAMIs. The pavement was instrumented and trafficked. Trafficking was stopped when the pavement was deemed to have failed. The results showed that the measured permanent deformation values of the control sections were less than the sections having SAMIs. The increased permanent deformation values indicate that the introduction of SAMIs causes more vertical/horizontal deformation of the pavement. It was also found that the permanent deformation values varied depending on the composition and thickness of the SAMIs.

  13. Solar-reflective coating as a cooling overlay for asphalt pavement

    Science.gov (United States)

    Wang, He; Xu, Geng; Feng, Decheng; Zhong, Jing; Xie, Ning

    2012-04-01

    Rutting is one of the most serious problems on asphalt pavements. Decrease the surface temperature of the asphalt pavement is an effective method to solve the rutting problem on asphalt pavements. In this study, nano sized particles filled polymer composite was developed as an overlay to reflect the solar energy and decrease the surface temperature of asphalt pavements. The overlay was composed of acrylic or epoxy resin filled with nano TiO2 or nano TiNO2. The solar reflection of the nano particle filled polymers was tested and the results showed that solar reflection effectiveness of the epoxy/TiO2 composite reached the highest value. The results of outdoor temperature test indicate that the solar-reflective overlay could decrease the surface temperature of asphalt pavements about 10 °C when the pavement temperature is about 60 °C. Pavement skid resistance was also tested, which expressed by micro/macrotexture depth and the results of which showed that both matrix was qualified after coated with aggregates on the surface.

  14. Natural Airfield Pavements, Load-Carrying Capacities There Of, Principles Of Construction And Operational Use

    Directory of Open Access Journals (Sweden)

    Nita Piotr

    2015-09-01

    Full Text Available The paper has been intended to present analytically derived relationships for aircraft wheels that move through the soil medium. The analyses have been conducted for both the rigid wheel and the pneumatic whell. The most fundamental principles of constructing natural(soil and sod/grass airfield pavements have been diccussed. Characteristic of soils typical of such pavements /surfaces have been defined. Proped are criteria for the evaluation of load-carring capacities of such pavements. The most essential principles that goven the operational use there of follow.

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

    International Nuclear Information System (INIS)

    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

  16. 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

  17. Horowitz-Strominger Black Hole Entropy Without Brick Wall

    Institute of Scientific and Technical Information of China (English)

    ZHANG Li-Chun; ZHAO Ren; LIN Hai

    2004-01-01

    @@ A Horowitz-Strominger black hole is discussed through a new equation of state density motivated by the generalized uncertainty relation in quantum gravity. There is no burst in the last stage of emission from a HorowitzStrominger black hole. When the new equation of state density is used to investigate the entropy of bosonic field and fermionic field outside the horizon of a static Horowitz-Strominger black hole, the divergence that appears in the brick-wall model is removed without any cutoff. The entropy proportional to the horizon area is derived from the contribution in the vicinity of the horizon.

  18. Application of INAA for chemical characterization of ancient bricks

    International Nuclear Information System (INIS)

    Instrumental neutron activation analysis (INAA) is a powerful nuclear analytical technique for non-destructive analysis of solid samples including ceramics. INAA using high flux reactor neutrons from Dhruva reactor was utilized for analysis 20 ancient bricks obtained from Buddhist sites of Andhra Pradesh, India. For comparison, two recent/modern potteries were also analyzed. Concentrations of 24 elements were determined by relative method. Concentration ratios (La/Ce) as well as statistical cluster analysis (using 14 selected elements) were used for grouping these artifacts, as part of provenance study. These results showed that the 22 samples fell in two major groups, which are in good agreement with collection locations. (author)

  19. Implementasi Konsep Kecerdasan Buatan Dalam Rancang Bangun Game Brick Breaker

    OpenAIRE

    Ayuni, Wulan

    2011-01-01

    Games as a medium of entertainment has grown rapidly along with the development of technology as well. One of the elements that play an important role in a games is artificial intelligence. With artificial intelligence, expected elements in the games can act as natural as possible like human being. In this Brick Breaker games, the author apply the concept of fuzzy logic in determining the strength and agility of reflector board of the ball against the arrival of the ball. In designing of this...

  20. A continuous OSL scanning method for analysis of radiation depth-dose profiles in bricks

    DEFF Research Database (Denmark)

    Bøtter-Jensen, L.; Jungner, H.; Poolton, N.R.J.

    1995-01-01

    This article describes the development of a method for directly measuring radiation depth-dose profiles from brick, tile and porcelain cores, without the need for sample separation techniques. For the brick cores, examples are shown of the profiles generated by artificial irradiation using the...

  1. Use of Cement-Sand Admixture in Laterite Brick Production for Low Cost Housing

    Directory of Open Access Journals (Sweden)

    Isaac Olufemi AGBEDE

    2008-06-01

    Full Text Available Laterite was modified with 45% sand content by dry weight and stabilized with up to 9% cement content respectively and used in the production of 330 mm × 150 mm × 150 mm bricks through the application of a pressure of 3 N/mm2 with a brick moulding machine. Results showed that laterite used in this study cannot be stabilized for brick production within the economic cement content of 5% specified for use in Nigeria. However, bricks made with laterite admixed with 45% sand and 5% cement attained a compressive strength of 1.80 N/mm2 which is greater than the specified minimum strength value of 1.65 N/mm2. Cost comparison of available walling materials in Makurdi metropolis showed that the use of bricks made from 45% sand and 5% cement resulted in a saving of 30 - 47% when compared with the use of sandcrete blocks while the use of fired clay bricks resulted in a savings of 19% per square meter of wall. The study therefore recommends the use of laterite bricks in Makurdi and other locations because it is more economical and environmental friendly than fired clay bricks.

  2. Preparation and mechanism of the sintered bricks produced from Yellow River silt and red mud.

    Science.gov (United States)

    He, Hongtao; Yue, Qinyan; Su, Yuan; Gao, Baoyu; Gao, Yue; Wang, Jingzhou; Yu, Hui

    2012-02-15

    The preparation, characteristics and mechanisms of sintered bricks manufactured by Yellow River silt and red mud were studied. The sintering shrinkage, weight loss on ignition, water absorption and compressive strength were tested to determine the optimum preparation condition. Sintering mechanisms were discussed through linear regression analysis. Crystalline components of raw materials and bricks were analyzed by X-ray diffraction. Leaching toxicity of raw materials and bricks were measured according to sulphuric acid and nitric acid method. Radiation safety of the sintered bricks was characterized by calculating internal exposure index and external exposure index. The results showed that at the chosen best parameters (red mud content of 40%, sintering temperature of 1050°C and sintering time of 2h), the best characteristics of sintered bricks could be obtained. The weight loss on ignition of sintered bricks was principally caused by the removal of absorbed water and crystal water. The sintering shrinkage of sintered bricks mainly depended on sodium compounds and iron compounds of red mud. The sintering process made some components of raw materials transform into other crystals having better thermostability. Besides, the leaching toxicity and radioactivity index of sintered bricks produced under the optimum condition were all below standards. PMID:22192584

  3. Development and Application of Zero Expansion Silica Brick for Hot Repairing of Coke Oven

    Institute of Scientific and Technical Information of China (English)

    ZHANG Xiuqin; ZHI Xiaoming; WANG Hongmei

    2003-01-01

    In order to meet the needs of hot repairing technology of coke oven, the zero expansion silica brick with super properties has been developed, and the problem of poor thermal stability of common silica brick has been overcomned. This product can be directly used after being rapidly heated after construction. At present, it has been applied in coke ovens in Italy and Baosteel.

  4. 77 FR 70185 - Silica Bricks and Shapes From China; Institution of an Antidumping Duty Investigation and...

    Science.gov (United States)

    2012-11-23

    ..., 76 FR 61937 (Oct. 6, 2011) and the Commission's Handbook on Filing Procedures, 76 FR 62092 (Oct. 6... COMMISSION Silica Bricks and Shapes From China; Institution of an Antidumping Duty Investigation and... from China of silica bricks and shapes, provided for in subheading 6902.20.10 of the Harmonized...

  5. 75 FR 28237 - Certain Magnesia Carbon Bricks From the People's Republic of China: Notice of Preliminary...

    Science.gov (United States)

    2010-05-20

    ... Dumping, 75 FR 20335 (April19, 2010). \\3\\ See Certain Magnesia Carbon Bricks From China and Mexico...-468 and 731-TA-116667 (Preliminary) Certain Magnesia Carbon Bricks From China, 74 FR 49889 (September... Value, 75 FR 11847 (March 12, 2010) (``Preliminary Determination''). On April 21, 2010, the...

  6. 75 FR 56556 - Certain Magnesia Carbon Bricks From China and Mexico

    Science.gov (United States)

    2010-09-16

    ... Register of April 23, 2010 (75 FR 21346). The hearing was held in Washington, DC, on July 27, 2010, and all... COMMISSION Certain Magnesia Carbon Bricks From China and Mexico Determinations On the basis of the record \\1... from China and Mexico of certain magnesia carbon bricks, provided for in subheadings 6902.10.10,...

  7. 75 FR 4528 - Certain Magnesia Carbon Bricks From the People's Republic of China: Alignment of Final...

    Science.gov (United States)

    2010-01-28

    ... Carbon Bricks from the People's Republic of China: Initiation of Countervailing Duty Investigation, 74 FR... Bricks From the People's Republic of China: Preliminary Negative Countervailing Duty Determination, 74 FR... Mexico: Initiation of Antidumping Duty Investigations, 74 FR 42852 (August 25, 2009). The...

  8. Perceptions on Barriers to the Use of Burnt Clay Bricks for Housing Construction

    Directory of Open Access Journals (Sweden)

    Bernard K. Baiden

    2014-01-01

    Full Text Available Burnt clay bricks can be readily manufactured in Ghana as all ten regions have significant clay deposits with the Ashanti region having the highest estimated deposit of 37.1 million metric tonnes. In recent times, burnt clay bricks have been regarded as old fashioned and replaced by other perceived modern walling units within Kumasi, the metropolitan capital of Ashanti Region, despite its availability, unique advantages (aesthetics, low maintenance cost, etc., and structural and nonstructural properties. This study involved a questionnaire survey of 85 respondents made up of architects, brick manufacturing firms, and brick house owners or occupants in the Kumasi Metropolis of Ghana and sought to examine their perceptions on barriers to the use of burnt clay bricks for housing construction. The findings revealed that the key factors inhibiting the use of burnt clay bricks for housing construction are low material demand, excessive cost implications, inappropriate use in construction, noncompatibility of burnt clay bricks with other materials, unreliable production, and transportation problems. The findings however provide a platform for stakeholders to address the barriers to enable the extensive use of clay bricks in housing constructions.

  9. The gamma-ray and neutron shielding factors of fly-ash brick materials

    International Nuclear Information System (INIS)

    A comprehensive study of gamma-ray exposure build-up factors (EBFs) of fly-ash brick materials has been carried out for photon energies of 0.015–15 MeV up to a penetration depth of 40 mfp (mean free path) by a geometrical progression (GP) fitting method. The EBF values of the fly-ash brick materials were found to be dependent upon the photon energy, penetration depth and chemical composition, and were found to be higher than the values for mud bricks and common bricks. Above a photon energy of 3 MeV for large penetration depths (>10 mfp), the EBF becomes directly proportional to Zeq. EBFs of fly-ashes were found to be less than or equal to those of concrete for low penetration depths (<10 mfp) for intermediate photon energies up to 1.5 MeV. The EBF values of fly-ash materials were found to be almost independent of Si concentration. The fast neutron removal cross sections of the fly-ash brick materials, mud bricks and common bricks were also calculated to understand their shielding effectiveness. The shielding effectiveness of the fly-ash materials against gamma-ray radiation was lower than that of common and mud bricks. (paper)

  10. Investigation of gamma-ray activity and radiological hazards of the bricks fabricated around Lahore (Pakistan)

    International Nuclear Information System (INIS)

    Employing state of art measurement techniques and software, gamma ray activity due to /sup 224/Ra, /sup 232/Th and /sup 40/K have been measured from bricks fabricated around Lahore, Pakistan. External and internal hazards due to dose rate from radioactivity of bricks have calculated from several samples. (author)

  11. The gamma-ray and neutron shielding factors of fly-ash brick materials.

    Science.gov (United States)

    Singh, Vishwanath P; Badiger, N M

    2014-03-01

    A comprehensive study of gamma-ray exposure build-up factors (EBFs) of fly-ash brick materials has been carried out for photon energies of 0.015-15 MeV up to a penetration depth of 40 mfp (mean free path) by a geometrical progression (GP) fitting method. The EBF values of the fly-ash brick materials were found to be dependent upon the photon energy, penetration depth and chemical composition, and were found to be higher than the values for mud bricks and common bricks. Above a photon energy of 3 MeV for large penetration depths (>10 mfp), the EBF becomes directly proportional to Zeq. EBFs of fly-ashes were found to be less than or equal to those of concrete for low penetration depths (brick materials, mud bricks and common bricks were also calculated to understand their shielding effectiveness. The shielding effectiveness of the fly-ash materials against gamma-ray radiation was lower than that of common and mud bricks. PMID:24270465

  12. GPU-based simulations of fracture in idealized brick and mortar composites

    Science.gov (United States)

    William Pro, J.; Kwei Lim, Rone; Petzold, Linda R.; Utz, Marcel; Begley, Matthew R.

    2015-07-01

    Stiff ceramic platelets (or bricks) that are aligned and bonded to a second ductile phase with low volume fraction (mortar) are a promising pathway to produce stiff, high-toughness composites. For certain ranges of constituent properties, including those of some synthetic analogs to nacre, one can demonstrate that the deformation is dominated by relative brick motions. This paper describes simulations of fracture that explicitly track the motions of individual rigid bricks in an idealized microstructure; cohesive tractions acting between the bricks introduce elastic, plastic and rupture behaviors. Results are presented for the stresses and damage near macroscopic cracks with different brick orientations relative to the loading orientation. The anisotropic macroscopic initiation toughness is computed for small-scale yielding conditions and is shown to be independent of specimen geometry and loading configuration. The results are shown to be in agreement with previously published experiments on synthetic nacre.

  13. A new method to determine thermophysical properties of PCM-concrete brick

    DEFF Research Database (Denmark)

    Cheng, Rui; Pomianowski, Michal Zbigniew; Wang, Xin; Heiselberg, Per; Zhang, Yinping

    2013-01-01

    Accurate measurement of thermophysical properties of PCM-concrete brick is very important for simulation and evaluation of its energy saving performance. However, there is currently no effective way to accurately measure thermophysical properties of PCM-concrete brick. First we analyzed the...... shortcomings of using traditional testing methods to measure thermophysical properties of PCM-concrete brick. We then proposed a new method based on the inverse problem, which deals with the measurements of thermal conductivity and specific heat of PCM-concrete brick during the phase change process. The...... equivalent specific heat distributions of 4 wt% and 6 wt% PCM-concrete brick were determined using this method. We found that the accuracy (the relative error of the calculated cp based on the inverse problem and their real values ranges from 10.43% to 19.4%) was acceptable for engineering use. The...

  14. Spectroscopic investigation on the production of clay bricks with SCBA waste.

    Science.gov (United States)

    Viruthagiri, G; Sathiya priya, S; Shanmugam, N; Balaji, A; Balamurugan, K; Gopinathan, E

    2015-10-01

    In this paper, the effect of sugarcane bagasse ash (SCBA) addition to the brick making clay has been analyzed using spectroscopic techniques. For that, mixtures of brick making clay (BMC) with sugarcane bagasse ash (SCBA) in proportions of 0-20 wt.% were hydraulic uniaxially pressed and sintered at temperatures of 800-1100 °C. The partial replacement of the brick making clay with SCBA was studied with chemical and mineralogical analyzes (XRF and X-ray diffraction). The quantitative estimation of minerals was made by FTIR analysis. The results of FT-IR reveal that kaolinite, quartz, and lignin are predominant, whereas, cellulose and calcite are in moderate levels. In addition, magnetite and hematite are found in trace level. The overall results reveal that the brick making clay substituted with 15 wt.% of SCBA can open up a new path for the fabrication of quality bricks at low cost. PMID:25978014

  15. Lightweight Brick by Carbon Ash from The Mixed Plastic Waste Treatment Plant

    Directory of Open Access Journals (Sweden)

    Chen Kuo-Wei

    2016-01-01

    Full Text Available This study was designed to investigate the mixed plastic waste from the production of light carbon ash bricks performance. The mixed waste plastic pyrolysis process generated waste - Carbon ash. After extrusion, a Lightweight brick was made by carbon ash, additive and Cement mortar. In general, the set compressive strength and insulation effect of lightweight bricks with carbon ash proportion for significant impact. The set water absorption and thermal conductivity of lightweight bricks with carbon ash proportion for significant impact. The set density of lightweight brick ameliorates with M3824 additive and CM3 cement mortar for significant impact. Under conditions of technology and economic, the results of this study as reference for market-oriented marketing and commercialization of production.

  16. Reissner-Nordstrom Black Hole Entropy Inside and Outside the Brick Wall

    Institute of Scientific and Technical Information of China (English)

    刘文彪

    2003-01-01

    Applying the generalized uncertainty relation to the calculation of the free energy and entropy of a Reissner Nordstrom black hole inside the brick wall, the entropy proportional to the horizon area is derived from the contribution of the vicinity of the horizon. This is compared with the entropy calculated via the original brick wall model. The entropy given by the original brick wall model comes from the outside of the brick wall seemingly.The inside result using generalized uncertainty relation is similar to the outside result using original uncertainty relation, and the divergence inside the brick wall disappears. It is apparent that the cutoff is something related to the quantum theory of gravity.

  17. A Study on Electrically Conducting Magnesia—carbon Bricks for DC EAF

    Institute of Scientific and Technical Information of China (English)

    TONGXiaojun; YANLiyi; 等

    1998-01-01

    This paper gives a brief introduction to a kind of special refractories for DC EAF-electrically conducting magnesia-carbon bricks.The application of the conductive magnesia-carbon brick as a hearth electrode is a trend of development in DC arc furnace hearth bootom because of its features of anti corrosion and easy repatching,This is a proven process already available abroad.After a study of teh effect of different amount of graphite added and pretreating temperatures on the eletric-conductivity of magnesia-carbon bricks it has been found that for a balance between electric and thermal conductivities,the proper amount of graphite to be added should be 8%-14% and the pretreatment at temperature of 1300-1500℃ will result in the formation inside the magnesia-carbon bricks of a continuous three-dimensional network of graphite and semi-coke,thus making the brick conductive.

  18. Molecular mechanics of DNA bricks: in situ structure, mechanical properties and ionic conductivity

    Science.gov (United States)

    Slone, Scott Michael; Li, Chen-Yu; Yoo, Jejoong; Aksimentiev, Aleksei

    2016-05-01

    The DNA bricks method exploits self-assembly of short DNA fragments to produce custom three-dimensional objects with subnanometer precision. In contrast to DNA origami, the DNA brick method permits a variety of different structures to be realized using the same library of DNA strands. As a consequence of their design, however, assembled DNA brick structures have fewer interhelical connections in comparison to equivalent DNA origami structures. Although the overall shape of the DNA brick objects has been characterized and found to conform to the features of the target designs, the microscopic properties of DNA brick objects remain yet to be determined. Here, we use the all-atom molecular dynamics method to directly compare the structure, mechanical properties and ionic conductivity of DNA brick and DNA origami structures different only by internal connectivity of their consistituent DNA strands. In comparison to equivalent DNA origami structures, the DNA brick structures are found to be less rigid and less dense and have a larger cross-section area normal to the DNA helix direction. At the microscopic level, the junction in the DNA brick structures are found to be right-handed, similar to the structure of individual Holliday junctions (HJ) in solution, which contrasts with the left-handed structure of HJ in DNA origami. Subject to external electric field, a DNA brick plate is more leaky to ions than an equivalent DNA origami plate because of its lower density and larger cross-section area. Overall, our results indicate that the structures produced by the DNA brick method are fairly similar in their overall appearance to those created by the DNA origami method but are more compliant when subject to external forces, which likely is a consequence of their single crossover design.

  19. Integration and road tests of a self-sensing CNT concrete pavement system for traffic detection

    International Nuclear Information System (INIS)

    In this paper, a self-sensing carbon nanotube (CNT) concrete pavement system for traffic detection is proposed and tested in a roadway. Pre-cast and cast-in-place self-sensing CNT concrete sensors were simultaneously integrated into a controlled pavement test section at the Minnesota Road Research Facility (MnROAD), USA. Road tests of the system were conducted by using an MnROAD five-axle semi-trailer tractor truck and a van, respectively, both in the winter and summer. Test results show that the proposed self-sensing pavement system can accurately detect the passing of different vehicles under different vehicular speeds and test environments. These findings indicate that the developed self-sensing CNT concrete pavement system can achieve real-time vehicle flow detection with a high detection rate and a low false-alarm rate. (paper)

  20. TPF 5(063) "Improving the Quality of Pavement Profile Measurement" Update

    OpenAIRE

    Mikhail, Magdy

    2014-01-01

    Functional Session 1: Longitudinal Profile Moderated by Magdy Mikhail This presentation was held at the Pavement Evaluation 2014 Conference, which took place from September 15-18, 2014 in Blacksburg, Virginia. Presentation only

  1. Theoretical analysis of piezoelectric energy harvesting from traffic induced deformation of pavements

    Science.gov (United States)

    Xiang, H. J.; Wang, J. J.; Shi, Z. F.; Zhang, Z. W.

    2013-09-01

    The problem of energy harvesting using piezoelectric transducers for pavement system applications is formulated with a focus on moving vehicle excitations. The pavement behavior is described by an infinite Bernoulli-Euler beam subjected to a moving line load and resting on a Winkler foundation. A closed-form dynamic response of the pavement is determined by a Fourier transform and the residue theorem. The voltage and power outputs of the piezoelectric harvester embedded in the pavements are then obtained by the direct piezoelectric effect. A comprehensive parametric study is conducted to show the effect of damping, the Winkler modulus, and the velocity of moving vehicles on the voltage and power output of the piezoelectric harvester. It is found that the output increases sharply when the velocity of the vehicle is close to the so-called critical velocity.

  2. Integration and road tests of a self-sensing CNT concrete pavement system for traffic detection

    Science.gov (United States)

    Han, Baoguo; Zhang, Kun; Burnham, Tom; Kwon, Eil; Yu, Xun

    2013-01-01

    In this paper, a self-sensing carbon nanotube (CNT) concrete pavement system for traffic detection is proposed and tested in a roadway. Pre-cast and cast-in-place self-sensing CNT concrete sensors were simultaneously integrated into a controlled pavement test section at the Minnesota Road Research Facility (MnROAD), USA. Road tests of the system were conducted by using an MnROAD five-axle semi-trailer tractor truck and a van, respectively, both in the winter and summer. Test results show that the proposed self-sensing pavement system can accurately detect the passing of different vehicles under different vehicular speeds and test environments. These findings indicate that the developed self-sensing CNT concrete pavement system can achieve real-time vehicle flow detection with a high detection rate and a low false-alarm rate.

  3. The Comparison of Measured and Simulated Dynamic Responses of Vehicles Indicated by Road Pavement Unevenness

    Directory of Open Access Journals (Sweden)

    Decký Martin

    2015-05-01

    Full Text Available The article presents the comparison of measured and simulated dynamic responses of heavy vehicle which are indicated by road pavement unevenness. This unevenness was represented by speed control bumps, potholes and stochastic pavement unevenness. The objective simulations were realized through the medium Quarter- Car Simulation by means of application of simulated theory of dynamic systems. The reliability of used model was verificated with comparison of measured and simulated values of sprung mass T815 vehicle accelerations. In the article, there are presented courses of total vertical forces of Quarter-Car Simulation for the first, the second and the fourth classification degree of unevenness, which was considered through the world's respected parameter IRI (International Roughness Index. Obtained simulated dynamic effects of the vehicle on the pavement were used for modification of a relevant Slovak design method of asphalt pavements.

  4. 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

  5. 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.

  6. Contributions of performance-graded asphalt to low temperature cracking resistance of pavements. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Loh, S.W.; Olek, J.

    1999-05-01

    The purpose of this research was to study and evaluate the role that asphalt cracking. As part of the Strategic Highway Research Program (SHRP) new specifications for asphalt binders were developed that are based on the performance of the material. The asphalt binder graded and specified according to these new performance-based specifications is called PG binder. These new specifications are commonly referred to as Superpave (Superior Performing Asphalt Pavement) binder specifications. A section of Interstate 64 in southern Indiana was experiencing severe low temperature cracking before it was reconstructed over the summers of 1995 and 1996. The binder used in the new pavement mixes was PG material. Dynamic Shear Rheometer (DSR) tests, Bending Beam Rheometer (BBR) tests, and viscosity tests were performed on this binder. Comparisons were made between test results obtained from the binders in the old pavement and the new pavement. All tests and comparisons were based on the Superpave binder specifications.

  7. Development of Knowledge-Based Expert System for Flexible Pavement Design

    Directory of Open Access Journals (Sweden)

    Deprizon

    2009-01-01

    Full Text Available In this study, the knowledge-based expert system approach was used to design a programmer using shell expert system of KAPPA PC Version 2.4 that is object oriented and displaying higher graphic resolutions. The flexible pavement design based on the accumulation of knowledge from several experts, books and journals results in a modular approach. Normally, the process of flexible pavement design is done by experts. The process was computerized and apply artificial intelligent that is a new technology in providing a system that can design and give the suggestion for user to choices the best and economy of the thickness of pavement layers. The expert system was tested using several design calculation samples. From the test, the success is 100% for pavement design. The expert system has revealed satisfactorily findings in a faster layers design.

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

    Science.gov (United States)

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

  9. 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

    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 as a......The problem of stiffness degradation in composite pavement systems from localised fracture damage in the quasibrittle cement bound granular mixture are today taken into account only by empirical formulas. These formulas deals with a limited number of materials in a restricted range of design...... 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 be...

  10. Assessment of Clogging Dynamics in Permeable Pavement Systems with Time Domain Reflectometers

    Science.gov (United States)

    Infiltration is a primary functional mechanism in green infrastructure stormwater controls. This study used time domain reflectometers (TDRs) to measure spatial infiltration and assess clogging dynamics of permeable pavement systems in Edison, NJ, and Louisville, KY. In 2009, t...

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

    Directory of Open Access Journals (Sweden)

    Kundan Meshram

    2013-03-01

    Full Text Available EverFE is a user-friendly 3D finite-element analysis tool for simulating the response of jointed plain concrete pavement (JPCP systems to axle loads and environmental effects. EverFE is useful for both concrete pavement researchers and designers who must perform either complex nonlinear or simple linear stress analyses of JPCP.With help of this develop any type of model of rigid pavement considering practical condition thus getting more accurate and advance analysis for rigid pavement. It can also determine effective k-values for different combination of granular sub-base and dry lean concrete. A comparative study is done for two types of loading i.e. single and tandem axle. Edge and Corner stresses are also calculated for Class-AA of loading. Also calculate moment and shear force transfer by dowel bar by EverFE.

  12. INVESTIGATION OF THERMAL SHOCK BEHAVIOUR IN ALUMINA BASED REFRACTORY BRICKS

    Directory of Open Access Journals (Sweden)

    N. Sinan KÖKSAL

    2003-02-01

    Full Text Available cUnderstanding of mechanical and thermal properties of refractory bricks used in industry is an important aspect to determine appropriate operating conditions. In this study, commercial refractory materials used in the sector of iron steel 45 % and 80 % alumina (Al2O3 of content refractory bricks were investigated. To determinate thermal shock behavior and mechanical properties of samples, thermal shock tests were applied by quenching in the water at the temperature differences of 500, 700, 900 and 1000 0 C. Three point bending test was examined for changes occured in the microstructure of materials. The critical temperature difference, modulus of rupture (MOR, changes of elastic modulus (E, thermal shock parameters such as resistance to crack initiation (R and resistance to crack propagation (R''' were calculated. Not with thermal treatment samples was examined same properties in the room temperature and to compare results of tests. The critical temperature difference of materials was found to be about 600 0 C. Crack start from samples of edges, space of spilling grains and microcracks occured around grains and they cause a damage by connecting to each other.

  13. Utilizing wood wastes as reinforcement in wood cement composite bricks

    Directory of Open Access Journals (Sweden)

    Nusirat Aderinsola Sadiku

    2015-07-01

    Full Text Available This paper presents the research work undertaken to study the properties of Wood Cement Composite Bricks (WCCB from different wood wastes and cement / wood content. The WCBBs with nominal density of 1200 kg m-3 were produced from three tropical wood species and at varying cement and wood content of 2:1, 2.5:1 and 3:1 on a weight to weight basis. The properties evaluated were compressive strength, Ultra Pulse Velocity (UPV, water absorption (WA and thickness swelling (TS. The Compressive strength values ranged from 0.25 to 1.13 N mm-2 and UPV values ranged from 18753 to 49992 m s-1. The mean values of WA after 672 hours (28 days of water soaking of the WCCBs ranged from 9.50% to 47.13% where there were no noticeable change in the TS of the bricks. The observed density (OD ranged from 627 to 1159 kg m-3. A. zygia from the three wood/cement content were more dimensionally stable and better in compressive strength than the other two species where T. scleroxylon had the best performance in terms of UPV. All the properties improved with increasing cement content. WCCBs at 3.0:1 cement/wood content are suitable for structural application such as panelling, ceiling and partitioning

  14. Brick Walls for Black Holes in AdS/CFT

    CERN Document Server

    Iizuka, Norihiro

    2013-01-01

    We study the 't Hooft's brick wall model for black holes in a holographic context. The brick wall model suggests that without an appropriate near horizon IR cut-off, the free energy of the probe fields show the divergence due to the large degenerate states near the horizons. After studying the universal nature of the divergence in various holographic setting in various dimensions, we interpret the nature of the divergence in a holographic context. The free energy divergence is due to the large degeneracy and continuity of the low energy spectrum in the boundary theory at the deconfinement phase. These divergence and continuity should be removed by finite N effects, which make the spectrum discrete even at the deconfinement phase. On the other hand, in the bulk, these degenerate states are localized near the horizon, and the universal divergence of these degenerate states implies that the naive counting of the degrees of freedom in bulk should be modified once we take into account the non-perturbative quantum ...

  15. Brick walls for black holes in AdS/CFT

    Directory of Open Access Journals (Sweden)

    Norihiro Iizuka

    2015-06-01

    Full Text Available We study the 't Hooft's brick wall model for black holes in a holographic context. The brick wall model suggests that without an appropriate near horizon IR cut-off, the free energy of the probe fields shows the divergence due to the large degenerate states near the horizons. After studying the universal nature of the divergence in various holographic settings in various dimensions, we interpret the nature of the divergence in a holographic context. The free energy divergence is due to the large degeneracy and continuity of the low energy spectrum in the boundary theory at the deconfinement phase. These divergence and continuity should be removed by finite N effects, which make the spectrum discrete even at the deconfinement phase. On the other hand, in the bulk, these degenerate states are localized near the horizon, and the universal divergence of these degenerate states implies that the naive counting of the degrees of freedom in bulk should be modified once we take into account the non-perturbative quantum gravity effects near the horizon. Depending on the microscopic degrees of freedom, the position, where the effective field theory description to count the states breaks down, has different Planck scale dependence. It also implies the difficulty to have an electron like gauge-singlet elementary field in the boundary theory Lagrangian. These singlet fields are at most composite fields, because they show divergent free energy, suggesting a positive power of N at the deconfinement phase.

  16. Brick walls for black holes in AdS/CFT

    Energy Technology Data Exchange (ETDEWEB)

    Iizuka, Norihiro, E-mail: iizuka@yukawa.kyoto-u.ac.jp; Terashima, Seiji, E-mail: terasima@yukawa.kyoto-u.ac.jp

    2015-06-15

    We study the 't Hooft's brick wall model for black holes in a holographic context. The brick wall model suggests that without an appropriate near horizon IR cut-off, the free energy of the probe fields shows the divergence due to the large degenerate states near the horizons. After studying the universal nature of the divergence in various holographic settings in various dimensions, we interpret the nature of the divergence in a holographic context. The free energy divergence is due to the large degeneracy and continuity of the low energy spectrum in the boundary theory at the deconfinement phase. These divergence and continuity should be removed by finite N effects, which make the spectrum discrete even at the deconfinement phase. On the other hand, in the bulk, these degenerate states are localized near the horizon, and the universal divergence of these degenerate states implies that the naive counting of the degrees of freedom in bulk should be modified once we take into account the non-perturbative quantum gravity effects near the horizon. Depending on the microscopic degrees of freedom, the position, where the effective field theory description to count the states breaks down, has different Planck scale dependence. It also implies the difficulty to have an electron like gauge-singlet elementary field in the boundary theory Lagrangian. These singlet fields are at most composite fields, because they show divergent free energy, suggesting a positive power of N at the deconfinement phase.

  17. Brick walls for black holes in AdS/CFT

    Science.gov (United States)

    Iizuka, Norihiro; Terashima, Seiji

    2015-06-01

    We study the 't Hooft's brick wall model for black holes in a holographic context. The brick wall model suggests that without an appropriate near horizon IR cut-off, the free energy of the probe fields shows the divergence due to the large degenerate states near the horizons. After studying the universal nature of the divergence in various holographic settings in various dimensions, we interpret the nature of the divergence in a holographic context. The free energy divergence is due to the large degeneracy and continuity of the low energy spectrum in the boundary theory at the deconfinement phase. These divergence and continuity should be removed by finite N effects, which make the spectrum discrete even at the deconfinement phase. On the other hand, in the bulk, these degenerate states are localized near the horizon, and the universal divergence of these degenerate states implies that the naive counting of the degrees of freedom in bulk should be modified once we take into account the non-perturbative quantum gravity effects near the horizon. Depending on the microscopic degrees of freedom, the position, where the effective field theory description to count the states breaks down, has different Planck scale dependence. It also implies the difficulty to have an electron like gauge-singlet elementary field in the boundary theory Lagrangian. These singlet fields are at most composite fields, because they show divergent free energy, suggesting a positive power of N at the deconfinement phase.

  18. Process parameter optimization for fly ash brick by Taguchi method

    Directory of Open Access Journals (Sweden)

    Prabir Kumar Chaulia

    2008-06-01

    Full Text Available This paper presents the results of an experimental investigation carried out to optimize the mix proportions of the fly ash brick by Taguchi method of parameter design. The experiments have been designed using an L9 orthogonal array with four factors and three levels each. Small quantity of cement has been mixed as binding materials. Both cement and the fly ash used are indicated as binding material and water binder ratio has been considered as one of the control factors. So the effects of water/binder ratio, fly ash, coarse sand, and stone dust on the performance characteristic are analyzed using signal-to-noise ratios and mean response data. According to the results, water/binder ratio and stone dust play the significant role on the compressive strength of the brick. Furthermore, the estimated optimum values of the process parameters are corresponding to water/binder ratio of 0.4, fly ash of 39%, coarse sand of 24%, and stone dust of 30%. The mean value of optimal strength is predicted as 166.22 kg.cm-2 with a tolerance of ± 10.97 kg.cm-2. Confirmatory experimental result obtained for the optimum conditions is 160.17 kg.cm-2.

  19. Building the Platform of Digital Earth with Sphere Split Bricks

    Directory of Open Access Journals (Sweden)

    WANG Jinxin

    2015-06-01

    Full Text Available Discrete global grids, a modeling framework for big geo-spatial data, is always used to build the Digital Earth platform. Based on the sphere split bricks (Earth system spatial grids, it can not only build the true three-dimensional digital Earth model, but also can achieve integration, fusion, expression and application of the spatial data which locates on, under or above the Earth subsurface. The theoretical system of spheroid geodesic QTM octree grid is discussed, including the partition principle, analysis of grid geometry features and coding/ decoding method etc, and a prototype system of true-3D digital Earth platform with the sphere split bricks is developed. The functions of the system mainly include the arbitrary sphere segmentation and the visualization of physical models of underground, surface and aerial entities. Results show that the sphere geodesic QTM octree grid has many application advantages, such as simple subdivision rules, the grid system neat, clear geometric features, strong applicability etc. In particular, it can be extended to the ellipsoid, so it can be used for organization, management, integration and application of the global spatial big data.

  20. Brick walls for black holes in AdS/CFT

    International Nuclear Information System (INIS)

    We study the 't Hooft's brick wall model for black holes in a holographic context. The brick wall model suggests that without an appropriate near horizon IR cut-off, the free energy of the probe fields shows the divergence due to the large degenerate states near the horizons. After studying the universal nature of the divergence in various holographic settings in various dimensions, we interpret the nature of the divergence in a holographic context. The free energy divergence is due to the large degeneracy and continuity of the low energy spectrum in the boundary theory at the deconfinement phase. These divergence and continuity should be removed by finite N effects, which make the spectrum discrete even at the deconfinement phase. On the other hand, in the bulk, these degenerate states are localized near the horizon, and the universal divergence of these degenerate states implies that the naive counting of the degrees of freedom in bulk should be modified once we take into account the non-perturbative quantum gravity effects near the horizon. Depending on the microscopic degrees of freedom, the position, where the effective field theory description to count the states breaks down, has different Planck scale dependence. It also implies the difficulty to have an electron like gauge-singlet elementary field in the boundary theory Lagrangian. These singlet fields are at most composite fields, because they show divergent free energy, suggesting a positive power of N at the deconfinement phase

  1. Manufacture of sintered bricks of high density from beryllium oxide

    International Nuclear Information System (INIS)

    Beryllium oxide bricks of nuclear purity 100 x 100 x 50 and 100 x 100 x 100 mm of very high density (between 2.85 and 3.00) are manufactured by sintering under pressure in graphite moulds at temperatures between 1,750 and 1,850 deg. C, and under a pressure of 150 kg/cm2. The physico-chemical state of the saw material is of considerable importance with regard to the success of the sintering operation. In addition, a study of the sintering of a BeO mixture with 3 to 5 per cent of boron introduced in the form of boric acid, boron carbide or elementary boron shows that high densities can only be obtained by sintering under pressure. For technical reasons of manufacture, only the mixture based on boron carbide is used. The sintering is carried out in graphite moulds at 1500 deg. C under 150 kg/cm2 pressure, and bricks can be obtained with density between 2,85 and 2,90. Laboratory studies and the industrial manufacture of various sinters are described in detail. (author)

  2. 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

  3. Desert Pavement Process and Form: Modes and Scales of Landscape Stability and Instability in Arid Regions

    Science.gov (United States)

    Wells, Stephen G.; McFadden, Leslie D.; McDonald, Eric V.; Eppes, Martha C.; Young, Michael H.; Wood, Yvonne A.

    2014-05-01

    Desert pavements are recognized in arid landscapes around the world, developing via diminution of constructional/depositional landform relief and creating a 1-2 stone thick armor over a "stone free" layer. Surface exposure dating demonstrates that clasts forming the desert pavements are maintained at the land surface over hundreds of thousands of years, as aeolian fines are deposited on the land surface, transported into the underlying parent material and incorporated into accretionary soil horizons (e.g., the stone free or vesicular [Av] horizon). This surface armor provides long-term stability over extensive regions of the landscape. Over shorter time periods and at the landform-element scale, dynamic surficial processes (i.e., weathering, runoff) continue to modify the pavement form. Clast size reduction in comparison to underlying parent material, along with armoring and packing of clasts in pavements contribute to their persistence, and studies of crack orientations in pavement clasts indicate physical weathering and diminution of particle size are driven by diurnal solar insolation. Over geologic time, cracks form and propagate from tensile stresses related to temporal and spatial gradients in temperature that evolve and rotate in alignment with the sun's rays. Observed multimodal nature of crack orientations appear related to seasonally varying, latitude-dependent temperature fields resulting from solar angle and weather conditions. Surface properties and their underlying soil profiles vary across pavement surfaces, forming a landscape mosaic and controlling surface hydrology, ecosystem function and the ultimate life-cycle of arid landscapes. In areas of well-developed pavements, surface infiltration and soluble salt concentrations indicate that saturated hydraulic conductivity of Av horizons decline on progressively older alluvial fan surfaces. Field observations and measurements from well-developed desert pavement surfaces landforms also yield

  4. 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.

  5. Design of a sensor for asphalt pavement pressure field measurements

    Science.gov (United States)

    Liu, Hongyue; Liang, Dakai; Han, Xiaolin; Wang, Xiaogang

    2013-06-01

    From the sensitivity of the FBG center wavelength changing with strain changes on the surface, the design of a FBG strain-based asphalt pavement pressure sensor is described by designing a special FBG asphalt box-film packaging structure. The compactness and simplicity of the device are achieved by using the corresponding package obtained from common available asphalt. Numerical analysis and experimental results show that the response of the sensor has good regularity for a wide range of travel (0MPa to 5.3312MPa). In the load range, the FBG center wavelength increases from 1548.264nm to 1548.346nm which shows a good correspondence with loads. Linearity, travel and sensitivity are experimentally determined by different packaging parameters. A design chart that includes the travel (0MPa to 5.3312MPa) and the sensitivity (15.3812pm/MPa) is finally proposed.

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

    OpenAIRE

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

    2012-01-01

    The traffic volume and the number of heavy vehicles are growing enormously nowadays. There is a need for designing a durable asphalt pavement with innovative technologies. Pavement structures and materials with self healing and self repairing capability are believed to be very useful in such a system. This paper is aiming to understand the self healing behaviour through mechanical testing and finite element modelling. Instead of a complex and time consuming fatigue involved self healing inves...

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

    International Nuclear Information System (INIS)

    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

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

    OpenAIRE

    F Netterberg; Beer, M

    2012-01-01

    Weak layers, interlayers, laminations and/or interfaces in the upper structural layers of road pavements are specifically prohibited in most road-building specifications. However, such layers are extremely common and often lead to premature pavement distress. In Part 1 of this two-part set of papers, it is shown that from experience with heavy vehicle simulator (HVS) and dynamic cone penetrometer (DCP) testing, the presence of such layers and/or conditions at any depth in the structural layer...

  9. Long-Term Pavement Performance (LTPP) InfoPave: Extracting Practical Information out of the Data

    OpenAIRE

    Ahmad, Riaz; Daleiden, Jerome; Kargah-Ostadi, Nima

    2015-01-01

    Long-Term Pavement Performance (LTPP) InfoPave is the web interface for the world's largest pavement performance database. This web interface is being developed under the Federal Highway Administration (FHWA) LTPP program to achieve the strategic goal of utilizing LTPP data effectively. An effective web interface helps reach users crossing all levels of expertise and geographical boundaries and helps information sharing which adds value to tax payers' dollars. To overcome the hurdles for easy...

  10. The Effect of Alternative Heavy Truck Suspensions on Flexible Pavement Response

    OpenAIRE

    Hedrick, J. K.; Yi, K.

    1991-01-01

    In this paper, the dynamic effects of heavy vehicle suspensions are investigated by analyzing parametric studies performed using previously developed simulation tools. In particular, the truck simulation package, VESYM, and the flexible pavement simulation package. VESYS, are used to look at the influence of alternative suspension types, e.g., walking beam, leaf spring/short rocker, air spring and semi-active shock absorbers on pavement response. The intent of the study is to determi...

  11. The influence of recycled asphalt pavement on 20mm binder course mix performance

    OpenAIRE

    Tabakovic, Amir; Gibney, Amanda; Gilchrist, M. D.; McNally, Ciaran

    2006-01-01

    This paper presents the results of ongoing research on the mechanical performance of a 20mm binder course asphalt pavement mix incorporating recycled asphalt pavement (RAP). A series of binder course mixes were designed containing varying percentages of RAP. A mix made only from virgin material was selected as the control mix for the investigation. The effect of introducing RAP into the binder course mix was evaluated through a series of laboratory tests including the Marshall Test, Indire...

  12. Infrastructure Pavement Assessment & Management Applications Enabled by the Connected Vehicles Environment – Proof-of-Concept

    OpenAIRE

    Flintsch, Gerardo; Smith, Brian

    2015-01-01

    The objective of this project was to develop prototypes and conduct a field test of system level applications of a connected vehicle pavement condition measurement system. This allowed the research team to: (1) investigate different approaches to a connected vehicle pavement measurement system; and (2) determine the optimum procedures for collecting, processing, aggregating, and storing the data to support engineering and management decisions. The study found that roughness measures obtain...

  13. Calculating rutting of some thin flexible pavements from repeated load triaxial test data

    OpenAIRE

    Qiao, Yaning; Dawson, Andrew; Huvstig, Anders; Korkiala-Tanttu, Leena

    2015-01-01

    This paper describes parts of a Nordic pavement performance prediction model study (at the project level of the NordFoU project) where a material performance model, developed at VTT research centre in Finland, has been selected as a mean of calculating the permanently accumulated (plastic) deformation (i.e. rutting) of unbound granular materials (UGMs) in flexible pavements subjected to trafficking. The paper aims to assess the suitability of this VTT model application to Swedish roads compri...

  14. INVESTIGATION OF SKID RESISTANCE PROPERTIES OF AGGREGATES USED IN AFYONKARAHISAR CITY PAVEMENTS

    OpenAIRE

    Gürer, Cahit; AKBULUT, Hüseyin; ÇETİN, Sedat

    2007-01-01

    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 w...

  15. Assessing the Impacts of Pavement Surface Condition on the Performance of Signalized Intersections

    OpenAIRE

    Hussein, Nasreen A.; Hassan, Rayya A.; Evans, Robert

    2015-01-01

    Signalized intersections are one of the most dangerous places on the road network as they carry a very high crash risk. This may be exacerbated by inadequate pavement surface condition. The main objective of this study was to assess the effect of pavement surface condition (in terms of skid resistance, roughness and rutting) at intersections and approaches on users' safety. In particular, this paper studied the change in crash frequency for numerous signalized intersections before and after s...

  16. Determination Of Correlation Between Road Pavement Skid Resistance And Braking Deceleration

    OpenAIRE

    KOKOT, D; Rijavec, R.; Ambroz, M.

    2012-01-01

    There are many situations when road pavement surface skid resistance drops to unacceptable levels. Skid resistance is an essential pavement property for road safety, but drivers are not able to assess its degree by visual means, although in the end they must be able to stop their vehicles safely within the stopping sight distance. In our research normalized braking deceleration was related to SCRIMTEX SFC values and analyzed for different driving conditions (wet/dry), vehicle systems, skid re...

  17. Laser Scanning on Road Pavements: A New Approach for Characterizing Surface Texture

    OpenAIRE

    Gabriele Bitelli; Andrea Simone; Fabrizio Girardi; Claudio Lantieri

    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 experime...

  18. 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.

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

    OpenAIRE

    Sañudo Fontaneda, Luis Ángel; Charlesworth, Susanne M.; Castro Fresno, Daniel; Andrés Valeri, Valero Carlos Alessio; Rodríguez Hernández, 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 a...

  20. 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.

  1. Investigating In Situ Properties of Recycled Asphalt Pavement with Foamed Asphalt as Base Stabilizer

    OpenAIRE

    Antonis Kaltsounis; Vasilis Papavasiliou; Andreas Loizos; Christina Plati

    2010-01-01

    The objective of the present study was to conduct a comprehensive field experiment for the in situ assessment of in-depth recycled asphalt pavement using foamed asphalt as a stabilization treatment for base works. For this purpose Nondestructive Testing (NDT) data collected using the Falling Weight Deflectometer (FWD) and Ground Penetrating Radar (GPR) along a foamed asphalt recycled pavement section was thoroughly analysed. Critical issues including the stabilized material curing and the con...

  2. 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.

  3. Laboratory analysis of the infiltration capacity of interlocking concrete block pavements in car parks

    OpenAIRE

    Sañudo Fontaneda, Luis Ángel; Rodríguez Hernández, Jorge; Vega Zamanillo, Angel; Castro Fresno, Daniel

    2013-01-01

    Interlocking Concrete Block Pavements (ICBPs) have been widely used in car parks to reduce runoff. Researches have demonstrated that clogging is the most influential factor in the reduction of the infiltration capacity of this type of permeable pavement. Nevertheless, there is no laboratory study of the infiltration performance of ICBPs that combines clogging levels with variables related with the topography of car parks such as runoff surface length (RSL) and surface slope (SS). This paper s...

  4. Modelling of Mechanical Properties of Cement Concrete Incorporating Reclaimed Asphalt Pavement

    OpenAIRE

    MATHIAS, Vincent; SEDRAN, Thierry; De Larrard, François

    2009-01-01

    In many countries there is a trend to recycle wastes obtained during pavement maintenance or reconstruction, and to forbid the landfill of these products. Thus, in some circumstances it can be tempting to use reclaimed asphalt pavement (RAP) in new hydraulic concrete mixtures. This paper presents experimental data and modelling about the effect of RAP incorporation on cement concrete mechanical properties (compressive strength, tensile strengths and E-modulus). All these properties tend to de...

  5. Adaptive road crack detection system by pavement classification.

    Science.gov (United States)

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

    2011-01-01

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

  6. 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.

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

    Directory of Open Access Journals (Sweden)

    F Netterberg

    2012-04-01

    Full Text Available Weak layers, interlayers, laminations and/or interfaces in the upper structural layers of road pavements are specifically prohibited in most road-building specifications. However, such layers are extremely common and often lead to premature pavement distress. In Part 1 of this two-part set of papers, it is shown that from experience with heavy vehicle simulator (HVS and dynamic cone penetrometer (DCP testing, the presence of such layers and/or conditions at any depth in the structural layers of a flexible or semi-flexible pavement is far more deleterious than is commonly appreciated. In Part 2 the effects of these weak layers are further modelled and discussed using various examples based an HVS testing and mechanistic pavement analyses. In particular, a weak upper base course of a cemented pavement under a thin bituminous surfacing may lead to severe surfacing (and upper base failure within a matter of weeks to months after opening to traffic, not excluding failure even during construction. In this paper (Part 1, the causes of weak layers, interlayers, laminations and/or interfaces, together with simple methods for their detection during construction and analyses of their effects on the structural capacity of flexible and semi-rigid (cemented road pavements, are briefly discussed.

  8. Pavement response to vehicular loads: a mechanistic approach involving nondestructive evaluation techniques

    Science.gov (United States)

    Kennedy, James C., Jr.

    1996-11-01

    The need for effective design in the nation's highways is greater now, more than ever, due to shrinking funds for new construction and rehabilitation/maintenance practices and the need to preserve the lands that are not now part of the roadway system. Most of the nation's highways were constructed within the last 30 years and many of these are due for significant rehabilitation and even reconstruction. Thus, the need to infuse robust design methods into these rehabilitation and reconstruction strategies is paramount. Currently, methods for cost allocation for pavement rehabilitation/maintenance activities and pavement management estimations are based on empirical and semi- empirical founded predictions that come up short, particularly when the roadway i subjected to multi-axle, heavy weight vehicles. Additionally, materials currently used int he construction of the pavement structure do not always behave in an elastic manner and the ability to predict the pavement response in the presence of other than elastic material behavior is essential. Finally, prediction of pavement states of distress based on empirical methods and elastic material behavior are inadequate, particularly when heavy weight vehicular traffic is involved. This paper includes descriptions of the overall methodology for pavement design and the unique requirements for the design and implementation of the structural and environmental sensing elements. Description of the mechanistic aspects in the software for the structural and material models is discussed and comparison of predicted and field measured results are presented.

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

    Science.gov (United States)

    Liu, Xiaoyu; Cui, Qingbin; Schwartz, Charles

    2014-01-01

    Pavement rehabilitation is carbon intensive and the choice of pavement type is a critical factor in controlling greenhouse gas (GHG) emissions. The existing body of knowledge is not able to support decision-making on pavement choice due to a lack of consensus on the system boundaries, the functional units and the estimation periods. Excessive data requirements further inhibit the generalization of the existing methodologies for design evaluation at the early planning stage. This study proposes a practical life-cycle GHG estimation approach, which is arguably effective to benchmark pavement emissions given project bid tabulation. A set of case studies conducted for this study suggest that recycled asphalt pavement (e.g., foam stabilized base (FSB), and warm mix asphalt (WMA)) would prevent up to 50% of GHGs from the initial construction phase. However, from a life-cycle perspective, pavement emissions are dictated largely by the traffic characteristics and the analysis period for the use phase. The benefits from using recycled materials (e.g., FSB) are likely to diminish if the recycled products do not perform as well as those properly proportioned with less recycled materials, or if the recycled materials are locally unavailable. When the AADT reaches 10,000, use phase releases more than 97% of the life cycle emissions and the emissions difference among alternative designs will be within 1%. PMID:24333742

  10. 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, 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.

  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. 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. PMID:23434738

  13. 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.

  14. 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.

  15. 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.

  16. New Asphalt Pavement Failure Criterion Based on Unifi ed Strength Theory

    Institute of Scientific and Technical Information of China (English)

    YANG Qun; CHEN Lu; WANG Ping; DAI Jingwang

    2015-01-01

    This study aims to introduce an appropriate analytical method for asphalt pavement based upon unified strength theory (UST). The traditional maximum shear stress strength theory (MSST) cannot describe the marked difference between tension strength and compressive strength or variable intermediate principal stress, which significantly affects the geotechnical materials. Our studies try to find a new asphalt pavement failure criterion that considers the influence of both tension-compression strength ratio and intermediate principal stress of asphalt mixture. In order to select a suitable theory on pavement material, the UST is introduced and compared with the traditional theory. Results show that the tension-compression strength ratio of asphalt mixture, which is used as a material parameter, dramatically affects the stress and stress distribution law in pavement; the pavement stress level increases dramatically after considering the intermediate principal stresses. Therefore, the UST which considers both tension-compression strength ratio and intermediate principal stress is more in line with the material characteristics of asphalt pavement.

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

    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.

  18. Synthesis Study on Use of Concrete Recycled from Pavement and Building Rubble in the Indiana Highway System

    OpenAIRE

    Burke, Thomas T.; Cohen, Menashi D.; Scholer, Charles F.

    1992-01-01

    The demolition of buildings and highway pavements in the State of Indiana generates a considerable amount of waste materials. The disposal of these materials causes strain on the existing landfills which are rapidly approaching their full capacity. This study is a synthesis of the information on the use of concrete recycled from pavements and building rubble for use in the Indiana highway system. Test results have shown that recycled pavement concrete made chiefly from broken-up and crushed o...

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

    OpenAIRE

    Jorge Rodriguez-Hernandez; Valerio C. Andrés-Valeri; Miguel A. Calzada-Pérez; Ángel Vega-Zamanillo; Daniel Castro-Fresno

    2015-01-01

    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 asph...

  20. Traffic noise abatement : how different pavements, vehicle speeds and traffic densities affect annoyance levels

    OpenAIRE

    Freitas, Elisabete F.; Mendonça, Catarina; Santos, Jorge A.; Murteira, Carla; Ferreira, João Amaro Oliveira

    2012-01-01

    In this paper, annoyance ratings from traffic noise recorded on cobblestones, dense asphalt, and open asphalt rubber pavements are assessed with regard to car speeds and traffic den- sities. It was found that cobblestones pavements are the most annoying; also while open asphalt rubber pavement imposes less annoyance than dense asphalt it is not significantly different. Higher car speeds always lead to greater annoyance, as does higher traffic densi- ties. LAeq and LAmax correl...

  1. Evaluation of a new experimental test procedure to more accurately determine the surface infiltration rate of permeable pavement systems

    OpenAIRE

    Lucke, T.; Boogaard, F.; Van den Ven, F.

    2014-01-01

    Permeable pavements are specifically designed to promote the infiltration of stormwater through the paving surface in order to reduce run-off volumes and to improve water quality by removing sediment and other pollutants. However, research has shown that permeable pavements can become clogged over time and this reduces their infiltration capacity. In order to assess the infiltration of permeable pavements, a variety of infiltration test procedures have been utilised in the past. However, the ...

  2. The Contrivance of New Mud Bricks for Restoring and Preserving the Edfa Ancient Granary - Sohag, Egypt

    Directory of Open Access Journals (Sweden)

    Mohammed EL-GOHARY

    2012-06-01

    Full Text Available A mud brick functions as an element of masonry structures. Being an integral part of a wall mass, it must be understood structurally and chemically. The susceptibility of a mud brick to be affected by decay agents depends on the type of raw materials used, the methods of construction, location, the microclimatic conditions, the mechanical and microstructural characteristics of the mud brick itself. In this research, mineralogical composition and granulometric distribution of ancient mud bricks were studied by using some scientific techniques such as XRD, SEM and electrical mechanical sieves, to determine the main components and characteristics, which will serve as reference for the contrivance of new mud bricks. In addition, special knowledge of the physical properties of historic mud bricks were defined by some scientific techniques to get some information about their properties, such as density, porosity, water absorption and shrinkage. Furthermore, all of those characteristics were studied in two groups of new mud bricks, to determine their properties. Finally, ourresults proved that the 6th category in the 1st group and the 10th category in the 2nd group are the most appropriate types for restoring and preserving the studied monument, due to their good physical properties, morphological appearances and their suitable characteristics.

  3. Durability of fired clay bricks containing granite powder

    Directory of Open Access Journals (Sweden)

    Xavier, G. C.

    2012-06-01

    Full Text Available Over the past few decades, hundreds of papers have been published on the benefits of including rock powder as a raw material in fired clay brick manufacture. Very little has been written, however, about the durability and long-term behaviour of the final product. As a rule, the ceramic bricks used in construction in developing countries are fired at low temperatures, which detracts from their mechanical performance. This is particularly visible in harsh environmental conditions, where weathering causes severe deterioration. The present paper describes the impact of weathering on clay bricks containing from 0 to 10% granite powder, an industrial by-product. The specimens were fired at 500, 700 or 900 ºC and subsequently exposed to natural environmental conditions or accelerated laboratory weathering. Their physical and mechanical properties were evaluated to determine the effect of the composition of raw materials on fired clay product durability.

    En las últimas décadas se han publicado cientos de artículos sobre las ventajas de incluir polvo de roca como materia prima en la fabricación de los ladrillos cerámicos. Sin embargo, la durabilidad y el comportamiento a largo plazo del producto final han sido objeto de pocas investigaciones. Por lo general, los ladrillos cerámicos empleados en la construcción en los países en vías de desarrollo se cuecen a temperaturas bajas, lo que impide el desarrollo de sus propiedades mecánicas. Esto queda especialmente patente cuando las condiciones ambientales son severas, en cuyo caso la meteorización puede provocar un deterioro importante. En este artículo se describe el efecto de la meteorización en ladrillos cerámicos que incorporaban entre un 0 y un 10% de polvo de granito, que es un derivado industrial. Las probetas se cocieron a 500, 700 o 900 °C y luego se sometieron a condiciones ambientales naturales o a un proceso de laboratorio de meteorización acelerada. Se evaluaron sus

  4. Aerosol Radiative Forcing Estimates from South Asian Clay Brick Production Based on Direct Emission Measurements

    Science.gov (United States)

    Weyant, C.; Athalye, V.; Ragavan, S.; Rajarathnam, U.; Kr, B.; Lalchandani, D.; Maithel, S.; Malhotra, G.; Bhanware, P.; Thoa, V.; Phuong, N.; Baum, E.; Bond, T. C.

    2012-12-01

    About 150-200 billion clay bricks are produced in India every year. Most of these bricks are fired in small-scale traditional kilns that burn coal or biomass without pollution controls. Reddy and Venkataraman (2001) estimated that 8% of fossil fuel related PM2.5 emissions and 23% of black carbon emissions in India are released from brick production. Few direct emissions measurements have been done in this industry and black carbon emissions, in particular, have not been previously measured. In this study, 9 kilns representing five common brick kiln technologies were tested for aerosol properties and gaseous pollutant emissions, including optical scattering and absorption and thermal-optical OC/EC. Simple relationships are then used to estimate the radiative-forcing impact. Kiln design and fuel quality greatly affect the overall emission profiles and relative climate warming. Batch production kilns, such as the Downdraft kiln, produce the most PM2.5 (0.97 gPM2.5/fired brick) with an OC/EC fraction of 0.3. Vertical Shaft Brick kilns using internally mixed fuels produce the least PM (0.09 gPM2.5/kg fired brick) with the least EC (OC/EC = 16.5), but these kilns are expensive to implement and their use throughout Southern Asia is minimal. The most popular kiln in India, the Bull's Trench kiln, had fewer emissions per brick than the Downdraft kiln, but an even higher EC fraction (OC/EC = 0.05). The Zig-zag kiln is similar in structure to the Bull's Trench kiln, but the emission factors are significantly lower: 50% reduction for CO, 17% for PM2.5 and 60% for black carbon. This difference in emissions suggests that converting traditional Bull's Trench kilns into less polluting Zig-zag kilns would result in reduced atmospheric warming from brick production.

  5. Preparation and mechanism of the sintered bricks produced from Yellow River silt and red mud

    International Nuclear Information System (INIS)

    Highlights: ► The best condition was red mud content of 40% and sintering at 1050 °C for 2 h. ► Bricks’ weight loss was caused by the removal of absorbed water and crystal water. ► Bricks’ sintering shrinkage depended on the sodium and iron compounds of red mud. ► Sintering can strengthen bricks and decrease leaching concentration of toxic metal. - Abstract: The preparation, characteristics and mechanisms of sintered bricks manufactured by Yellow River silt and red mud were studied. The sintering shrinkage, weight loss on ignition, water absorption and compressive strength were tested to determine the optimum preparation condition. Sintering mechanisms were discussed through linear regression analysis. Crystalline components of raw materials and bricks were analyzed by X-ray diffraction. Leaching toxicity of raw materials and bricks were measured according to sulphuric acid and nitric acid method. Radiation safety of the sintered bricks was characterized by calculating internal exposure index and external exposure index. The results showed that at the chosen best parameters (red mud content of 40%, sintering temperature of 1050 °C and sintering time of 2 h), the best characteristics of sintered bricks could be obtained. The weight loss on ignition of sintered bricks was principally caused by the removal of absorbed water and crystal water. The sintering shrinkage of sintered bricks mainly depended on sodium compounds and iron compounds of red mud. The sintering process made some components of raw materials transform into other crystals having better thermostability. Besides, the leaching toxicity and radioactivity index of sintered bricks produced under the optimum condition were all below standards.

  6. Effects of impervious pavements on reducing runoff in an arid urban catchment

    Science.gov (United States)

    Epshtein, O.; Turnbull, L.; Earl, S.

    2011-12-01

    The progressive urbanization of US arid and semi-arid southwestern territories has transformed undeveloped aridlands into dynamic, radially expanding metropolitan centers. As these mature, infill development further reduces undeveloped area, inversely coupling surface imperviousness to infiltration rates, with a subsequent increase in runoff generation. Intensified runoff carries undesirable environmental consequences, magnifying urban flooding events and concentrations, transport, and propagation of contaminants. Pervious pavements offer one potential solution for decreased urban infiltration. At present, the application potential of pervious pavements as an effective urban infiltration management tool exceeds its exploitation. While entirely eliminating urban Total Impervious Area is not a feasible solution, pervious pavements significantly reduce Effective Impervious Area at costs competitive with traditional Best Management Practices. Previous research into pervious pavements has largely consisted of laboratory prototypes or small-scale field experiments, with a heavy bias towards parking lots. In this study we explore the effectiveness of pervious pavements in increasing infiltration, thus decreasing runoff volume during summer monsoonal and winter convective rainfall events in an 8 ha residential catchment in Scottsdale, Arizona. Analysis focuses on the interaction dynamics between surface area of pervious pavement application and its net effect on runoff response at the catchment level. Hydrological response was modeled using MAHLERAN (Model for Assessing Hillslope-Landscape Erosion, Runoff and Nutrients), a spatially explicit, event-based model, parameterized at a spatial resolution of 0.25 sq m. Data for model parameterization was obtained from analysis of aerial imagery and field-based monitoring of surface properties. The model was tested against measurements of flow at the catchment outlet for multiple rainfall events with total event rainfall ranging

  7. The Heat Transfer Coefficient of Recycled Concrete Bricks Combination with EPS Insulation Board Wall

    Directory of Open Access Journals (Sweden)

    Jianhua Li

    2015-01-01

    Full Text Available Four tectonic forms samples were conducted to test their heat transfer coefficients. By analyzing and comparing the test values and theoretical values of the heat transfer coefficient, a corrected-value calculation method for determining the heat transfer coefficient was proposed; the proposed method was proved to be reasonably correct. The results indicated that the recycled concrete brick wall heat transfer coefficient is higher than that of the clay brick wall, the heat transfer coefficient of recycled concrete brick wall could be effectively reduced when combined with the EPS insulation board, and the sandwich insulation type was better than that of external thermal insulation type.

  8. Dating bricks of the last two millennia from Newcastle upon Tyne: a preliminary study

    International Nuclear Information System (INIS)

    Bricks from a group of four independently dated late medieval buildings in Newcastle upon Tyne have been tested to establish their suitability for luminescence dating as part of a wider study of the dating of post-Roman and medieval brick buildings. The luminescence characteristics of quartz extracted from the bricks were determined using TL (210 deg. C peak) and OSL measurement procedures. Both TL and OSL measurement procedures based on SAR and SARA protocols were applied to determine the palaeodose. The luminescence dates for three sampled locations are in good agreement with the assigned architectural dates; the fourth appears to be older raising doubts concerning the architectural assessment of the sampled phase

  9. Utilization of mixed pond ash in integrated steel plant for manufacturing superior quality bricks

    Indian Academy of Sciences (India)

    Piyush Kant Pandey; Raj Kumar Agrawal

    2002-10-01

    Fly ash (FA) poses serious problems to the industries. Integrated steel plants generate huge quantity of FA from their captive power plants and other furnaces. This ash is generally disposed off in the ash ponds along with other sludges and residues of steel making operations. This changes the constitution of FA and makes the brick manufacturing difficult. This paper has attempted to devise the ways for the use of this mixed ash for manufacturing mixed ash clay bricks successfully. The bricks thus made are superior in structural and aesthetic qualities and portents huge saving in the manufacturing costs with better consumer response.

  10. The Effects of Non—Metal Additives on Hydration Reisitance of MgO—C Bricks

    Institute of Scientific and Technical Information of China (English)

    OUYAGNG; WANGRuikun; 等

    2000-01-01

    The general method of solving the problem of hydration of MgO-C brick is by adding with metal Si,Mg or compround metal additives,but metal additives have bad effect on the MgO-C brick,The test tried adding non-metal additives to matrix material.The results showed that a suitable amount of this kind of additives not only inhibits hydration of MgO-C brick and does not affect corrosion resistance and avoids thermal expansion,but also can improve oxidation resistance.

  11. Effects of occupational heat exposure on female brick workers in West Bengal, India

    OpenAIRE

    Sett, Moumita; Sahu, Subhashis

    2014-01-01

    Background: Manual brick-manufacturing units in India engage a large number of female workers on a daily-wage basis for a period of 8 months per year. There are two groups of female workers in the brickfields: the brick molders and the brick carriers. These brickfields are mostly unorganized, and the workers are exposed to extreme conditions such as very high seasonal heat. The present trend of increasing temperatures, as a result of global warming and climate change, will put an additional b...

  12. Characterization, reproduction and optimization of traditional adobe bricks

    Science.gov (United States)

    Ioannou, Ioannis; Eftychiou, Marina; Costi de Castrillo, Maria; Illampas, Rogiros

    2013-04-01

    Adobe bricks were first introduced 10-12,000 years ago. Extensive use of the material throughout the centuries has led to strong local traditions of building with earth and has established adobe masonry as an important feature of the international architectural heritage. Today, despite no longer being a prevalent building material, adobes are still in use, since a number of earthen structures survive worldwide. Furthermore, the simplicity, low cost and almost negligible embodied energy associated with the production of adobes, as well as their good thermal and acoustic properties, render them an attractive option for use in contemporary sustainable construction. Therefore, several ongoing research projects internationally investigate the physicochemical and mechanical properties of traditional adobe bricks and the design/production of optimized adobes, with improved characteristics, for use in contemporary architecture. Here, we present ongoing research on adobe bricks carried out in the framework of the project E& IXEIPH EI / POION/0609/41, which is co-funded by the European Regional Development Fund and the Republic of Cyprus, through the Cyprus Research Promotion Foundation. Our work focuses on the characterization of traditional adobes, their reproduction and optimization in the laboratory to produce materials with improved physicomechanical properties. Results up-to-date show that traditional adobes are mostly composed of random quantities of silt and clay. Calcite is also predominant in relevant X-ray diffraction analyses. The average capillary water absorption coefficient (measured against a saturated sponge surface) of samples collected from market suppliers rarely exceeds 1 mm/min1 -2, while their thermal conductivity is around 0.55 W/mK. The response of traditional adobes to compression is characterized by intense deformability. The average compressive strength recorded depends on the form of test specimen (cube, cylinder, prism). Samples with aspect

  13. A New Norisoprenoid and Other Compounds from Fuzhuan Brick Tea

    Directory of Open Access Journals (Sweden)

    Xiao-Chun Wan

    2012-03-01

    Full Text Available Fuzhuan brick tea, a kind of dark tea consumed mainly in the border regions of Southwestern and Northwestern China since the 1860s, is produced from the leaves of Camellia sinensis var. sinensis by microbial fermentation. From this special fermented tea, a new norisoprenoid, 3R,9R-oxido-5-megastigmene, was isolated, together with α-linolenic acid, strictin, isovitexin, astragalin, (+-catechin, (−-epicatechin, (−-epicatechin gallate, (+-gallocatechin, (−-epigallocatechin, (−-epigallocatechin gallate and gallic acid. The structures of the compounds were identified by spectroscopic means. The new compound didn’t show any inhibition activity against the tested enteric pathogenic microorganisms at a concentration of 800 μg/mL by the hole plate diffusion method.

  14. Influence of mixture composition on the noise and frictional characteristics of flexible pavements

    Science.gov (United States)

    Kowalski, Karol J.

    Both traffic noise and wet pavement-tire friction are mainly affected by the tire/pavement interaction. Existing laboratory test methods allow for evaluation of polishing resistance of the aggregates only. Currently, there is no generally accepted standardized laboratory test method to address noise related issues and the overall frictional properties of pavements (including macrotexture). In this research, which included both laboratory and field components, friction and noise properties of the flexible (asphalt) pavements were investigated. As a part of this study, a laboratory device to polish asphalt specimens was developed and the procedure to evaluate mixture frictional properties was proposed. Following this procedure, forty-six different Superpave mixtures (each utilizing a different aggregate blends), one stone matrix asphalt (SMA) mixture and one porous friction course (PFC) mixture were tested. Six of the above mixes (four Superpave mixtures, SMA mixture and PFC mixture) were selected for laboratory noise testing. This testing was performed using a one-of-a-kind tester called the Tire/Pavement Test Apparatus (TPTA). In addition, the field sections constructed using Superpave, SMA and PFC mixtures were also periodically tested for friction and noise. Field measurements included testing of total of 23 different asphalt and two concrete pavements. The field friction testing was performed using both portable CTM and DFT devices and the (ASTM E 274) locked wheel friction trailer. The laboratory friction testing was performed using CTM and DFT devices only. The results of both field and laboratory friction measurements were used to develop an International Friction Index (IFI)-based frictional requirement for laboratory friction measurements. The results collected in the course of the study indicate that the IFI-based flag values could be successfully used in place of SN-based flag values to characterize frictional characteristics of pavements.

  15. 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

  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. Anisotropy of Expansion Coefficient and Slag Resistance of Spinel Carbon Bricks

    Institute of Scientific and Technical Information of China (English)

    YANG Ding'ao; YUAN Shouqian; JIANG Mingxue; DONG Sunzhen; ZHAO Zijian

    2006-01-01

    Effects of the pressure direction on the thermal expansion and slag corrosion resistance were investigated and anisotropic microstructures of flaky graphite in spinel carbon bricks were examined. The experimental results show that slag corrosion velocities in the direction parallel to the pressure direction display a decrease of 34% compared to those in the vertical direction. Meantime, the linear expansion coefficient in the direction parallel to the pressure direction is 2.45 times as large as that in the vertical pressure direction. Slag corrosion velocities of spinel carbon bricks soaked in the AOD melting slag display a 46%-47% decrease compared to those of magnesia carbon bricks. The microstructure observation shows that spinel carbon bricks have a high degree of preferred orientation.

  18. Development and Application of High Quality Silica Brick for Coke Ovens

    Institute of Scientific and Technical Information of China (English)

    WANGHongmei; XIAOChangyu

    1998-01-01

    As coke oven becoming larger,silica brick for coke oven is required to be of high uqality,Luoyang Refractories(Grop)Co.Ltd.(LRCO) has re-searched the mineralizer which contains Ca2+,R+,Al3+,F-,emphatically and proposed the principle of composite mineralizer basd on the properties of raw materials used .High performance silia brick which is characterized by low thermal expansion rate,good high temperature properties,residual quartz<0.5%,true density 2.31,and high bulk density silica brick for carbonization room with apparent porosity 13% ,bulk density l.96 g/cm3 have been developed and produced successfully by LR-CO.The quality of the bricks has reached the inter-national advenced level.

  19. A view of microstructure with technological behavior of waste incorporated ceramic bricks.

    Science.gov (United States)

    Nirmala, G; Viruthagiri, G

    2015-01-25

    Production of ceramic bricks from mixtures of ceramic industry wastes (up to 50 wt%) from the area of Vriddhachalam, Cuddalore district, Tamilnadu, India and kaolinitic clay from Thiruvananthapuram district, Kerala were investigated. The firing behavior of the ceramic mixtures was studied by determining their changes in mineralogy and basic ceramic properties such as water absorption, porosity, compressive strength and firing shrinkage at temperatures ranging from 900 to 1200 °C in short firing cycles. The effect of the rejects addition gradually up to 50 wt% was analyzed with the variation of temperature on the mechanical properties and microstructure of the bricks. The highest compressive strength and lowest water absorption is observed for the sample with 40% rejects at 1100 °C which is supported by the results of SEM analysis. The resulting ceramic bricks exhibit features that suggest possibilities of using the ceramic rejects in the conventional brick making methods. PMID:25062052

  20. Speciation and bioaccessibility of mercury in adobe bricks and dirt floors in Huancavelica, Peru

    Science.gov (United States)

    Background: Huancavelica, Peru, a historic cinnabar refining site, is one of the most mercury (Hg) contaminated urban areas in the world. Residents’ exposures are amplified because residents build their adobe brick homes from contaminated soil. Objectives: The objectives of th...

  1. Engineering Properties of Locally Manufactured Burnt Brick Pavers for Agrarian and Rural Earth Roads

    Directory of Open Access Journals (Sweden)

    Emmanuel A. OkunadeBurnt brick pavers

    2008-01-01

    Full Text Available This study explored the possibility of employing burnt bricks produced locally by completely traditional methods as pavers on unpaved agrarian and rural earth roads in indigent communities. The pavers would eliminate the problems on such roads of being waterlogged and impassible during the rainy season months and those of environmental and health hazards from raised dust during the dry season months. Three clay soils were investigated in the Ado region of Western Nigeria. Burnt brick pavers were produced using entirely traditional methods readily available in the indigent and rural environments. The engineering properties of the brick pavers were determined and it was found that they satisfied the requirements stipulated by ASTM C 902 Specification for Pedestrian and Light Traffic Paving Brick, thus making them suitable for usage on the earth roads.

  2. Screening of waste for use in clay-based bricks in the Arctic

    DEFF Research Database (Denmark)

    Belmonte, Louise Josefine; Ottosen, Lisbeth M.; Kirkelund, Gunvor Marie;

    2014-01-01

    hazardous waste, municipal solid waste incineration (MSWI) ashes and minetailings from Greenland, were investigated in order to determine their potential suitability for incorporationin the production of clay-based bricks. Furthermore, the MSWI fly ash was subjected to two remediation techniques......Clay-based ceramics, such as bricks, are heterogeneous materials, which can incorporate raw materials ofwide ranging compositions, without impairing their technical properties (Dondi et al., 1997a,b). Due to thisability, bricks have become a popular material in waste management research worldwide...... and several studies have demonstrated that clay-based bricks and tiles can successfully accommodate waste types,such as incineration ashes, mine tailings and dredged harbour sediments (Zhang et al., 2011; Roy et al.,2007; Mezencevova et al., 2012). In the vulnerable Arctic environment, the impact of...

  3. A Review: Durability of Fired Clay Brick Masonry Wall due to Salt Attack

    Directory of Open Access Journals (Sweden)

    B.H. Abu Bakar

    2009-12-01

    Full Text Available This paper offers a review on durability of fired clay brick masonry wall due to salt attack. Durability of brick normally affected when an external masonry walls are exposed to aggressive environment. Masonry structures, when subjected to salt attack or exposed to aggressive environment during their service life may suffer degradation due to the formation of crystallization pressure as a result of the evaporation of soluble salt in clay masonry structures. The crystallization pressures produce normally higher than tensile stress of clay brick and sufficient to damage the masonry structures. The mechanism of salt attack must be prevented and addressed thoroughly in order to maintain the integrity and service life of masonry wall. Therefore, the summary of durability, factors, mechanism and main sources of salt attack on fired clay brick masonry walls are discussed.

  4. Several problems in survey of buildings finished with face brick in Saint-Petersburg

    Directory of Open Access Journals (Sweden)

    V.M. Ogorodnik

    2010-11-01

    Full Text Available The authors emphasize two types of brick walls defects: defects of mortar and defects of masonry stones. Causes of these defects are analysed, such as moisturing of masonry; material quality; quality of contractor work; project errors.

  5. Use of accelerated aging to predict behavior of recycled materials in concrete pavements. Physical and environmental comparison of laboratory-aged samples with field pavements

    Energy Technology Data Exchange (ETDEWEB)

    Van der Sloot, H.A. [ECN Clean Fossil Fuels, Petten (Netherlands); Eighmy, T.T.; Cook, R.A.; Gress, D.L.; Coviello, A.; Spear, J.C.M. [University of New Hampshire, Durham, NH (United States); Hover, K.; Pinto, R.; Hobbs, S. [Cornell University, Ithaca, NY (United States); Kosson, D.S.; Sanchez, F. [Vanderbilt University, Nashville, TN (United States); Korhonen, C. [US Army Corps of Engineers Cold Regions Research and Engineering Laboratory, Hanover, NH (United States); Simon, M. [Turner-Fairbank Highway Research Center, McLean, VA (United States)

    2002-11-01

    Future behavior of recycled materials in highway applications is often difficult to predict. Accelerated aging is one means of exploring the long-term physical and environmental performance. Coal fly ash (CFA), routinely used as a cementitious replacement in portland cement concrete pavement, was selected as a model system in an accelerated aging approach. US-20 near Fort Dodge, Iowa, was used as a source of field-aged pavement slab material and concrete mixture proportions. This pavement, constructed in 1987, experienced early failure and distress. The role of CFA, if any, in the failure is not known. Three types of accelerated aging treatments were chosen and applied on laboratory prisms made with the US-20 mixture proportions: arrhenius ageing (AA), cyclic loading, and freeze-thaw exposure. Physical and environmental response variables were used to examine the pavement slab and the aged laboratory prisms. The aging protocol affected both physical and chemical properties of the monoliths. It took about 9 months of elapsed time to age specimens to an equivalent age of about 4 years. The equivalent ages matched well with the time frame seen in the field for the onset of early distress. Most response variables for the aged laboratory prisms and the field samples were similar, suggesting that the aging method reasonably produced a pavement of similar age and distress. The AA treatment produced an unexpected loss of strength, suggesting that the accelerated aging promoted the onset of a deleterious reaction. Distinguishing the source of trace metals in leachates was difficult, for all components (CFA, aggregates, cement) had similar elemental compositions and leachability. The use of both physical and environmental response variables showed linkages between compressive strength, microcracking, fine pore structure, Cl diffusive leaching (efflux related to road slating that increases the concentration of Cl in the monolith), and Ca diffusive leaching (related to change

  6. Study of the geometry of a voided clay brick using rectangular perforations to optimize its thermal properties

    International Nuclear Information System (INIS)

    This study was undertaken to optimize the equivalent transmittance of a wall consisting of voided clay bricks using ceramic material Termoarcilla 29 ECO, complying with the Spanish UNE , European EN and international ISO standards. Various geometries were investigated for the bricks' cross sections, starting from a commercialized block and improvements in its thermal conductivity were studied by varying parameters such as a number of rows in the brick, the type of tongue and grooving and the alternation between contiguous rows in the brick. Simulations were made using a finite elements application . The conclusions of the study were that the thermal properties of a brick are improved by placing the perforations of the voids in a quincunx (in parallel rows, so that every hole is placed between those of the immediate rows, forming equilateral triangles) and that the greater the number of rows, the better the thermal behaviour. Further, if these perforations are extended to the tongue and groove area and a certain clearance is left between the tongue and groove of each brick, the wall's equivalent transmittance is reduced. - Highlights: → This study tries to optimize the equivalent transmittance of a wall of bricks. → Thermal properties of a brick are improved by placing the perforations in a quincunx. → If perforations are extended to the tongue the wall's transmittance is reduced. → A clearance left in the joint of the bricks, reduces the wall's transmittance. → A brick with 26 rows of rectangles with Ueq2-K is obtained.

  7. Hydrogen fluoride damage to vegetation from peri-urban brick kilns in Asia: A growing but unrecognised problem?

    International Nuclear Information System (INIS)

    The rapid urbanisation of many cities in south and south-east Asia has increased the demand for bricks, which are typically supplied from brick kilns in peri-urban areas. We report visible foliar damage to mango, apricot and plum trees in the vicinity of traditional Bull’s Trench brick kilns in Peshawar, Pakistan. Visible injury symptoms, hydrogen fluoride concentrations in air, and foliar fluoride concentrations were all greater in the vicinity of brick kilns than at more distant sites, indicating that fluoride emissions from brick kilns were the main cause of damage. Interviews with local farmers established the significant impact of this damage on their livelihoods. Since poorly regulated brick kilns are often found close to important peri-urban agricultural areas, we suggest that this may be a growing but unrecognised environmental problem in regions of Asia where emission control in brick kilns has not been improved. - Highlights: ► Demand for bricks is increasing in many parts of Asia. ► Fluoride emissions from brick kilns may pose a threat to peri-urban agriculture. ► We found extensive injury to fruit orchards close to brick kilns in Peshawar. ► Local farmers suffered large economic losses but did not identify brick kilns as a cause of this. ► The extent of crop damage from brick kilns with poor emission control in the region may not be fully recognised. - Hydrogen fluoride emissions from brick kilns may cause extensive but unrecognised damage to peri-urban crops in Asia.

  8. Road roughness evaluation using in-pavement strain sensors

    Science.gov (United States)

    Zhang, Zhiming; Deng, Fodan; Huang, Ying; Bridgelall, Raj

    2015-11-01

    The international roughness index (IRI) is a characterization of road roughness or ride quality that transportation agencies most often report. The prevalent method of acquiring IRI data requires instrumented vehicles and technicians with specialized training to interpret the results. The extensive labor and high cost requirements associated with the existing approaches limit data collection to at most once per year for portions of the national highway system. Agencies characterize roughness only for some secondary roads but much less frequently, such as once every five years, resulting in outdated roughness information. This research developed a real-time roughness evaluation approach that links the output of durable in-pavement strain sensors to prevailing indices that summarize road roughness. Field experiments validated the high consistency of the approach by showing that it is within 3.3% of relative IRI estimates. After their installation and calibration during road construction, the ruggedized strain sensors will report road roughness continuously. Thus, the solution will provide agencies a real-time roughness monitoring solution over the remaining service life of road assets.

  9. 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.

  10. Effects of conductive fillers on temperature distribution of asphalt pavements

    International Nuclear Information System (INIS)

    The sun provides a cheap and abundant source of clean and renewable energy. Solar cells have been used to capture this energy and generate electricity. A more useful form of the solar cell would be asphalt pavements, which get heated up by solar radiation. Graphite powders are utilized as thermal conductive fillers to make an asphalt collector conductive so as to improve the efficiency of the asphalt collector. Accounting for the important application conditions and evaluating the effects of the heat conductive materials and the solar energy absorbability of the conductive asphalt collector, a finite element model has been developed to predict temperature distributions in the conductive asphalt solar collector. In this study, an experimental validation exercise was conducted using the measured data taken from full-depth asphalt slabs. Validation results showed that the model can satisfactorily predict the temperature distributions in asphalt concrete slabs. The optimal depth is 25-50 mm for placing pipes that serve as the heat exchanger. Meanwhile, the effect of the surroundings on the solar energy potential of the asphalt collector was noticeable.

  11. 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.

  12. A real-time 3D scanning system for pavement distortion inspection

    International Nuclear Information System (INIS)

    Pavement distortions, such as rutting and shoving, are the common pavement distress problems that need to be inspected and repaired in a timely manner to ensure ride quality and traffic safety. This paper introduces a real-time, low-cost inspection system devoted to detecting these distress features using high-speed 3D transverse scanning techniques. The detection principle is the dynamic generation and characterization of the 3D pavement profile based on structured light triangulation. To improve the accuracy of the system, a multi-view coplanar scheme is employed in the calibration procedure so that more feature points can be used and distributed across the field of view of the camera. A sub-pixel line extraction method is applied for the laser stripe location, which includes filtering, edge detection and spline interpolation. The pavement transverse profile is then generated from the laser stripe curve and approximated by line segments. The second-order derivatives of the segment endpoints are used to identify the feature points of possible distortions. The system can output the real-time measurements and 3D visualization of rutting and shoving distress in a scanned pavement

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

    Science.gov (United States)

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

    2016-01-01

    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. PMID:27347987

  14. 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.

  15. 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. PMID:22049757

  16. 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.

  17. 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.

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

    Science.gov (United States)

    Van Metre, Peter C; Mahler, Barbara J; Wilson, Jennifer 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 SigmaPAH concentrations in dust from sealcoated and unsealcoated pavement are 2200 and 27 mg/kg, respectively. For three western cities, median SigmaPAH 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 dustfrom coal-tarsealcoated pavement and adjacent soils greatly exceed generic soil screening levels, suggesting that research on human-health risk is warranted. PMID:19209579

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

    Energy Technology Data Exchange (ETDEWEB)

    Peter C. Van Metre; Barbara J. Mahler; Jennifer T. Wilson [U.S. Geological Survey, Austin, TX (USA)

    2009-01-15

    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 {Sigma}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 SPAH concentrations in dust from sealcoated and unsealcoated pavement are 2200 and 27 mg/kg, respectively. For three western cities, median SPAH 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. 30 refs., 4 figs., 2 tabs.

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

    Science.gov (United States)

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

    2016-01-01

    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. PMID:27347987

  1. The Heat Transfer Coefficient of Recycled Concrete Bricks Combination with EPS Insulation Board Wall

    OpenAIRE

    Jianhua Li; Wanlin Cao

    2015-01-01

    Four tectonic forms samples were conducted to test their heat transfer coefficients. By analyzing and comparing the test values and theoretical values of the heat transfer coefficient, a corrected-value calculation method for determining the heat transfer coefficient was proposed; the proposed method was proved to be reasonably correct. The results indicated that the recycled concrete brick wall heat transfer coefficient is higher than that of the clay brick wall, the heat transfer coefficien...

  2. The quantitative estimation of the vulnerability of brick and concrete building impacted by debris flow

    OpenAIRE

    Zhang, J.; Guo, Z. X.; Wang, D; Qian, H.

    2015-01-01

    There is little historic data about the vulnerability of the damage elements in debris flow disaster in China. Therefore, it is difficult to estimate the vulnerability of debris flow quantitatively. This paper was devoted to the research of the vulnerability of brick and concrete building impacted by debris flow which widely existed in affected area. Under two assumptions, several prototype walls of brick and concrete were constructed to simulate the damaged...

  3. Biofouling Prevention of Ancient Brick Surfaces by TiO2-Based Nano-Coatings

    OpenAIRE

    Lorenzo Graziani; Marco D'Orazio

    2015-01-01

    Brick constitutes a significant part of the construction materials used in historic buildings around the world. This material was used in Architectural Heritage for structural scope, and even for building envelopes. Thus, components made of clay brick were subjected to weathering for a long time, and this causes their deterioration. One of the most important causes for deterioration is biodeterioration caused by algae and cyanobacteria. It compromises the aesthetical properties, and, at a lat...

  4. BRICKS WITH TOTAL REPLACEMENT OF CLAY BY FLY ASH MIXED WITH DIFFERENT MATERIALS

    Directory of Open Access Journals (Sweden)

    J.N Akhtar

    2011-10-01

    Full Text Available Fly ash is a powdery substance obtained from the dust collectors in the Thermal power plants that use coal as fuel. From the cement point of view the mineralogy of Fly ash is important as it contains 80% - 90% of glass. The impurities in coal-mostly clays, shale’s, limestone & dolomite; they cannot be burned so they turn up as ash. The Fly ash of class C category was used as a raw material to total replacement of clay for making Fly ash bricks. In present study the effect of Fly ash with high replacement of clay mixed with different materials werestudied at a constant percentage of cement i.e 10%. Three Categories of bricks were to be studied namely Plain Fly ash brick (FAB, Treated Fly ash brick (TFAB and Treated Fly ash stone dust brick (TFASDB.In all the above mentioned categories the quantity of Fly ash was kept constant as 80%. It is found that the compressivestrength of plain Fly ash brick (15FAB and Treated Fly ash brick (15TFAB was found to be higher with 5% coarse sand and 15% sand combination at 10% cement. The gain in strength continues for Treated Fly ash Stone dust Brick (10TFASDB and found to be higher with 10% stone dust and 10% sand combination. A variation in the quantity of Fly ash was also attempted and it was found that the 25TFASDB with 50% flyash, 25% stone dust and 25% sand combination at 10% cement achieved highest compressive strength.

  5. Design, Construction and Testing Of a Multipurpose Brick/Block Moulding Machine

    Directory of Open Access Journals (Sweden)

    S.O. Yakubu

    2015-02-01

    Full Text Available The provision of shelter is one the most basic demand of a Man all over the World. It is one the most important challenges a man faces in his life. The problem of good shelter varies from place to place. A good shelter provides, first and foremost Security and Privacy. In the developed world the problem is less pronounced, but in the developing nation like Nigeria, the problem of shelter is more pronounced. There is about eighteen (18 million housing units’ deficit in Nigeria. One of the most important materials used for building of a shelter is block/brick, but majority of the people cannot afford these materials (blocks or bricks due high cost. Therefore, the production of high quality and affordable blocks/bricks is paramount to solving housing problems in developing countries especially in Nigeria. Thus, this research focused on design construction and testing of a multipurpose machine that produces high quality blocks/bricks for low cost housing. That is, for low income communities/earners. The constructed motorized compressive earth brick (CEB/block making machine can produce on average a total of 2,215 bricks per day and 950 blocks per day. The cost of production of the machine was two hundred and eighty six thousand, eight hundred ninety (N286, 890.00 naira only. Whereas, the most common high-tech motorized CEB machine in Nigeria (Hydraform® with an average capacity of about 3,000 bricks per day costs about six million naira (N6,000,000.00K only. Thus, the machine is very affordable for small scale enterprise (SME. In other words, bricks or blocks produced by using this machine are relatively cheap and affordable for those in the rural areas and for low income earners.

  6. Thermal Performance of Hollow Clay Brick with Low Emissivity Treatment in Surface Enclosures

    OpenAIRE

    Roberto Fioretti; Paolo Principi

    2014-01-01

    External walls made with hollow clay brick or block are widely used for their thermal, acoustic and structural properties. However, the performance of the bricks frequently does not conform with the minimum legal requirements or the values required for high efficiency buildings, and for this reason, they need to be integrated with layers of thermal insulation. In this paper, the thermal behavior of hollow clay block with low emissivity treatment on the internal cavity surfaces has been invest...

  7. Engineering Properties of Locally Manufactured Burnt Brick Pavers for Agrarian and Rural Earth Roads

    OpenAIRE

    Emmanuel A. OkunadeBurnt brick pavers

    2008-01-01

    This study explored the possibility of employing burnt bricks produced locally by completely traditional methods as pavers on unpaved agrarian and rural earth roads in indigent communities. The pavers would eliminate the problems on such roads of being waterlogged and impassible during the rainy season months and those of environmental and health hazards from raised dust during the dry season months. Three clay soils were investigated in the Ado region of Western Nigeria. Burnt brick pavers w...

  8. Determine the Compressive Strength of Calcium Silicate Bricks by Combined Nondestructive Method

    OpenAIRE

    2014-01-01

    The paper deals with the application of combined nondestructive method for assessment of compressive strength of calcium silicate bricks. In this case, it is a combination of the rebound hammer method and ultrasonic pulse method. Calibration relationships for determining compressive strength of calcium silicate bricks obtained from nondestructive parameter testing for the combined method as well as for the L-type Schmidt rebound hammer and ultrasonic pulse method are quoted here. Calibration ...

  9. The Mechanical Strength Property of Brick Material and its Impact on the Processing Quality

    Institute of Scientific and Technical Information of China (English)

    LI Cui-ming; WANG Qi-chao; YANG Ping

    2011-01-01

    A large number of experiments have been done for analyzing the two important indicators -compressive strength and flexural strength, which affect computer numerical control (CNC) engraving material physical properties. Using Matlab for simulation experiment, the processing quality of different intensity brick materials is analyzed by the theory of fracture toughness. The result show that porosity is an important factor for engraving, and the research also provide a reference for further study which can improve the quality of brick carving.

  10. Basic Deformation Parameters of Solid Clay Bricks and Small Masonry Walls

    OpenAIRE

    P. Bouška; D. Pume

    2000-01-01

    The basic mechanical properties of clay brick masonry and its components were experimentally investigated in the laboratories of the Klokner Institute. The test specimens of masonry materials and the relevant mechanical properties have been identified in solid clay bricks and cement-lime mortar. The aim of the research activity was to study both the deformability of the prevailing type of clay masonry in the existing buildings, i.e. the masonry made from the solid clay units and the lim...

  11. 公路路面扩宽中新老路面拼接的施工技术%Construction Technology of New and Old Pavement Splicing in Highway Pavement Widening

    Institute of Scientific and Technical Information of China (English)

    涂序广

    2014-01-01

    本文首先分析公路旧路面中存在的病害,然后分析在新旧路面拼接前对旧路面的处理,最后分析新老路面拼接施工技术在公路路面扩宽中的应用,供相关人员参考。%This paper firstly analyzes the existing diseases in old highway pavement, then analyzes the treatment of old pav-ement before the splicing of old and new pavement, final y an-alyzes the application of construction technology of new and old pavement splicing in highway pavement widening, to pro-vide a reference for the related personnel.

  12. Preparation and characterization of regenerated MgO-CaO refractory bricks sintered under different atmospheres

    Institute of Scientific and Technical Information of China (English)

    Gui-bo Qiu; Chang-sheng Yue; Xiang Li; Min Guo; Mei Zhang

    2014-01-01

    Regenerated MgO–CaO brick samples containing 80wt%, 70wt%, and 60wt%MgO were prepared using spent MgO–CaO bricks and fused magnesia as raw materials and paraffin as a binder. The bricks were sintered at 1873 K for 2 h under an air atmosphere and under an isolating system. The microstructure, mechanical properties at room temperature, and hydration resistance of the regenerated samples were measured and compared. The results indicated that the isolating sintering generated a strongly reducing atmosphere as a result of the incomplete combustion of paraffin, and the partial oxygen pressure was approximately 6.68 × 10–7 Pa. The properties of the regenerated bricks sintered under air conditions were all higher than those of the bricks sintered under a reducing atmosphere. The deterioration of the bricks was a result of MgO reduction and a decrease in the amount of liquid phase formed during sintering under a reducing atmosphere.

  13. Control methods for strength of ceramic bricks in the inspection of buildings

    Directory of Open Access Journals (Sweden)

    Ulybin A.V.

    2012-05-01

    Full Text Available The paper brings up the problem of finding the most accurate, reliable and, at the same time, less time-consuming and relatively inexpensive method of determining strength of ceramic bricks. This task is particularly important in the context of the lack of standards governing the use of nondestructive testing methods for ceramic bricks, and the difficulties associated with sampling of ceramic brick masonry for standard tests.In the paper the possibility of determining the compressive strength of corpulent ceramic bricks by testing cylindrical samples taken from the body of masonry, is explored. The relation between standard samples tests results according to GOST standards № 8265-84 and testing of cylindrical samples is given.The experimental results for influence of the direction of kern selection (horizontally and vertically in reference to flat of brick on the strength is presented. The possibility of application of nondestructive testing methods for measuring strength of ceramic bricks is considered. Also the paper includes the examples of field and laboratory experiments.

  14. Recycling waste brick from construction and demolition of buildings as pozzolanic materials.

    Science.gov (United States)

    Lin, Kae-Long; Wu, Hsiu-Hsien; Shie, Je-Lueng; Hwang, Chao-Lung; An Cheng

    2010-07-01

    This investigation elucidates the pozzolic characteristics of pastes that contain waste brick from building construction and demolition wastes. The TCLP leaching concentrations of waste brick for the target cations or heavy metals were all lower than the current regulatory thresholds of the Taiwan EPA. Waste brick had a pozzolanic strength activity index of 107% after 28 days. It can be regarded as a strong pozzolanic material. The compressive strengths of waste brick blended cement (WBBC) that contain 10% waste brick increased from 71.2 MPa at 28 days to 75.1 MPa at 60 days, an increase of approximately 5% over that period. At 28 days, the pozzolanic reaction began, reducing the amount of Ca(OH)(2) and increasing the densification. The intensity of the peak at 3640 cm(- 1) associated with Ca(OH)(2) is approximately the same for ordinary Portland cement (OPC) pastes. The hydration products of all the samples yield characteristics peaks at 978 cm(-1) associated with C-S-H, and at ~3011 cm(-1) and 1640 cm(-1) associated with water. The samples yield peaks at 1112 cm(-1), revealing the formation of ettringite. In WBBC pastes, the ratio Q(2)/Q(1) increases with curing time. These results demonstrate that increasing the curing time increases the number of linear polysilicate anions in C-S-H. Experimental results reveal that waste brick has potential as a pozzolanic material in the partial replacement of cement. PMID:20154026

  15. Biocalcification using B. pasteurii for strengthening brick masonry civil engineering structures.

    Science.gov (United States)

    Raut, Supriya H; Sarode, D D; Lele, S S

    2014-01-01

    Microbiologically induced calcite precipitation in bricks by bacterium Bacillus pasteurii (NCIM 2477) using a media especially optimized for urease production (OptU) was demonstrated in this study. Effect of biocalcification activity on compressive strength and water absorption capacity of bricks was investigated. Various other parameters such as pH, growth profile, urease activity, urea breakdown and calcite precipitated were monitored during the 28 days curing period. Efficiency of B. pasteurii to form microbial aided calcite precipitate in OptU media resulted into 83.9% increase in strength of the bricks as compared to only 24.9% with standard media, nutrient broth (NB). In addition to significant increase in the compressive strength, bricks treated with B. pasteurii grown in OptU media resulted in 48.9 % reduction in water absorption capacity as compared to control bricks immersed in tap water. Thus it was successfully demonstrated that microbial calcification in optimized media by Bacillus pasteurii has good potential for commercial application to improve the life span of structures constructed with bricks, particularly structures of heritage importance. PMID:23884843

  16. 30 Years – 20 State DOTs: Trends in Pavement Management observed through real world Implementation at the State DOT Level

    OpenAIRE

    Zavitski, Jeffrey L.; Piane, Robert R.

    2013-01-01

    Since the first International Conference on Managing Pavement Assets 30 years ago in 1985, there has been continuous enhancement and evolution of pavement management system (PMS) technology to produce more effective recommendations coming out of an agency's PMS. Improvements in data collection, performance measures, deterioration modeling, dynamic segmentation, treatment algorithms, triggering mechanisms and optimization technologies have led to significant improvements in PMS strategy recomm...

  17. 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.

    2016-05-01

    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.

  18. Evaluation of a new experimental test procedure to more accurately determine the surface infiltration rate of permeable pavement systems

    NARCIS (Netherlands)

    Lucke, T.; Boogaard, F.; Van den Ven, F.

    2014-01-01

    Permeable pavements are specifically designed to promote the infiltration of stormwater through the paving surface in order to reduce run-off volumes and to improve water quality by removing sediment and other pollutants. However, research has shown that permeable pavements can become clogged over t

  19. 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

  20. Evaluating the Infiltration Performance of Eight Dutch Permeable Pavements Using a New Full-Scale Infiltration Testing Method

    Directory of Open Access Journals (Sweden)

    Floris Boogaard

    2014-07-01

    Full Text Available Permeable pavements are a type of sustainable urban drainage system (SUDS technique that are used around the world to infiltrate and treat urban stormwater runoff and to minimize runoff volumes. Urban stormwater runoff contains significant concentrations of suspended sediments that can cause clogging and reduce the infiltration capacity and effectiveness of permeable pavements. It is important for stormwater managers to be able to determine when the level of clogging has reached an unacceptable level, so that they can schedule maintenance or replacement activities as required. Newly-installed permeable pavements in the Netherlands must demonstrate a minimum infiltration capacity of 194 mm/h (540 l/s/ha. Other commonly used permeable pavement guidelines in the Netherlands recommend that maintenance is undertaken on permeable pavements when the infiltration falls below 0.50 m/d (20.8 mm/h. This study used a newly-developed, full-scale infiltration test procedure to evaluate the infiltration performance of eight permeable pavements in five municipalities that had been in service for over seven years in the Netherlands. The determined infiltration capacities vary between 29 and 342 mm/h. Two of the eight pavements show an infiltration capacity higher than 194 mm/h, and all infiltration capacities are higher than 20.8 mm/h. According to the guidelines, this suggests that none of the pavements tested in this study would require immediate maintenance.