WorldWideScience

Sample records for curing concrete pavements

  1. Concrete Pavement Joint Deterioration

    OpenAIRE

    2016-01-01

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

  2. Concrete Block Pavements

    Science.gov (United States)

    1983-03-01

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

  3. Pavement management and rehabilitation of portland cement concrete pavements

    Science.gov (United States)

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

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

  4. Precast Concrete Pavements

    Science.gov (United States)

    1981-11-01

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

  5. 水泥混凝土路面施工养护措施的可行性及有效性%Feasibility and Effectiveness of the Timely Curing Methods in Cement Concrete Pavement

    Institute of Scientific and Technical Information of China (English)

    于蕾; 张金喜

    2012-01-01

    系统研究了不同养护措施对水泥混凝土路面早期塑性收缩裂缝防治效果,对比分析了喷洒养护剂养护、覆盖遮盖物养护、混凝土上方喷雾养护、二次抹压养护等常用养护措施养护效果的优劣,总结了新浇筑混凝土路面的及时养护材料和施工方法,为水泥混凝土路面施工中有效抑制塑性收缩裂缝提供参考意见和建议.%Experiments are carried out to compare the feasibility and effectiveness of curing methods for preventing the early-age plastic shrinkage cracking of the cement concrete pavement.These methods include spraying concrete curing compound for curing,covering the awning for curing,spraying water mist over the pavement for curing,and smoothing the surface of the pavement multiply for curing.The effective curing materials and methods for preventing the early-age plastic shrinkage cracking of the cement concrete pavement are summarized.These curing materials and methods can offer references and advices for the units during construction.

  6. 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…

  7. 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…

  8. 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.

  9. Variation Of Characteristics Of Vibropressed Concrete Pavement Blocks

    Directory of Open Access Journals (Sweden)

    Skripkiūnas Gintautas

    2014-10-01

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

  10. Novel techniques for concrete curing

    DEFF Research Database (Denmark)

    Kovler, Konstantin; Jensen, Ole Mejlhede

    2005-01-01

    It is known that some high-strength/high-performance concretes (HSC/HPC) are prone to cracking at an early age unless special precautions are taken. The paper deals with the methods of curing as one of the main strategies to ensure good performance of concrete. Curing by both external (conventional......) and internal methods is reviewed and analyzed, among other methods of mitigating shrinkage and cracking of concrete. The focus is on the mitigation of autogenous shrinkage of low water to binder ratio (w/b) concrete by means of internal curing. The concepts of internal curing are based on using lightweight...... aggregate, superabsorbent polymers or water-soluble chemicals, which reduce water evaporation (so called "internal sealing"). These concepts have been intensively researched in the 90s, but still are not widespread among contractors and concrete suppliers. The differences between conventional methods...

  11. Curing of Concrete

    African Journals Online (AJOL)

    and pipes illustrate defects frequently caused by improper curing. Proper ... because in such pastes the layers of hydrated ... *3) When cement hydrates the solid products occupy a volume equal to the sum of volumes of anhydrous cement and.

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

    CSIR Research Space (South Africa)

    Perrie, BD

    2007-08-01

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

  13. Importance of dowels in transversal joints in concrete pavements

    Science.gov (United States)

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

    2017-09-01

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

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

    Directory of Open Access Journals (Sweden)

    Myle N. James

    2011-01-01

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

  15. Techniques for internal water curing of concrete

    DEFF Research Database (Denmark)

    Jensen, Ole Mejlhede; Pietro, Lura

    2003-01-01

    This paper gives an overview of different techniques for incorporation of internal curing water in concrete. Internal curing can be used to mitigate self-desiccation and self-desiccation shrinkage. Some concretes may need 50 kg/m3 of internal curing water for this purpose. The price of the internal...

  16. 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

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

    NARCIS (Netherlands)

    Huurman, M.

    1996-01-01

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

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

    CSIR Research Space (South Africa)

    Heath, AC

    2009-01-29

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

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

    Directory of Open Access Journals (Sweden)

    Ding Fei

    2017-01-01

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

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

    Science.gov (United States)

    Yoshitake, Isamu; Ishida, Takeo; Fukumoto, Sunao

    2015-08-21

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

  1. 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.

  2. 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.

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

    Science.gov (United States)

    Scholer, C. F.

    1980-12-01

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

  4. Precast concrete pavement – systems and performance review

    Science.gov (United States)

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

    2017-09-01

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

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

    NARCIS (Netherlands)

    Ren, D.

    2015-01-01

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

  6. 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

  7. 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

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

    DEFF Research Database (Denmark)

    Bendixen, Søren; Stang, Henrik

    1996-01-01

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

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

    National Research Council Canada - National Science Library

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

    2016-01-01

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

  10. Highly Conductive Carbon Fiber Reinforced Concrete for Icing Prevention and Curing

    Directory of Open Access Journals (Sweden)

    Oscar Galao

    2016-04-01

    Full Text Available This paper aims to study the feasibility of highly conductive carbon fiber reinforced concrete (CFRC as a self-heating material for ice formation prevention and curing in pavements. Tests were carried out in lab ambient conditions at different fixed voltages and then introduced in a freezer at −15 °C. The specimens inside the freezer were exposed to different fixed voltages when reaching +5 °C for prevention of icing and when reaching the temperature inside the freezer, i.e., −15 °C, for curing of icing. Results show that this concrete could act as a heating element in pavements with risk of ice formation, consuming a reasonable amount of energy for both anti-icing (prevention and deicing (curing, which could turn into an environmentally friendly and cost-effective deicing method.

  11. 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.

  12. EVALUATION OF TIRE RUBBER DISPOSAL IN CONCRETE FOR PAVEMENTS

    Directory of Open Access Journals (Sweden)

    Rosa Cristina Cecche Lintz

    2009-01-01

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

  13. Polypropylene Fibers in Portland Cement Concrete Pavements.

    Science.gov (United States)

    1992-08-01

    Bibliography on Fiber- Reinforced Cement and Concrete," Miscellaneous Paper C-76-6, with supplements 1, 2, 3, and 4 ( 1977 , 1979, 1980, and 1982), US Army... Mindess , S., Bentur, A., Yan, C., and Vondran, G., "Impact Resistance of Concrete Containing Both Conventional Steel Reinforcement and Fibrillated...Roads, Streets, Walks, and Open Storage Areas," TM 5-822-6/AFM 88-7, Chap. 7, Washington, DC, 1977 . 18. __ , "Concrete Floor Slabs on Grade Subjected

  14. 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.

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

    OpenAIRE

    1996-01-01

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

  16. 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

  17. Concrete Pavement Service Condition Assessment Using Infrared Thermography

    Directory of Open Access Journals (Sweden)

    Yang Lu

    2017-01-01

    Full Text Available Infrared thermography (IRT, an effective nondestructive testing method, is used to obtain an initial evaluation of the concrete pavement surface and near surface in a time effective manner. In this paper, the effect of the depth of delamination inside concrete pavement on infrared thermography technique is studied for bridge decks inspection. To be able to mimic the delamination in subsurface, two Styrofoam cubes have been inserted in different depth near the surface of the concrete cylinder. After heating up the specimen, thermal images were taken from the surface using an infrared thermal camera to evaluate the effect of subsurface defects on detection sensitivity and accuracy. We also investigated the precision to which the shape and the size of the subsurface anomalies can be perceived using an uncooled thermal camera. To achieve this goal, we used image processing technique to accurately compute the size of delamination in order to compare it with the actual size. In addition, distance/thermal graph is used to detect the presence of the defect underneath the concrete surface. Furthermore, thermal transfer modeling was adopted in this paper to assist the setup of this experiment and the results are compared with laboratory findings.

  18. Porous concrete mixtures for pervious urban pavements

    Directory of Open Access Journals (Sweden)

    Castro, J.

    2007-08-01

    Full Text Available The present study aimed to analyze the hydraulic and mechanical behaviour of a series of roller-compacted, laboratory porous concrete mixtures. The mix design variables examined were the actual void ratio in the hardened concrete and the water/cement ratio. From these results the better dosages from the mechanical and hydraulical behaviour point of view were determined. One of the designs developed was found to exhibit excellent hydraulic capacity and 20% greater strength than the mixtures recommended in the literature. Moreover, concrete with an actual void ratio of only 14% was observed to meet permeability requirements. Maximum flexural strength of concretes with different w/c ratios was achieved with a cement paste content of 250 l/m3. Relationships were found between the void ratio and both 28-day concrete permeability and flexural strength. Finally, the doses exhibiting the best mechanical and hydraulic performance were identified.El trabajo realizado en este estudio consistió en analizar el comportamiento de diferentes dosificaciones de mezclas de hormigón poroso, fabricadas en laboratorio y compactadas con rodillo pesado para simular las condiciones de terreno. Las variables consideradas para el diseño de las mezclas fueron el porcentaje real de huecos en el hormigón endurecido y la razón agua/cemento. A partir de estos resultados se determinaron las dosificaciones que presentan mejor comportamiento desde el punto de vista mecánico e hidráulico. Los resultados muestran que existe una dosificación de hormigón poroso, distinta a las encontradas actualmente en la literatura internacional, que permite obtener resistencias hasta 20% más altas, manteniendo todavía una excelente capacidad hidráulica. Se determinó que una permeabilidad suficiente se puede obtener con un porcentaje real de huecos de 14%, y que agregar pasta de cemento en una proporción de 250 l/m3 permite maximizar la resistencia a flexotracción de hormigones que

  19. SYSTEMATIC FORMULATION OF HIGH PERFORMANCE CONCRETE PAVEMENT

    Directory of Open Access Journals (Sweden)

    Salil Kumar Roy

    2005-01-01

    Full Text Available Following a 25-1 fractional factorial design concept, an experiment was planned ; sixteen experimental mixes were calculated from a basic mix (cement : sand : aggregates : fly ash = 1 : 1.3 : 2.6 : 0.8 and W/C ratio of 0.37 and determined changes (cement = 0.1 ; sand = 0.1 ; aggregates = 0.2 ; fly ash = 0.04 and changing W/C ratio by 0.01 using Taguchi’s orthogonal array. Samples were made from each data point. Compressive strength and water absorption were determined after each of two curing conditions (a 28 days in the water, (b 28 days in the water and 32 days in the air after that. Mix no 12 [Cement : Sand : Gravel : Fly Ash = 0.9 : 1.2 : 2.8 : 0.76] was found to have highest compressive strength and lowest water absorption.

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

    Science.gov (United States)

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

    1981-08-01

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

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

    Directory of Open Access Journals (Sweden)

    M. K. Pshembaev

    2015-01-01

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

  2. 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.

  3. Techniques and materials for internal water curing of concrete

    DEFF Research Database (Denmark)

    Jensen, Ole Mejlhede; Lura, Pietro

    2006-01-01

    This paper gives an overview of different techniques for incorporation of internal curing water in concrete. Internal water curing can be used to mitigate self-desiccation and selfdesiccation shrinkage. Some concretes may need 50 kg/m3 of internal curing water for this purpose. The price of the i...

  4. Deployment of Palmic Concrete Pavement Blocks in Light and Heavy Traffic Situations

    Directory of Open Access Journals (Sweden)

    Eric Ababio Ohemeng

    2015-04-01

    Full Text Available The main objective of this research was to investigate the viability of deploying palmic concrete pavement blocks (PCPBs in light and heavy traffic situations. The term “palmic concrete” refers to any concrete containing palm kernel shell and ordinary aggregates. In this study cement, fine aggregate, coarse aggregate and palm kernel shell (PKS were used. It was observed that density and strengths of the PCPBs decreased as the PKS content increased. Although, the strengths of the PCPBs lowered as the percentage of PKS increased, compressive strengths of 30.00 N/mm2 to 48.70 N/mm2 which are satisfactory for light traffic and heavy traffic situations could be achieved if 0% to 30% PKS contents are used. A model was also developed to predict the density of PCPBs through laboratory analysis. The model is only capable of predicting the density of palmic concrete products if the water cement ratio, the curing age, the aggregates cement ratio and the curing condition used are within the tested range.

  5. Development of various curing effect of nominal strength Geopolymer concrete

    Directory of Open Access Journals (Sweden)

    S. Kumaravel

    2014-04-01

    Full Text Available Geopolymer concrete is an innovative method and is produced by complete elimination of ordinary Portland cement byproduced in fly ash. This study on different condition of curing in geopolymer concrete suitable for curing at ambient and heat-cured condition of temperature will widen its application to concrete structures. Low lime fly ash is used as the base material, which is reacted by alkaline solution and additional use of ground granulated blast furnace slag. Workability of fresh concrete and compressive strength of geopolymer concrete was investigated. The curing effect of geopolymer concrete is steam, hot air and ambient cubes specimens are tested in different days. Results are compared for various curing and strength of concrete.

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

    Directory of Open Access Journals (Sweden)

    Malaiškienė Jurgita

    2014-12-01

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

  7. 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.

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

    OpenAIRE

    2014-01-01

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

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

    OpenAIRE

    2014-01-01

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

  10. Curing Methods and Their Effects on The Strength of Concrete

    OpenAIRE

    Nuruddeen Usman; Muhammad Nura Isa

    2015-01-01

    There are a lot of arguments on which method of curing concrete gives good strength. These different opinions results into this study, which aim at investigating the effects of different curing methods on the strength of concrete. Laboratory test was employed for this study. Normal concretes were prepared using specified mix ratio of 1:2:4 and 1:3:6. The cubes tested for compressive strength at 3, 7, 21, and 28 days of curing respectively using four curing methods namely immersion...

  11. Dynamic response of concrete pavement structure with asphalt isolating layer under moving loads

    Directory of Open Access Journals (Sweden)

    Jianmin Wu

    2014-12-01

    Full Text Available A three-dimensional finite element model (3D FEM is built using ABAQUS to analyze the dynamic response of a concrete pavement structure with an asphalt isolating layer under moving loads. The 3D model is prepared and validated in the state of no asphalt isolating layer. Stress and deflection at the critical load position are calculated by changing thickness, modulus of isolating layer and the combination between the isolating layer and concrete slab. Analysis result shows that the stress and deflection of the concrete slab increase with the increase of thickness. The stress and deflection of the concrete slab decrease with the increase of combination between the isolating layer and concrete slab. The influence of changing the isolating layer modulus to the stress and deflection of the concrete slab is not significant. From the results, asphalt isolating layer design is suggested in concrete pavement.

  12. Experimental observation of internal water curing of concrete

    DEFF Research Database (Denmark)

    Lura, Pietro; Jensen, Ole Mejlhede

    2007-01-01

    Internal water curing has a significant effect on concrete. In addition to affecting hydration and moisture distribution, it influences most concrete properties, such as strength, shrinkage, cracking, and durability. The following paper is an overview of experimental methods to study internal water...... curing of concrete and its consequences. The special techniques needed to study internal water curing are dealt with along with the consequences of this process. Examples of applications are given and new measuring techniques that may potentially be applied to this field are addressed....

  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

    2016-06-24

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

  14. Assessment of Curing Efficiency and Effect of Moist Curing on Performance of Fly Ash Concrete

    Institute of Scientific and Technical Information of China (English)

    LI Meili; QIAN Jueshi; WANG Lixia; XU Shanshan; JIA Xingwen; FAN Yunyan

    2011-01-01

    This study was conducted to evaluate the sensitivity of compressive strength,water permeability and electrical resistance of near-surface layer concrete with different fly ash contents to curing conditions. It is shown that the sensitivity to curing condition and fly ash content descends in the following order: difference between internal and surface resistivity (ρ)at 28 days, water permeability and compressive strength; both of longer duration of moist curing and use of fly ash in concrete enhanced the water penetration resistance. It is indicated that the resistivity difference p at 28 days can reflect accurately the curing history of fly ash concrete regardless of mix proportions; and use of fly ash in concrete requires longer moist curing duration.

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

    Science.gov (United States)

    Burke, Martin P., Jr.

    2001-08-01

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

  16. Fracture in high performance fibre reinforced concrete pavement materials

    CSIR Research Space (South Africa)

    Denneman, E

    2011-05-01

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

  17. Development of Geopolymer Concrete with Different Curing Conditions

    Directory of Open Access Journals (Sweden)

    M.F. Nuruddin Nuruddin

    2011-02-01

    Full Text Available Environmental issues resulted from cement production have become a major concern today. To develop a sustainable future it is encouraged to limit the use of this construction material that can affect the environment. Cement replacement material was proposed to partially replace cement portion in concrete. Geopolymer is a part of inorganic polymer material that has similar bonding function like cement in concrete. It consists of alkaline solutions and geological source material. Alkaline liquids used in this research are 8 M sodium hydroxide (NaOH solution and sodium silicate (Na2SiO3 solutions, while source materials are fly ash and microwave incinerated rice husk ash (MIRHA. Three different curing regimes, namely hot gunny curing, ambient curing, and external exposure curing, were applied to obtain suitable method that was suitable with cast in situ application. Geopolymer concrete samples were tested on their compressive strength and microstructure properties. It was found that external exposure curing had the highest compressive strength compared to other two curing methods. Scanning electron microscopy analysis also showed better improvement in interfacial transition zone for concrete sample with external exposure curing.

  18. Dataset of producing and curing concrete using domestic treated wastewater.

    Science.gov (United States)

    Asadollahfardi, Gholamreza; Delnavaz, Mohammad; Rashnoiee, Vahid; Fazeli, Alireza; Gonabadi, Navid

    2016-03-01

    We tested the setting time of cement, slump and compressive and tensile strength of 54 triplicate cubic samples and 9 cylindrical samples of concrete with and without a Super plasticizer admixture. We produced concrete samples made with drinking water and treated domestic wastewater containing 300, 400 kg/m(3) of cement before chlorination and then cured concrete samples made with drinking water and treated wastewater. Second, concrete samples made with 350 kg/m(3) of cement with a Superplasticizer admixture made with drinking water and treated wastewater and then cured with treated wastewater. The compressive strength of all the concrete samples made with treated wastewater had a high coefficient of determination with the control concrete samples. A 28-day tensile strength of all the samples was 96-100% of the tensile strength of the control samples and the setting time was reduced by 30 min which was consistent with a ASTMC191 standard. All samples produced and cured with treated waste water did not have a significant effect on water absorption, slump and surface electrical resistivity tests. However, compressive strength at 21 days of concrete samples using 300 kg/m(3) of cement in rapid freezing and thawing conditions was about 11% lower than concrete samples made with drinking water.

  19. Autogenous Deformation and Internal Curing of Concrete

    NARCIS (Netherlands)

    Lura, P.

    2003-01-01

    High-performance concrete (HPC) is generally characterized by a low water/binder ratio and by silica-fume addition, which guarantee a low porosity and a discontinuous capillary pore structure of the cement paste. Modern concretes possess some highly advantageous properties compared to traditional co

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

    Science.gov (United States)

    2007-04-01

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

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

    DEFF Research Database (Denmark)

    Skar, Asmus; Poulsen, Peter Noe

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

  2. The interaction between the atmosphere and curing concrete bridge decks

    Science.gov (United States)

    Wojcik, Gary S.

    The long-term durability of concrete can be compromised by excessive concrete temperatures or temperature gradients and lack of moisture during the first few days after placement. Because the concrete binder components undergo temperature-dependent hydration reactions during this period, atmospheric and construction conditions influence the ultimate concrete quality. To understand this interaction, curing concrete bridge energy balances were estimated with meteorological techniques and calorimetry and model experiments were performed. The agreement of concrete hydration heat estimates from the energy balances, calorimetry experiments, and model simulations validates our methodology and results. In Chapter 2, we estimate from meteorological measurements and techniques the energy balances of four curing concrete bridge decks. One challenge is to determine fluxes from small surfaces (largest horizontal dimension exchange coefficients for small areas is developed. Chapter 3, we improve with calorimetry experiments a simple bimolecular heat generation expression for hydrating binder. We show that this expression, with a new parameterization accounting for retarder effects on hydration rates, simulates temperatures to within 2°C and 72 h heat generation (˜265 kJ kg-1) to within 10% of the observed. In Chapter 4, we present models developed with the field and laboratory work and show that the highest concrete temperatures occur at high initial concrete temperatures and air temperatures and humidities, and at low wind speeds and cloud cover fractions. Peak bridge concrete temperatures can exceed 60°C. Large concrete temperature gradients (˜2°C cm-1 ) occur at the concrete top surface and the support beam top. An application of the 1D model with input from a weather forecast model predicts concrete temperatures within 2°C of the observed and so is a suitable operational model.

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

    Directory of Open Access Journals (Sweden)

    Stelios Kallis

    2011-07-01

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

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

    Institute of Scientific and Technical Information of China (English)

    王星茹

    2016-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Zheng LU

    2014-12-01

    Full Text Available 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 the compatibility condition at the interface of the structural layers. By introducing FFT (Fast Fourier Transform algorithm, some numerical results are presented. Comparisons of the theoretical and experimental result implied that the proposed method is reasonable in predicting the stress and displacement of a multi-layered pavement with bituminous or concrete materials. DOI: http://dx.doi.org/10.5755/j01.ms.20.4.6071

  6. Condition assessment of concrete pavements using both ground penetrating radar and stress-wave based techniques

    Science.gov (United States)

    Li, Mengxing; Anderson, Neil; Sneed, Lesley; Torgashov, Evgeniy

    2016-12-01

    Two stress-wave based techniques, ultrasonic surface wave (USW) and impact echo (IE), as well as ground penetrating radar (GPR) were used to assess the condition of a segment of concrete pavement that includes a layer of concrete, a granular base and their interface. Core specimens retrieved at multiple locations were used to confirm the accuracy and reliability of each non-destructive testing (NDT) result. Results from this study demonstrate that the GPR method is accurate for estimating the pavement thickness and locating separations (air voids) between the concrete and granular base layers. The USW method is a rapid way to estimate the in-situ elastic modulus (dynamic elastic modulus) of the concrete, however, the existence of air voids at the interface could potentially affect the accuracy and reliability of the USW test results. The estimation of the dynamic modulus and the P-wave velocity of concrete was improved when a shorter wavelength range (3 in. to 8.5 in.) corresponding to the concrete layer thickness was applied instead of the full wavelength rage (3 in. to 11 in.) based on the standard spacing of the receiver transducers. The IE method is proved to be fairly accurate in estimating the thickness of concrete pavements. However, the flexural mode vibration could affect the accuracy and reliability of the test results. Furthermore, the existence of air voids between the concrete and granular base layers could affect the estimation of the compression wave velocity of concrete when the full wavelength range was applied (3 in. to 11 in.). Future work is needed in order to improve the accuracy and reliability of both USW and IE test results.

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

    Directory of Open Access Journals (Sweden)

    Marcelo GONZALEZ

    2016-09-01

    Full Text Available This paper presents the feasibility of superhydrophobic films to create the nano-lotus leaf effect on concrete surface and their influence on sound absorption and friction properties of concrete for application in rigid pavements. The study involved an evaluation of nanomaterials at the laboratory scale to analyze the effects of microtexture modification on the friction and sound absorption of concrete pavement. A number of laboratory specimens were produced by applying different amounts of nano-lotus leaf coating on the top of the textured concrete surface. The British pendulum test was used to measure the friction number, and an impedance tube was used to determine the sound absorption coefficient. Laboratory results indicate that nano-lotus leaf coated concrete can maintain the required friction property for rigid pavement, but may not increase the noise absorption. Further research must be carried out to determine possible benefit of the lotus leaf effect for reducing hydroplaning, particularly during heavy rainfall.DOI: http://dx.doi.org/10.5755/j01.ms.22.3.7638

  8. The Use of Waste Plastic as a Partial Substitution Aggregate in Asphalt Concrete Pavement

    Directory of Open Access Journals (Sweden)

    Imam Aschuri

    2016-04-01

    Full Text Available As a developing country, Indonesia faces serious problems managing solid waste such as plastic. Annually, Indonesia produces approximately 5.4 million tons of waste plastic, accounting for 14% of the country’s total solid waste production. Using waste plastic as a partial substitution aggregate in asphalt concrete pavement would be one of solutions for reducing environmental problems from the high volume of waste plastic. Previous studies show that it may be possible to use waste plastic in road pavement to improve the engineering performance of road pavement and increase its service life. This study investigates the performance of asphalt concrete mixtures containing varying amounts of waste plastic as a partial aggregate substitution as compared to that of conventional mixtures. The waste plastic used in this study was chopped into small pieces of approximately passing sieve number 30 and retained sieve number 40, which would replace (by weight a portion of the mineral aggregates. All mixtures were prepared using 5.82% optimum bitumen content. The performance of asphalt concrete characteristics was studied using the Marshall test, The Indirect Tensile Strength (ITS test, The Indirect Tensile Stiffness Modulus (ITSM test, and the Cantabro Loss (CL test in terms of strength, stiffness modulus, and durability characteristics. In general, laboratory results showed that asphalt concrete mixtures containing waste plastic have higher performance than conventional asphalt concrete mixtures.

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

    Directory of Open Access Journals (Sweden)

    Marcelo GONZALEZ

    2016-09-01

    Full Text Available This paper presents the feasibility of superhydrophobic films to create the nano-lotus leaf effect on concrete surface and their influence on sound absorption and friction properties of concrete for application in rigid pavements. The study involved an evaluation of nanomaterials at the laboratory scale to analyze the effects of microtexture modification on the friction and sound absorption of concrete pavement. A number of laboratory specimens were produced by applying different amounts of nano-lotus leaf coating on the top of the textured concrete surface. The British pendulum test was used to measure the friction number, and an impedance tube was used to determine the sound absorption coefficient. Laboratory results indicate that nano-lotus leaf coated concrete can maintain the required friction property for rigid pavement, but may not increase the noise absorption. Further research must be carried out to determine possible benefit of the lotus leaf effect for reducing hydroplaning, particularly during heavy rainfall.DOI: http://dx.doi.org/10.5755/j01.ms.22.3.7638

  10. Effect of Nano Silica on the Physical Property of Porous Concrete Pavement

    Science.gov (United States)

    Yusak, Mohd Ibrahim Mohd; Ezree Abdullah, Mohd; Putra Jaya, Ramadhansyah; Rosli Hainin, Mohd; Ibrahim, Mohd Haziman Wan

    2017-08-01

    Rice husk can be categorized as an organic waste material from paddy industries. Silica is a major inorganic element of the rice husk. The aim of present study is to evaluate the effect of Nano silica on the physical properties of porous concrete pavement. Rice husk has been burned in the furnace (650°C for 6 hours) and ground for four different grinding times (33, 48, 63 and 81 hours). Five types of mixes were prepared to evaluate the different Nano silica grinding time. A Nano silica dosage of 10% by weight of binder was used throughout the experiments. The physical properties were examined through compressive strength, transmission electron microscopy and x-ray fluorescence. The experimental results indicate that the different Nano size gives a different effect to porous concrete strength. Based on the results obtained, Nano silica ground for 63 hours (65.84nm) gives the best result and performance to porous concrete pavement specimens.

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

    Science.gov (United States)

    Janků, Michal; Stryk, Josef

    2017-09-01

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

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

    Directory of Open Access Journals (Sweden)

    Matić Bojan J.

    2016-01-01

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

  13. Assessment of Asphalt Concrete Reinforcement Grid in Flexible Pavements

    Science.gov (United States)

    2016-05-01

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

  14. 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.

  15. The Effect of Temperature Curing on Geopolymer Concrete

    Directory of Open Access Journals (Sweden)

    Triwulan

    2017-01-01

    Full Text Available This study presents curing temperature influences to behaviors of geopolymer concrete. The concrete was fly ash based, with the ratio of fly ash to alkaline activator was 65%:35%. Ratio coarse aggregate to fine aggregate was 60%:40%, ratios Na2SiO3/NaOH were 1.5:2 and 2.5. A polycarboxilate superplasticizer with ratio was 2% to fly ash weight. Form of the test specimens were cylinder with diameter of 10 cm and 20 cm high. Steam curing conducted were at 40°C, 60°C and 80°C for 24 hours. The control specimens were treated at normal moist curing. Tests conducted were compressive strength, tensile strength, porosity and elasticity modulus. The results indicated that at the elevated temperature the compressive strength increases as well as tensile strength but decreases the closed porosity of specimens. The elasticity modulus had a similar tendency.

  16. Using Recycled Glass and Zeolite in Concrete Pavement to Mitigate Heat Island and Reduce Thermal Cracks

    Directory of Open Access Journals (Sweden)

    Erhan Burak Pancar

    2016-01-01

    Full Text Available Urban heat island (UHI effect is built environmental issue related to pavements. It is desired to reduce pavement high surface temperature in summer to mitigate UHI effect. High surface temperature also affects slab temperature difference (the top surface temperature minus the bottom surface temperature of the slab. The increased slab temperature difference induces a high possibility of cracking in concrete roads. The prime aim of this study was to reduce the slab surface temperature by using recycled glass as a fine aggregate and zeolite as cement in concrete. Recycled glass was used to replace fine aggregate in proportions of 10%, 20%, and 30% by total weight of aggregate. Zeolite replaced Portland cement in proportions of 10% and 30% for three different proportions of recycled glass concrete mixtures. Optimum proportions were determined by examining mechanical properties of samples and alkali-silica reactions. It was noticed that using recycled glass and zeolite together in concrete reduces pavement surface temperature and temperature gradient in summer.

  17. Factors affecting the deterioration of concrete pavement slabs

    Directory of Open Access Journals (Sweden)

    N.M. Morozov

    2015-11-01

    Full Text Available The behavior of constructions under actual operating conditions is affected by exposure to the environment. It is important that concrete roads and airport pavings are resistant not only to mechanical damage, but also to the effects of alternate freezing and thawing. The causes of early failure in concrete have been shown using prefabricated road slabs as an example. The causes of loss of performance properties of the roadway have been established, which are primarily dependent on the quality of raw materials in the concrete. It was found that, aside from durability, uniformity and porosity are important factors in determining the frost resistance of concrete roadways. It was shown that high aluminate content in the cement leads to concrete destruction in the first year of structure use. The results may also indirectly indicate a violation of forming technology during slab production.

  18. Studies on Scrap Tyre Added Concrete for Rigid Pavements

    OpenAIRE

    Eldhose C.; Dr. Soosan T. G

    2014-01-01

    Waste tyre treatment is now global threat. Waste tyre dumping, disposal of these materials or burning these tyres cause serious environmental and health problems. This paper investigate the wide range of physical and mechanical properties of concrete containing waste tyre aggregates and assess its suitability as a construction material. Waste tyres are powdered into fine particles of various sizes and are used to replace the fine aggregate used in concrete. The fine scrap...

  19. Criteria for asphalt-rubber concrete in civil airport pavements: Mixture design

    Science.gov (United States)

    Roberts, F. L.; Lytton, R. L.; Hoyt, D.

    1986-07-01

    A mixture design procedure is developed to allow the use of asphalt-rubber binders in concrete for flexible airport pavement. The asphalt-rubber is produced by reacting asphalt with ground, scrap tire rubber to produce the binder for the asphalt-rubber concrete. Procedures for laboratory preparation of alsphalt-rubber binders using an equipment setup that was found by researchers to produce laboratory binders with similar properties to field processes are included. The rubber-asphalt concrete mixture design procedure includes adjustments to the aggregate gradation to permit space for the rubber particles in the asphalt-rubber binder as well as suggested mixing and compaction temperatures, and compaction efforts. While the procedure was used in the laboratory to successfully produce asphalt-rubber concrete mixtures, it should be evaluated in the field to ensure that consistent results can be achieved in a production environment.

  20. Laboratory Analysis of Fly Ash Mix Cement Concrete for Rigid Pavement.

    Directory of Open Access Journals (Sweden)

    Er.Amit Kumar Ahirwar

    2015-02-01

    Full Text Available This experiment was conducted to investigate the engineering properties of fly ash cement concrete for rigid pavement construction. Results have shown that 30% of fly ash and 70% of cement has a superior performance. In addition, the use of fly ash would result in reduction of the cost of cement which is usually expensive in all construction materials. High strength of concrete can be made by this and the further integration of admixture or alternate adds to improve the properties of concrete. Test result of specimens indicates that the workability and strength chacteristcs are changed due to incorporation with fly ash. Slump test having an appropriate workable mix of a concrete, gave sufficient compressive strength and flexural strength. Test results of 28 days specimens have graphically interpolated for the different results and so that to calculate the optimum content of fly ash.

  1. Mechanical and Permeability Characteristics of Latex-Modified Pre-Packed Pavement Repair Concrete as a Function of the Rapid-Set Binder Content

    Directory of Open Access Journals (Sweden)

    Jae-Woong Han

    2015-10-01

    Full Text Available We evaluated the strength and durability characteristics of latex-polymer-modified, pre-packed pavement repair concrete (LMPPRC with a rapid-set binder. The rapid-set binder was a mixture of rapid-set cement and silica sand, where the fluidity was controlled using a latex polymer. The resulting mix exhibited a compressive strength of ¥21 MPa and a flexural strength of ¥3.5 MPa after 4 h of curing (i.e., the traffic opening term for emergency repairs of pavement. The ratio of latex polymer to rapid-set binder material was varied through 0.40, 0.33, 0.29, and 0.25. Mechanical characterization revealed that the mechanical performance, permeability, and impact resistance increased as the ratio of latex polymer to rapid-set binder decreased. The mixture exhibited a compressive strength of ¥21 MPa after 4 h when the ratio of latex polymer to rapid-set binder material was ¤0.29. The mixture exhibited a flexural strength of ¥3.5 MPa after 4 h when the ratio of latex polymer to rapid-set binder material was ¤0.33. The permeability resistance to chloride ions satisfied 2000 C after 7 days of curing for all ratios. The ratio of latex polymer to rapid-set binder material that satisfied all conditions for emergency pavement repair was ¤0.29.

  2. Cement treated recycled crushed concrete and masonry aggregates for pavements

    NARCIS (Netherlands)

    Xuan, D.X.

    2012-01-01

    This research is focusing on the characterization of the mechanical and deformation properties of cement treated mixtures made of recycled concrete and masonry aggregates (CTMiGr) in relation to their mixture variables. An extensive laboratory investigation was carried out, in which the mechanical p

  3. Differences in Infiltration and Evaporation of Diesel and Gasoline Droplets Spilled onto Concrete Pavement

    Directory of Open Access Journals (Sweden)

    Bernat Adrià Mora

    2017-07-01

    Full Text Available Pollution at gas stations due to small spills that occur during vehicle refueling have received little attention. We have performed laboratory experiments to assess evaporation and infiltration of fuel spilled onto concrete. Changes in the concrete mass after small amounts of diesel and gasoline were spilled have been analyzed. Variation in humidity, among other parameters, clearly affects the measured mass since condensed water is constantly added to or released from the concrete. This mass experiences an about exponential decay in time. The difference in behavior between both fuel types is important as the percentage of evaporated mass is much larger for gasoline, while infiltration is more significant for diesel. A statistical analysis suggests that the initial spill amount does not significantly affect the fraction of infiltrated fuel over time. This finding is in agreement with pore-scale simulations that we performed. A significant amount of fuel could be seeping into soil and groundwater underneath concrete pavement at gas stations or could be released to the atmosphere. Possible solutions for pavement and groundwater pollution are considered.

  4. Prediction of 28-day Compressive Strength of Concrete from Early Strength and Accelerated Curing Parameters

    OpenAIRE

    T.R. Neelakantan; S. Ramasundaram; Shanmugavel, R.; R. Vinoth

    2013-01-01

    Predicting 28-day compressive strength of concrete is an important research task for many years. In this study, concrete specimens were cured in two phases, initially at room temperature for a maximum of 30 h and later at a higher temperature for accelerated curing for a maximum of 3 h. Using the early strength obtained after the two-phase curing and the curing parameters, regression equations were developed to predict the 28-day compressive strength. For the accelerated curing (higher temper...

  5. Heterogeneous Photocatalysis Applied to Concrete Pavement for Air Remediation

    Science.gov (United States)

    Ballari, M. M.; Hunger, M.; Hüsken, G.; Brouwers, H. J. H.

    In the present work the degradation of nitrogen oxides (NOx) by concrete paving stones containing TiO2 to be applied in road construction is studied. A kinetic model is proposed to describe the photocatalytic reaction of nitric oxide (NO) in a standard flow laminar photoreactor irradiated with UV lamps. In addition the influence of several parameters that can affect the performance of these stones under outdoor conditions are investigated, such as irradiance, relative humidity and wind speed. The kinetic parameters present in the NO reaction rate are estimated employing experimental data obtained in the photoreactor. The obtained model predictions employing the determined kinetic constants are in good agreement with the experimental results of NO concentration at the reactor outlet.

  6. Cause Analysis on the Void under Slabs of Cement Concrete Pavement

    Science.gov (United States)

    Wen, Li; Zhu, Guo Xin; Baozhu

    2017-06-01

    This paper made a systematic analysis on the influence of the construction, environment, water and loads on the void beneath road slabs, and also introduced the formation process of structural void and pumping void, and summarizes the deep reasons for the bottom of the cement concrete pavement. Based on the analysis above, this paper has found out the evolution law of the void under slabs which claimed that the void usually appeared in the slab corners and then the cross joint, resulting void in the four sides with the void area under the front slab larger than the rear one.

  7. HOW TO OBTAIN ECONOMICALLY EFFICIENT ASPHALT CONCRETE MIXTURES FOR CONSTRUCTIVE AUTOMOBILE ROAD AND STREET PAVEMENTS

    Directory of Open Access Journals (Sweden)

    V. A. Verenko

    2009-01-01

    Full Text Available The paper describes a methodology for evaluation of technical and economic efficiency of asphalt concrete mixture components. The method allows to perform a directed search for new materials which are used for mixture preparation and it also provides an efficient use of monetary funds. Firstly, it is possible to obtain this result due to optimum price-quality ratio of asphalt mixture which is determined by its service life in a pavement; secondly, it is possible to obtain this result due to  exclusion of errors while selecting components of the asphalt mixture out of the whole range applied presently in the world practice.

  8. The Technology of Bare Concrete Pavement%清水混凝土人行道工艺

    Institute of Scientific and Technical Information of China (English)

    陈靖

    2014-01-01

    本文概述了道路清水混凝土人行道面层的设计及施工控制要点,阐述了如何完成美观与强度、耐久性兼容的混凝土面层。%This article summarizes the design and the key points of construction control to the surface of bare concrete pavement, and expounds how to achieve concrete pavement compatible with beauty, strength and durability.

  9. Cause Analysis of Asphalt Concrete Pavement Disease%沥青路面病害的成因分析

    Institute of Scientific and Technical Information of China (English)

    高雪

    2013-01-01

    From raw materials selection, structure design and construction of asphalt concrete pavement, the article made a detailed description on disease types, causes and prevention measures of the asphalt concrete pavement.%  文章从沥青混凝土路面的原材料选择、结构设计、施工等方面入手,对沥青混凝土路面病害的类型、发生原因及防治措施进行详细说明。

  10. INVESTIGATION OF CONDITIONS FOR SIMPLE INSULATION CURING CORRESPONDING TO TEMPERATURE HISTORY OF CONCRETE STRUCTURE

    OpenAIRE

    劉, 宏涛; 濱, 幸雄; 友澤, 史紀; 桑原, 隆司

    2002-01-01

    In this paper, conditions of simple insulation curing of test specimens were studied, for purposes of strength control of concrete structures in cold weather. The temperature histories of the specimens in the simple insulation curing boxes corresponding to those of the concrete structures were researched by means of concrete experiments and temperature analysis by finite element method. Based on the result of the experiments and the analysis, the conditions of simple insulation curing of test...

  11. Development of Deflection Prediction Model for Concrete Block Pavement Considering the Block Shapes and Construction Patterns

    Directory of Open Access Journals (Sweden)

    Wuguang Lin

    2016-01-01

    Full Text Available Concrete block pavement (CBP is distinct from typical concrete or asphalt pavements. It is built by using individual blocks with unique construction patterns forming a discrete surface layer to bear traffic loadings. The surface structure of CBP varies depending on the block shapes and construction patterns, so it is hard to apply a general equivalent elastic modulus estimation method to define the surface structural strength. In this study, FEM analysis and dynamic loading test were carried out to develop a deflection prediction model for CBP considering the block shapes and construction patterns. Based on the analysis results, it was found that block shapes did not have much effect on load distribution, whereas construction patterns did. By applying the deflection prediction model to the rutting model for CBP proposed by Sun, the herringbone bond pattern showed the best performance comparing with stretcher bond or basket weave bond pattern. As the load repetition increased to 1.2 million, the rutting depth of CBP constructed by herringbone bond pattern was 2 mm smaller than those constructed by the other two patterns.

  12. 沥青砼路面裂缝预防措施%Prevention Measures on the Asphalt Concrete Pavement Crevices

    Institute of Scientific and Technical Information of China (English)

    贾陇春

    2014-01-01

    文章简单介绍了沥青砼路面裂缝的集中类型,对沥青砼路面产生裂缝的原因进行了分析,着重提出了相应的沥青砼路面裂缝预防措施。希望能进一步延长沥青砼路面的使用寿命,提升路面服务质量,为工程技术人员提供一定的参考和借鉴。%This paper briefly introduces the main types of asphalt concrete pavement crevices and analyzed the causes of crevices, focusing on corresponding prevention measures. By this, the author hoped to further extend the service life of asphalt concrete pavement and improved the pavement quality, providing a reference for engineering and technical personnel.

  13. State of art an Overview on the Tensile Strength and Flexural Strength of Concrete in different Curing Methods

    Directory of Open Access Journals (Sweden)

    J. Allen Paul Edson

    2014-11-01

    Full Text Available The concrete is made of different ingredients such as cement, fine aggregate, and coarse aggregate but it is a homogeneous material when it is in a harden concrete. The strength of concrete decides the life span of any concrete structure. The factors which affect the strength of concrete are the type of material used, size of aggregate, water cement ratio, improper compaction and improper curing. Curing is one of the major factors in the failure of concrete. Curing is defined as the process of promoting the hydration of cement. The grade used in the manufacture of concrete may be M20, M30 grade. This paper deals with the overview on the tensile strength and flexural strength of concrete when the concrete is exposed to various curing methods such as Water curing (Ponding and Immersion, Air Curing (Dry air curing, and plastic film curing at 3 days, 7 days, 28 days and 56 days. It is studied that the tensile and flexural strength of concrete during immersion method is high when compared with Air curing and plastic film curing. It is found that the water curing is the most effective method of curing with the maximum of 10% increase in tensile strength and 15% increase in flexural strength of concrete when compared with other curing methods. On comparison with self compacting concrete (SCC and Normal cement concrete (NCC under different curing methods the tensile strength and flexural strength of SCC is high than NCC.

  14. 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.

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

    CSIR Research Space (South Africa)

    Dlamini, N

    2011-09-01

    Full Text Available presentation to the RRA board of directors that outlined the advantages of Ultrathin Continuously Reinforced Concrete Pavements (UTCRCP). From this presentation the board initiated a meeting between the members of the RRA namely SIRDC, CSIR and BOTEC. Aurecon...

  16. Characterization of Moisture Diffusion in Cured Concrete Slabs at Early Ages

    OpenAIRE

    Xiao Zhang; Hongduo Zhao

    2015-01-01

    The objective of this paper is to investigate the characterization of moisture diffusion inside early-age concrete slabs subjected to curing. Time-dependent relative humidity (RH) distributions of three mixture proportions subjected to three different curing methods (i.e., air curing, water curing, and membrane-forming compounds curing) and sealed condition were measured for 28 days. A one-dimensional nonlinear moisture diffusion partial differential equation (PDE) based on Fick’s second law,...

  17. Integration of a prototype wireless communication system with micro-electromechanical temperature and humidity sensor for concrete pavement health monitoring

    Directory of Open Access Journals (Sweden)

    Shuo Yang

    2015-12-01

    Full Text Available In recent years, structural health monitoring and management (SHMM has become a popular approach and is considered essential for achieving well-performing, long-lasting, sustainable transportation infrastructure systems. Key requirements in ideal SHMM of road infrastructure include long-term, continuous, and real-time monitoring of pavement response and performance under various pavement geometry-materials-loading configurations and environmental conditions. With advancements in wireless technologies, integration of wireless communications into sensing device is considered an alternate and superior solution to existing time- and labor-intensive wired sensing systems in meeting the requirements of an ideal SHMM. This study explored the development and integration of a wireless communications sub-system into a commercial off-the-shelf micro-electromechanical sensor-based concrete pavement monitoring system. A success-rate test was performed after the wireless transmission system was buried in the concrete slab, and the test results indicated that the system was able to provide reliable communications at a distance of more than 46 m (150 feet. This will be a useful feature for highway engineers performing routine pavement scans from the pavement shoulder without the need for traffic control or road closure.

  18. Prediction of Concrete Strength Using Microwave Based Accelerated Curing Parameters by Neural Network

    OpenAIRE

    Ramasundaram, S; T.R. Neelakantan; R. Vinoth

    2013-01-01

    Prediction of compressive strength of concrete is very useful for economic constructions. The compressive strength can be estimated after 28 days of casting the specimen cubes or may be predictedbased on the quantum and quality of ingredients used in making the concrete. When the first one requires a 28-day time, the second one does have problem of accuracy. Hence, a hybrid model is proposed in which the concrete cube is cured using the microwave based accelerated curing procedure and the ear...

  19. Estimating Strain Changes in Concrete during Curing Using Regression and Artificial Neural Network

    OpenAIRE

    Kaveh Ahangari; Zahra Najafi; Seyed Jamal Sheikh Zakariaee; Alireza Arab

    2013-01-01

    Due to the cement hydration heat, concrete deforms during curing. These deformations may lead to cracks in the concrete. Therefore, a method which estimates the strain during curing is very valuable. In this research, two methods of multivariable regression and neural network were studied with the aim of estimating strain changes in concrete. For this purpose, laboratory cylindrical specimens were prepared under controlled situation at first and then vibration wire strain gauges equipped with...

  20. Assessment of the aging level of rejuvenated hot mixed asphalt concrete pavements

    Science.gov (United States)

    McGovern, Megan; Buttlar, William G.; Reis, Henrique

    2016-04-01

    The efficacy of asphalt rejuvenator on restoring the properties of oxidatively aged asphalt was tested via a non-collinear ultrasonic subsurface wave mixing technique modified for field use. Longitudinal transducers were mounted on angle wedges to generate subsurface dilatational waves to allow for pavement evaluation when there is only access to one side. Because in the field the asphalt concrete (AC) pavement properties (i.e., ultrasonic velocities and attenuations) are unknown, a pre-determined fixed incident angle (based on the AC mixture type) was used, which allows for practical implementation in the field. Oxidative aged AC specimens were coated with rejuvenator (10% by weight of the binder) and left to dwell for varying amounts of time. Once the dwell time reached the desired amount, the specimen was immediately ultrasonically tested. The frequency ratio, f2/f1, at which the interaction took place and the normalized nonlinear wave generation parameter, β/β0, were recorded and compared against a reference plot. It was observed that the rejuvenator had the effect of restoring the nonlinear properties to those corresponding to a virgin sample after a sufficient amount of dwell time. The ability of the rejuvenator to fully penetrate and act on the binder was observed to be dependent on the porosity and aggregate structure, and thus varied for each specimen. As a result, some portions of the binder were restored to a greater extent than others. This non-uniform nature was captured via the nonlinear ultrasonic technique.

  1. The interaction between concrete pavement and corrosion-induced copper runoff from buildings.

    Science.gov (United States)

    Bahar, B; Herting, G; Wallinder, I Odnevall; Hakkila, K; Leygraf, C; Virta, M

    2008-05-01

    Changes in chemical speciation of copper and the capacity of concrete pavement to retain copper in runoff water from external buildings have been investigated at urban field conditions, and in parallel laboratory experiments simulating outdoor scenarios. The research study showed the concrete surface to form a copper rich surface layer ( approximately 50 microm thick) upon exposure, and a high capacity to significantly reduce the bioavailable fraction of released copper (20-95%). The retention capacity of copper varied between 5 and 20% during single runoff events in the laboratory, and between 10 and 40% of the total copper release during single natural runoff events. The capacity to retain and reduce the bioavailable fraction of non-retained copper increased with increasing wetness of the concrete surfaces, increasing pH of the runoff water and decreasing flow rates. Bioassay testing with bacterial and yeast bioreporters showed the bioavailable fraction of non-retained copper to be significantly lower than the total copper concentration in the runoff water, between 22 and 40% for bacteria and between 8 and 31% for yeast. The application of generated data to simulate a fictive outdoor scenario, suggests a significant reduction of bioavailable and total copper to background values during environmental entry as a result of dilution, and the interaction with solid surfaces, organic matter and complexing agents already in the drainage system.

  2. Characterization of Moisture Diffusion in Cured Concrete Slabs at Early Ages

    Directory of Open Access Journals (Sweden)

    Xiao Zhang

    2015-01-01

    Full Text Available The objective of this paper is to investigate the characterization of moisture diffusion inside early-age concrete slabs subjected to curing. Time-dependent relative humidity (RH distributions of three mixture proportions subjected to three different curing methods (i.e., air curing, water curing, and membrane-forming compounds curing and sealed condition were measured for 28 days. A one-dimensional nonlinear moisture diffusion partial differential equation (PDE based on Fick’s second law, which incorporates the effect of curing in the Dirichlet boundary condition using a concept of curing factor, is developed to simulate the diffusion process. Model parameters are calibrated by a genetic algorithm (GA. Experimental results show that the RH reducing rate inside concrete under air curing is greater than the rates under membrane-forming compound curing and water curing. It is shown that the effect of water-to-cement (w/c ratio on self-desiccation is significant. Lower w/c ratio tends to result in larger RH reduction. RH reduction considering both effect of diffusion and self-desiccation in early-age concrete is not sensitive to w/c ratio, but to curing method. Comparison between model simulation and experimental results indicates that the improved model is able to reflect the effect of curing on moisture diffusion in early-age concrete slabs.

  3. Three-dimensional Finite Element Analysis on the Layer Steel Fiber Reinforced Concrete Pavement:A New Type of Pavement Material

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    An investigation was conducted on the design of layer steel fiber reinforced concrete (LSFRC) pavement.Finite element method was applied to the analysis on the stress distribution in order to determine the thickness and segregation distance of LSFRC pavement slabs.

  4. Experimental and mumerical validation of the technique for concrete cure monitoring using piezoelectric admittance measurement

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Wan Cheol; Park, Gyu Hae [Dept. of Mechanical Engineering, Chonnam National University, Gwangju (Korea, Republic of)

    2016-06-15

    This paper presents a new technique for monitoring the concrete curing process using embedded piezoelectric transducers via admittance measurements. When a piezoelectric transducer is embedded in a structure, the electrical impedance (admittance) of the transducer is coupled with the mechanical impedance of the host structure, which allows monitoring of the structural condition. In this study, the admittance signatures are used for monitoring the concrete curing process. This new method is based on an admittance-based sensor diagnostic process, in which the capacitance values of the piezoelectric transducers are dependent on the strength of the host structure. We numerically and experimentally investigated the variations in capacitive value during the curing process. The results demonstrate that there is a clear relationship between the concrete curing status and the slope, this indicates that the proposed method could be efficiently used for monitoring the curing status of a concrete structure.

  5. The Prediction of Concrete Temperature during Curing Using Regression and Artificial Neural Network

    OpenAIRE

    Zahra Najafi; Kaveh Ahangari

    2013-01-01

    Cement hydration plays a vital role in the temperature development of early-age concrete due to the heat generation. Concrete temperature affects the workability, and its measurement is an important element in any quality control program. In this regard, a method, which estimates the concrete temperature during curing, is very valuable. In this paper, multivariable regression and neural network methods were used for estimating concrete temperature. In order to achieve this purpose, ten labora...

  6. Activities of RILEM Technical Committee: Internal Curing of Concrete and Anticipated Research

    DEFF Research Database (Denmark)

    Kovler, Konstantin; Jensen, Ole Mejlhede

    in the domain. To account for the different practices and different standards around the world, the TC included representatives from three different world regions: Europe, North America and Asia. Totally more than 30 members from 17 countries contributed in the committee work. Some of them serve in parallel...... in ACI, JCI (Japan Concrete Institute) and other well-known research associations in the field of concrete science and engineering. Internal curing, as well as external curing, can be classified into two categories: • Internal water curing (sometimes called “water entrainment”), when the curing agent...... performs as a water reservoir, which gradually releases water, and • Internal sealing, when the curing agent is intended to delay or prevent loss of water from the hardening concrete. The committee addressed both internal water curing and internal sealing, but focused on the first method, which is much...

  7. Combined Effects of Curing Temperatures and Alkaline Concrete on Tensile Properties of GFRP Bars

    Directory of Open Access Journals (Sweden)

    Wen-rui Yang

    2017-01-01

    Full Text Available A significant number of studies have been conducted on the tensile properties of GFRP bars embedded in concrete under different environments. However, most of these studies have been experimentally based on the environmental immersion test after standard-curing and the lack of influence on the tensile properties of GFRP bars embedded in concrete during the curing process of concrete. This paper presents the results of the microscopic structures through scanning electron microscopy (SEM, Fourier transform infrared spectroscopy (FTIR, differential scanning calorimetry (DSC, and tensile properties of GFRP bars, which were employed to investigate the combined effects of curing temperatures and alkaline concrete on tensile properties of GFRP bars. The results showed that the higher curing temperature aggravated the influence of the alkaline concrete environment on GFRP bars but did not change the mechanisms of mechanical degradation of the GFRP bars. The influence of different curing temperatures on the tensile strength of GFRP bars was different between the bare bar and bars in concrete. Finally, the exponential correlation equation of two different test methods was established, and the attenuation ratio of the tensile strength of GFRP bars embedded in concrete under different curing temperatures was predicted by the bare test.

  8. 变压式水泥混凝土智能养护研究%The study of intelligent curing cement concrete by changing water pressure

    Institute of Scientific and Technical Information of China (English)

    甘露

    2015-01-01

    为实现施工现场水泥混凝土养护的智能化、自动化,提出了变压式水泥混凝土智能养护,变压式智能混凝土养护机通过检测混凝土路面、桥面或者楼板的温度湿度,并通过ZigBee无线传输将数据传给主机,主机根据相关数据改变出水水压,控制定时器及电磁阀,实现混凝土的定向定距喷灌,对提高养护效率以及养护规范性有重要作用。%To implement the intelligent of the cement concrete auto curing,this paper puts forward pressure type cement concrete intelligent main-tenance,variable pressure type intelligent concrete curing machine through the test of concrete pavement and bridge deck or slab temperature, humidity,and through the ZigBee wireless transmission to transmit the data to host,the host according to the relevant data change of water pres-sure,water control timer and solenoid valve,realize the directional distance of concrete irrigation,to improve the efficiency of maintenance and maintenance normative has vital function.

  9. Efficiency of Sodium Polyacrylate to Improve Durability of Concrete under Adverse Curing Condition

    Directory of Open Access Journals (Sweden)

    Tanvir Manzur

    2015-01-01

    Full Text Available The conventional external curing process requires supply of large amount of water in addition to mixing water as well as strict quality control protocol. However, in a developing country like Bangladesh, many local contractors do not have awareness and required knowledge on importance of curing which often results in weaker concrete with durability issues. Moreover, at times it is difficult to maintain proper external curing process due to nonavailability of water and skilled laborer. Internal curing can be adopted under such scenario since this method is simple and less quality intensive. Usually, naturally occurring porous light weight aggregates (LWA are used as internal curing agent. However, naturally occurring LWA are not available in many countries like Bangladesh. Under these circumstances, Super Absorbent Polymer (SAP can be utilized as an alternative internal curing agent. In this study, sodium polyacrylate (SP as SAP has been used to produce internally cured concrete. Desorption isotherm of SP has been developed to investigate its effectiveness as internal curing agent. Test results showed that internally cured concrete with SP performed better in terms of both strength and durability as compared to control samples when subjected to adverse curing conditions where supply of additional water for external curing was absent.

  10. About the sizes of elastomer particles in the asphalt concrete binder providing the maximum service life of pavements

    Science.gov (United States)

    Kaplan, A. M.; Chekunaev, N. I.

    2014-05-01

    It is noted that the durability of asphalt concrete pavements is determined by the time of the trunk cracks formation in the polymer-containing composites - in the modified by elastomers (e.g., by rubber) bitumenous binder of asphalt. Developed by the authors previously the theory of the cracks propagation in heterosystems [1] has allowed to investigate the problem of the cracks propagation in the rubber-bitumen composite. This investigations show that most effectively to prevente the trunk cracks formation in asphalt concrete can ultrafine rubber particles (150-750 nm) in a bitumenos binder of asphalt.

  11. Alkali-silica reaction of aggregates for concrete pavements in Chihuahua’s State, Mexico

    Directory of Open Access Journals (Sweden)

    Olague, C.

    2002-12-01

    Full Text Available The concrete of pavements must resist the climatic conditions, heavy traffic, chemical agents or any other type of aggressive agent. A methodology for characterizing materials that would influence concrete durability was developed considering chemical and physical factors. This methodology allows the consideration of several factors like physiography, geology, and climate, among others that would be of great importance to prevent future durability problems of pavements. This methodology takes into account several tests and this paper presents the results of potential reactivity aggregates of the State of Chihuahua. The tests for evaluating the reactive siliceous aggregate and the potential alkali-silica reactivity were performed according to the: petrographic examination (ASTM C 295 and standard quick chemical test (ASTM C 289. 38% of the tested sites resulted innocuous, 48% potentially reactive and 13% reactive. It is discussed the benefit of applying a conscious methodology in order to obtain the best results with a representative quantity of tests.

    El hormigón de los pavimentos debe ser resistente a las condiciones climáticas, tránsito pesado, agentes químicos o cualquier otro tipo de agente agresivo. Se desarrolló una metodología para caracterización de materiales considerando factores físicos y químicos que influyen en la durabilidad del hormigón. Esta metodología se basa en la consideración de varios factores como: fisiografía, geología y clima, entre otros, que podrían ser de gran importancia para prevenir futuros problemas de durabilidad en pavimentos de hormigón. La metodología en cuestión considera varias pruebas, en este artículo se presentan los resultados de la reactividad potencial de los áridos del Estado de Chihuahua. Las pruebas para evaluar la reactividad de áridos silíceos y la reactividad potencial álcali-sílice fueron ejecutadas de acuerdo a: examen petrográfico (ASTM C 295 y la prueba qu

  12. Application of Old Cement Concrete Pavement in Steel Fiber Reinforced Concrete Surface Layer%浅谈旧水泥砼路面加铺钢纤维砼面层的应用

    Institute of Scientific and Technical Information of China (English)

    丁海萍; 刘妙

    2013-01-01

    Layered steel fiber concrete pavement is a new kind of pavement structure.The steel fiber is bestrewed on top and under surface of the concrete pavement plate at the time of construction,and two layers of steel fiber concrete network is formed.It can protect the position easily damaged in concrete pavement effectively,and It is important to improve bending ability of concrete pavement and reduce the thickness of concrete pavement at design time.The performance and road condition of this pavement structure is very good after consign,and pavement maintenance cost is very low.It can increase the service life of pavement greatly.The social and economic benefit is significant at the same time.%上下层布式钢纤维砼路面是一种比较新颖的路面结构.在施工的时候,在砼路面板顶面和底面上撒布钢纤维,并形成两层的钢纤维砼网.可以有效的保护砼路面容易发生破损的部位,对提升砼路面的抗弯拉能力也有很大的帮助,并能够在设计的时候,降低砼路面的厚度.这种结构的路面结构在施工交付使用后,使用的性能非常好,路面状况也很好,路面的养护和维修费用低.同时能较大提高路面的使用寿命,其社会效益、经济效益特别显著.

  13. Ageing of portland cement concrete cured under moist conditions

    NARCIS (Netherlands)

    Yu, Z.; Ye, G.; Van Breugel, K.; Chen, W.

    2014-01-01

    Deterioration of microstructure in cement concrete will cause changes in the transport properties of the concrete. Transport properties at different ages of the concrete provide information about the microstructural changes of the material. A way to measure the transport properties, i.e. the chlorid

  14. Can superabsorent polymers mitigate autogenous shrinkage of internally cured concrete without compromising the strength?

    DEFF Research Database (Denmark)

    Hasholt, Marianne Tange; Jensen, Ole Mejlhede; Kovler, Konstantin

    2012-01-01

    The paper “Super absorbing polymers as an internal curing agent for mitigation of early-age cracking of high-performance concrete bridge decks” deals with different aspects of using superabsorbent polymers (SAP) in concrete to mitigate self-desiccation. The paper concludes that “Addition of SAP l...

  15. Activities of RILEM Technical Committee: Internal Curing of Concrete and Anticipated Research

    DEFF Research Database (Denmark)

    Kovler, Konstantin; Jensen, Ole Mejlhede

    Novel methods of shrinkage mitigation, based on special advanced methods of internal curing (IC), are currently being intensively studied in research groups in several countries. They have been the focus of the State-of-the-Art report prepared by the Technical Committee TC 196-ICC “Internal Curing...... of Concrete” of the International Union of Laboratories and Experts in Construction Materials, Systems and Structures (RILEM). The authors of this short communication served as a chair (K. Kovler) and secretary (O.M. Jensen) of the TC. The regular and corresponding members were acknowledged RILEM experts...... in ACI, JCI (Japan Concrete Institute) and other well-known research associations in the field of concrete science and engineering. Internal curing, as well as external curing, can be classified into two categories: • Internal water curing (sometimes called “water entrainment”), when the curing agent...

  16. A study of sound absorption by street canyon boundaries and asphalt rubber concrete pavement

    Science.gov (United States)

    Drysdale, Graeme Robert

    A sound field model, based on a classical diffusion equation, is extended to account for sound absorption in a diffusion parameter used to model sound energy in a narrow street canyon. The model accounts for a single sound absorption coefficient, separate accommodation coefficients and a combination of separate absorption and accommodation coefficients from parallel canyon walls. The new expressions are compared to the original formula through numerical simulations to reveal the effect of absorption on sound diffusion. The newly established analytical formulae demonstrate satisfactory agreement with their predecessor under perfect reflection. As well, the influence of the extended diffusion parameter on normalized sound pressure levels in a narrow street canyon is in agreement with experimental data. The diffusion parameters are used to model sound energy density in a street canyon as a function of the sound absorption coefficient of the street canyon walls. The acoustic and material properties of conventional and asphalt rubber concrete (ARC) pavement are also studied to assess how the crumb rubber content influences sound absorption in street canyons. The porosity and absolute permeability of compacted specimens of asphalt rubber concrete are measured and compared to their normal and random incidence sound absorption coefficients as a function of crumb rubber content in the modified binder. Nonlinear trends are found between the sound absorption coefficients, porosity and absolute permeability of the compacted specimens and the percentage of crumb rubber in the modified binders. The cross-sectional areas of the air voids on the surfaces of the compacted specimens are measured using digital image processing techniques and a linear relationship is obtained between the average void area and crumb rubber content. The measured material properties are used to construct an empirical formula relating the average porosity, normal incidence noise reduction coefficients and

  17. Experimental Analysis of Fly Ash & Coir Fiber Mix Cement Concrete for Rigid Pavement

    Directory of Open Access Journals (Sweden)

    Er. Amit Kumar Ahirwar

    2015-04-01

    Full Text Available In India Thermal power plants which use pounded coal as a fuel, generates million tones of fly ash every year as a waste. Conservative clearance of this material which gets easily air-borne and constitutes a serious health hazards to the community, is an expensive operation. A part from this compacted fly ash can be used in embankments, road sub-bases and also for structural fills. The major drawbacks of such materials are their limited load carrying capacity and poor settlement characteristics. The concert of such materials can substantially be improved by introducing reinforcing element in the direction of improving its compressive and flexural strength for superior durability. Use of natural materials such as Jute, coir and bamboo, as reinforcing materials to fly ash are very cheap and they are locally available in huge quantity, of all the natural fibers, coir has the greatest tearing strength and it retains this property even in wet conditions. In this framework a composite with fly ash, conventional concrete and treated coconut fibers, available in plenty in rural areas of India have been investigated. These composites can be a good proposition and with this, experimental investigation to study the effects of replacement of cement (by volume with different percentages of fly ash and the effects of addition of processed natural coconut fiber on flexural strength, compressive strength, splitting tensile strength and modulus of elasticity was taken up. AS per IRC, A Design mix proportion was designed for the normally popular M30 concrete for pavement construction in India. In this, Cement was replaced with percentages (10, 20, 30 and 40% of Class C fly ash and of coconut fibers (0.50 and 1.0 % having 40 mm length were used. Test results show that the replacement of 43 grades ordinary Portland cement with fly ash showed an increase in compressive strength and flexural strength for the chosen mix proportion.

  18. State of art an Overview on the Tensile Strength and Flexural Strength of Concrete in different Curing Methods

    OpenAIRE

    J. Allen Paul Edson; M. Kamesh Amudhan

    2014-01-01

    The concrete is made of different ingredients such as cement, fine aggregate, and coarse aggregate but it is a homogeneous material when it is in a harden concrete. The strength of concrete decides the life span of any concrete structure. The factors which affect the strength of concrete are the type of material used, size of aggregate, water cement ratio, improper compaction and improper curing. Curing is one of the major factors in the failure of concrete. Curing is defined as the process o...

  19. Use of microwave energy for accelerated curing of concrete: a review

    Directory of Open Access Journals (Sweden)

    P. Ratanadecho

    2009-01-01

    Full Text Available Microwaves (MWs are one of the most popular energy sources to heat dielectric materials in various industrial processes. One application is the rapid thermal cure of concrete. Due to the advantages of volumetric heating, MWs can be implemented in a reasonable way to accelerate the rate of strength development. However, these fields have been grown only gradually, as there has been not much research and practical work over the last years. The climate change issue and the discussion around the non-renewable energy resources triggered a change for better energy-utilizing systems. One is the useof clean energy in the cement and concrete production. Nevertheless, simultaneously efforts also needed to make towards an improvement of concrete properties. Therefore, suitable MWs curing method and processes involved are indispensable factors for research and subsequent developing into applications. The present paper reviews the historical evolution of the MWs energy implementation to cure concrete. It further provides a deeper understanding of this technology and proposes suitable points for future study and development. The first part describes the necessity of thermal curing on the strength development of concrete at early age and then discusses its factors affecting. Also curing criteria and the disadvantages of the conventional methods used to stimulate the rate of hydration reaction of concrete are summarized. The second partreports the implementing method for achieving this purpose covering dielectric properties involved and related heatingmechanisms. Finally, some aspects for future studies are proposed to build a forward-complementing knowledge from the current one.

  20. Prediction of Concrete Strength Using Microwave Based Accelerated Curing Parameters by Neural Network

    Directory of Open Access Journals (Sweden)

    S. Ramasundaram

    2013-02-01

    Full Text Available Prediction of compressive strength of concrete is very useful for economic constructions. The compressive strength can be estimated after 28 days of casting the specimen cubes or may be predictedbased on the quantum and quality of ingredients used in making the concrete. When the first one requires a 28-day time, the second one does have problem of accuracy. Hence, a hybrid model is proposed in which the concrete cube is cured using the microwave based accelerated curing procedure and the early strength is used to predict the 28-day strength. Feed-forward neural network model was used to predict compressive strength of the concrete after the microwave curing to ascertain the predictability of neural network models. The results indicate that the neural network models have a good scope for further study and implementations.

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

    Science.gov (United States)

    2010-06-01

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

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

    Science.gov (United States)

    2013-07-01

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

  3. effect of curing methods on the compressive strength of concrete

    African Journals Online (AJOL)

    ods on the compressive strength as well as the density of concrete. A total of 72 cubes of ... Review of Related Literatures. In concrete ... and plastic sheet is essential in order to pro- .... This is due to improved pore structure and lower porosity.

  4. Effect of In-Situ Curing on Compressive Strength of Reactive Powder Concrete

    OpenAIRE

    Bali Ika; Kushartomo Widodo; Jonathan

    2016-01-01

    A development of Reactive Powder Concrete (RPC) currently is the use of quartz powder as a stabilizing agent with the content to cement ratio of 30% and steam curing method in an autoclave temperature of 250ºC which produced a high compressive strength of 180 MPa. That RPC can be generated due to one reason for using the technique of steam curing in an autoclave in the laboratory. This study proposes in-situ curing method in order the curing can be applied in the field and with a reasonable c...

  5. Hydration evolution of pre-cast concrete with steam and water curing

    Institute of Scientific and Technical Information of China (English)

    巴明芳; 钱春香

    2013-01-01

    The hydration characteristics of pre-cast concrete considering the effects of effective initial steam-curing and water-curing duration were measured and analyzed with XRD, TG, X-ray CT, SEM-BSE and MIP techniques. The results show that the effective initial steam-curing duration for pre-cast concrete with lower water-binder ratio was 10 14 h at 50 °C and the initial water-curing duration was 7 14 d. And the hydration evolution of cement, fly ash and slag in pre-cast concrete was obtained respectively by combining the hydrochlorides and EDTA selecting dissolution methods, based on which the contents of hydrated and anhydrate in concrete were calculated and the corresponding dynamic capillary porosity was also determined. Moreover, the comparison between calculated results and experimental ones indicates that the proposed evolution models of microscopic characteristics corresponding to hydration kinetics of cemented materials could be adopted to predict the developing trend of capillary porosity and hydration-products content in pre-cast concrete with fly ash and slag under certain curing conditions.

  6. 水泥混凝土桥面铺装施工质量控制%Pavement construction quality control of cement concrete bridge deck

    Institute of Scientific and Technical Information of China (English)

    贾志民

    2009-01-01

    Combining with construction practice of the bridge deck pavement, the author introduces the quality control points in the cement concrete bridge deck pavement construction from aspects of hinge joint concrete construction and bridge deck pavement concrete construction, so as to perfect bridge deck pavement construction technology, ensure that the bridge deck concrete pavement layer has design strength, in-tegrity and anti-permeability, anti-crack and anti-impact performance.%结合桥面铺装的施工实践,从铰缝混凝土施工和桥面铺装混凝土施工两方面介绍了水泥混凝土桥面铺装施工中的质量控制要点,以完善桥面铺装施工工艺,保证桥面混凝土铺装层具有设计强度、整体性及抗渗抗裂抗冲击性.

  7. Internal Curing Using Water-releasing Material for High Strength Micro-expansive Concrete

    Institute of Scientific and Technical Information of China (English)

    LU Linnu; YANG Wen; HE Yongjia; WU Jing; HU Shuguang

    2009-01-01

    Due to its low water content,it is difficult for expansive agent to have an effective expansive effect on high strength concrete to compensate its extensive shrinkage and form a certain expansion.To solve this problem,water-releasing material with water storage and releasing characteristics was incorporated into high strength micro-expansive concrete to provide internal curing,and expansive effect of expansive agent was improved.Migration of water from initially saturated water-releasing material to the surrounding hydrating cement paste was investigated.Based on a given efficient diffusion distance of water stored in water-releasing material,the mass and real water-cement ratio of cured cement paste were estimated.At the same time,the effect of internal curing of water-releasing material on the volume deformation of high strength micro-expansive concrete was investigated.

  8. Investigation of Self Consolidating Concrete Containing High Volume of Supplementary Cementitious Materials and Recycled Asphalt Pavement Aggregates

    Science.gov (United States)

    Patibandla, Varun chowdary

    The use of sustainable technologies such as supplementary cementitiuous materials (SCMs), and/or recycled materials is expected to positively affect the performance of concrete mixtures. However, it is important to study and qualify such mixtures and check if the required specifications of their intended application are met before they can be implemented in practice. This study presents the results of a laboratory investigation of Self Consolidating concrete (SCC) containing sustainable technologies. A total of twelve concrete mixtures were prepared with various combinations of fly ash, slag, and recycled asphalt pavement (RAP). The mixtures were divided into three groups with constant water to cementitiuous materials ratio of 0.37, and based on the RAP content; 0, 25, and 50% of coarse aggregate replaced by RAP. All mixtures were prepared to achieve a target slump flow equal to or higher than 500 mm (24in). A control mixture for each group was prepared with 100% Portland cement whereas all other mixtures were designed to have up to 70% of portland cement replaced by a combination of supplementary cementitiuous materials (SCMs) such as class C fly ash and granulated blast furnace slag. The properties of fresh concrete investigated in this study include flowability, deformability; filling capacity, and resistance to segregation. In addition, the compressive strength at 3, 14, and 28 days, the tensile strength, and the unrestrained shrinkage up to 80 days was also investigated. As expected the inclusion of the sustainable technologies affected both fresh and hardened concrete properties. Analysis of the experimental data indicated that inclusion of RAP not only reduces the ultimate strength, but it also affected the compressive strength development rate. Moreover, several mixes satisfied compressive strength requirements for pavements and bridges; those mixes included relatively high percentages of SCMs and RAP. Based on the results obtained in this study, it is not

  9. Estimating Strain Changes in Concrete during Curing Using Regression and Artificial Neural Network

    Directory of Open Access Journals (Sweden)

    Kaveh Ahangari

    2013-01-01

    Full Text Available Due to the cement hydration heat, concrete deforms during curing. These deformations may lead to cracks in the concrete. Therefore, a method which estimates the strain during curing is very valuable. In this research, two methods of multivariable regression and neural network were studied with the aim of estimating strain changes in concrete. For this purpose, laboratory cylindrical specimens were prepared under controlled situation at first and then vibration wire strain gauges equipped with thermistors were placed inside each sample to measure the deformations. Two different groups of input data were used in which variables included time, environment temperature, concrete temperature, water-to-cement ratio, aggregate content, height, and specimen diameter. CEM I, 42.5 R was utilized in set (I and strain changes have been measured in six concrete specimens. In set (II CEM II, 52.5 R was employed and strain changes were measured in three different specimens in which the diameter was held constant. The best multivariate regression equations calculated the determined coefficients at 0.804 and 0.82 for sets (I and (II, whereas the artificial neural networks predicted the strain with higher of 1 and 0.996. Results show that the neural network method can be utilized as an efficient tool for estimating concrete strain during curing.

  10. Determination of the heating temperature of potholes surface on road pavement in the process of repairs using hot asphalt concrete mixes

    Directory of Open Access Journals (Sweden)

    Giyasov Botir Iminzhonovich

    2014-12-01

    Full Text Available In the process of roads construction the necessary transport and operational characteristics should be achieved, which depend on the quality of the applied, material and technologies. Under the loads of transport means and the influence of weather conditions on the road pavement deformations and destructions occur, which lead to worsening of transport and operational characteristics, decrease of operational life of the road and they are often the reason of road accidents. According to the data of the Strategic Research Center of "Rosgosstrah" more than 20 % of road accidents in Russia occur due to bad quality of road pavement. One of the main directions in traffic security control and prolongation of operational life for road pavement of non-rigid type is road works, as a result of which defects of pavement are eliminated and in case of timely repairs of high quality the operational life of the road increases for several years. The most widely used material for non-rigid pavement repairs is hot road concrete mixes and in case of adherence to specifications they provide high quality of works. The authors investigate the problems of hot asphalt concrete mixes for repairs of road surfaces of non-rigid type. The results of the study hot asphalt concrete mix’s temperature regimes are offered in case of repair works considering the temperature delivered to the work site and the ambient temperature depending on the type of mix and class of bitumen.

  11. Damage and deterioration mechanism and curing technique of concrete structure in main coal cleaning plants

    Institute of Scientific and Technical Information of China (English)

    LV Heng-lin; ZHAO Cheng-ming; SONG Lei; MA Ying; XU Chun-hua

    2009-01-01

    Concrete structures in main coal cleaning plants have been rebuilt and reinforced in the coal mines of the Shanghai Da-tun Energy Sources Co. Ltd., the first colliery of the Pingdingshan Coal Co. Ltd. and the Sanhejian mine of the Xuzhou Mining Group Co. Ltd. In these projects, the operating environment and reliability of concrete structures in the main plants of the three companies were investigated and the safety of the structures inspected. Qualitative and quantitative analyses were made on the spe-cial natural, technological and mechanical environments around the structures. On the basis of these analyses, we discuss the long-term, combined actions of the harsh natural (corrosive gases, liquids and solids) and mechanical environments on concrete structures and further investigated the damage and deteriorating mechanisms and curing techniques of concrete structures in the main coal cleaning plants. Our study can provide a theoretical basis for ensuring the reliability of concrete structures in main coal cleaning plants.

  12. Effect of In-Situ Curing on Compressive Strength of Reactive Powder Concrete

    Directory of Open Access Journals (Sweden)

    Bali Ika

    2016-01-01

    Full Text Available A development of Reactive Powder Concrete (RPC currently is the use of quartz powder as a stabilizing agent with the content to cement ratio of 30% and steam curing method in an autoclave temperature of 250ºC which produced a high compressive strength of 180 MPa. That RPC can be generated due to one reason for using the technique of steam curing in an autoclave in the laboratory. This study proposes in-situ curing method in order the curing can be applied in the field and with a reasonable compressive strength results of RPC. As the benchmarks in this study are the curing methods in laboratory that are steam curing of 90°C for 8 hours (C1, and water curing for 28 days (C2. For the in-situ curing methods that are covering with tarpaulins and flowed steam of 3 hours per day for 7 days (C3, covering with wet sacks for 28 days (C4, and covering with wet sacks for 28 days for specimen with unwashed sand as fine aggregate (C5. The comparison of compressive strength of the specimens in this study showed compressive strength of RPC with in-situ steam curing (101.64 MPa close to the compressive strength of RPC with steam curing in the laboratory with 8.2% of different. While in-situ wet curing compared with the water curing in laboratory has the different of 3.4%. These results indicated that the proposed in-situ curing methods are reasonable good in term of the compressive strength that can be achieved.

  13. The Prediction of Concrete Temperature during Curing Using Regression and Artificial Neural Network

    Directory of Open Access Journals (Sweden)

    Zahra Najafi

    2013-01-01

    Full Text Available Cement hydration plays a vital role in the temperature development of early-age concrete due to the heat generation. Concrete temperature affects the workability, and its measurement is an important element in any quality control program. In this regard, a method, which estimates the concrete temperature during curing, is very valuable. In this paper, multivariable regression and neural network methods were used for estimating concrete temperature. In order to achieve this purpose, ten laboratory cylindrical specimens were prepared under controlled situation, and concrete temperature was measured by thermistors existent in vibrating wire strain gauges. Input data variables consist of time (hour, environment temperature, water to cement ratio, aggregate content, height, and specimen diameter. Concrete temperature has been measured in ten different concrete specimens. Nonlinear regression achieved the determined coefficient ( of 0.873. By using the same input set, the artificial neural network predicted concrete temperature with higher of 0.999. The results show that artificial neural network method significantly can be used to predict concrete temperature when regression results do not have appropriate accuracy.

  14. Influence of curing regimes on compressive strength of ultra high performance concrete

    Indian Academy of Sciences (India)

    Prabhat Ranjan Prem; B H Bharatkumar; Nagesh R Iyer

    2013-12-01

    The present paper is aimed to identify an efficient curing regime for ultra high performance concrete (UHPC), to achieve a target compressive strength more than 150 MPa, using indigenous materials. The thermal regime plays a vital role due to the limited fineness of ingredients and low water/binder ratio. By activation of the reaction kinetics, the effectiveness of the binder is enhanced which leads to improvements in mechanical as well as durability properties. The curing cycle employed are ambient air curing, water curing and hot air curing. The specimens were exposed to thermal regime at (90°C/150°C/200°C) for duration of 24, 48 or 72 hours at the age of 3rd and 7th day followed with air curing or water curing till 28 days. The results showed a marked difference in compressive strength ranging from 217 to 142 MPa with change in curing regimes. The samples when thermally cured at the age of 3rd and 7th day produced an average ultimate strength of 217–152 MPa and 196–150 MPa, respectively.

  15. Effect of high temperature curing on the compressive strength of concrete incorporating large volumes of fly ash

    Energy Technology Data Exchange (ETDEWEB)

    Rivera-Villarreal, R. [Universidad Autonoma de Nuevo Leon, Monterrey (Mexico)

    2001-07-01

    The effect of using different types of heat treatment on the compressive strength of concrete with and without large volumes of fly ash was studied. Curing of concrete is important to obtain a good quality concrete, but it is important to keep concrete from drying until the originally water-filled space in fresh cement paste has been filled to the desired extent by the products of hydration. In hot weather, high temperature promotes faster drying of concrete so a given degree of hydration is reached more rapidly than at lower temperatures. The provision of moist curing is advantageous because of a gradual gain in strength and because of reduced plastic shrinkage and drying shrinkage-cracking. The portland cement content in all the mixtures used in this study was 200 kg per cubic metre and the amount of fly ash varied from 0 to 33, 43, 50 and 56 per cent by mass of the total binder. A superplasticizer was used to obtain 200-220 mm slump. The compressive strength was tested at 3, 7, 14, 28, 56 days and at 6 months. Results showed that, using ASTM standard curing, the compressive strength of portland cement concrete made at 35 degrees C was reduced by about 12 per cent at 28 days compared to that of the concrete made at 23 degrees C. The AASHTO curing strength was found to be a bit higher than with the ASTM curing. The concrete made at 35 degrees C showed no loss of strength when continuous moist-curing was applied. The fly ash concrete mixtures that were cast at 35 degrees C were cured by covering them with membrane curing compounds and placed under ambient conditions. It was crucial to allow enough curing water to promote the pozzolanic reaction. The membrane curing did not allow the ingress of water to the concrete mass. 6 refs., 4 tabs., 13 figs.

  16. A Microstructure Based Strength Model for Slag Blended Concrete with Various Curing Temperatures

    Directory of Open Access Journals (Sweden)

    Li-Na Zhang

    2016-01-01

    Full Text Available Ground granulated blast furnace slag, which is a byproduct obtained during steel manufacture, has been widely used for concrete structures in order to reduce carbon dioxide emissions and improve durability. This paper presents a numerical model to evaluate compressive strength development of slag blended concrete at isothermal curing temperatures and time varying curing temperatures. First, the numerical model starts with a cement-slag blended hydration model which simulates both cement hydration and slag reaction. The accelerations of cement hydration and slag reaction at elevated temperatures are modeled by Arrhenius law. Second, the gel-space ratios of hardening concrete are calculated using reaction degrees of cement and slag. Using a modified Powers’ gel-space ratio strength theory, the strength of slag blended concrete is evaluated considering both strengthening factors and weakening factors involved in strength development process. The proposed model is verified using experimental results of strength development of slag blended concrete with different slag contents and different curing temperatures.

  17. Performance Based Evaluation of Concrete Strength under Various Curing Conditions to Investigate Climate Change Effects

    Directory of Open Access Journals (Sweden)

    Tae-Kyun Kim

    2015-07-01

    Full Text Available Recently, the manifestation of global warming-induced climate change has been observed through super typhoons, heavy snowfalls, torrential rains, and extended heat waves. These climate changes have been occurring all over the world and natural disasters have caused severe damage and deterioration of concrete structures and infrastructure. In an effort to deal with these problems due to extreme and abnormal climate changes, studies have been conducted to develop construction technologies and design guidelines. Nevertheless, study results applicable to construction sites continue to be ineffective and insufficient. Therefore, this study proposes ways to cope with climate change by considering the effect of concrete curing condition variations on concrete material performance. More specifically, the 3-, 7- and 28-day compressive and split tensile strength properties of concrete mix cured under various climatic factors including temperature, relative humidity, wind speed, and sunlight exposure time were evaluated to determine whether the concrete meets the current design requirements. Thereafter, a performance based evaluation (PBE was performed using satisfaction probabilities based on the test values to understand the problems associated with the current mix proportion design practice and to identify countermeasures to deal with climate change-induced curing conditions.

  18. Recommendations for the repair, the lining or the strengthening of concrete slabs or pavements with bonded cement-based material overlays

    OpenAIRE

    Courard, Luc; Bissonnette, Benoît; Beushausen, Hans; Fowler,David; Trevino, Manuel; Alex, Vaysburd; Johan, Silfwerbrand

    2013-01-01

    The recommendations presented in this publication are inspired by the State of the Art Report edited by the RILEM technical committee TC 193 RLS Bonded cement-based material overlays for the repair, the lining or the strengthening of slabs and pavements. The objective is to lay out all the practical aspects to be considered in the design of concrete overlays: bonded concrete overlay process, assessment of the existing structure, surface preparation, overlay materials, design methods, construc...

  19. Strain distribution and crack detection in thin unbonded concrete pavement overlays with fully distributed fiber optic sensors

    Science.gov (United States)

    Bao, Yi; Chen, Genda

    2016-01-01

    This study aims at evaluating the feasibility of strain measurement and crack detection in thin unbonded concrete pavement overlays with pulse prepump Brillouin optical time domain analysis. Single-mode optical fibers with two-layer and three-layer coatings, respectively, were applied as fully distributed sensors, their performances were compared with analytical predictions. They were successfully protected from damage during concrete casting of three full-scale concrete panels when 5 to 10-cm-thick protective mortar covers had been set for 2 h. Experimental results from three-point loading tests of the panels indicated that the strain distributions measured from the two types of sensors were in good agreement, and cracks can be detected at sharp peaks of the measured strain distributions. The two-layer and three-layer coated fibers can be used to measure strains up to 2.33% and 2.42% with a corresponding sensitivity of 5.43×10-5 and 4.66×10-5 GHz/μɛ, respectively. Two cracks as close as 7 to 9 cm can be clearly detected. The measured strains in optical fiber were lower than the analytical prediction by 10% to 25%. Their difference likely resulted from strain transfer through various coatings, idealized point loading, varying optical fiber embedment, and concrete heterogeneity.

  20. Research on the Skidproof and Wearable Cement Concrete Pavements%水泥混凝土路面抗滑、耐磨性的研究

    Institute of Scientific and Technical Information of China (English)

    谷惠菊; 毕东辉

    2000-01-01

    通过分析水泥砼路面抗滑、耐磨性的影响因素,介绍了水泥砼路面抗滑、耐磨性的技术条件及措施。%Through the analyses of the skidproof and wearable cement concrete pavements the countermeasures are given.

  1. Discussion on maintenance of asphalt concrete pavement in the rural highway%论农村公路沥青混凝土路面养护方法

    Institute of Scientific and Technical Information of China (English)

    邹海洋

    2013-01-01

    Asphalt concrete pavement with many excellent properties is widely used in road construction.But the asphalt concrete pavement in the use of the process will still exist all kinds of diseases,these diseases will have a very negative impact on the road quality and traffic safety.This paper expounds the importance of rural highway maintenance,then introduces the diseases and causes of asphalt concrete pavement,at last puts forward maintenance measures of asphalt concrete pavement of rural highway.%沥青混凝土路面具备很多优良的性能,在道路建设中应用非常广泛。但是沥青混凝土路面在使用过程中,还是会存在各种各样的病害,这些病害对公路质量水平和行车安全会产生十分不利的影响。文章阐述了农村公路养护的重要性,介绍了沥青混凝土路面的病害和成因,并提出了农村公路沥青混凝土路面养护措施。

  2. Effect of Curing Temperature Histories on the Compressive Strength Development of High-Strength Concrete

    Directory of Open Access Journals (Sweden)

    Keun-Hyeok Yang

    2015-01-01

    Full Text Available This study examined the relative strength-maturity relationship of high-strength concrete (HSC specifically developed for nuclear facility structures while considering the economic efficiency and durability of the concrete. Two types of mixture proportions with water-to-binder ratios of 0.4 and 0.28 were tested under different temperature histories including (1 isothermal curing conditions of 5°C, 20°C, and 40°C and (2 terraced temperature histories of 20°C for an initial age of individual 1, 3, or 7 days and a constant temperature of 5°C for the subsequent ages. On the basis of the test results, the traditional maturity function of an equivalent age was modified to consider the offset maturity and the insignificance of subsequent curing temperature after an age of 3 days on later strength of concrete. To determine the key parameters in the maturity function, the setting behavior, apparent activation energy, and rate constant of the prepared mixtures were also measured. This study reveals that the compressive strength development of HSC cured at the reference temperature for an early age of 3 days is insignificantly affected by the subsequent curing temperature histories. The proposed maturity approach with the modified equivalent age accurately predicts the strength development of HSC.

  3. Environmental performance and mechanical analysis of concrete containing recycled asphalt pavement (RAP) and waste precast concrete as aggregate.

    Science.gov (United States)

    Erdem, Savaş; Blankson, Marva Angela

    2014-01-15

    The overall objective of this research project was to investigate the feasibility of incorporating 100% recycled aggregates, either waste precast concrete or waste asphalt planning, as replacements for virgin aggregates in structural concrete and to determine the mechanical and environmental performance of concrete containing these aggregates. Four different types of concrete mixtures were designed with the same total water cement ratio (w/c=0.74) either by using natural aggregate as reference or by totally replacing the natural aggregate with recycled material. Ground granulated blast furnace slag (GGBS) was used as a mineral addition (35%) in all mixtures. The test results showed that it is possible to obtain satisfactory performance for strength characteristics of concrete containing recycled aggregates, if these aggregates are sourced from old precast concrete. However, from the perspective of the mechanical properties, the test results indicated that concrete with RAP aggregate cannot be used for structural applications. In terms of leaching, the results also showed that the environmental behaviour of the recycled aggregate concrete is similar to that of the natural aggregate concrete. Copyright © 2013 Elsevier B.V. All rights reserved.

  4. Field Investigation of High Performance Pavements in Virginia

    OpenAIRE

    2005-01-01

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

  5. Construction Techniques of Asphalt Concrete Pavement%浅析沥青混凝土路面施工技术

    Institute of Scientific and Technical Information of China (English)

    席晓彬

    2012-01-01

    随着我国公路建设事业的发展,沥青混凝土路面由于具有表面平整、行车舒适、耐磨、噪音小、施工周期短、养护维修简便等优点,无扬尘、无振动,还具有良好的抗滑性,因而被越来越多地应用到公路建设中。因此,只有对施工组织设计以及每道工序严格地控制,才能保证沥青混凝土路面的质量。%With the development of highway construction in China,asphalt concrete pavement is widely used for its advantages of smooth surface,comfortable driving,abrasion resistance,low noise,short construction period and easy maintenance and repair,and its non-dust and non-vibration construction with better slip resistance.Therefore,every procedure in construction and design should be strictly controlled to guarantee the quality of the pavement.

  6. The Impact of Traffic-Induced Bridge Vibration on Rapid Repairing High-Performance Concrete for Bridge Deck Pavement Repairs

    Directory of Open Access Journals (Sweden)

    Wei Wang

    2014-01-01

    Full Text Available Based on forced vibration tests for high-performance concrete (HPC, the influence of bridge vibration induced by traveling vehicle on compressive strength and durability of HPC has been studied. It is concluded that 1 d and 2 d compressive strength of HPC decreased significantly, and the maximum reduction rate is 9.1%, while 28 d compressive strength of HPC had a slight lower with a 3% maximal drop under the action of two simple harmonic vibrations with 2 Hz, 3 mm amplitude, and 4 Hz, 3 mm amplitude. Moreover, the vibration had a slight effect on the compressive strength of HPC when the simple harmonic vibration had 4 Hz and 1 mm amplitude; it is indicated that the amplitude exerts a more prominent influence on the earlier compressive strength with the comparison of the frequency. In addition, the impact of simple harmonic vibration on durability of HPC can be ignored; this shows the self-healing function of concrete resulting from later hydration reaction. Thus, the research achievements mentioned above can contribute to learning the laws by which bridge vibration affects the properties of concrete and provide technical support for the design and construction of the bridge deck pavement maintenance.

  7. Structuring of nanomodified concrete cured in different temperature and humidity conditions

    Directory of Open Access Journals (Sweden)

    Voronin Viktor

    2016-01-01

    Full Text Available The article deals with the issues on the influence of the curing conditions on the formation of structure and properties of the concrete with nanomodifiers. Mechanochemically activated waste generated by the production of mineral fertilizers was used as nanomodified additives. It was established that providing favorable conditions for the initial structuring of concrete was the purpose of erecting structures made of concrete mix with said nanomodified additives in different temperature and humidity environments. It is provided that different types of production waste gaining the properties of efficient additives for binders, concrete mixes and compositions made on their basis as the result of the corresponding processing will be used as mineral fillers. Production waste is generally characterized by a heterogeneous composition and structure, by impurity content and by low chemical activity. Thus, one of the methods for increasing the efficiency of the waste is mechanical, chemical or physical activation. As the result of such activation, nanosizeparticles appear, and additional defects of mineral lattices are generated, which leads to accelerating the elementary interaction of the surface layer particles. Data on the research of macro- and microstructure of concrete and composites with nanomodifiers cured in different temperature and humidity conditions is given in the table.

  8. 贝克曼梁法测试水泥砼路面弯沉及路面持荷能力评价%Backman Beam Method Test of Cement Concrete Pavement Deflection and Pavement Loading Capacity Evaluation

    Institute of Scientific and Technical Information of China (English)

    2013-01-01

    Backman beam method for detection of the cement concrete pavement is widely used at home and abroad, and it is the main method of cement concrete pavement strength of our survey, there are a lot of the joint of cement concrete pavement, in the long-term running effect and infiltration of rainwater ef-fect, very easy to cause the void beneath slab. According to the Backman beam method detection deflection data, this paper pr-oposes treatment scheme on the plate considering the road blo-ck bearing capacity, load transfer capability, and verifies.%  贝克曼梁法检测水泥混凝土路面板底脱空是国内外广泛使用的方法,也是我国水泥混凝土路面路面强度调查的主要方法,水泥混凝土路面有很多接缝,在长期行车作用及雨水渗入作用下,很容易造成板底脱空。本文根据贝克曼梁法检测的弯沉数据,在综合考虑路面板块承载能力、传荷能力的情况对板块提出了处理方案,并进行了实例验证。

  9. 高性能沥青混凝土机场道面结构%Airfield pavement with high performance asphalt concrete

    Institute of Scientific and Technical Information of China (English)

    钱振东; 孟凡奇; 曾靖

    2015-01-01

    To improve the anti-rutting performance of airfield pavement, a high performance airfield pavement based on a new type of epoxy asphalt concrete was proposed.With the new type of epoxy asphalt concrete EAC20 as the middle surface course, SMA13 asphalt concrete as the first surface course, and AC20 asphalt concrete as the base surface course, the SEA airfield pavement was built up.The mechanical responses of the SEA airfield pavement under the static loads of the aircraft A380 were analyzed.The permanent deformation tests of the asphalt concrete in different airfield pavement layers were carried out.The creep parameters of the asphalt concrete in each layer were obtained by using the multiple linear regression method to simulate the permanent deformation of the SEA airfield pavement.The results demonstrate that taking the new type of epoxy asphalt concrete as the middle surface course can reduce the strain of the airfield pavement.The maximum tensile strain and the maximum compressive strain on the bottom of the asphalt surface course are respectively about 68%and 72%those of the traditional airfield pavement.Under 1 ×105 loads, the permanent deformation of the SEA airfield pavement is only 6 mm, which is about 42.9%that of the traditional SAA airfield pavement.%为增强机场沥青道面的抗轮辙性能,提出了一种基于新型环氧沥青混凝土的高性能机场道面结构.将新型环氧沥青混凝土EAC20作为机场道面的中面层,SMA13型沥青混凝土作为上面层,AC20型沥青混凝土作为下面层,由此构成SEA机场道面结构.分析了新一代大型客机A380荷载作用下SEA机场道面结构的力学响应,针对机场道面各层沥青混凝土进行永久变形试验,并采用多元线性回归得到各层材料的蠕变参数,以模拟SEA机场道面结构的永久变形.研究结果表明,将新型环氧沥青混凝土作为中面层应用于机场道面,可以减小机场道面结构的应变,沥

  10. An Investigation of Steam Curing Pressure Effect on Pozzolan Additive Autoclaved Aerated Concrete

    Directory of Open Access Journals (Sweden)

    Kadir Güçlüer

    2015-02-01

    Full Text Available Autoclaved Aerated Concrete (AAC is a porous light weight concrete obtained by adding a pore-forming material to a mixture made of finely pulverized siliceous aggregate and inorganic binder (lime and/or cement and hardened by steam cure. In this study fly ash was used instead of siliceous aggregate and experiment samples were obtained by adding 3%, 6%, 9%, 12% silica fume to the cement. Samples were cured under 1560C and 4 bars and 1770C and 8 bars, and were investigated for compressive strength, bulk density and ultrasound pulse velocity to determine their mechanical and physical properties. Microstructure of samples was observed by using SEM and XRD techniques. Samples’ bulk density values and compressive strengths are changing between 0.6-0.7 kg/dm3 and 2.5-4.4 MPa respectively.

  11. Evaluation of Precast Portland Cement Concrete Panels for Airfield Pavement Repairs

    Science.gov (United States)

    2015-05-01

    space for thermal expansion of the parent PCC and panels. Dowels that are too small or weak grout around the dowels could also cause high stress...resulting from either settlement of the pavement from a weak foundation or significant abrupt surface deterioration. Elevation changes in excess of 3...face is calculated using the equation tP zM 0 2 . (E.14) To calculate the deflection at the face of the joint (x=0) where the maxi - mum

  12. The influence of the curing conditions of concrete on durability after freeze-thaw accelerated testing

    Directory of Open Access Journals (Sweden)

    Al-Assadi, G.

    2015-12-01

    Full Text Available This work relates the curing conditions of concrete with the damage caused by rapid freeze-thaw cycles (ASTM C 666. The “potential” durability of concrete after testing is also studied. In countries with a continental climate, the curing of concrete in summer is performed under high-temperature and low-humidity conditions, and during the winter the concrete undergoes freezing and thawing. This paper shows the experimental results of the behaviour of concrete specimens cured under climatic summer conditions and then subjected to freeze-thaw cycles. Curing of the specimens includes conditions of good and bad practice in relation to wetting and protection of the concrete. Mechanical properties, cement hydration, volume and pore sizes, oxygen permeability, chloride diffusion and water penetration under pressure tests of the concrete are assessed. These tests were performed before and after the application of the freeze-thaw cycles. Statistical analysis of the correlation among variables is also included.Este trabajo relaciona las condiciones de curado del hormigón con los daños causados por ciclos hielo-deshielo (ASTM C 666. Estudia la durabilidad “potencial” del hormigón dañado por este ensayo. En países con clima continental, el curado del hormigón en verano se realiza con alta temperatura y baja humedad, y durante el invierno sufre condiciones de hielo-deshielo. Se presentan los resultados experimentales de probetas de hormigón curadas bajo condiciones climáticas del verano y luego sometidas a ciclos hielo-deshielo. El curado de las probetas incluye condiciones de buenas y malas prácticas en relación con el curado del hormigón. Se miden las propiedades mecánicas, grado de hidratación, volumen de poros y distribución de tamaños, permeabilidad al oxígeno, penetración de agua bajo presión y coeficiente de difusión de cloruros antes y después de la aplicación de los ciclos de hielo-deshielo. Se incluye un estudio estad

  13. Cracking of open traffic rigid pavement

    Directory of Open Access Journals (Sweden)

    Niken Chatarina

    2017-01-01

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

  14. Discussion on crack problems of asphalt concrete pavement%沥青混凝土路面裂缝问题的探讨

    Institute of Scientific and Technical Information of China (English)

    李泽林

    2012-01-01

    分析了公路沥青混凝土路面裂缝的类型、形成原因及影响因素,阐述了裂缝对路面的危害,提出了对沥青路面裂缝的预防措施与处治方法,并分别作了具体介绍,以期指导实践。%This paper analysed the crack types, formation causes and influence factors of highway asphalt concrete pavement, elaborated the harm of cracks to pavement, proposed to the prevention measures and treatment methods to asphalt pavement cracks, and made detailed introduction, in order to guide practice.

  15. Comparison of Strength for Concrete with GGBS and Cement Using Accelerated Curing Method

    Directory of Open Access Journals (Sweden)

    K. Shyamala

    2016-10-01

    Full Text Available Ground granulated blast-furnace slag ( GGBS is the granular material formed iron ore is molted. blast furnace slag is by-product of steel manufacture which is sometimes used as a substitute for Portland cement. In steel industry when iron ore is molted, then in the molted state all the impurities come at its surface which are removed called slag. It consists mainly of the silicates and alumino silicates of calcium, which are formed in the blast furnace in molten form simultaneously with the metallic iron. Blast furnace slag is blended with Portland cement clinker to form portland blast furnace slag cement. GGBS is used to make durable concrete structures in combination with ordinary Portland cement and/or other pozzolanic materials. GGBFS has been widely used in Europe, and increasingly in the United States and in Asia (particularly in Japan and Singapore for its superiority in concrete durability, extending the lifespan of buildings from fifty years to a hundred years. This project presents the feasibility of the usage of GGBS as hundred percent substitutes for Ordinary portland cement in concrete. Design mix for M20 and M30 has been calculated using IS 10262-2009 for both accelrated curing in warm water and accelrated curing in boiling water method. Tests were conducted on cubes to study the strength of concrete by using GGBS and Ordinary portland cement

  16. 机场水泥混凝土道面施工质量控制技术%Quality Control Technology for Airport Cement Concrete Pavement Construction

    Institute of Scientific and Technical Information of China (English)

    董军; 贡文献

    2011-01-01

    针对机场水泥混凝土道面施工中容易出现掉边掉角、表面网状或环状裂纹、板体断裂和蜂窝麻面等质量通病,根据大面积混凝土铺筑施工的特点和环境因素,综合分析其质量通病产生的原因,并提出相应的施工控制措施,在实践中取得了明显效果,可供水泥混凝土道面施工参考.%For the common quality defects on airport cement concrete pavement such as side or corner peeling,surface pattern crack or annular crack, slab fracture, and voids and pits, according to the characteristics of large area concrete pavement construction and environmental factors, the causes of these quality defects are analyzed and the corresponding control measures are put forward, which have achieved significant effect in practical engineering. These measures can be reference for cement concrete pavement construction.

  17. Strength development characteristics of concrete produced with blended cement using ground granulated blast furnace slag (GGBS) under various curing conditions

    Indian Academy of Sciences (India)

    SHAHAB SAMAD; ATTAULLAH SHAH; MUKESH C LIMBACHIYA

    2017-07-01

    To reduce the embodied carbon dioxide of structural concrete, Portland cement (PC) in concrete can be partially replaced with ground granulated blast furnace slag (GGBS). In this research effect of partial replacement of cement with GGBS on strength development of concrete and cured under summer and wintercuring environments is established. Three levels of cement substitution i.e., 30%, 40% and 50% have been selected. Early-age strength of GGBS concrete is lower than the normal PC concrete which limits its use in the fast-track construction and post-tensioned beams which are subjected to high early loads. The strength gainunder winter curing condition was observed as slower. By keeping the water cement ratio low as 0.35, concrete containing GGBS up to 50% can achieve high early-age strength. GGBS concrete gains more strength than the PC concrete after the age of 28 day till 56 day. The mechanical properties of blended concrete for various levels of cement replacement have been observed as higher than control concrete mix having no GGBS.

  18. Investigation of photon shielding property changes in curing high density concrete.

    Science.gov (United States)

    Marsh, Matthew B; Peters, Christopher; Rawluk, Nicholas; Schreiner, L John

    2013-10-01

    High density concrete is usually used for radiation shielding around radiotherapy treatment rooms. Because the concrete is specified differently at the design, construction, and verification stages, the relationship between the intended performance and the actual performance of the shielding material might not be entirely clear. In this study, cylindrical samples of high density shielding concrete were taken as each section of a new radiotherapy bunker was poured. The shielding performance of each sample [measured by beam attenuation and tenth-value layers (TVL)] was evaluated for 15 MV and 6 MV x-ray beams and for the 1.25 MeV monoenergetic gamma beam from a Co source. Transmission curves to 3 TVL were mapped for a representative sample. The samples were also imaged and analyzed using Co Cone Beam Computed Tomography (CoCBCT). Results indicate no significant change in the TVL of high density concrete samples as they cure. The minor fluctuations in shielding properties observed are explained by the heterogeneous structure of the samples as indicated in the CoCBCT images.

  19. Experimental and Empirical Time to Corrosion of Reinforced Concrete Structures under Different Curing Conditions

    Directory of Open Access Journals (Sweden)

    Ahmed A. Abouhussien

    2014-01-01

    Full Text Available Reinforced concrete structures, especially those in marine environments, are commonly subjected to high concentrations of chlorides, which eventually leads to corrosion of the embedded reinforcing steel. The total time to corrosion of such structures may be divided into three stages: corrosion initiation, cracking, and damage periods. This paper evaluates, both empirically and experimentally, the expected time to corrosion of reinforced concrete structures. The tested reinforced concrete samples were subjected to ten alternative curing techniques, including hot, cold, and normal temperatures, prior to testing. The corrosion initiation, cracking, and damage periods in this investigation were experimentally monitored by an accelerated corrosion test performed on reinforced concrete samples. Alternatively, the corrosion initiation time for counterpart samples was empirically predicted using Fick’s second law of diffusion for comparison. The results showed that the corrosion initiation periods obtained experimentally were comparable to those obtained empirically. The corrosion initiation was found to occur at the first jump of the current measurement in the accelerated corrosion test which matched the half-cell potential reading of around −350 mV.

  20. Multifractal Characteristics of Asphalt Concrete Pavement Macrotexture%沥青混凝土路面宏观纹理的多重分形特征

    Institute of Scientific and Technical Information of China (English)

    苗英豪; 宋萍萍

    2013-01-01

    为深入分析沥青混凝土路面表面宏观纹理特征,在12条不同等级的道路上,选取了包含沥青混凝土(AC)、沥青玛蹄脂碎石(SMA)、开级配抗滑磨耗层(OGFC)、微表处(MS)和稀浆封层(SS)等路面类型的35个测试点,利用激光断面仪开展了路面表面宏观纹理断面的现场测试.分析表明,沥青混凝土路面表面宏观纹理断面具有典型的多重分形特征,多重分形谱呈向右的钩形,多重分形谱的分布宽度(△a)反映了路面断面起伏幅度的变化范围,与路面表面平均断面深度(MPD)之间有较为显著的相关性.最小概率子集与最大概率子集的分形维数差(△f(a))表征了路面表面纹理不同起伏幅度的分布情况,从一个新的角度描述了路面表面断面的特征,丰富了对路面表面宏观纹理特征的描述.%To deeply understand the features of asphalt concrete pavement macrotexture, field tests are conducted using laser profile tester at 35 test sites in 12 sections with 5 pavement types including Asphalt Concrete (AC), Stone Matrix Asphalt (SMA), Open Graded Friction Course (OGFC), Micro-Surfacing (MS) , and Slurry Seal (SS). It is shown that profile of asphalt concrete pavement macrotexture has significant multifractal property. All multifractal spectrums are like a hook facing right. The width of multifractal spectrum (△a) indicates the variation range of profile amplitude, which has significant correlation-ship with the Mean Profile Depth (MPD). Fractal dimension difference between the subset with minimum probability and the subset with maximum probability (△f(a)) describes the distribution of profile amplitude which characterizes the pavement macrotexture from another view and is a new choice for asphalt concrete pavement macrotexture charecterization.

  1. Producing Durable Continuously Reinforced Concrete Pavement using Glass-ceramic Coated Reinforcing Steel

    Science.gov (United States)

    2010-02-01

    Portland cement is manufactured by firing the clinker at 1400 C Enamel application produces no changes BUILDING STRONG® Treatment Average Peak...ceramic Coated Reinforcing Steel 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) 5d. PROJECT NUMBER 5e. TASK NUMBER... transition zone at the surface of the reinforcement steel is often the most permeable part of the concrete BUILDING STRONG® Schematic of Ceramic

  2. es on Strength Characteristics of Pond Ash Replaced Fibre Reinforced Pavement Quality Concrete

    Directory of Open Access Journals (Sweden)

    Anand G Patil

    2015-08-01

    Full Text Available Energy consumption and generation is increasing day by day due to rapid industrialization & urbanization. A major portion of the energy is generated by Thermal Power Plants. Pond ash (PA and other by-products from these plants are disposed in large quantities. Pond ash utilization helps to reduce the consumption of natural resources. Hence there is scope for using Pond ash as Fine Aggregate (FA. Use of alternative material in concrete such as industrial by-products like Coal Ash (Fly Ash and Pond Ash is eco-friendly. This study reports the results of experimental studies carried out on the use of Pond ash as Fine Aggregate (FA in concrete with and without fibre reinforcement. The properties of Pond Ash were compared to the standard sand. The pond ash added by weight is 10%,20%,30%,40%,50% and 60% respectively as replacement of FA in concrete and 2% low tensile steel fibre was used for reinforcement. Experiments carried out indicate that Pond ash as partial replacement of sand has beneficial effect on the mechanical properties. The strength properties are determined for various percentages (10-60% of replacement of Fine Aggregate with Pond ash with and without fibre reinforcement. The test results indicate that the optimum PA replacement is 20% for both the cases.

  3. Effect of GGBS and curing temperature on microstructure characteristics of lightweight geopolymer concrete

    Directory of Open Access Journals (Sweden)

    El-Hassan Hilal

    2017-01-01

    Full Text Available Cement replacement by supplementary cementitious materials has been gaining momentum as a sustainable mechanism to reduce greenhouse gas emissions while also recycling industrial by-products. This paper presents the development and microstructure characterization of fly ash-based lightweight geopolymer concrete incorporating ground granulated blast furnace slag (GGBS. Concrete samples were prepared with 0%, 25% and 50% GGBS replacement and cured at 30°C, 60°C, and ambient temperature. While dune sand and lightweight expanded clay were used as aggregates, a mixture of sodium silicate and sodium hydroxide served as the alkaline activation solution. Microstructure evaluation was carried out at 7 and 28 days employing scanning electron microscopy (SEM, Fourier transform infrared spectroscopy (FTIR, and differential scanning calorimetry (DSC. Residual fly ash and GGBS were identified in the concrete and bonded to geopolymeric reaction products. The microstructure highlighted the formation and coexistence of aluminosilicate hydrate and aluminum-rich calcium silicate hydrate with traces of sodium. Subsequent polymerization was also verified by an increase in FTIR and DSC peaks.

  4. Application of Polyester Fiber Concrete in Steel Footbridge Pavement%聚酯纤维混凝土在钢制人行天桥铺装中的应用

    Institute of Scientific and Technical Information of China (English)

    马淑霞; 李强

    2015-01-01

    Aiming at the steel footbridge, this paper discusses and summarizes the relevant issues in the application of fiber concrete in bridge pavement, and observes the pavement effect.%本文针对钢制人行天桥,讨论并总结了纤维混凝土在桥面铺装应用中的相关问题,跟踪观察了铺装效果。

  5. Properties of microcracks formed on surface of concrete at steam curing period; Concrete no joki yosei katei de hasseisuru hyomen bisai hibiware no seijo ni kansuru kenkyu

    Energy Technology Data Exchange (ETDEWEB)

    Otsuka, K. [Tohoku Gakuin Univ., Miyagi (Japan). Faculty of Engineering; Shoya, M. [Hachinohe Inst. of Technology, Aomori (Japan). Faculty of Engineering; Koseki, K. [PS Co. Ltd., Tokyo (Japan); Aba, M. [Tohoku Gakuin Univ., Miyagi (Japan). Graduate School

    1995-08-20

    Development of microcracks on the surface of steam curing concrete is considered as a main cause for damage claim on manufactured products while in use. Melting and freezing characters of seepage liquid through surface cracks are regarded as drawbacks for the durability of manufactured products. In this study, an unique X-ray inspection technique is developed to investigate the microcrack formation. Considering reinforced concrete specimens, effects of steam curing conditions on the formation of microcracks are investigated by experiments. Three different kinds of microcracks are observed at each steam curing conditions. Influences of various factors on microcrack formation are also studied. Impacts of pre-curing period, rate of cooling and rate of temperature rise on the microcrack formation are very large, large and small respectively. Again the results are analyzed by comparing with various steam curing specifications from the crack prevention point of view. The results under pre-curing condition are not satisfied with the steam curing specifications. 9 refs., 28 figs., 11 tabs.

  6. Application Study on Geotextile as Bond-Breaking Layer Between Concrete Pavement Slab and Lean Concrete Base%土工布作水泥混凝土路面隔离层应用研究

    Institute of Scientific and Technical Information of China (English)

    林天干; 姚佳良; 于远征; 袁剑波

    2012-01-01

    主要结合广东、湖南等省高速公路中采用土工布作水泥混凝土路面隔离层进行的路面层间力学性能试验与工程应用研究,探讨了贫混凝土基层上铺筑水泥混凝土面层时采用土工布隔离层与无隔离层时的层间力学性能差别.通过现场试验路施工,总结了土工布用于路面隔离层的施工控制技术.获得的土工布隔离层层间力学性能参数与施工应用技术,为实体工程路面设计、施工控制提供了科学依据.%This research explored the difference in mechanical performance of slab-base interface between the pavements without a bond-breaking layer and the pavements with geotextile as the bond-breaking layer installed between the concrete pavement surface slab and the lean concrete base, via the field tests for mechanical performance of slab-base interface treated with geotextile as the bond-breaking layers in some highway projects of Hunan and Guangdong Provinces. The techniques of construction control in placing geotextile atop the lean concrete base as the bond-breaking layer is concluded from the construction of the field test roads. The mechanical performance of slab-base interface with geotextile as the bond-brea king medium derived from this research and the techniques of construction offer scientific reference to pavement design and construction control in the practical road engineering projects.

  7. Application of Concrete Curing Technology in Practice%混凝土养护技术在实际当中的应用

    Institute of Scientific and Technical Information of China (English)

    李庆利

    2015-01-01

    This paper introduce the concrete curing principle.And briefly introduce the concrete curing technology standards,concrete curing technology of natural curing method, heating curing method and cold raise law enforcement three different curing methods, make people understand the concrete curing technology.%本文介绍了混凝土的养护原理,并简述混凝土养护技术的相关标准,混凝土养护技术的自然养护方法、加热养护方法和冷养护法三种不同的养护方法,使人们了解混凝土养护技术.

  8. Infiltration and Evaporation of Diesel and Gasoline Droplets Spilled onto Concrete Pavement

    Science.gov (United States)

    Hilpert, M.; Adria-Mora, B.

    2015-12-01

    Pollution at gas stations due to small spills that occur during refueling of customer vehicles has received little attention. We have performed laboratory experiments in order to assess the processes of evaporation and infiltration of fuel spilled onto concrete samples. Changes in mass of both spilled diesel and gasoline droplets as a function of time have been analyzed. The infiltrated mass is affected by variations in humidity, among other parameters, which influence the amount of water condensed onto the concrete. Therefore, we used a humidity data logger and statistical tools to predict the evolution of the real mass of infiltrated fuel. The infiltrated mass roughly decreases exponentially, but the difference in behavior between both fuel types is important. The percentage of evaporated mass is much larger for gasoline, while infiltration is more significant for diesel. Also, the percentage of infiltrated liquid depends on the initial droplet mass. We also developed a multiphysics model, which couples pore-scale infiltration to turbulent atmospheric transport, to explain the experimental data. In conclusion, a substantial amount of fuel could both seep into the ground to contaminate groundwater and be released to the atmosphere. More studies are needed to quantify the public health implications of the released pollutants.

  9. Influence of Curing Age and Mix Composition on Compressive Strength of Volcanic Ash Blended Cement Laterized Concrete

    Directory of Open Access Journals (Sweden)

    Babafemi A.J.

    2012-01-01

    Full Text Available This study investigates the influence of curing age and mix proportions on the compressive strength of volcanic ash (VA blended cement laterized concrete. A total of 288 cubes of 100mm dimensions were cast and cured in water for 3, 7, 28, 56, 90 and 120 days of hydration with cement replacement by VA and sand replacement by laterite both ranging from 0 to 30% respectively while a control mix of 28-day target strength of 25N/mm2 (using British Method was adopted. The results show that the compressive strength of the VA-blended cement laterized concrete increased with the increase in curing age but decreased as the VA and laterite (LAT contents increased. The optimum replacement level was 20%LAT/20%VA. At this level the compressive strength increased with curing age at a decreasing rate beyond 28 days. The target compressive strength of 25N/mm2 was achieved for this mixture at 90 days of curing. VA content and curing age was noted to have significant effect (α ≤ 0.5 on the compressive strength of the VA-blended cement laterized concrete.

  10. 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。

  11. Optimization of the accelerated curing process of concrete using a fibre Bragg grating-based control system and microwave technology

    Science.gov (United States)

    Fabian, Matthias; Jia, Yaodong; Shi, Shi; McCague, Colum; Bai, Yun; Sun, Tong; Grattan, Kenneth T. V.

    2016-05-01

    In this paper, an investigation into the suitability of using fibre Bragg gratings (FBGs) for monitoring the accelerated curing process of concrete in a microwave heating environment is presented. In this approach, the temperature data provided by the FBGs are used to regulate automatically the microwave power so that a pre-defined temperature profile is maintained to optimize the curing process, achieving early strength values comparable to those of conventional heat-curing techniques but with significantly reduced energy consumption. The immunity of the FBGs to interference from the microwave radiation used ensures stable readings in the targeted environment, unlike conventional electronic sensor probes.

  12. 浅谈水泥混凝土路面平面及接缝设计%Discussion on Cement Concrete Pavement Plane and Joints Design

    Institute of Scientific and Technical Information of China (English)

    郝勇

    2011-01-01

    对于不配钢筋的水泥混凝土路面,须按照温度应力的计算方法确定板块平面尺寸,并遵循一定的规则将公路路面分割为整齐的平面块体,以防止不规则裂缝的产生.%For the cement concrete pavement which is not equipped with rebar, we should determine the plate plane size in accordance with the calculating method of temperature stress, and make road surface divide into tidy flat block following certain rules to prevent irregular cracks.

  13. 再生混凝土路面砖性能研究进展%Research progress on properties of recycled concrete pavement brick

    Institute of Scientific and Technical Information of China (English)

    夏雄; 李淋淋; 谢飞飞; 朱平华

    2016-01-01

    Recent advances on the influence of several factors on strength property of recycled concrete pavement brick were summa-rized comprehensively,including the water-binder ratio,quality and dosages of recycled coarse aggregate,type and volumes of mineral additions and sulfate attack. It was pointed out that lower water-binder ratio,recycled coarse aggregate with high quality and mineral admixture with appropriate amount were effective ways to enhanced strength of recycled concrete road brick. Then,abrasion resistance, anti-frost performance and dry shrinkage of recycled concrete pavement brick were introduced briefly. Properties of recycled concrete road brick were also considered in the complicated surroundings. Finally,some key scientific issues in performances of recycled concrete pavement brick were put forward,including change regulation and evolution mechanism of properties of recycled concrete road brick subjected to load and multi-environmental factors simultaneously.%首先从水胶比、再生粗骨料质量及掺量、矿物掺合料种类与掺量以及硫酸盐侵蚀4个因素入手对再生混凝土路面砖强度影响的研究进展进行了归纳总结,指出降低水胶比、提高再生粗骨料的质量、掺加适量的矿物掺合料是提高再生混凝土路面砖强度的有效途径。简要介绍了再生混凝土路面砖的耐磨性、抗冻性以及干燥收缩性,认为应考虑复杂环境下再生混凝土路面砖的性能。提出了再生混凝土路面砖亟待解决的一些关键问题,包括荷载与环境因素耦合下再生混凝土路面性能变化规律与演变机理。

  14. 机场道面混凝土夏季施工裂缝防治措施%Crack Prevention Measures for Airport Concrete Pavement in Summer

    Institute of Scientific and Technical Information of China (English)

    朱仁兴; 许军; 许永坤; 杨大志; 叶勇

    2011-01-01

    针对某机场现浇混凝土道面板在夏季施工过程中出现的裂缝现象,综合考虑环境条件与工程特点,从材料品质、施工和环境条件等方面分析了裂缝产生的原因,并提出了相应的防治措施,在实践中取得了显著效果,可供干旱、多风地区道面混凝土夏季施工参考。%Against the cracks in cast-in-situ slab of airport concrete pavement during construction in summer,considering the environmental conditions and engineering characteristics,the causes of cracks in the aspects of material,construction and environment are analyzed,and the corresponding control measures are put forward in this paper.These measures have achieved good results in practice,which can serve as a reference for concrete pavement construction in summer in drought and windy areas.

  15. Numerical Study on Mechanical Action of Concrete Pavement of Continuous T-beam%连续T梁桥面混凝土铺装层力学行为数值分析研究

    Institute of Scientific and Technical Information of China (English)

    马文栋

    2011-01-01

    通过对连续T梁混凝土铺装层进行三维有限元分析,研究了在车辆荷载下铺装层力学响应的最不利荷载位置,随后分别考虑了水平荷载、超载、铺装层厚度以及弹性模量对铺装层力学响应的影响,得出了一些有益的结论,对铺装层设计和施工有一定的指导作用.%Through the Sd finite element analysis of concrete pavement of continuous T-beam, the position of the most unfavorable load for the concrete pavement mechanical response is studied under the vehicle load, then the mechanical response influence of the horizontal load, overload, pavement thickness and pavement elastic modulus is respectively researched. Some useful conclusions are obtained, which may provide reference for the concrete pavement design and construction.

  16. Deflection Control in Rigid Pavements

    Science.gov (United States)

    Varunkrishna, Nulu; Jayasankar, R.

    2017-07-01

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

  17. Experimental Research on Surface Characteristics of Epoxy Asphalt Concrete Pavement%环氧沥青混凝土铺装表面特性试验研究

    Institute of Scientific and Technical Information of China (English)

    罗桑; 钱振东

    2012-01-01

    To evaluate the surface characteristics of epoxy asphalt concrete pavement,the permeability test,dynamic friction test,Cantabro test,Hamburg test,and laser texture scanning test were conducted.Results show that the coefficient of water permeability of epoxy asphalt concrete is zero,the british pendulum number is 83.6,the mass abrasion rate is 12.5%,the mean profile depth is 0.305 mm,and the estimated texture depth is 0.432 mm.Results show that the water is held into steel deck,because the waterproof performance of epoxy asphalt concrete pavement is excellent.The skid resistance is qualified for the design of bridge deck pavements,but skid of a vehicle occurs when the speed of the vehicle is high on rainy days.Raveling happens under high-temperature water and tire contact loading.The smoothness of epoxy asphalt concrete pavement is good.The surface characteristics of epoxy asphalt concrete pavement satisfy design requirement.However,skid and raveling occur under adverse weather conditions.%为了解环氧沥青混凝土铺装的表面特性,采用渗透性试验、摆式摩擦系数试验、动态摩擦系数试验、肯塔堡飞散试验、汉堡车辙试验和激光纹理扫描试验,对环氧沥青混凝土铺装的渗水性能、抗滑性能、抗松散性能以及表面纹理特征等表面特性进行了试验评价.试验结果显示,环氧沥青混凝土铺装的渗水系数基本为0,摆式摩擦系数为83.6,飞散损失率为12.5%,轮廓深度平均值为0.305 mm,纹理深度估计值为0.432 mm.研究表明,环氧沥青混凝土铺装密水性好,能有效阻止雨水侵蚀钢桥面板;抗滑性能满足设计要求,但在雨天车辆行驶速度高时,易出现车辆打滑现象;抗松散能力较好,但在高温水浴和钢轮轮载的双重作用下,混合料会出现松散和剥落情况;环氧沥青混凝土铺装表面平整度好.环氧沥青混凝土铺装层表面特性符合钢桥面铺装层的设计使用要求,但在不利天气条件下,

  18. Countermeasures for Cracks and Broken Board of Cement Concrete Pavement in Hexi Corridor Area%浅谈河西走廊地区水泥混凝土路面断板裂缝防治对策

    Institute of Scientific and Technical Information of China (English)

    徐继承

    2013-01-01

    Through the brief analysis of causes of cracks and broken board in cement concrete pavement in Hexi Corridor area, this paper expounds the prevention and treatment measures of cement concrete pavement construction in temperate mainland climate zone, which has reference significance for the road pavement construction in desert region of northwestern China.%  本文通过河西走廊地区水泥混凝土路面断板、裂缝成的简要分析,阐述了温带大陆型气候区水泥混凝土路面施工的预防和处治措施,对我国西北干旱、荒漠区路面施工具有借鉴意义。

  19. 水泥混凝土路面快速薄层修补设计与施工方法%Rapid thin-layer mending design and construction methods of cement concrete pavement

    Institute of Scientific and Technical Information of China (English)

    谢子荣

    2015-01-01

    The paper introduces the development conditions of rapid thin-layer mending material of cement concrete pavement,analyzes strengthe-ning design of rapid thin-layer mending structure of cement concrete pavement and recovering pavement function design,and explores its applica-bility construction strategies,so as to achieve good mending effect.%介绍了水泥混凝土路面快速薄层修补材料的发展状况,对水泥混凝土路面快速薄层修补结构补强设计与恢复路面功能设计进行了分析,探讨了其实用性的施工策略,以收到良好的修补效果。

  20. 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.

  1. EFFECTS OF VARYING CURING AGE AND WATER/CEMENT RATIO ON THE ELASTIC PROPERTIES OF LATERIZED CONCRETE

    Directory of Open Access Journals (Sweden)

    Ata Olugbenga

    2007-01-01

    Full Text Available This paper reports the results of investigations carried out on the effect of varying curing age and water/cement ratio on the modulus of elasticity and modulus of deformability of laterized concrete. The test specimens were made with sieved samples of selected grain size ranges of laterite used as fine aggregates to replace sand in normal concrete. Batching was by weight. Three mix ratios of (1:1½:3, (1:2:4 and (1:3:6 were used. Water/cement ratio of 0.5, 0.6, 0.7 and 0.75 were used for each of the mix ratios. The specimens were tested at curing ages of seven to 28 days. The results showed that there was a corresponding increase in both modulus of elasticity and modulus of deformability of laterized concrete due to increase in curing ages. The mix proportion, compressive strength and water/cement ratio were found to have significant effects on both modulus of elasticity and modulus of deformability of laterized concrete.

  2. 新型改性环氧沥青混合料的性能研究%Study on pavement performance of new type modified epoxy asphalt concrete

    Institute of Scientific and Technical Information of China (English)

    张昭; 李璐; 盛兴跃

    2012-01-01

    This paper manufactured a new type modified epoxy asphalt concrete by laboratory experiments. By comparing it' s Marshall performance, high-low temperature performance, and fatigue performance with American epoxy asphalt concrete, we found that the compatibility of new type modified epoxy asphalt concrete was very good, and it' s pavement performance and flexibility was better than American epoxy asphalt concrete, so it is worth being further extended.%通过室内试验,研制出了一种新型改性环氧沥青混合料,并将其马歇尔性能、高低温性能以及疲劳性能与同类进口产品美国环氧沥青混凝土进行了对比分析,发现所研制的新型环氧沥青混合料不仅相容性好,而且具有更优异的路用性能和柔韧性,值得推广应用。

  3. Strain distribution in thin concrete pavement panels under three-point loading to failure with pre-pulse-pump Brillouin optical time domain analysis (Presentation Video)

    Science.gov (United States)

    Bao, Yi; Cain, John; Chen, Yizheng; Huang, Ying; Chen, Genda; Palek, Leonard

    2015-04-01

    three types of fibers were functional until the concrete panels have experienced inelastic deformation, making the distributed strain sensing technology promising for real applications in pavement engineering.

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

    Science.gov (United States)

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

    1980-08-01

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

  5. Structural Design and Mechanical Analysis of Full-Depth High Modulus Asphalt Concrete Pavement%全厚式高模量沥青混凝土路面结构设计及力学分析

    Institute of Scientific and Technical Information of China (English)

    李涛; 刘宁; 张涛

    2013-01-01

    The pavement special program PADS is used to calculate the three kinds of asphalt concrete pavement structure thickness which are full-depth high modulus, full-depth ordinary and semi-rigid base asphalt concrete pavement, respectively. The 3-D element model of asphalt concrete pavement structure is built based on the elastic mechanics to evaluate the design bottom stress state under loads. The rutting of the three kinds of pavement is determined by using asphalt concrete pavement permanent deformation prediction method in MEPDG of the United States. Also, their fatigue life is calculated. The results show that the full-depth high modulus asphalt concrete pavement structure is able to effectively decrease the thickness of the pavement structure, at the same time exhibits the best overall performance in rutting resistance and fatigue properties.%利用路面专用程序PADS计算全厚式高模量、全厚式普通和半刚性基层3种沥青混凝土路面结构厚度;根据弹性层状理论体系,建立了上述3种沥青混凝土路面结构三维有限元模型,对路面结构在荷载作用下的设计层层底应力状态进行对比分析;应用美国MEPDG推荐的沥青混凝土路面永久变形预估方法对沥青混凝土路面结构进行车辙预估,并对其疲劳寿命进行了计算.结果表明,全厚式高模量沥青混凝土路面结构能够有效减薄路面结构厚度,是抗车辙性能及疲劳性能综合最优的路面结构类型.

  6. 南京铁心桥钢桥面热拌环氧混凝土铺装工艺研究%Hot-mixing Epoxy Asphalt Concrete Pavement Technology for Steel BridgeDeck Pavement of Tiexin Bridge in Nanjing City

    Institute of Scientific and Technical Information of China (English)

    潘军; 杨文

    2016-01-01

    Based on the steel bridge deck pavement engineering of Tiexin bridge in Nanjing city,the pavement technologies of hot mixing epoxy asphalt concrete using on steel deck were studied,inclu-ding the pavement structure design,mix design,pavement performance evaluation and construction technology.The difference of pavement construction between hot mixing and warm mixing epoxy as-phalt were also introduced in this paper.Research results show that hot mixing epoxy asphalt is suit-able for steel deck pavement due to its high stability,excellent high temperature performance and con-venient workability.%结合南京铁心桥钢桥面环氧铺装实体工程,对热拌环氧沥青混凝土铺装结构形式、热拌环氧沥青性能与混合料配合比设计、路用性能评价,以及施工工艺进行了系统研究,全面比较了热、温拌环氧沥青铺装施工工艺的区别。结果表明,热拌环氧沥青混凝土具有高强度、出色的高温稳定性,以及便捷的施工可操作性,非常适用于大跨钢桥铺装工程。

  7. Numerical Analysis on Multi-scale Structure of Asphalt Concrete Pavement%沥青路面多尺度结构的荷载响应分析

    Institute of Scientific and Technical Information of China (English)

    陈俊; 黄晓明

    2012-01-01

    In order to explore the stress and strain relation in the pavement layers under traffic load from a meso-structural perspective, the single-scale discrete element model of asphalt pavement structure was built using discrete element method (DEM). The stress and strain at the bottom of the asphalt concrete layer under vertical load were calculated. The validation of discrete element model of asphalt pavement structure was conducted by the comparison of discrete element prediction with the results from the classical program. The distribution and volumetric fraction of coarse aggregate, asphalt mastic and air voids were taken into consideration at the bottom of the asphalt layer in the validated discrete element model to build the multi-scale structure of asphalt concrete pavement. The tensile stress and strain in asphalt mastics and interface between aggregate and mastic were obtained and compared with the results from the single-scale model. Results show that the stress and strain in multi-scale structure is heterogeneous distribution. The tensile stress at the interface between aggregate and mastic is much higher than that in mastic. The ratio of stress at interfaces to the stress in mastics increases as the mastic stiffness decreases. The pavement design based on single-scale model may underestimate the tensile stress at interface between aggregate and mastic and overestimate the tensile stress in mastic.%为了从材料细观结构角度研究沥青路面结构的荷载响应,采用离散元方法,建立了柔性基层沥青路面典型结构模型,并进行了竖向荷载作用下沥青混凝土层应力和应变的计算,通过与经典路面响应程序计算结果的比较,验证了路面结构离散元模型和离散元计算方法的正确性.以验证过的路面结构模型为基础,采用较小的细观尺度描述了沥青混凝土结构层底部位置处粗集料、沥青砂浆和空隙的分布和体积大小,从而建立了路面结构的多尺度模

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

    Science.gov (United States)

    2013-09-01

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

  9. An experimental study on freeze-thaw resistance of runway pavement concrete mixed with fly ash%掺粉煤灰机场道面混凝土抗冻融试验研究

    Institute of Scientific and Technical Information of China (English)

    徐洪坤; 蔡汉

    2012-01-01

    In view of the bad durability phenomenon of airport pavement concrete in cold region of our country, based on an airport project, experimental studies on the feezing and thawing durability of runway pavement concrete mixed with fly ash. The effects of water-cement ratio,fly ash amount ratio and fly air-entraining agent of concrete were investigated. With the fly ash and content increased,the freeze-thaw resistance has been improved .which is essential to design,maintenance and predict the remaining life of cement concrete of airport pavement.%针对我国高寒地区机场道面混凝土抗冻融性能不良的现象,结合某机场工程,对掺粉煤灰机场道面混凝土进行冻融试验,探讨了水胶比、粉煤灰掺量、引气减水剂掺量对粉煤灰混凝土抗冻融耐久性的影响.结果表明,随着粉煤灰及引气减水剂掺量的增加,机场混凝土道面的抗冻融性能会相应地提高.可对高寒地区机场水泥混凝土道面设计、维护及剩余寿命预测等问题提供参考.

  10. Calculation of the temperature of asphalt concrete at making the joints of multilane road pavement of non-rigid type

    OpenAIRE

    Giyasov Botir Iminzhonovich; Kupriyanov Roman Valer’evich; Andrianov Konstantin Anatol’evich; Zubkov Anatoliy Fedorovich

    2015-01-01

    The construction quality of road surface of non-rigid type essentially depend on providing the temperature regimes in the process of laying and packing of hot asphalt concrete mixtures. In order to provide the required characteristics of asphalt concrete due to the surface width it is necessary to provide the temperature regimes of hot asphalt concrete mixture in the zones of lane connection. The hot mixture is promptly cooling right after laying within several minutes, which results, accordi...

  11. Research on Influencing Factors for Compaction Performance of Asphalt Concrete Pavement%沥青混凝土路面压实性能影响因素分析

    Institute of Scientific and Technical Information of China (English)

    韩树峰

    2013-01-01

    The compaction quality of an asphalt concrete pavement has a pivotal role on the long-term performance of the pavement. Focusing on the main influencing factors such as the material composition of asphalt mixture, pavement structure, natural environment conditions, compaction machinery and so on, the impact mode and impact extent on the compaction performance of asphalt pavement are explored and discussed here in detail. The research results could provide some references for the design of asphalt pavement materials, structure and construction.%沥青混凝土路面的压实质量对路面的长期性能具有举足轻重的作用.重点从沥青混合料的组成材料因素、路面结构、自然环境条件、压实机械设备等方面探讨其对沥青路面压实性能的影响方式和影响程度.研究成果可为沥青路面材料和结构设计及施工等方面提供一定的参考价值.

  12. Traffic generated non-exhaust particulate emissions from concrete pavement: A mass and particle size study for two-wheelers and small cars

    Science.gov (United States)

    Aatmeeyata; Kaul, D. S.; Sharma, Mukesh

    This study aimed to understand the non-exhaust (NE) emission of particles from wear of summer tire and concrete pavement, especially for two wheelers and small cars. A fully enclosed laboratory-scale model was fabricated to simulate road tire interaction with a facility to collect particles in different sizes. A road was cast using the M-45 concrete mixture and the centrifugal casting method. It was observed that emission of large particle non exhaust emission (LPNE) as well as PM 10 and PM 2.5 increased with increasing load. The LPNE was 3.5 mg tire -1 km -1 for a two wheeler and 6.4 mg tire -1 km -1 for a small car. The LPNE can lead to water pollution through water run-off from the roads. The contribution of the PM 10 and PM 2.5 was smaller compared to the LPNE particles (less than 0.1%). About 32 percent of particle mass of PM 10 was present below 1 μm. The number as well as mass size distribution for PM 10 was observed to be bi-modal with peaks at 0.3 μm and 4-5 μm. The NE emissions did not show any significant trend with change in tire pressure.

  13. The research of concrete pavement patching material based on magnesium phosphate cement%磷酸盐水泥基普通混凝土路面修补剂的研究

    Institute of Scientific and Technical Information of China (English)

    周启兆; 焦宝祥; 丁胜; 刘孝江; 蔡玉斌; 成扬

    2011-01-01

    A kind of magnesium phosphate cement(MPC) cementing agent for the use of cement concrete pavement patching is researched. The main factora influencing final setting time and compressive strength of MPC were explored. The results show that the final setting time of the optimizing MPC samples reaches 20 min.thP compressive strength of samples cured for 3 d and 28 d reaches respectively 43 MPa and 62 MPa,and its bond strength reaches respectively 6.2 MPa and 8.6 MPa when MPC made by horax and magnesium oxide which has a surface area of 1889cm2/g.the mol ratio of disodium hydrogen phosphate and potassium dihydrogen phosphate to be 1/5.%研究了一种用于水泥混凝土路面修补用的磷酸镁水泥(MPC)胶结剂,探讨了影响磷酸镁水泥终凝时间和抗压强度的主要因素.结果表明,以比表面积为1889 cm2/g的氧化镁粉末,与磷酸氢二钠/磷酸二氧钾(摩尔比)=1/5复合,并掺加硼砂可以制备终凝时间20min,3d和28d抗压强度分别达43、62MPa,粘结强度达6.2、8.6 MPa的磷酸镁水泥.

  14. 土工布在水泥混凝土路面加铺沥青层中的应用%Application of geotextile in cement concrete pavement paving asphalt layer

    Institute of Scientific and Technical Information of China (English)

    王强林

    2011-01-01

    Combining with the application of geotextile in the construction of Gui-Liu highway pavement paving asphalt layer, this paper detailedly elaborated the application of geotextile in cement concrete pavement paving asphalt concrete surface layer, emphatically introduced the materi- al properties and construction technology of geotextile, accumulated valuable experience for future similar projects construction.%结合土工布在桂柳高速公路路面加铺沥青层工程的应用,详细阐述了土工布在水泥混凝土路面加铺沥青混凝土面层中的应用,着重介绍了土工布的材料特性和施工工艺,为今后同类工程施工积累了宝贵经验。

  15. Design of Pervious Concrete Pavement and Constructed Wetland System for Rainwater Collection and Treatment%透水混凝土路面/人工湿地雨水收集处理系统的设计

    Institute of Scientific and Technical Information of China (English)

    吴文伶; 宋中南; 石云兴; 罗兰; 王珂; 戢文占; 张涛; 冯建华; 李艳稳

    2011-01-01

    Pervious concrete pavement for rainwater collection and constructed wetland for rainwater treatment are used in a rainwater collection and utilization project in Lisui town of Shunyi District, Beijing City. The design methods of pervious concrete pavement, detention tank and constructed wetland are introduced. Furthermore, the technology advantages, process flow and structure design are discussed.%北京市顺义区李遂镇某雨水收集利用工程采用透水混凝土路面收集雨水并应用人工湿地进行雨水处理,详细介绍了透水混凝土路面、调节池、人工湿地的设计方法,并对该技术的优势、工艺流程、结构设计等进行了详细探讨.

  16. 长寿命沥青混凝土路面结构特点与设计分析%Structural characteristics and design analysis of perpetual asphalt concrete pavements

    Institute of Scientific and Technical Information of China (English)

    张耀将

    2016-01-01

    关于长寿面沥青混凝土路面应用与管理的研究应该形成一个完整的体系,只是对这个话题初步进行了分析了。要加强对沥青混凝土的研究,以路面使用时间短、路面损坏现象严重的问题。%There should be a complete system about the application and management research on perpetual asphalt concrete pavements.This paper preliminarily discusses the topic.It points out that we should strengthen the research of perpetual as-phalt concrete,to solve the problem of use shortly -time -using and badly -damaged pavement.

  17. Analysis of Force Bearing Properties of Cement Concrete Pavement Base Analysis%水泥混凝土路面基层受力特性分析

    Institute of Scientific and Technical Information of China (English)

    王国业; 胡昌斌; 杨建军; 李生效

    2011-01-01

    Base is an important component of the cement concrete pavement structure.EevrFE 3-D finite element program is adopted to analyze the force bearing properties of the base.When single axle load works on the centre of the slab longitudinal joint edge,the force beating of the base is in the most unfavorable condition,and the closer the cohesion of the interlayer is ,the greater the base stress is.The base stress increases in accordance with the increase of the base module, but decreases with the increase of the pavement slab thickness, the base thickness, the base reaction module and the thickness and module of the base cushion layer.It is found that in comparison with the affecting degrees of all the structural layers on the base stress, the base module and thickness as well as the properfies of the interlayer contact face are the major elements of affecting the force bearing properties of the base.%采用EevrFE三维有限元程序对混凝土基层的受力特性进行分析.当单轴轴载作用于板纵缝边缘中部时,基层受力最为不利,层间粘结越紧密基层应力越大;基层应力随基层模量的增加而增大,但随路面板厚度、基层厚度和地基反应模量以及垫层厚度和模量的增大而降低.对比各结构层对基层应力的影响程度发现,基层模量和厚度以及层间接触界面特性是影响基层受力特性的主要因素.

  18. Mechanism of Reflection Crack Prevention by Gravel Transformation of Old Cement Concrete Pavement%旧水泥混凝土路面碎石化后防止反射裂缝机理

    Institute of Scientific and Technical Information of China (English)

    罗岩; 张涛

    2011-01-01

    At present, gravel transformation technology is commonly used to prevent reflection crack on asphalt overlay in domestic when cement concrete pavement is out of service or damaged for whatever reason.In this paper, through analyzing the causes of cracks on asphalt overlay that is directly paved on cement concrete pavement, the mechanism of reflection crack prevention by gravel transformation of cement concrete pavement is analyzed.%目前,水泥混凝土路面到达其使用年限,或其他原因遭受破坏需要重建时,国内多采用碎石化工艺来防止沥青罩面反射裂缝的产生.通过对水泥混凝土面板上直接加铺沥青层开裂成因的探讨,分析了水泥混凝土路面经碎石化后防止反射裂缝的机理.

  19. SEVERAL ISSUES ON CONCRETE CURING AGENT STUDYING AND APPLYING%混凝土养护剂研究和应用的若干问题

    Institute of Scientific and Technical Information of China (English)

    屈志中

    2001-01-01

    Earlier after concrete has been poured,curing agent is as if a water evaporating resistance.When a membrane formed,it became a vapor barrier.In the early hardening stage curing agent may prevent the concrete from over- drying;accelerate hydration and hardening;improve its strength, density, impermeability and durability in concrete cooling and curing process. Furthermore,it can also restrain shrinkage and cracks.It is efficient to use concrete curing agent in evaporating and curing process for ready- made reinforced concrete elements production.%在混凝土浇筑后初期,养护剂犹如水蒸发的抑制剂,而随着薄膜的形成,则犹如蒸汽不通过膜。在硬化的早期阶段,养护剂可阻碍混凝土结构的冷却及蒸养过程的过干燥,加速水泥的水化和混凝土的硬化,提高混凝土的强度、密度、抗渗性和耐久性,降低收缩,并可预防裂缝。在蒸养预制钢筋混凝土生产中应用养护剂是有效的。

  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. The Effects of Design Strength, Fly Ash Content and Curing Method on Compressive Strength of High Volume Fly Ash Concrete: A Design of Experimental

    Directory of Open Access Journals (Sweden)

    Solikin Mochamad

    2017-01-01

    Full Text Available High volume fly ash concrete becomes one of alternatives to produce green concrete as it uses waste material and significantly reduces the utilization of Portland cement in concrete production. Although using less cement, its compressive strength is comparable to ordinary Portland cement (hereafter OPC and the its durability increases significantly. This paper reports investigation on the effect of design strength, fly ash content and curing method on compressive strength of High Volume Fly Ash Concrete. The experiment and data analysis were prepared using minitab, a statistic software for design of experimental. The specimens were concrete cylinder with diameter of 15 cm and height of 30 cm, tested for its compressive strength at 56 days. The result of the research demonstrates that high volume fly ash concrete can produce comparable compressive strength which meets the strength of OPC design strength especially for high strength concrete. In addition, the best mix proportion to achieve the design strength is the combination of high strength concrete and 50% content of fly ash. Moreover, the use of spraying method for curing method of concrete on site is still recommended as it would not significantly reduce the compressive strength result.

  2. EFFECT OF LDPE RAW MATERIAL ON STRENGTH, CORROSION AND SORPTIVITY OF CONCRETE

    Directory of Open Access Journals (Sweden)

    R. MANIKANDRAN

    2015-04-01

    Full Text Available Many researchers focused on effect of Low Density Poly Ethylene (LDPE on bituminous pavements or concrete to modify the strength and ductility in view of reusing the abundant quantity of non-degradable LDPE material available. It also reduces the use of bituminous materials and disposal problems of such waste material. Developing countries are moving towards construction concrete pavement or converting bituminous pavements into concrete pavements. Hence in this paper an attempt has been made to study the feasibility of using LDPE raw material itself as a modifier in cement concrete with a characteristic compressive strength of 20 MPa. Present study focuses on effect of addition of LDPE raw material (3, 4 and 5% under different temperatures (70°C, 80°C and 90°C and duration of thermal curing (4, 8 and 16 hours on compressive strength, corrosion resistance and sorptivity. It was inferred from the results that, addition of LDPE raw material considerably increases the compressive strength, resistance against corrosion and permeability. Results also revealed that concrete with 3% LDPE modifier for 80°C with 4 hours of thermal curing was found to be optimum.

  3. Effect of High-Temperature Curing Methods on the Compressive Strength Development of Concrete Containing High Volumes of Ground Granulated Blast-Furnace Slag

    Directory of Open Access Journals (Sweden)

    Wonsuk Jung

    2017-01-01

    Full Text Available This paper investigates the effect of the high-temperature curing methods on the compressive strength of concrete containing high volumes of ground granulated blast-furnace slag (GGBS. GGBS was used to replace Portland cement at a replacement ratio of 60% by binder mass. The high-temperature curing parameters used in this study were the delay period, temperature rise, peak temperature (PT, peak period, and temperature down. Test results demonstrate that the compressive strength of the samples with PTs of 65°C and 75°C was about 88% higher than that of the samples with a PT of 55°C after 1 day. According to this investigation, there might be optimum high-temperature curing conditions for preparing a concrete containing high volumes of GGBS, and incorporating GGBS into precast concrete mixes can be a very effective tool in increasing the applicability of this by-product.

  4. 粉煤灰地聚合物在水泥混凝土路面修复中的应用研究%Application of Fly Ash Geopolymer in Cement Concrete Pavement Repair

    Institute of Scientific and Technical Information of China (English)

    朱宝权

    2015-01-01

    为解决水泥混凝土路面修补材料存在的路面开放交通时间偏长和耐久性较差的问题,通过进一步实验、研究粉煤灰地聚合物混凝土制备、特性及机理,并将其应用于水泥混凝土路面的快速修补。实验后,粉煤灰地聚合物早期抗弯拉强度高,其力学强度、粘结强度均满足路面修补混凝土的技术要求,在路面快速修补材料中应用前景十分广阔。%To address the problems of a relatively long open transport time and poor durability for cement concrete pave-ment repair material,through further experiments,preparation,characteristics and mechanism of fly ash geopolymer con-crete,it was applied to the quick fix of cement concrete pavement.After the experiments,the anti-flexural-tensile strength of fly ash geopolymer was high at the early stage,and its mechanical strength and bond strength could both meet the tech-nology requirements of pavement mending concrete,which could have broad application prospects in the rapid repair materi-als of pavement.

  5. The use of a non-standard high calcium fly ash in concrete and its response to accelerated curing

    Directory of Open Access Journals (Sweden)

    Atis, C. D.

    2002-09-01

    Full Text Available An experimental work was carried out to investigate the use of a non-standard high calcium fly ash in concrete. The response of the same fly ash to the accelerated curing was also explored. With three different cementitious material contents, a total of 48 concretes were produced. The water/ cement ratios were varied from 0.40 to 0.87. Compressive strengths of the moist cured cube specimens cast from the concrete mixtures made with 0%, 15%, 30% and 45% replacement of normal Portland cement with fly ash were measured at 28 days and 3 months. Accelerated compressive strengths were also measured using warmwater method and boiling-water method in accordance with the relevant ASTM and Turkish Standards. Despite the fact that the fly ash used was a non-standard, the laboratory test results showed that it could be utilized in concrete production at a replacement level between 15% and 30% by weight basis because fly ash concrete developed comparable or higher compressive strength than that of corresponding normal Portland cement concrete. The laboratory test results also indicated that the accelerated curing could be used to predict the compressive strength of fly ash concrete with 85% correlation coefficient. The amount of fly ash was found to be immaterial in the strength prediction. The relation between warm-water method and boiling-water method was of linear form with 93% correlation coefficient.

    Se llevó a cabo un trabajo experimental para investigar el uso de una ceniza volante de alto contenido en cal en el hormigón, la cual no cumple las especificaciones recogidas en norma. También, se estudió el comportamiento de la ceniza bajo un curado acelerado. Se elaboraron un total de 48 hormigones con tres proporciones diferentes de material cementante. Las relaciones agua/cemento (a/c usadas estaban comprendidas entre 0,40 y 0,87. A 28 días y 3 meses de curado, se determinaron las resistencias a compresión de probetas cúbicas de hormig

  6. The effects of silica fume and hydrated lime on the strength development and durability characteristics of concrete under hot water curing condition

    Directory of Open Access Journals (Sweden)

    Hamza Ali

    2017-01-01

    Full Text Available Sustainability is considered to be highly important for preserving continued industrial growth and human development. Concrete, being the world’s largest manufacturing material comprises cement as an essential binding component for strength development. However, excessive production of cement due to high degree of construction practices around the world frames cement as a leading pollutant of releasing significant amounts of CO2 in the atmosphere. To overcome this environmental degradation, silica fume and hydrated lime are used as partial replacements to cement. This paper begins with the examination of the partial replacement levels of hydrated lime and silica fume in concrete and their influence on the mechanical properties and durability characteristics of concrete. The effect of hot water curing on concrete incorporated with both silica fume and hydrated lime is also investigated in this paper. The results reported in this paper show that the use of silica fume as a partial replacement material improved both the mechanical properties and durability characteristics of concrete due to the formation of calcium silica hydrate crystals through the pozzolanic reaction. Although the hydrated lime did not significantly contribute in the development of strength, its presence enhanced the durability of concrete especially at long-term. The results also showed that hot water curing enhanced the strength development of concrete incorporated with silica fume due to the accelerated rate of both the hydration and pozzolanic reaction that takes place between silica fume and calcium hydroxide of the cement matrix particularly at early times. The results reported in this paper have significant contribution in the development of sustainable concrete. The paper does not only address the use of alternative binders as a partial replacement material in concrete but also suggest proper curing conditions for the proposed replacement materials. These practices

  7. Pervious Concrete

    OpenAIRE

    2012-01-01

    Pervious concrete is a type of concrete with little or no fines which give a large void. This enables high permeability and because of this it enables water to percolate through the concrete. Pervious concrete have been used in many years both as pavement material and on several other applications in the U.S and in other countries in Western Europe. In Norway pervious concrete is not currently in use. This thesis aims to investigate if pervious concrete can withstand the harsh Norwegian clima...

  8. 氯盐类融雪剂对混凝土路面危害分析%The analysis of chloride deicing salts’ hazard on concrete pavement

    Institute of Scientific and Technical Information of China (English)

    王有振

    2014-01-01

    氯盐类融雪剂在我国北方地区有着广泛的使用,但在使用过程中,存在对融雪剂的腐蚀性认识不足,缺乏相应产品标准和使用规范等问题。本文对融雪剂的类型进行了介绍,对氯盐类融雪剂对混凝土路面的腐蚀机理进行分析。通过冻融循环实验,研究了几种常见氯盐类融雪剂的腐蚀特性,并得出实验结论。%Chloride deicing salts has been widely used in northern China ,but the corrosion of deicing salt usually has been neglected during the use,and there is a lack of the appropriate product standards and the use of norms.In this paper,types of deicing salt are introduced;deicing salts of chlorine on the corrosion mechanism of concrete pavement are analyzed .By freeze-thaw cycle experiments ,the corrosion properties of several common chloride deicing salts has been studied ,and the conclusions of the experiment has been drawn .

  9. High Performance Concrete

    OpenAIRE

    Traian Oneţ

    2009-01-01

    The paper presents the last studies and researches accomplished in Cluj-Napoca related to high performance concrete, high strength concrete and self compacting concrete. The purpose of this paper is to raid upon the advantages and inconveniences when a particular concrete type is used. Two concrete recipes are presented, namely for the concrete used in rigid pavement for roads and another one for self-compacting concrete.

  10. High Performance Concrete

    Directory of Open Access Journals (Sweden)

    Traian Oneţ

    2009-01-01

    Full Text Available The paper presents the last studies and researches accomplished in Cluj-Napoca related to high performance concrete, high strength concrete and self compacting concrete. The purpose of this paper is to raid upon the advantages and inconveniences when a particular concrete type is used. Two concrete recipes are presented, namely for the concrete used in rigid pavement for roads and another one for self-compacting concrete.

  11. Anti-sliding performance analysis of cement concrete pavement based on BP neural network%基于BP神经网络的水泥混凝土路面抗滑性能分析

    Institute of Scientific and Technical Information of China (English)

    喻小毛

    2012-01-01

    以水泥混凝土路面材料设计方案以及月降水量为输入,以路面摩擦系数表征路面抗滑性能为输出,利用BP神经网络分析水泥混凝土路面抗滑性能,研究表明,BP网络能考虑不同公路的实际差异,找到路面材料设计方案及月降水量与抗滑性能的最佳组合,为实际施工提供指导。%Taking cement concrete pavement material design scheme and monthly precipitation as the input, and taking anti-friction coefficient embodying anti-sliding property as the output, the paper analyzes the anti-sliding performance of cement concrete pavement by applying BP neu- ral network. Results show that BP network finds out the optimal combination of pavement material design scheme and monthly precipitation and anti-sliding performance by considering various highway conditions, which has provided guidance for actual construction.

  12. Calculation of the temperature of asphalt concrete at making the joints of multilane road pavement of non-rigid type

    Directory of Open Access Journals (Sweden)

    Giyasov Botir Iminzhonovich

    2015-03-01

    Full Text Available The construction quality of road surface of non-rigid type essentially depend on providing the temperature regimes in the process of laying and packing of hot asphalt concrete mixtures. In order to provide the required characteristics of asphalt concrete due to the surface width it is necessary to provide the temperature regimes of hot asphalt concrete mixture in the zones of lane connection. The hot mixture is promptly cooling right after laying within several minutes, which results, according to the construction technology and the specific conditions of work production, in temperature abuse of the mixture at joints of the lanes at packing. The authors present the analysis of the technology of arranging multilane road surface by one paver with the possibility of heating the surface lane edge with the temperature of the adjacent lane. The results of the studies of the production conditions effect on the temperature of edge heating of the previously laid lanes, and the time required to achieve the maximum heating temperature depending on the relative thickness of coating layers.

  13. Porous Flame-retarded Asphalt Pavement for Highway Tunnel

    Institute of Scientific and Technical Information of China (English)

    HU Shuguang; HUANG Shaolong; Ding Qingjun

    2008-01-01

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

  14. Explore the Damage Problems and Effective Protection Measures of Highway Asphalt Concrete Pavement%探究高速公路沥青混凝土路面破损问题及有效防护措施

    Institute of Scientific and Technical Information of China (English)

    何娅兰

    2014-01-01

    高速公路是我国重要的交通设施,对我国的经济发展具有极大影响。本文列举了高速公路沥青混凝土路面破损的几种类型,并对沥青路面破损的原因和防护措施进行了分析。%Highway is Chinese important traffic facilities, which has a great influence on the economic development of China. This paper enumerates several types of highway asphalt concrete pavement damage and carries on the analysis of the causes and protective measures of the asphalt pavement da-mage.

  15. Effects of the different atmospheric steam curing processes on the properties of self-compacting-concrete containing microsilica

    Indian Academy of Sciences (India)

    Abdulkadir Cüneyt Aydin; Ali Öz; Riza Polat; Harun Mindivan

    2015-06-01

    In this paper an attempt has been made to study the use of microsilica on the properties of self-compacting-concrete (SCC) such as compressive strength, splitting tensile strength, flexural strength, ultrasonic pulse velocity (UPV) and micro-hardness when exposed to different atmospheric steam curing temperatures. The influence of microsilica as partial replacement of cement on the properties of SCC is investigated. In this study, mixes were prepared with three percentages of microsilica ranging from 5% to 10% and one controlled mixture without microsilica was also prepared for comparison. The specimens of each concrete mixture were heated up to different temperatures (65°C, 70°C and 75°C). The variables included were the temperature effects (65°C, 70°C and 75°C) using Cem I 42.5. SCC mixes enhanced atmospheric steam curing compressive strength ranging from 29.20 to 38.50 MPa, flexural strength ranging from 4.95 to 6.56 MPa and splitting tensile strength ranging from 1.18 to 1.63 MPa. Test results clearly show that there is little improvement in the compressive strength within temperature range of 70°C as compared to 65 and 75°C, although there is little reduction in splitting tensile strength ranging from 65 to 75°C and with the increase in percentage of microsilica. However, the rate of splitting tensile strength and flexural strength was higher than that of the compressive strength at elevated temperatures and with the increase in percentage of microsilica. In this paper, scanning electron microscopic (SEM) observations were also made to explain the observed residual compressive strength increase between 65°C, 70°C and 75°C.

  16. The Gravel Construction Technology and Quality Control of Cement Concrete Pavement%水泥混凝土路面碎石化施工工艺及质量控制

    Institute of Scientific and Technical Information of China (English)

    王方河

    2013-01-01

    The technology of rubblization is an important me-ans to overhaul of cement concrete pavement, which broke the cement concrete pavement into smal interlocking particles to provide ideal primary for the new asphalt concrete overlay. In this article, the author bases on the example of rebuild project of G312 Luan, and talk about some ideas on the gravel constr-uction technology and quality control.%  碎石化技术是水泥混凝土路面大修改造的重要手段,该技术通过将水泥混凝土路面破碎成小粒径嵌挤颗粒,从而为新的沥青混凝土加铺层提供理想的基层。本文主要结合G312六安段改建工程的实际情况,对碎石化施工工艺及质量控制谈一点心得。

  17. 改性透水混凝土铺装对雨水径流净化研究进展%Purification performance of modified permeable concrete pavement to storm water runoff

    Institute of Scientific and Technical Information of China (English)

    王俊岭; 王雪明; 冯萃敏; 张玉玉; 魏胜

    2016-01-01

    Permeable concrete pavement has been widely used in many places,such as sidewalks,parks,light load roads,parking lots and so on. Modified permeable concrete pavement has better performance and potential in the purification of rainwater runoff,and it is of great significance to collect,store,purify,recycle the rainwater. It summarized the methods of modification and the status quo and trend of purification performance of rainwater runoff at home and abroad. At last,research and development direction in the future are also proposed. It can improve the development of permeable concrete pavement and has a positive effect on the further study.%透水混凝土铺装已经广泛应用于人行道、公园、广场、轻载道路、停车场等处。改性透水混凝土铺装在净化雨水径流中表现出了良好的性能和潜力,对实现雨水径流的收集、储存、净化和回用补充地下水具有重要意义。通过总结分析国内外相关文献资料,重点介绍透水混凝土铺装的改性方法和对雨水径流净化性能方面的研究现状和行业趋势,并对研究和发展的未来领域提出建议,对透水混凝土铺装的进一步深入研究具有积极意义。

  18. Inverted base pavements: construction and performance

    KAUST Repository

    Papadopoulos, Efthymios

    2017-05-11

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

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

    Science.gov (United States)

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

  20. The Curing Meter

    DEFF Research Database (Denmark)

    Jensen, Ole Mejlhede

    2006-01-01

    Curing technology concerns adjustment and control of temperature and moisture conditions in hardening structures and elements of concrete. The curing technology comprises e.g. measurement, adjustment and control of the moisture conditions during the early hardening phase of the concrete to achiev...... from concrete surfaces in the early hardening phase. The Concrete Curing Meter is designed for simple and reliable monitoring of water loss from a wet surface of fresh concrete. This new measuring technique has been tested with several prototypes of the Curing Meter....

  1. 除冰剂对机场跑道混凝土抗冻性能影响%Effects of deicing agent on freezing resistance of airfieId pavement concrete

    Institute of Scientific and Technical Information of China (English)

    陈继超; 李玉香; 朱晓燕; 郑召; 付玉龙

    2015-01-01

    The freezing resistance of airport pavement concretes which were immersed in different concentrations of ethylene glycol so-lution was investigated by single side freezing-thawing method,and the amount of samples′s caling was regarded as evaluation parame-ters of the freezing-thawing durability of concrete. Results show that the freezing-thawing damage is the most serious in low salt con-centrations,and when the concentration of ethylene glycol was 3%,freezing-thawing damage reaches the maximum;By the failure mechanism of airport pavement concrete analysis,the damage was significantly affected by the concrete bibulous rate and deicing agent itself freezing inflation rate.%采用单面冻融法,以试件表面剥落量作为混凝土抗冻性能的评定参数,探讨了经不同浓度乙二醇溶液浸泡后的机场道面混凝土的抗冻性能。结果表明,混凝土经中低浓度乙二醇溶液浸泡后,冻融破坏严重,当乙二醇浓度为3%时,冻融破坏达最大值;通过机场道面混凝土破坏机理分析,破坏主要受混凝土中溶液吸入率、除冰剂自结冰膨胀率影响显著。

  2. Pavement noise measurements in Poland

    Science.gov (United States)

    Zofka, Ewa; Zofka, Adam; Mechowski, Tomasz

    2017-09-01

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

  3. 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.

  4. 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.

  5. 关于沥青混凝土道面公路飞机跑道结构设计方法的分析与研究%Analysis and Research on Structure Design Method of Asphalt Concrete Pavement Airfield Runway on Highway

    Institute of Scientific and Technical Information of China (English)

    曲旭光; 王建宇

    2014-01-01

    This paper put forward a structural design method of asphalt concrete airport pavement about the airfield runway on highway,by study the structural design method of asphalt concrete pavement about the airfield runway,including structure design theories foundation,design indexes,control standard, mechanical response of the pavement and the design steps and flow-chart etc.%从公路飞机跑道沥青混凝土道面结构设计的理论基础、设计指标、控制标准、道面结构力学响应分析、设计流程及步骤等方面进行分析研究,提出了公路飞机跑道沥青混凝土道面结构设计方法。

  6. Determination of transmission factors of concretes with different water/cement ratio, curing condition, and dosage of cement and air entraining agent

    Energy Technology Data Exchange (ETDEWEB)

    Sahin, Remzi, E-mail: rsahin@atauni.edu.tr [Dept. of Civil Eng., Faculty of Eng., Atatuerk University, Erzurum (Turkey); Polat, Recep [Dept. of Physics, Faculty of Education, Erzincan University, Erzincan (Turkey); Icelli, Orhan [Dept. of Physics, Faculty of Arts and Science, Yildiz Technical University, Istanbul (Turkey); Celik, Cafer [Dept. of Industrial Eng., Faculty of Eng., Atatuerk University, Erzurum (Turkey)

    2011-07-15

    Highlights: > We determined transmission factors of parameters affecting properties of concrete. > The most important parameter is W/C ratio for attenuation of radiation of concrete. > Taguchi Method provides an appropriate methodology for parameter reduction. - Abstract: This study focuses on determination of transmission factors of main parameters affecting the properties of both normal- and heavy-weight concrete in order to increase knowledge and understanding of radiation attenuation in concrete at a later age. Water/cement (W/C) ratio, curing condition, cement quantity and air entraining agent (AEA) were selected as the main parameters. Eight energy values have been selected within the energy interval of 30.85-383.85 keV to be used in the radiation source. The Taguchi Method was used as the method of optimization. It was determined in the study that the most important parameter affecting the attenuation of the radiation of the concrete is the W/C ratio and the concretes produced with the lowest level of W/C ratio absorb more radiation. However, it was also determined that there was a combined effect between the W/C ratio and the cement dosage.

  7. Concrete

    OpenAIRE

    2015-01-01

    Concrete is a component of coherent transition between a concrete base and a wooden construction. The structure is based on a quantity of investigations of the design possibilities that arise when combining digital fabrication tools and material capacities.Through tangible experiments the project discusses materiality and digitally controlled fabrications tools as direct expansions of the architect’s digital drawing and workflow. The project sees this expansion as an opportunity to connect th...

  8. Dynamic response of cement concrete pavement under aircraft taxiing load%飞机滑行作用下水泥混凝土道面板动响应分析

    Institute of Scientific and Technical Information of China (English)

    翁兴中; 寇雅楠; 颜祥程

    2012-01-01

    研究了飞机滑行作用下机场水泥混凝土道面板动响应问题.将道面结构视为粘弹性层状地基上单块四边自由的矩形板,采用半解析法,建立力学模型和计算方法.飞机滑行作用在道面板上的荷载是由自身重量和滑行产生的升力决定的;并计算了飞机滑行作用下道面板的响应.采用在道面内部钻孔安装位移传器的方法,对H-6飞机以不同滑行速度通过道面板时,道面板产生的动挠度进行了实测.计算结果与实测结果对比表明,两者误差在3%以内.说明所建立的计算方法是正确的,该方法可用来进行机场水泥混凝土道面板在飞机滑行作用下动响应的计算.%The dynamic responses of airfield cement concrete pavement were analysed when an aircraft taxies on the pavement. The pavement was regarded as a single rectangular slab with free edges resting on a viscoelastic layered foundation. A semi-analysis method was proposed and a mechanical model was established to calculate the dynamic response of slab under aircraft taxiing load, which consists of its weight and the lift force. The displacement transducers were installed inside the hole drilled on the pavement, and the dynamic deflections of the slab were measured when H-6 aircraft taxies on the pavement at different velocities. The theoretical solutions compared with the experimental results show the relative error between them is less than 3%. It indicates that the calculating method is correct and effective.

  9. Dynamic Response Analysis with 3D Finite Element Method for Two Typical Kinds of Asphalt Concrete Pavements with Saturated Asphalt Layer%两种典型沥青混凝土路面结构沥青层饱水状态动力响应三维有限元分析

    Institute of Scientific and Technical Information of China (English)

    任瑞波; 祁文洋; 徐强

    2011-01-01

    水和动态荷载耦合作用是沥青混凝土路面发生水损害的主要原因.首先基于多孔介质理论,假定路面结构中的沥青混凝土材料为完全饱水的多孔介质材料,对两种典型路面结构--半刚性沥青混凝土路面、具有柔性基层的半刚性沥青混凝土路面分别建立了三维有限元模型;而后对比分析了两种路面结构在动态荷载作用下的竖向应力、竖向应变、孔隙水压力的空间分布情况以及时程变化规律.结果表明:具有柔性基层的半剐性沥青混凝土路面结构具有较好的抗水损害性能,半刚性沥青混凝土路面结构则表现出较差的抗水损害性能.%The coupled moisture-loading action is the primary factor of initial failure for asphalt concrete pavement. At first, based on the porous media theory , assuming the asphalt concrete as saturated porous media material,two three-dimensional finite element models are established for two typical kinds of asphalt concrete pavements which included the semi-rigid base asphalt concrete pavement, the semi-rigid base asphalt concrete pavement with flexible base. Then the comparison and analysis of the spatial distribution and time change regulation for asphalt concrete pavement between the two kinds of structures are carried out which included vertical stress, vertical strain, and pore pressure. The result indicates that the semi-rigid asphalt concrete pavement stucture with flexible base shows the best performance of resisting the moisture damage, relatively the semi-rigid asphalt pavement structure gives the worse performance.

  10. THE MODEL OF RURAL HIGHWAY PAVEMENT—CURING TYPE PAVEMENT%农村公路的新型路面——固化类路面

    Institute of Scientific and Technical Information of China (English)

    武魁; 周亦唐; 靳旭

    2013-01-01

    针对云南省农村公路等级低、抗灾能力弱的问题,农村公路交通量小,建设资金比较紧张的情况下容易造成投资浪费等现象,基于对西山区低等级公路的调查研究,提出了农村公路的固化路面形式,阐述了固化类路面的结构设计、施工等注意问题,为农村公路的建设、养护和改建提出建议.%In view of the low level and weak resilience problems of rural roads, the current lower traffic flow and the tension construction funds of rural roads easily cause the investment waste in Yunnan Province, based on the research of low level roads in Xishan District, this thesis proposes the form of solidify pavement for rural roads, declares the matters for attention on the structure design and construction of solidify pavement, and the recommendations on construction, maintenance, and rebuild of rural roads.

  11. 纤维、粉煤灰复合高性能道面混凝土试验研究%Test study on fiber and fly powder conplex high performance pavement concrete

    Institute of Scientific and Technical Information of China (English)

    殷民动; 李光元

    2012-01-01

    Common airfield pavement concrete is poor endurable performance and easy craze in north cold and aridity area. This paper produce high performance pavement concrete by adding fiber and fly powder,it fit cold and aridity environment. Tests show:fiber or fly powder can raise the concrete performance of and craze,anti seep,anti freeze and anti-abrade. Especially when fiber and fly-powder are added together,super repeat domino effect can produced,synthesis performance can be advanced.%针对目前北方寒冷干旱地区普通道面混凝土耐久性差、易开裂的现象,通过在普通混凝土中掺纤维或粉煤灰以及纤维与粉煤灰双掺的技术路线,研究配制了适合寒冷干旱地区的高性能道面混凝土,并进行了相应的抗裂性、耐久性试验.研究结果表明,纤维或粉煤灰均能提高混凝土的抗裂、抗渗、抗冻、耐磨性能,尤其是纤维与粉煤灰复合产生了1+1>2的超叠加综合效应,更能够全面地提高道面混凝土的综合耐久性能.

  12. SENSITIVITY ANALYSIS OF CONCRETE PERFORMANCE USING FINITE ELEMENT APPROACH

    OpenAIRE

    Parjoko, Y. H.

    2012-01-01

    This study aims to understand the effect of applying several parameters: different axle load configuration, concrete properties, subgrade properties, slab thickness, joint characteristics, shoulder construction, bounded HMA overlay on concrete pavement, and bounded and unbounded CTB foundation over subgrade on the fatigue and erosion related distresses in concrete pavements. KENSLAB, an elaborate finite element program is used to determine the concrete pavement responses: stresses and deflect...

  13. New photo-thermal-synthesized polymer for self-compacting concrete to increase productivity, minimize pollution,and eliminate steam curing in precast concrete

    Institute of Scientific and Technical Information of China (English)

    F. C.Lai; M. F.Mohd Zain; WANG Bao-min; K. C. Lee

    2006-01-01

    The objective in this study is to apply the sustainable chemistry and photo-thermal synthesis technology to produce the sustainable eco-superplasticiser for the sustainable high performance SCC concrete especially in hot tropical countries. A photo-thermal synthesized eco-superplasticiser (PSES) was produced by using photo-thermal catalyst in a solar chemical reactor. In this preliminary study, an unique high early strength of SCC concrete has been successfully produced by imposing an unique proportion of the photo-thermal-synthesized ecoSuperplasticiser (PSES), local fly ash, sand and aggregate. The SCC concrete is preliminary tried in the precast concrete product to produce the complicated geometries as Tunnel segment, U-shape beam, and Box girder which have the critical reinforcement and thin section concrete. Surprisingly, this SCC provide the benefits as eliminating steaming energy, increased productivity, and minimize pollution. These unique properties of sustainable SCC concrete can not be achieved by the convention concrete by using ligno, naphthalene and melamine base superplasticiser. The synthesized sustainable eco-superplasticiser is a perfect choice to fully utilized the renewable energy and improve the concrete working environment.

  14. The Curing Meter

    DEFF Research Database (Denmark)

    Jensen, Ole Mejlhede

    2006-01-01

    Curing technology concerns adjustment and control of temperature and moisture conditions in hardening structures and elements of concrete. The curing technology comprises e.g. measurement, adjustment and control of the moisture conditions during the early hardening phase of the concrete to achiev...... from concrete surfaces in the early hardening phase. The Concrete Curing Meter is designed for simple and reliable monitoring of water loss from a wet surface of fresh concrete. This new measuring technique has been tested with several prototypes of the Curing Meter.......Curing technology concerns adjustment and control of temperature and moisture conditions in hardening structures and elements of concrete. The curing technology comprises e.g. measurement, adjustment and control of the moisture conditions during the early hardening phase of the concrete to achieve...... an optimal development of properties in the hardening concrete – so-called "moisture curing". Proper moisture curing is vital to concrete but laborious to accomplish and difficult to control at the construction site with present methods. This paper concerns a new method for site measurement of evaporation...

  15. Effects of Different Water and Super Plasticizer Amount, Pre-Setting and Curing Regimes on the Behavior of Reactive Powder Concrete

    Directory of Open Access Journals (Sweden)

    M. A. Dashti Rahmatabadi

    2014-12-01

    Full Text Available Reactive Powder Concrete (RPC is an ultra high performance concrete which has superior mechanical and physical properties. The RPC is composed of cement and very fine powders such as crushed quartz (100–600 μm and silica fume with very low water/binder ratio (W/B (less than 0.20 and Super Plasticizer (SP. The RPC has a very high compressive and tensile strength with better durability properties than current high performance concretes. Application of very low water/binder ratio with a high dosage of super plasticizer, different heat curing processes and pre-setting pressure improve mechanical and physical properties of RPC. In this study, the RPC is composed of available materials in Iran. Two different mixing proportions, different water/binder ratios for preparation of samples, different super plasticizer dosages, five different (0, 25, 50, 100 and 150 MPa pre-setting pressure and 7 different curing regimes were used in samples preparation and experiments. Results showed that appropriate water/binder ratio and super plasticizer dosage, higher temperature and pre-setting pressure increase the workability, density and compressive strength of compositions.

  16. Design and Model Test of Cement Concrete Pavement Slab Based on Phase Change and Temperature Control%相变控温水泥混凝土路面板设计及模型试验

    Institute of Scientific and Technical Information of China (English)

    高英力; 胡柏学; 贺敬; 杨文剑

    2011-01-01

    Based on the phase change energy storage material and functionally-graded material design method, the conventional structure of cement concrete pavement slab was designed for enhancing the function of anti-freezing and wear-resistance, and the model test of pavement slab was carried out. The step cooling test method was adopted to select the composite phase change material, and then it was placed in the high-strength seamless steel pipe. The size of the formed cement concrete pavement slab model was 500 mm × 400 mm × 80 mm. Anti-freezing and wearresistance property test of the model was carried out. Results indicate that phase change temperature point of the selected phase change material is about 5 ℃, and at the point, the liquidsolid phase transition happens to reject heat which can play better ice-melting effect and delay or control the low-temperature freezing phenomena of the pavement slab model surface. The wearresistance of the pavement slab surface material is excellent and its 28-day wear rate is only 51.9% of the standard limited value. The reinforced role of steel pipe in the phase change function layer can prevent the problem of inconsistent volume deformation between the main structure layer and surface layer and also can enhance interface stability.%引入相变储能材料及梯度功能材料设计方法,对传统水泥混凝土路面板结构进行防冻、耐磨功能设计,开展路面板模型试验研究.采取步冷试验方法,将优选出的复合相变储能材料封装入高强度无缝钢管中,制成500 mm×400 mm×80 mm的水泥混凝土路面板模型,进行模型的防冻性能和耐磨性能试验.结果表明:优选的相变材料体系相变温度点可控制在5℃左右,并产生液-固相变过程,放出热量,起到了较好的融冰效果,延缓或控制了路面板模型表面的低温冰冻现象;表面层材料耐磨性优良,28 d磨耗率仅为标准限值的51.9%;相变功能层中钢管的加筋作用可防止主

  17. 水泥混凝土桥梁长寿命桥面铺装层复合结构疲劳特性%Fatigue Performance of Composite Structure for Perpetual Pavement on Cement Concrete Bridge Deck

    Institute of Scientific and Technical Information of China (English)

    钱振东; 王江洋; 王亚奇

    2012-01-01

    In order concrete bridge, to design the perpetual pavement with excellent fatigue behavior for the cement based on the characteristics required for perpetual road pavement, three composite structures were tested with four-point flexural bending test to investigate fatigue properties based on the Weibull distribution theory. The double-logarithm fatigue equations for perpetual pavement were established. The results show that the fatigue lives of three composite structures follow the double-parameter Weibull distribution. With the failure probability of 0.1, the fatigue performance of composite structure, when the lower layer is AC while the lower layer uses epoxy asphalt mixture (EAM) as a substitute for stone mastic asphalt (SMA), is improved significantly. In addition, the fatigue performance of composite structure, when the lower layer is EAM while the upper layer uses SMA as a substitute for asphalt concrete (AC), is improved more. The combination structure of EAM and SMA has the best fatigue performance, and totally satisfies the structure design feature requirement for perpetual pavement. The research results provide a reliable foundation for the further study of the perpetual bridge deck pavement.%为了构建疲劳性能优异的水泥混凝土桥梁长寿命铺装结构,借鉴长寿命沥青路面设计的基本思路,选取3种铺装复合结构方案,采用应变控制的四点弯曲疲劳试验,并基于Weibull分布理论对复合结构的疲劳特性进行分析,建立长寿命桥面铺装复合结构双对数疲劳预估方程。研究结果表明:3种铺装复合结构的疲劳寿命均服从双参数Weibull分布;在失效概率为0.1时,复合结构上面层同为AC,下面层采用环氧沥青混合料(EAM)代替SMA后,其疲劳性能得到提高,复合结构下面层同为EAM,上面层采用SMA代替AC后,疲劳性能得到再次提高;"EAM+SMA"的组合具有较好的抗疲劳性能,同时满足长寿命桥面铺装的结构最优设

  18. Experimental study of the effect of the thermal conductivity of EAF slag aggregates used in asphaltic concrete of wearing courses on the durability of road pavements

    OpenAIRE

    Barra Bizinotto, Marilda; Aponte Hernández, Diego Fernando; Vázquez Ramonich, Enric; Méndez Candelario, Braulio Aquilino; Miró Recasens, José Rodrigo; Valls del Barrio, Susanna

    2017-01-01

    Electric Arc Furnace (EAF) steel slag is the basic material used to obtain good quality aggregates in different layers of road pavements. Many scientific papers have reported on the high frictional and abrasion resistance of this material. EAF slag aggregates are hard, dense, chemically stable and have good adhesion with bitumen, all characteristics related with its high alkaline character. These properties are important in hot mix asphalt for wearing courses where high wear is present and op...

  19. Factors Influencing Air Content of Pavement Concrete for Plateau Airport and Its Control Measures%高原机场道面混凝土含气量的影响因素及控制措施

    Institute of Scientific and Technical Information of China (English)

    岑国平; 洪刚; 王金华; 杨文科; 谭晓刚

    2012-01-01

    通过室内和现场试验,研究了青藏高原地区环境气压、拌合水温和细骨料含泥量对机场道面混凝土含气量的影响.结果表明,相同的配合比,高原地区混凝土含气量明显小于平原地区,引入的气泡数量少、消退快.砂子 含泥量对混凝土含气量和强度均有显著影响,拌合水温对含气量也有一定影响.为保证混凝土含气量,结合玉树机场实际情况,提出了相应的技术措施.%By indoor and in-situ experiments, the influences of environmental air pressure, temperature of mixing water and mud content of fine aggregate on the air content of airport pavement concrete were studied for Qinghai-Tibet plateau region. The results showed that the air content of concrete in plateau is much less than that in plain area at the same mix proportion. Number of air bubbles is less and the bubbles fade faster in plateau. The mud content of sand has a strong influence on both the air content and concrete strength. The temperature of mixing water also affects the air content of concrete. In order to ensure enough air content, some technique measures were put forward in the construction of Yushu Airport.

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

    Directory of Open Access Journals (Sweden)

    Valašková Veronika

    2017-01-01

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

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

    OpenAIRE

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

    2009-01-01

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

  2. Effect of Steam-Autoclaved Curing on Chloride Permeability of High Strength Concrete%二次高温养护对高强混凝土抗 Cl-渗透性的影响

    Institute of Scientific and Technical Information of China (English)

    刘东升; 朱建舟; 谭克锋

    2014-01-01

    利用氯离子快速渗透法(RCM)研究了普通蒸汽养护后(80℃,0.1 MPa)再进行压蒸(180℃,1 MPa)养护,即二次高温养护,对不同胶凝材料体系的高强混凝土抗Cl-渗透性的影响。结果表明:对于纯水泥混凝土,与标养相比,“蒸养-压蒸”养护使混凝土抗Cl -渗透性能劣化。掺入粉煤灰、矿粉以及硅灰以等比例取代水泥时,“蒸养-压蒸”都较为充分地激发了上述混合材的火山灰活性,但不同掺合料对“蒸养-压蒸”后高强混凝土抗Cl-渗透性能影响差别较大。 XRD和SEM研究表明上述结果的产生与高温下水化产物的种类和分布有关。%Rapid choloride migration test (RCMT) was used to investigate the influence of curing methods and mineral admixtures on chloride ingress resistance of high strength concrete .The results indicate that steam cu-ring and autoclaving curing , especially autoclaving curing , considerably aggravated the chloride penetration through pure cement concrete when compared with normal curing .Incorporating silica fume can improve the chloride ingress resistance of steam curing concrete but degrades autoclaving curing concrete .Adding fly ash with low pozzolanic activity can increase chloride ingress resistance of autoclaving curing concrete , while chlo-ride penetration resistance of steam curing concrete becomes lower .The measure of multi-elements mineral admixtures mixing is propitious to improving the chloride ingress resistance of concrete compared with pure ce-ment concrete under same curing conditions .Results above was analyzed by XRD and SEM .

  3. Photocatalyticpaving concrete

    Directory of Open Access Journals (Sweden)

    Lyapidevskaya Ol'ga Borisovna

    2014-02-01

    Full Text Available Today bituminous concrete is a conventional paving material. Among its advantages one can name dustlessness and noiselessness, fine wear (up to 1 mm a year and fine maintainability. As the main disadvantages of this material one can name high slipperiness under humidification, low durability and weather resistance. Besides that, during placement of the bituminous concrete a lot of different air pollutants are emitted, which are harmful for environment and human’s health (they are listed in the paper according to the US Environmental Protection Agency materials. As an alternative, one can use cement-concrete pavement, which is in many ways more efficient than the bituminous concrete. It is proposed to enhance environmental performance of the cement-concrete pavement via usage of photocatalysis. The mechanism of different photocatalytic reactions is described in the paper, namely heterogeneous and homogeneous photocatalysis, photo-induces, photoactivated catalysis and catalytical photoreactions. It is pro-posed to use heterogeneous photocatalysis with titanium dioxide as a photocatalyst. The mechanism of photo oxidation of air contaminants, with the usage of titanium dioxide is2described. The paper sets problems, connected with the sensibilization of TiOto thevisible light (it is proposed to use titanium dioxide, doped with the atoms of certain elements to increase its sensibility to the visible light and with the development of a new photocatalytic paving concrete, which will meet the requirements, specified for paving in the climatic and traffic conditions of the Russian Federation.

  4. The Construction Technology and Quality Control of Hot Mix Asphalt Concrete Pavement%热拌沥青混凝土路面施工工艺及质量控制

    Institute of Scientific and Technical Information of China (English)

    卢宪法

    2014-01-01

    热拌沥青混凝土作为公路路面施工的重要组成部分,其选材、施工工艺、质量控制等流程对公路的建成性能都具有决定性的影响。笔者结合近年来的学习工作经验,主要从材料、沥青混凝土的配比、施工工艺、质量控制几个方面作简要阐述。%Hot mix asphalt concrete as an important part of highway pavement construction, the material selection, constr-uction technology and quality control hasa decisive influence on the process of highway completed performance. The author combines with work experience in recent years to elaborate from several aspects of material, the ratio of asphalt concrete, construction technology, and quality control, etc.

  5. 旧水泥混凝土路面缩缝加设传力杆的力学效应分析%MECHANICS EFFECTIVENESS AND ANALYSIS OF THE CONSTRACTION JIONT ADDED DOWEL BAR ON OLD CEMENT CONCRETE PAVEMENT

    Institute of Scientific and Technical Information of China (English)

    陈骁; 宋祖科

    2013-01-01

    In order to study the comprehensive effectiveness induced by adding dowel bars, we add dowel bars to contraction joints on old cement concrete of expressway pavement, and construct different testing roads in accordance with different design plans. The test indicates that the transfer coefficient of contraction joints without adding dowel bars is 0.2-0.4, which is improved to 0.7-1.0 when dowel bars is added, and the transfer capacity is improved 2~5 times. The average deflection value of a direct loading concrete board falls from 0.587mm to 0.331mm, reduced about 1.8 times. The three-dimensional model of adding dowel bars to old cement concrete pavement by ANSYS finite element analysis was established, made a simulation comparison to 5 kinds of contraction joint design program for broken and no broken boards respectively. Research indicates that it is quite economic and reasonable to add 8 dowel bars to a contraction joint section on old cement concrete pavement when the diameter is 28mm and spacing 26cm, adding dowel bars will bring enormously benefits, thus provides a theory basis for the economical and reasonable transformation design plan.%为研究旧水泥混凝土路面加设传力杆带来的综合效应,对某高速公路路面缩缝加设传力杆,并修筑了不同方案的试验路,测试表明:未加设传力杆缩缝的传荷系数为0.2~0.4,加设后提高到0.7~1.0,传荷能力提高了2倍~5倍;直接受荷板的平均挠度值从0.587mm降到0.331mm,减少约1.8倍.通过ANSYS有限元建立旧水泥混凝土路面缩缝加设传力杆的三维模型,分别对已断板和未断板的5种缩缝设计方案进行的模拟对比,研究表明:旧水泥混凝土路面缩缝断面加设8根传力杆,直径28mm,间距26cm是比较经济合理的,缩缝加设传力杆将会产生很大效益,为确定经济、合理的改造设计方案提供理论依据.

  6. The influence of alkalinity of portland cement on the absorption characteristics of superabsorbent polymers (SAP) for use in internally cured concrete

    Science.gov (United States)

    Tabares Tamayo, Juan D.

    The concrete industry increasingly emphasizes advances in novel materials that promote construction of more resilient infrastructure. Due to its potential to improve concrete durability, internal curing (IC) of concrete by means of superabsorbent polymers (SAP) has been identified as one of the most promising technologies of the 21st century. The addition of superabsorbent polymers into a cementitious system promotes further hydration of cement by providing internal moisture during the hardening and strength development periods, and thus limits self-desiccation, shrinkage, and cracking. This thesis presents the work performed on the series of cement pastes with varying alkalinity of their pore solutions to provide a better understanding of: (1) the influence of the chemistry of the pore solution (i.e. its level of alkalinity and the type of ionic species present) on the absorption capacity of SAP, and (2) the effectiveness of SAP with different absorption capacities as an internal curing agent. This research work was divided into three stages: (a) materials characterization, (b) measurement of absorption capacity of SAP in synthetic pore solutions, and (c) evaluation of the internal curing effectiveness of SAP. During the first stage (Materials Characterization), pore solutions were extracted from the fresh (5 minutes old) cement pastes prepared using cements with three different levels of alkalinity. The pH values of the extracted solutions were determined (using the pH meter) and their chemical analysis was performed by means of titration (concentration of hydroxyl), ion chromatography (sulfates and chlorides), atomic absorption (AA) and inductively coupled plasma optical emission spectrometry (ICP) (sodium, potassium and calcium). The commercial SAP adopted for this study was used with "as-supplied" gradation and with the finer gradation obtained by grinding the original polymer in the 6850 Cryomilling Freezer/Mill. The physical properties of these SAP's, such

  7. Variability of pavement noise benefit by vehicle type

    Science.gov (United States)

    Rochat, Judith L.; Read, David R.

    2005-09-01

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

  8. CRC+AC复合式路面的合理配筋率%Reasonable Reinforcement Ratio of Continuously Reinforced Concrete Composite Asphalt Pavement

    Institute of Scientific and Technical Information of China (English)

    李盛; 刘朝晖; 李宇峙

    2012-01-01

    针对CRC+ AC复合式路面的结构特点和现有研究的不足,对现行规范的纵向配筋设计进行了分析,运用传热学理论和有限元法,研究了AC层的温度效应,计算和分析了AC层温度效应对CRC+ AC复合式路面纵向配筋率的影响规律.研究结果表明:CRC+ AC复合路面结构的纵向配筋设计不需要考虑剥落、渗水和冲断破坏,只需考虑钢筋的拉断破坏即可;由于AC层的隔热作用明显,CRC+ AC复合路面结构的纵向配筋率可以相应减少,以AC层厚度10 cm为例,CRC层的纵向配筋率可减少0.12%左右;钢筋的架设建议采用滑动支架,纵向钢筋的连接建议采用绑扎方式,搭接长度约为35倍钢筋直径.%Focused on the structure characteristics and the flaws of existing studies of CRC + AC composite pavement, longitudinal reinforcement design in current specifications was analyzed. By using heattransfer theory and finite element method, temperature effect of AC layer was researched, and the influence of temperature effect of AC layer on longitudinal reinforcement ratio of CRC + AC composite pavement was calculated and analyzed. The results show that ( 1) longitudinal reinforcement design of CRC + AC composite pavement needs not to consider spalling, seepage and thrust failure, just needs to consider tensile failure of reinforcement; (2) longitudinal reinforcement ratio of CRC + AC composite pavement can be reduced due to the efficient heat insulation of AC layer, for instance, the thickness of AC layer is 10 cm, the longitudinal reinforcement ratio of CRC layer can be reduced by about 0. 12%. It is recommended that the sliding stent be used in reinforcement erection, the banding way be used to joint longitudinal reinforcement, and the overlapped length is about 35 times the reinforcement diameter.

  9. Evaluation of Asphalt Concrete Pavement Based on Passenger Ride Comfort Level%基于驾乘舒适性的沥青混凝土路面评价

    Institute of Scientific and Technical Information of China (English)

    王锋; 张金喜

    2014-01-01

    In order to provide a theoretical basis for the ride comfort level evaluation, daily management,and maintenance of asphalt concrete pavement,the performance parameters and three-directional acceleration data of highway pavements were measured indoors and outdoors. Using these data,the relationship between the mean square of weighted acceleration and the pavement performance was studied. A linear regression equation that reflects the relationship between the root mean square of weighed acceleration,speed,and roughness was obtained by fitting 214 groups of experimental data. In addition,the outdoor experimental results were verified using a driving simulator. The results show that the root mean square of weighed acceleration is strongly correlated with roughness,moderately correlated with the speed,and weakly correlated with the dynamic friction coefficient. Given a certain dynamic friction coefficient,the ride comfort level of an asphalt concrete pavement reduces with its roughness and driving speed increasing. When the roughness is 1. 35 and 3. 05 mm/m,the maximum speed with an appropriate ride comfort level is 124. 1 and 88. 7 km/h,respectively.%为给沥青混凝土路面舒适性评价及日常管理养护提供理论依据,在测得室内外大量道路路面性能参数及三向加速度数据的基础上,研究了加权加速度均方根值与道路路面性能参数之间的关系.运用214组有效室外实验数据,拟合了加权加速度均方根、行驶速度与平整度关系的线性回归方程,并用驾驶模拟舱对室外实验结论进行了验证.结果表明:加权加速度均方根与平整度强相关,与速度中等程度相关,与动态摩擦系数弱相关,在动态摩擦系数一定的条件下,驾乘舒适性随平整度及行驶速度的增加而降低;当平整度为1.35和3.05 mm/m时,满足驾乘舒适性的最大速度分别为124.1和88.7 km/h.

  10. Expedient Repair Materials for Roadway Pavements

    Science.gov (United States)

    2005-03-01

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

  11. 地聚合物水泥路面快速修补材料性能研究%Study on the Properties of Geopolymer Concrete Using as Rapid Repair Materials for Cement Pavement

    Institute of Scientific and Technical Information of China (English)

    常利; 艾涛; 延西利; 吕霖; 杨慧成

    2014-01-01

    针对水泥路面修补后开放交通时间偏长、耐久性较差和施工工艺复杂的问题,采用固体复合激发剂、粉煤灰和偏高岭土及其他外加剂制备一种地聚合物水泥快速修补材料,并对其混凝土力学性能、界面粘结性能、收缩率、抗冻性能进行测试.结果表明,当掺入10%的复合激发剂和10%的普通硅酸盐水泥时,地聚合物水泥的早期力学性能达到最优,所制备的地聚合物水泥混凝土修补材料具有快凝早强和优良的耐久性等特点,扫描电子显微镜(SEM)微观分析表明,由于碱激发反应和未激发粉煤灰的填充效应,地聚合物水泥混凝土具有致密的微观结构.%In order to solve long opening-to-traffic time,poor durability and complex process of concrete pavement repaired problem,a kind of rapid repair geopolymer material was prepared using the solid composite activator,fly ash,metakaolin and other admixtures.The properties of the working performance,mechanical properties,bonding performance between New and old Concrete,shrinkage,frost resistance of geopolymer-cement-concrete were tested.The experimental results show that with 10% compound activators and 10% ordinary Portland cement,the early mechanical properties of the geopolymer cement can achieve the optimal; the rapid repair geopolymer-cement-concrete has the advantages of quick setting early strength and excellent durability.The scanning electron microscopy (SEM) results indicatethat the geopolymer-cement-concrete has micro compact structure as the result of the filling effect of inactivated fly ash and alkali activated reaction.

  12. Evaluation for Subgrade Permanent Deformation of Cement Concrete Pavement%水泥混凝土路面路基永久变形预估

    Institute of Scientific and Technical Information of China (English)

    谭悦

    2012-01-01

    Using the model of evaluation for subgrade permanent deformation and layerwise strain summation method, in considering the clay, silt and sand, the permanent deformations of subgrade are calculated with the load action on edge of board, center of board, and angle of board. Calculation shows that, for certain pavement structure and traffic axle load, permanent deformation of the clay subgrade is the largest, and the sand subgrade is the minimum; for the same soil, subgrade permanent deformation is the largest or minimum when angle of board loaded or center of board loaded; when edge of board loaded, the board's size smaller, the subgrade permanent deformation greater; subgrade permanent deformation caused by angle of board loaded is the most adverse condition for the pavement s force status.%结合修正后的路基永久变形预估模型和应变分层总和法,在考虑粘土、粉土和砂土3种不同土质状态下,分别预估了荷载作用于板边、板中及板角时路基产生的永久变形.计算表明,对于一定的路面结构和交通轴载,粘土路基的永久变形量最大,粉土次之,砂土最小;对于同一种土质,板角受荷时路基的永久变形最大,板边受荷次之,板中受荷最小;当荷载作用在板边时,板的尺寸越小,路基的永久变形越大;板角受荷造成的路基永久变形对水泥路面的受力状况是最为不利的.

  13. 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...

  14. 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...

  15. Bituminous Pavement Failures

    Directory of Open Access Journals (Sweden)

    Surajo Abubakar Wada

    2016-02-01

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

  16. Permeable pavement study (Edison)

    Data.gov (United States)

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

  17. Sustainable construction: Composite use of tyres and ash in concrete

    Energy Technology Data Exchange (ETDEWEB)

    Snelson, D.G.; Kinuthia, J.M.; Davies, P.A.; Chang, S.R. [University of Glamorgan, Pontypridd (United Kingdom). Faculty of Advanced Technology

    2009-01-15

    An investigation was carried out to establish the physical, mechanical and chemical characteristics of a non-standard (unprocessed) pulverised fuel ash (PFA) and waste tyres from a former landfill site at the Power Station Hill near Church Village, South Wales, United Kingdom. Investigations are on-going to establish the suitability of the fly ash and/or tyres in road construction (embankment and pavement) and also in concrete to be used in the construction of the proposed highway. This paper reports on concrete-based construction where concrete blends (using various levels of PFA as partial replacement for Portland cement (PC), and shredded waste tyres (chips 15-20 mm) as aggregate replacement) were subjected to unconfined compressive strength tests to establish performance, hence, optimising mix designs. Strength development up to 180 days for the concrete made with PC-PFA blends as binders (PC-PFA concrete), with and without aggregate replacement with tyre chips, is reported. The binary PC-PFA concrete does not have good early strength but tends to improve at longer curing periods. The low early strength observed means that PC-PFA concrete cannot be used for structures, hence, only as low to medium strength applications such as blinding, low-strength foundations, crash barriers, noise reduction barriers, cycle paths, footpaths and material for pipe bedding.

  18. 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.

  19. 成型方式和养护条件对多孔改性水泥混凝土性能的影响%Influence of Molding Method and Curing Conditions on Properties of Porous Modified Cement Concrete

    Institute of Scientific and Technical Information of China (English)

    王中合

    2014-01-01

    As a result of adding cement modifier and large porosity, porous modified cement concrete has different properties on different molding method or curing condition. Through the comparative test of dif-ferent molding methods and different curing condition, concrete porosity, bulk density, compressive strength and flexural strength are detected. The test results show that, porous modified concrete molding should adopt the method of light vibration in a short time or artificial pound. Its curing condition is stan-dard curing early, then natural curing.%由于添加了水泥改性剂且空隙率大,不同成型方式和养护条件对多孔改性水泥混凝土的性能产生不同的影响。通过不同成型方式和不同养护条件对比试验,检测混凝土的空隙率、毛体积密度、抗压强度、抗弯拉强度等性能。试验结果表明,多孔改性水泥混凝土成型宜采用短时间轻振或人工插捣的方式;适宜的养护条件是早期保湿养护,而后进行自然养护。

  20. 混凝土轨枕养护现状分析与技术改造实施方案%Analyses on Concrete Sleeper-Curing Status Quo and Technical Reconstruction Implementation Scheme

    Institute of Scientific and Technical Information of China (English)

    孙旭亮

    2012-01-01

    According to the standards of track concrete sleeper-curing specified in high-speed railway technical conditions, this paper briefly analyzes the importance of concrete curing. The paper, in combination with the problems of low temperature steam curing, also analyzes the reason why the existing curing pool is difficult to meet the technical requirements so as to renovate the existing curing pool. Finally, through sleeper static-load crack strength test, natural curing test and moisture curing test after sleepers being taken out from the pool before pool reconstruction and by way of test data analysis, this paper works out the reasonable curing system and puts forward the new method of sleeper curing.%依据高速铁路混凝土轨枕技术条件中规定的养护标准,浅析混凝土养护的重要性;结合执行低温蒸汽养护时遇到的问题,分析原有养护池难以达到技术要求的原因,对养护池进行改造;通过养护池改造前轨枕静载抗裂强度试验、养护池内自然养护试验、轨枕出池后保湿养护试验和试验数据分析,制定出合理的养护制度,提出了轨枕养护的新方法.

  1. Application of Energy Efficient Warm Mix Asphalt Concrete in Pavement Construction in Extremely Cold Areas%低能耗温拌沥青混凝土施工技术在高寒地区路面工程中的应用

    Institute of Scientific and Technical Information of China (English)

    唐忠平; 宋远慧

    2011-01-01

    温拌温铺沥青混凝土初次在青藏高原公路施工技术上的尝试和应用,克服了低温作业的影响,有效降低有害气体和粉尘颗粒排放,同时又保证了与热拌沥青混凝土基本相同的路用性能和施工和易性,为工程顺利实施赢得时间效益。%The first application of warm mix asphalt concrete in highway construction in Qinghai-Tibet Plateau overcame the impact of low temperature,reduced harmful gas and dust particles effectively and at the same time ensured the same pavement performance and construction workability with that of hot mix asphalt,which gained time efficiency for successful implementation of pavement engineering.

  2. Early age damage quantification of actively restrained concrete using inverse analysis

    Science.gov (United States)

    Albanna, Ali

    Early-age cracking can be a significant problem in concrete pavements, floors, and bridge decks. Cracking occurs when the volumetric changes associated with drying, hydration, and temperature reduction are prevented. Good knowledge about the characteristics of early age concrete is necessary to achieve reliable crack control. Volumetric changes due to shrinkage depend on the type of concrete and its components. It has been found that light weight aggregates can work as internal reservoir to supply the concrete matrix with water that is needed during the early age; this process is called internal curing. Also fibers can give more ductility to the concrete and produce less shrinkage. There is a need to better understand the effects of early age uniaxial restraint on long term concrete mechanical performance. In this study, two types of concrete were studied (high performance fiber reinforced concrete and ordinary concrete) under actively restrained loading conditions to assess the effect on the long term fracture toughness and energy. Single edge notched specimens having dimensions of 250 mm x 150 mm x 75 mm and a notch to depth ratio of 0.33 were caste and used in both direct tension and three point bending. The direct tension tests were carried out on a direct tension loading frame constructed in house that was supplied with two mechanical jacks and load cell.

  3. Research of cost aspects of cement pavements construction

    Science.gov (United States)

    Bezuglyi, Artem; Illiash, Sergii; Tymoshchuk, Oleksandr

    2017-09-01

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

  4. Morphological Algorithms For The Analysis Of Pavement Structure

    Science.gov (United States)

    Grivas, Dimitri A.; Skolnick, Michael M.

    1989-11-01

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

  5. Numerical study on the curling and warping of hardened rigid pavement slabs

    Science.gov (United States)

    Qin, Yinghong

    In-service hardened concrete pavement suffers from environmental loadings caused by curling and warping of the slab. Traditionally, these loadings are computed on the basis of treating the slab as an elastic material, and of evaluating separately the curling and warping components. This dissertation simulates temperature distribution and moisture distribution through the slabs by use of a developed numerical model that couples the heat transfer and moisture transport. The computation of environmental loadings treats the slab as an elastic-viscous material, which considers the relaxation behavior and Pickett effect of the concrete. The heat transfer model considers the impacts of solar radiation, wind speed, air temperature, pavement slab albedo, etc. on the pavement temperature distribution. This dissertation assesses the difference between documented models that aim to predict pavement temperature, highlighting their pros and cons. The moisture transport model is unique for the documented models; it mimics the wetting and drying events occurring at the slab surface. These events are estimated by a proposed statistical algorithm, which is verified by field rainfall data. Analysis of the predicted results examines on the roles of the local air RH (relative humidity), wind speed, rainy pattern in the moisture distribution through the slab. The findings reveal that seasonal air RH plays a decisive role on the slab's moisture distribution; but wind speed and its daily variation, daily RH variation, and seasonal rainfall pattern plays only a secondary role. This dissertation sheds light on the computation of environmental loadings that in-service pavement slabs suffer from. Analysis of the computed stresses centers on the stress relaxation near the surface, stress evolution after the curing ends, and the impact of construction season on the stress's magnitude. An unexpected finding is that the total environmental loadings at the cyclically-stable state divert from the

  6. 机场道面除冰液作用下大掺量粉煤灰混凝土的抗冻性%Freeze-thaw Durability of High Volume Fly Ash Content Concrete Exposed to Airfield Pavement Deicer

    Institute of Scientific and Technical Information of China (English)

    麻海燕; 吴雅玲; 余红发; 白康; 袁银峰

    2014-01-01

    The freeze-thaw durability of high volume fly ash content concrete (HFCC)specimens were tested by fast freezing-thawing experiments.In the experiments,HFCC specimens exposed to different solutions which were composed of airfield pavement deicer,NaCl solution,aircraft deicer (AD),commercial deicer and water.The airfield pavement deicer mainly contained calcium magnesium acetate (CMA)and was changed at mass fractions of 3.5%,12.5% and 25%.The mass fractions of NaCl solution,aircraft deicer and commercial deicer were 3 .5%,3 .5% and 25%,respectively.Through the experiments,the change rules of the mass loss rate per unit area and the relative dynamic elastic modulus of HFCC were obtained.The results show that freeze-thaw damage of HFCC exposed to 3 .5% NaCl solution is closely attributed to surface deterioration.When HFCC specimens exposed to 3 .5% AD or 3 .5% CMA solution,it will be damaged by internal freeze-thaw damage.Compared with water,freeze-thaw damage effect of HFCC is delayed by 3 .5% CMA solution.Freeze-thaw durability of concrete exposed to CMA solutions is closely related to the solution mass fractions,the higher the CMA mass fraction is,the smaller the freeze-thaw damage effects are.When the CMA mass fraction is greater than 12.5%, the mass loss rate and the relative dynamic elastic modulus losses are small after 600 times fast freeze-thaw cycle.HFCC has a poor freeze-thaw durability when exposed to 25% commercial deicer and has a good freeze-thaw durability when exposed to 25% airfield pavement deicer. Therefore,HFCC can be completely applied to the cement concrete airfield runway which is deiced by high mass fractions of CMA.%通过大掺量粉煤灰混凝土(HFCC)试件在质量分数为3.5%,12.5%,25%机场道面除冰液(CMA溶液)、质量分数为3.5%的NaCl溶液、质量分数为3.5%的飞机除冰液(AD溶液)、质量分数为25%的商品飞机除冰液与水中快速冻融试验

  7. 9 CFR 91.26 - Concrete flooring.

    Science.gov (United States)

    2010-01-01

    ... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Concrete flooring. 91.26 Section 91.26... LIVESTOCK FOR EXPORTATION Inspection of Vessels and Accommodations § 91.26 Concrete flooring. (a) Pens aboard an ocean vessel shall have a 3 inch concrete pavement, proportioned and mixed to give 2000 psi...

  8. Microencapsulation of Self-healing Concrete Properties

    Science.gov (United States)

    2012-08-01

    Smith, D. Performance Related Specifications for Concrete Pavements . FHWA-RD-93-042. Federal Highway Administration, Washington, D.C, 1993...application of self-healing concrete, the wall must be rigid and strong enough to endure an aqueous condition as well as the concrete environment

  9. 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…

  10. 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...

  11. Pavement Testing Facility

    Data.gov (United States)

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

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

    Science.gov (United States)

    2011-03-01

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

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

    OpenAIRE

    Aderinola, O.S

    2016-01-01

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

  14. Latex improvement of recycled asphalt pavement

    Science.gov (United States)

    Drennon, C.

    1982-08-01

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

  15. 机场水泥道面接缝位移及嵌缝材料结构应力%DispIacement of airport concrete pavement joints and structuraI stress of seaIants

    Institute of Scientific and Technical Information of China (English)

    苏尔好; 袁捷; 黄崇伟

    2015-01-01

    为深入研究机场道面接缝缝槽的水平和竖向位移对于嵌缝材料黏附性失效和嵌缝材料挤出的影响,采用有限元分析的手段,计算机场水泥道面接缝缝槽在环境温度和湿度变化下引起的缝槽水平位移量,以及飞机荷载作用引起的缝槽竖向位移量,并与实际观测数据进行对比分析.计算表明,机场水泥道面接缝缝槽水平位移量为2.2 mm左右,拉伸应变量可取为25%,与公路水泥路面基本相当;接缝缝槽的竖向位移量处于0.25~0.61 mm,剪切应变量处于3.1%~7.7%,较公路水泥路面大一些.选择包含弹簧单元及Kelvin模型的三参数固体模型描述嵌缝材料的流变特性,通过拉伸松弛实验实际测定3种典型嵌缝材料的弹簧系数和黏壶系数,利用缝槽内嵌缝材料拉伸应力和剪切应力的简化计算公式,计算3种典型嵌缝材料极限状态下的结构应力,结果表明,嵌缝材料的结构应力主要来自于接缝水平位移所引起的拉伸应力,剪切应力与接缝传荷能力的变化密切相关.%To study the influence of horizontal and vertical displacements of j oint on the cohesion failure and extrusion of the sealants in rigid pavement of airports,the displacement of the j oint and structural stress of the sealants were researched.Horizontal displacement caused by environmental temperature & humidity and vertical displancement caused by airplane loads were calculated separately by the finite element meth-ods,and the data of in-situ were compared with these calculation results.It is suggested that about 2.2 mm (corresponding to 25% tensile strain)of the horizontal displacement and 0.25—0.61 mm (corresponding to 3.1%—7.7% shear strain)of the vertical displacement are reasonable as the parameters for calculating the structural stress of sealants in concrete pavement j oints.The model containing of a spring element and a Kelvin model was used for depicting the sealants

  16. Effect of Airfield Pavement Deicer on Freeze-thaw Durability of High Performance Concrete%机场道面除冰液对高性能 混凝土抗冻性的影响

    Institute of Scientific and Technical Information of China (English)

    麻海燕; 余红发; 白康; 曹文涛; 周鹏; 韩丽娟

    2011-01-01

    Influence of calcium magnesium acetate (CMA) , which is the main composition of the most frequently used as airfield pavement dicer, on the freezing-thaw durability of high performance concrete (HPC ) were investigated. Freeze-thaw durability of HPC was tested by accelerated freezing-thawing test. Five kinds of solutions, namely tap water, 3.5%NaCl solution, 3.5%-25% calcium magnesium acetate (CMA), 25% glycol solution and commercial aircraft deicer were employed to be the freeze-thaw mediums. Results show that freeze-thaw durability of HPC exposed to CMA solutions is related to the solution concentrations. CMA solution with a concentration of 3. 5% is beneficial to durability of HPC. Freeze-thaw failure of concrete exposed to 3. 5% CMA solution is 1. 09 of that of HPC exposed to tap water; both are resulted from propagation of inner cracks. While freeze-thaw failure of HPC exposed toNaCl solution is different and characterized by surface deterioration. 25% CM A solution shows no damage to HPC'freeze-thaw durability, while both 25% glycol solution and commercial aircraft deicer demonstrate obviously damage to HPC'freeze-thaw durability. The results showed that CMA can effectively improve the freeze-thaw durability of HPC.%采用快冻法测定了高性能混凝土(High Performance Concrete,HPC)在水、浓度为3.5%的NaCl除冰盐、3.5%~25%的醋酸钙镁(Calcium magnesium acetate,CMA,机场道面除冰液)、25%的乙二醇(飞机除冰液)和商品飞机除冰液中的抗冻性.结果表明,在3.5% CMA溶液中,HPC抗冻性比水中冻融提高了1.09倍,其冻融破坏特征与水中冻融一样,均属于内部微裂纹扩展,完全不同于HPC在3.5% NaCl溶液中的盐冻表面剥蚀.在浓度为25%的条件下,CMA机场道面除冰液对HPC无冻融破坏作用,而乙二醇飞机除冰液、尤其是商品飞机除冰液对HPC有明显的冻融破坏作用.因此,CMA机场道面除冰液能够有效地延缓HPC的冻融破坏.

  17. Fast estimating concrete strength method applying microwave autoclave curing technology%应用微波蒸压技术的混凝土强度快速测定方法

    Institute of Scientific and Technical Information of China (English)

    蒋德稳; 田安国; 胡杰; 赵政

    2015-01-01

    为了快速测定混凝土强度,将微波技术应用到传统的蒸压养护工艺中,自行设计和制作了小型微波蒸压釜。通过试验得出了釜腔内温度压力大小、恒温恒压养护时间对混凝土早期强度的影响规律,进而总结出微波蒸压养护条件下混凝土快速养护制度。通过15批次(5种配合比)不同强度等级混凝土的微波蒸压养护和标准养护对比试验,建立了微波蒸压养护条件下的混凝土强度线性和非线性回归模型,模型中考虑了加速养护混凝土强度和混凝土水灰比,具有较好的相关关系。试验分析发现:运用微波技术,可以均匀、迅速地提高混凝土内部温度,减小温度应力,使混凝土1 h内获得较高(28 d强度40%~50%)、稳定的早期强度,可以作为预拌混凝土生产企业和施工现场进行强度控制和配合比调整时的依据。%In order to estimate concrete strength quickly,microwave was applied to the conditional autoclave curing. Small microwave autoclave suitable for the microwave autoclaved were self designed and made. By experiment research,the effect laws of temperature in autoclave and constant temperature curing time on the early strength of concrete were investigated,and rapid curing system was summa-rized on the condition of microwave and autoclave. By the contrast test of microwave autoclave curing and standard curing of 15 batches of different strength grade concrete,the linear and nonlinear regression model of concrete strength determination were established with better correlativity on the condition of microwave and autoclave. Concrete strength accelerated of curing and water-cement-ratio was considered in the model. It was found that the internal temperature of concrete would be uniformly,rapidly improved by microwave,and the temperature stress would be reduced.The high and stable early strength of concrete(40~50 percent of 28 d strength)was obtained

  18. Study on Concrete Pavement Materials Using Fluidized Bed Combustion Coal Ashes%燃煤固硫灰渣混凝土路面材料研究

    Institute of Scientific and Technical Information of China (English)

    黄煜镔; 钱觉时; 张建业; 党玉栋

    2011-01-01

    Using local industrial solid waste to reduce the building cost of rural road is very important. With the experimental study on cementitious system mixed with fluidized bed combustion coal ashes, the results show that; fluidized bed combustion coal ashes have a significant pozzolanic activity due to the characteristic of porous surface and low degree of anionic polymerization, and these ashes can be organized a cementitious systems with alkali and sulfate activator,in which the fluidized bed combustion coal ashes could be up to 70%. Mixing cement and increasing the amount of sulfate-activating agent can improve the early performance of the system significantly. Especially,the dosage of sodium sulfate must be more than 1. 5%. The properties of concrete mixed with fluidized bed combustion coal ashes are suitable in terms of strength and brittleness which make it be used in the rural road successfully.%降低农村公路造价具有重要的现实意义,利用地方工业固体废弃物是一种途径.通过对燃煤固硫灰渣胶凝系统的试验研究,结果表明:燃煤固硫灰渣表面疏松和阴离子聚合度低的特征,使其具有显著的火山灰效应,可与碱、硫酸盐激发剂组成胶凝系统,其中固硫灰渣占70%以上;掺加水泥和增大硫酸盐激发剂掺量能显著改善系统早期性能,硫酸盐掺量宜大于1.5%;燃煤固硫灰渣混凝土具有较好的强度性能和材料韧性,在农村公路中应用具有现实可行性.

  19. 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…

  20. 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.

  1. 水泥混凝土在机场道面除冰液作用下的化学腐蚀%Chemical Corrosion of Cement Concrete Exposed to Airport Pavement Deicers

    Institute of Scientific and Technical Information of China (English)

    马好霞; 余红发; 卢一亭; 刘曙光; 付同仁

    2012-01-01

    The immersion tests that ordinary Portland concrete (OPC) and high performance concrete (HPC) specimens placed in calcium magnesium acetate (CMA) of 3. 5%, 12. 5% and 25% mass fraction of solution were carried out, and the mass loss and the relative dynamic elastic modulus were measured. Meanwhile, the surface exfoliative characteristics of specimens were observed, the corrosion resistances between Portland cement HPC and resisting sulfate cement HPC in CMA were compared. The results show that the surface exfoliative phenomenon and the quality loss are the main characteristics of corrosive damage in the CMA, its inner relative dynamic elastic modulus doesn't reduced significantly. The concrete's CMA corrosive exfoliative degree is related with the concentration of CMA solution and the corrosion time. When soaked corrosive time is more than 450 d, the corrosive exfoliative phenomena grow serious when the CMA's concentration becomes greater, the corrosive exfoliative phenomenon is more obvious. The 25 % mass fraction of CMA solution has the most severe corrosion in OPC among the three kinds of concrete and the HPC-P·II 52. 5 is better than the HPC-P · HSR42. 5. Therefore, the CMA's corrosion and damage to the concrete are the surface corrosion not the interior corrosion, and the research of CMA to the concrete corrosion damage mechanism provides reliable experimental basis for the future. Furthermore, adopting HPC-P · II 52. 5 cement can solve the corrosive and damage problem which caused by the CMA deicing fluid and can provide a basis for the airport pavement HPC's research in the northern region.%进行了普通混凝土(OPC)和高性能混凝土(HPC)试件在质量分数为3.5%,12.5%,25%的醋酸钙镁(CMA)溶液中的浸泡试验,测定了腐蚀过程中混凝土试件的质量变化和相对动弹性模量,跟踪了试件表面的剥落特征,比较了硅酸盐水泥HPC和抗硫酸盐水泥HPC的抗CMA腐蚀性.结果表明:CMA对水泥混凝土的腐

  2. EFFECT OF CURING METHODS AND WET CURING DURATION ON PROPERTIES OF PLAIN AND SLAG-CEMENT CONCRETE%养护措施和湿养护时间对掺与未掺矿渣混凝土性能的影响

    Institute of Scientific and Technical Information of China (English)

    刘竞; 邓德华; 刘赞群

    2008-01-01

    Three curing methods were used for concrete curing with wet cotton mats, a curing agent and plastic film. The strength, shrinkage, central temperature and chloride permeability under various curing methods were studied. The effect of wet curing duration (1, 7, 14 and 28 d) on the strength, impermeability and corrosion resistance for protecting internal reinforcement of plain and slag-cement concrete (in which 40% (in mass) cement was replaced by blast furnace slag) was studied by experiments including strength, chloride penetration depth immersed in 5% (in mass) NaCl solution, half-cell potential and concrete cover cracking time in accelerated corrosion. The results show the proper curing methods can effectively increase the strength, reduce the central temperature due to hydration heat and the early shrinkage strain and improve the chloride impermeability. Longer wet curing duration is essential to achieve higher strength, durability and corrosion resistance characteristics while inadequate wet curing resulted in poorer chloride impermeability and corrosion resistance for both plain and slag cement concrete, but especially for slag cement concrete. The plain cement concrete is relatively more tolerant to inadequate curing. The higher potential chloride penetration resistance can not be activated later in the natural environment if wet curing was ceased on the 7th day.%研究了采用湿棉絮覆盖、喷养护剂、塑料薄膜密封3种养护措施对混凝土强度、收缩、中心温升、氯离子渗透性的影响,并通过不同龄期强度、氯离子渗透深度(5%NaCl溶液介质,质量分数)、钢筋腐蚀电位、加速腐蚀保护层开裂时间研究湿养护时间(1,7,14d和28d)对未掺和掺矿渣(等量取代水泥40%,质量分数)混凝土强度、抗渗性、护筋性的影响.结果表明:合适的养护措施能有效提高混凝土强度和抗渗性,降低水化温升和早期收缩.对未掺与掺矿渣的混凝土,更长的湿养护有

  3. The Use Of Pervious Concrete In Rainwater Management

    Directory of Open Access Journals (Sweden)

    Kshitija Nadgouda

    2015-01-01

    Full Text Available The primary characteristic of previous concrete is high porosity with interconnected voids between aggregate particles. This permits the use of this specialty concrete as a permeable pavement material. It prevents storm water runoff from causing flooding and erosion downstream. This paper attempts to optimize the compressive strength and infiltration rate of pervious concrete for use as a pavement material in low traffic parking lot areas at a site in suburban Mumbai.

  4. Grey Target Optimization of Waterproof Adhesive Material for Concrete Bridge Deck Pavement Based on Mechanical Analysis%基于力学分析的桥面铺装防水粘结层材料灰靶优选

    Institute of Scientific and Technical Information of China (English)

    于新; 李英涛; 刘云

    2012-01-01

    为了优选与混凝土箱梁桥防水粘结层实际受力状态相匹配的材料,以沪杭高速公路拓宽改建工程高架桥为例,采用有限元法建立了全桥模型,在分析刹车、超载、随机动荷载等因素对防水粘结层力学响应的基础上,利用灰靶理论优选室内实测典型防水粘结层的相关技术参数.研究结果表明:刹车超载使防水粘结层产生的剪应力大于由桥面不平度引起的防水粘结层剪应力,最大可达0.397 MPa;橡胶沥青和SBS改性沥青防水粘结层综合性能较优,可作为混凝土桥防水粘结层材料.%In order to select the optimal waterproof adhesive material that meets the stress needs of concrete box girder bridge deck pavement, taking the viaduct in widening project of the Shanghai-Hangzhou Expressway as an example, a composite structure model of the whole bridge was established using the finite element method, and the influence of braking, overloading, random dynamic loading on the mechanical response of the waterproof adhesive layer was analyzed. The technique parameters of some typical materials for waterproof adhesive layer were tested in lab, and then analyzed by the grey target theory. The result shows that braking plus overloading has a larger effect on the shear stress of adhesive layer than the random dynamic loading caused by bridge deck roughness, and may produce a maximum shear stress of 0. 397 MPa. The rubber asphalt and SBS modified asphalt both have good performance, and can be used as the material of waterproof adhesive layer.

  5. 不同养护条件对铁尾矿混凝土性能的影响%Influence of Different Curing Conditions on the Property of Concrete with Ore Tailings

    Institute of Scientific and Technical Information of China (English)

    崔孝炜; 倪文; 吴辉

    2013-01-01

    以未磨的鞍钢齐大山铁尾矿为骨料,以铁尾矿、高炉矿渣、水泥熟料和天然石膏3级梯级混磨产品为胶凝材料制成铁尾矿混凝土试块,对直接标准养护、先56℃蒸汽养护再标准养护、先90℃蒸汽养护再标准养护的混凝土试块进行了强度、水化产物及微观结构分析.结果表明:与直接标准养护比较,先56℃蒸汽养护可以提高试块不同龄期的强度,但先90℃蒸汽养护仅能提高试块的早期强度、对后期强度有负面影响;不同养护方式都形成由石英,未水化的C3S和C2S,水化产物CH、钙矾石和C-S-H凝胶组成的致密的铁尾矿高强结构材料,但对铁尾矿混凝土的水化硬化过程有重要影响.%With Angang Qidashan unground iron tailings as aggregate mixed with cementitious materials of iron tailings , blast furnace slag, cement clinker and natural gypsum of level 3 step mixed grindings, the concrete blocks of iron tailings are prepared. The concrete blocks under direct standard curing, 56 ℃C then standard steam curing and 90 ℃ then standard steam curing are separately analyzed from aspects of its strength, hydration products and microstructure. The results show that compared with the standard curing, 56 ℃ steam curing can improve the blocks strength at each stage, however 90℃ steam curing only improve the early blocks strength and have a negative impact on the later strength. All curing methods can form the compact high-strength iron tailings material consisting of quartz, the un-hydrated C3S and C2S, hydration products CH, ettringite and C-S-H gel, but have a different impact on the hydrating and hardening process of the i-ron tailings concrete.

  6. VISCOELASTIC STRUCTURAL MODEL OF ASPHALT CONCRETE

    Directory of Open Access Journals (Sweden)

    V. Bogomolov

    2016-06-01

    Full Text Available The viscoelastic rheological model of asphalt concrete based on the generalized Kelvin model is offered. The mathematical model of asphalt concrete viscoelastic behavior that can be used for calculation of asphalt concrete upper layers of non-rigid pavements for strength and rutting has been developed. It has been proved that the structural model of Burgers does not fully meet all the requirements of the asphalt-concrete.

  7. State-of-the-art and prospect for self-healing asphalt concrete

    Science.gov (United States)

    Xiao, Dong

    2017-08-01

    In order to solve the problem of asphalt concrete pavement cracks, this paper summarizes the principle of self-healing asphalt concrete, and describes asphalt concrete self-healing technology in various countries. This paper also analyses the factors of influencing the self-healing ability of asphalt concrete and the evaluation index, and describes the prospect of asphalt concrete self-healing technology.

  8. Toward Development of Self-Compacting No-Slump Concrete Mixtures

    NARCIS (Netherlands)

    Hoornahad, H.

    2014-01-01

    No-slump concrete (NSLC) is one of the commercial types of concrete that is known as a type of concrete with almost zero flowability. No-slump concrete is normally used for typical applications, like pavements construction and massive dam structures. The specific feature of a no-slump concrete is it

  9. 混凝土砂基透水路面砖制备及物理性能测试%Precasting method and physical property test of sand-based concrete permeable pavement bricks

    Institute of Scientific and Technical Information of China (English)

    徐向舟; 朱晓斌; 刘璐; 王云闯; 王萍萍

    2014-01-01

    Promoting sand-based permeable brick is an effective way to recycle desert sand.A kind of sand-based permeable brick with precast permeable pores is developed.The brick is composed with roast sand as the aggregate and high-strength grading concrete as the binder,and is formed under static pressure.A series of physical performance tests and cost analyses are then conducted.The results are as follows:(1)Compressive strength of the permeable brick reaches up to 100 MPa,which is highly above the requirement of Cc60 permeable brick in the Construction Material Industry Standard in China.(2 )The pre-fabricated penetrating hole makes the permeability of the brick far ahead of the Construction Material Industry Standard in China.Moreover,it is not so easy to clog, and does not influence the comfort of the pavement,for the hole is so small in diameter on the top and large at the bottom.(3)Comprehensively considering the compressive strength,permeability,water retention,cost and so on,the following two schemes are chosen for future study:The 20th group is selected as the high-strength permeable brick,of which the fine sand ratio is 70%,the water cement ratio is 0.34,the porosity is 2% and the additive is the aqueous neoprene,in short AN;and the 22th group is more suitable to be used on the plaza pavement,of which the fine sand ratio is 85%,the water cement ratio is 0.30,the porosity is 1%,and no additive is added.(4)Increasing the coarse aggregate content could significantly augment the compressive strength of permeable brick. A preferable fine sand ratio is 70%-85%.(5)On the other hand,to mix an appropriate kind of additive with proper dosage is another way to enhance the brick.(6)Except higher cost of groups 7,11,12, 19,the cost of other groups is between 60-100 Yuan/m2 ,which is close to that of general no-sand permeable concrete brick,and far lower than that of the same kind of sand-based permeable brick.%推广砂基透水砖是实现沙漠沙资源化的有效途径.

  10. Assessment of dynamic properties and stiffness of composite bridges with pavement defects

    Science.gov (United States)

    Kartopol'tsev, Vladimir; Kartopol'tsev, Andrei; Kolmakov, Boris

    2017-01-01

    This paper is aimed at assessing the dynamic properties and stiffness of the reinforced concrete roadway slab under live loads that impact composite bridge girders considering pavement defects. A special attention is paid to the reinforced concrete roadway slab as a transfer member of forced oscillations. The test results obtained for bridges with different spans ranging from 24 to 110 m are presented to assess the behavior of the reinforced concrete roadway slab and the dynamic stiffness of bridge span allowed for the pavement defects. Dynamic tests are carried out under controlled and random loads that simulate live load interaction with the span and the pavement with defects. The differential equations are presented for vertical oscillations of spans, pavement defect parameter, Eigen frequency and others. As a result of the experimental research the equation is derived to ascertain the dynamic stiffness of the vehicle-span system.

  11. Dynamic Response Analysis of Asphalt Concrete Pavement with Permeable Base Considering Moving and Overload Effect of Vehicles%考虑车辆移动效应和超载的排水基层路面结构动力分析

    Institute of Scientific and Technical Information of China (English)

    欧金秋; 崔新壮; 王聪; 郑骁

    2011-01-01

    In order to study the dynamic response of asphalt concrete pavement with permeable base under vehicle loads, based fast Lagrangian finite difference method, the dynamic analysis of asphalt concrete pavement under various conditions is conducted, considering the influence of moving vehicle load and different speed. The results show that the pavement dynamic deflection did not increase though the modulus of permeable base is low. The permeable base reduced the dynamic stress at the bottom of the subbase, which can inhibit the cracking of reflection. With the increase of speed, both the dynamic deflection and stress decreased, so in high temperature season, low-speed vehicle can cause larger rutting. Little vehicle overload can induce larger dynamic deflection and stress thus causes larger pavement deformation even plastic damage and the cracking. It is implied that the governance of overload is of great significance for extending road life and reducing maintenance costs.%为了研究车辆荷载作用下排水基层路面的动力响应,同时考虑车速和轴载的影响,采用移动加载的方法,对不同工况下沥青混凝土路面进行了快速Lagrange有限差分分析.结果表明,路面弯沉并未因排水基层的低模量而增大,峰值甚至有所减小;排水基层的存在减小了底基层底部的动应力,可以抑制反射裂缝的产生;弯沉及动应力均随车速的增大而减小,高温季节,低速行驶更容易引起大车辙;当车辆超载50%时,弯沉和动应力均成倍增大,导致路面产生较大变形甚至塑性破坏,且更容易引起路面开裂,表明治理超载对延长道路使用寿命、降低养护成本具有重要意义.

  12. NANOMODIFIED CONCRETE

    Directory of Open Access Journals (Sweden)

    B. M. Khroustalev

    2015-01-01

    Full Text Available One of the main directions in construction material science is the development of  next generation concrete that is ultra-dense, high-strength, ultra-porous, high heat efficient, extra corrosion-resistant. Selection of such direction is caused by extreme operational impacts on the concrete, namely: continuously increasing load on the concrete and various dynamics of such loads; the necessity in operation of concrete products in a wide temperature range and their exposure to various chemical and physical effects.The next generation concrete represents high-tech concrete mixtures with additives that takes on and retain the required properties when hardening and being used under any operational conditions. A differential characteristic of the next generation concrete is its complexity that presumes usage of various mineral dispersed components, two- and three fractional fine and coarse aggregates, complex chemical additives, combinations of polymer and iron reinforcement.Design strength and performance properties level of the next generation concrete is achieved by high-quality selection of the composition, proper selection of manufacturing techniques, concrete curing, bringing the quality of concrete items to the required level of technical condition during the operational phase. However, directed formation of its structure is necessary in order to obtain high-tech concrete.Along with the traditional methods for regulation of the next generation concrete structure, modification of concrete while using silica nanoparticles is also considered as a perspective one because the concrete patterning occurs due to introduction of a binder in a mineral matrix. Due to this it is possible to obtain nano-modified materials with completely new properties.The main problem with the creation of nano-modified concrete is a uniform distribution of nano-materials in the volume of the cement matrix which is particularly important in the cases of adding a modifier in

  13. Self-compacting concrete mixtures for road BUILDING

    Directory of Open Access Journals (Sweden)

    Tran Tuan My

    2012-10-01

    Therefore, effective concrete road pavements require self-compacting though non-segregating concrete mixtures to comply with the pre-set values of their properties, namely, bending and compressive strength, corrosion resistance, freeze resistance, etc. Acting in cooperation with Department of Technology of Binders and Concretes of MSUCE, NIIMosstroy developed and examined a self-compacting cast concrete mixture designated for durable monolithic road pavements. The composition in question was generated by adding a multi-component modifier into the mix. The modifier was composed of a hyperplasticiser, active (structureless fine and crystalline silica, and a concrete hardening control agent.

  14. Roodekrans trial sections: The role of structural support under very thin jointed CRC pavements subjected to heavy traffic

    CSIR Research Space (South Africa)

    Steyn, WJvdM

    2005-08-01

    Full Text Available The Roodekrans trial sections were constructed to evaluate the effect of aggregate interlock, dowels, continuous reinforcement and various supporting layers on the relative performance of very thin concrete pavements. The sections were constructed...

  15. 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.

  16. 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.

  17. 结合透水混凝土路面的垂直流要水平流组合人工湿地雨水收集处理系统设计%Constructed Wetland Rainwater Collection and Treatment System Design Combined with the Vertical Flow-Horizontal Flow Combination of Pervious Concrete Pavement

    Institute of Scientific and Technical Information of China (English)

    丁权福; 唐硕; 姜慧; 赵云科; 魏梦可; 孙加亮; 丁永昌; 徐栋栋

    2015-01-01

    本文重点阐述了一种结合透水混凝土路面的垂直流—水平流组合人工湿地系统的设计,通过人工湿地填料、植物选择及搭配来改善人工湿地系统处理污水的物理、生物、化学反应,从而提高系统对收集的雨水净化处理能力。%This paper focuses on the design of constructed wetland system combined with the vertical flow-horizontal flow combination of pervious concrete pavement, which can improve the physical, biological and chemical reaction of constructed wetland system treating the polluted water through constructed wetland fillers, plant selection and matching, thereby improving the rainwater purification capability of system.

  18. Heavy vehicle simulator testing on pre-cast concrete panels

    CSIR Research Space (South Africa)

    Du Plessis, L

    2007-07-01

    Full Text Available commonly found in California, pre-cast concrete slabs are considered to be a very suitable repair material for extending the service life of intermittently distressed concrete pavements. This is because of the long life expectancy of concrete slabs cast...

  19. Study of the effect of the nature of aggregates on the mechanical behaviour of the concrete in hot and dry zones «Contribution of the curing» Etude de l’effet de la nature des granulats sur le comportement mécanique du béton en zones chaudes et arides «Contribution de la cure»

    Directory of Open Access Journals (Sweden)

    Bendjillali K.

    2012-09-01

    Full Text Available Laghouat est parmi les villes de l’Algérie riches en matériaux de différentes natures, tels que les roches calcaires massives et les matériaux alluvionnaires meubles siliceux et silico-calcaires. L’objectif premier de ce travail est d’établir une comparaison des performances mécaniques des bétons préparés avec de granulats de natures différentes. Nôtre second objectif est l’étude de l’influence de la cure sur la résistance à la compression et la résistance à la flexion des bétons étudiés. Les échantillons sont conservés sous un climat chaud et sec réel qui est le climat de Laghouat. Nous avons utilisé comme cure: le film plastique, la toile de jute mouillée et l’immersion dans l’eau. A travers ce travail expérimental, nous avons pu constater que les meilleures résistances à la compression sont obtenues dans les bétons à sable siliceux et celles à la flexion sont obtenues dans les bétons à granulats calcaires. La conservation du béton dans une ambiance aride sans protection augmente sa résistance mécanique à jeune âge, mais à long terme, cette dernière chute d’une façon significative. L’étude a mis en évidence la nécessité de l’emploi d’un super plastifiant et de l’application immédiate de la cure pour le bétonnage en climat chaud. Laghouat is among the cities of Algeria rich in materials of various natures, such as the massive limestone rocks and the natural river materials. The first objective of this work is to establish a comparison of the mechanical performances between concretes with aggregates of different natures. The second objective is to study the effect of curing on the compressive and the flexural strength of concretes. Samples are conserved under a real hot and dry climate which is the climate of Laghouat. We used as curing: plastic film, wet hessian and immersing in water. Through this work, we noticed that the best compressive strengths are obtained in concretes

  20. Comparative Analysis of Mechanical Response of Asphalt Concrete Pavement to Different Loads%不同形式荷载下沥青混凝土路面结构力学响应的对比分析

    Institute of Scientific and Technical Information of China (English)

    陈俊; 陈景雅; 刘云; 吴建涛

    2013-01-01

    Wheel loads in present pavement analysis systems are commonly simplified as three forms,namely static load,vibrating load and moving load with a constant speed.In order to understand the diffe rence of pavement response subject to the three simplified loadings,the discrete element model of pavement structure is constructed according to a typical flexible pavement.The effects of loading on pavement structure are simulated using the discrete element method.Thereafter,comparisons of pavement response subject to the three different loading are performed.Results show that only the maximum response to moving load can be reflected by static and vibration loading.The alternation of tensile and compressive response and double-action of the horizontal shearing stress cannot be simulated by static and vibration loading.%在分析车辆荷载作用下路面结构响应时,车辆荷载通常被简化为静止、振动和匀速移动3类形式.为了准确把握荷载不同简化形式下路面结构响应的差异,根据柔性路面的典型结构形式,建立了路面结构的离散元模型;采用离散元颗粒流软件,分别模拟了静止、振动和移动荷载对路面结构的作用,并对比分析了不同荷载形式下路面结构的力学响应.结果表明,静止、振动荷载只能反映移动荷载作用于路面结构后最大响应,亦即移动荷载越过路面结构某位置的瞬间,静止荷载响应与振动和移动荷载响应的峰值相当;静止、振动荷载不能反映移动荷载对路面结构引起的拉、压交替响应,以及车辆移动引起的路面结构内水平剪应力不同方向的两次作用.

  1. Evaluation of precast concrete slabs using a heavy vehicle simulator

    CSIR Research Space (South Africa)

    Kohler, E

    2008-10-01

    Full Text Available -controlled conditions and that fully cured precast slabs can potentially be open to traffic almost immediately upon installation, making them attractive for use on heavily travelled highways. This paper describes an accelerated pavement testing experiment conducted...

  2. 青岛海湾大桥承台混凝土寒季养护技术%Cold Weather Curing of Cushion Cap Concrete in Qingdao Bay Bridge

    Institute of Scientific and Technical Information of China (English)

    郭保林; 刘征涯; 胡孝展

    2011-01-01

    青岛海湾大桥位于海水含盐度高且存在较严重自然冻融循环的胶州湾海域,施工环境与服役环境都比较恶劣.非通航孔桥承台位于潮差区与浪溅区,为了保证施工期及运营期的混凝土耐久性,采用低水胶比、大掺量矿物掺和料、适量引气的混凝土配制技术,并利用外部围水设施实现海上干法施工.在冬季,为了降低施工期外界环境对混凝土性能的不利影响,将围水设施顶部用帆布覆盖,内部空间布置加热水箱,承台侧面利用蓄水型模板衬里提供不间断的保湿养护.自浇筑至14d养护龄期内,承台侧面及顶面温度始终高于15℃,相对湿度高于95%,模板衬里内积蓄的水量高于混凝土养护所需要的水量,采取该养护方案实现了承台混凝土的持续保温保湿养护,保证了承台混凝土的各项性能健康发展.%The saline concentration of seawater is comparatively high and there are 50 times of freezing and thawing cycles in Kiaochow bay where the Qingdao Bay Bridge is located, moreover, the construction and service environment are very severe for reinforced concrete structure.The cushion caps of approach bridge are all among tidal zone and splash zone.Low water-cement-ratio, high volume mineral admixtures, and air entraining are the main technology to prepare cushion cap concrete.Some cofferdams are utilized to make the construction environment seawater free.In winter, the top of cofferdams are covered with canvas, the space between cushion cap and canvas are heated by several boiling water tanks, and the lateral surface of cushion cap are curing by controlled permeability formwork liner in order to reduce the disadvantage influence of construction factor to concrete.During the first 14 days curing,the environment temperature around the cushion cap are kept above 15℃ , and the RH is above 95%.The free water contained among controlled permeability formwork liner is more than the need of concrete

  3. Pavement Snow Melting

    Energy Technology Data Exchange (ETDEWEB)

    Lund, John W.

    2005-01-01

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

  4. DRAINAGE AND FLEXIBLE PAVEMENT PERFORMANCE

    Directory of Open Access Journals (Sweden)

    SIDDHARTHA ROKADE

    2012-04-01

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

  5. 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.

  6. 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.

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

    Directory of Open Access Journals (Sweden)

    Zhao Bing

    2015-05-01

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

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

    Science.gov (United States)

    2009-10-01

    ER D C/ CR R EL T R -0 9 -1 1 Transportation Pooled Fund Program Structural Improvements of Flexible Pavements Using Geosynthetics for...2009 Structural Improvements of Flexible Pavements Using Geosynthetics for Base Course Reinforcement Karen Henry, Ph.D., P.E. Department of Civil...concrete, thin or moderate base course thickness, and soft subgrades—see, for example, the summary of 15-years of geosynthetic -reinforced base research

  9. The Application of High Polymer Material Curing Membrane in the Channel Lining Construction with Concrete Water-saving and Moisturize%渠道衬砌工程中混凝土节水保湿高分子材料养护膜的应用

    Institute of Scientific and Technical Information of China (English)

    张迎晨

    2014-01-01

    In this article, the author takes the background of solving the concrete curing cracks in the channel lining project of northern Sinkiang, and combines with the application of hi-gh polymer material curing membrane with water-saving and moisturize in the curing test to provide certain reference for concrete curing.%本文以解决北疆某渠道衬砌工程中混凝土养护裂缝的产生为背景,结合养护试验中的应用节水保湿高分子材料养护膜,对混凝土养护方面起到了一定的参考作用。

  10. 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.

  11. Accelerated pavement testing of load transfer through aggregate interlock and the influence of crack width and aggregate type - a case study

    CSIR Research Space (South Africa)

    Du Plessis, L

    2007-10-01

    Full Text Available , 1685, South Africa 4 Pavement and Materials Specialist, South African National Roads Agency LTD, P.O. Box 100 410, Scottsville, 3209, South Africa. Abstract It is well known that performance of plain jointed concrete pavements depends... on aggregate interlock to transfer load from the one slab to the next. In order to quantify the relative contribution of crack width and the strength of the aggregate to the long- term performance of a plain jointed pavement, experimental sections of road...

  12. Application of Conductive Materials to Asphalt Pavement

    Directory of Open Access Journals (Sweden)

    Hai Viet Vo

    2017-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Saurabh Jain

    2013-09-01

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

  14. Finite Element Investigation of the Deterioration of Doweled Rigid Pavements

    CERN Document Server

    Ghauch, Ziad G

    2011-01-01

    The purpose of this study is to describe the failure of concrete around dowel bars in jointed rigid pavements, and the resulting effect on the pavement performance. In fact, under repetitive vehicle loading, concrete in contact with the dowel bar deteriorates, particularly at the joint face. The degradation of concrete around the dowel negatively affects the latter's performance in terms of transferring wheel loads through vertical shear action. In this context, a nonlinear 3D Finite Element analysis was performed using the commercial FE code Abaqus (v-6.11). The FE model was validated with classical analytical solutions of shear and moment along the dowel. A concrete damaged plasticity model was used for the PCC slab to model the degradation of concrete matrix around the dowels under incremental loading. Results obtained show, among other things, that the degradation of concrete matrix around the dowel was found to initiate at the face of the joint and propagate towards the interior of the dowel. Also, resul...

  15. 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.

  16. Investigations of the dynamics of road pavement reflectance

    Institute of Scientific and Technical Information of China (English)

    Kang Jiang; Kai Yu; Yongchao Zhao

    2012-01-01

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

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

    CSIR Research Space (South Africa)

    Steyn, WJvdM

    2001-07-01

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

  18. 蒸汽养护及矿粉对混凝土力学性能、抗氯离子渗透性和抗冻性能影响%Influence of Steam Curing and Slag on Physical Property, Chloride Penetration and Froze Resistance of Concrete

    Institute of Scientific and Technical Information of China (English)

    汪冬冬; 田伟丽; 王成启

    2011-01-01

    通过开展蒸汽养护与标准养护的对比试验,系统研究了混凝土的力学性能、抗氯离子渗透性能和抗冻性能,同时研究矿粉对混凝土性能的影响,并通过扫描电子显微镜的微观测试手段分析冻融前后混凝土的微观形貌.研究结果表明:蒸养对混凝土的抗氯离子渗透性和抗冻性产生不利影响,在混凝土中掺矿粉可以减小蒸养对混凝土微观结构和耐久性的负作用.%Comparative tests between steam curing and standard curing are carried out, systematically research are conducted on mechanical property, resistance to chloride penetration and to freezing-thawing, meanwhile, the influence of slag on concrete property is studied and the microphotography of hardened concrete before and after alternation of freezing and thawing is analyzed by scanning electron microscope (SEM). The results indicate that steam curing has negative effect on the resistance to chloride penetration and freezing-thawing and slag in concrete can reduce the negative effect of steam curing on micro structure and durability of concrete.

  19. Three Permeable Pavements Performances for Priority Metal Pollutants and Metals associated with Deicing Chemicals from Edison Parking Lot, NJ - abstract

    Science.gov (United States)

    The U.S. Environmental Protection Agency constructed a 4000-m2 parking lot in Edison, New Jersey in 2009. The parking lot is surfaced with three permeable pavements [permeable interlocking concrete pavers (PICP), pervious concrete (PC), and porous asphalt (PA)]. Samples of each p...

  20. Three Permeable Pavements Performances for Priority Metal Pollutants and Metals Associated with Deicing Chemicals from Edison Parking Lot, NJ

    Science.gov (United States)

    The U.S. Environmental Protection Agency constructed a 4000-m2 parking lot in Edison, New Jersey in 2009. The parking lot is surfaced with three permeable pavements [permeable interlocking concrete pavers (PICP), pervious concrete (PC), and porous asphalt (PA)]. Samples of each p...

  1. Comparative study on compressive strength of Self cured SCC and Normally cured SCC

    Directory of Open Access Journals (Sweden)

    Ms. Akanksha A. Patil

    2014-11-01

    Full Text Available Curing is the process of maintaining proper moisture content particularly within 28 days to promote optimum cement hydration immediately after placement. Self-compacting concrete is made up of admixture i.e. superplasticizer. In recent years, self-compacting concrete (SCC has gained wide use for placement in congested reinforced concrete structures with difficult casting conditions. Also various curing methods are adopted in the construction industry especially for vertical structures, inaccessible areas s.a. high rise buildings, water scarce areas etc. In such structures conventional curing is not practically possible in most of the cases. But we need efficient curing which improves the strength and durability of concrete. In the present work, comparison of compressive strength of normally cured SCC and SCC cured with self curing material i.e. wax based, white pigmented, membrane forming concrete curing compound has been done. This study is investigating that weather the use of self curing compound is economical or not in remote areas of water without compromising with the compressive strength of concrete.

  2. Geotextiles in Flexible Pavement Construction

    Science.gov (United States)

    Alungbe, Gabriel D.

    2004-01-01

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

  3. Pavement roughness and skid properties

    Science.gov (United States)

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

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

    Directory of Open Access Journals (Sweden)

    Ali Reza Ghanizadeh

    2016-01-01

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

  5. 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.

  6. Characterization of Failure and Permanent Deformation Behaviour of Asphalt Concrete

    NARCIS (Netherlands)

    Wang, J.G.

    2015-01-01

    Asphalt concrete is a viscoelastic material consisting of aggregates, filler and bitumen. The response of asphalt concrete is highly dependent on temperature, loading rate and confining pressure. Permanent deformation is one of the most important distresses developing during the flexible pavement

  7. Characterization of Failure and Permanent Deformation Behaviour of Asphalt Concrete

    NARCIS (Netherlands)

    Wang, J.G.

    2015-01-01

    Asphalt concrete is a viscoelastic material consisting of aggregates, filler and bitumen. The response of asphalt concrete is highly dependent on temperature, loading rate and confining pressure. Permanent deformation is one of the most important distresses developing during the flexible pavement se

  8. 码头面层纤维混凝土的抗冲击性能与增韧机理%IMPACT RESISTANCE PERFORMANCE AND TOUGHNESS REINFORCING MECHANISM OF FIBER REINFORCED CONCRETE USED ON SURFACE LAYER OF WHARF PAVEMENT

    Institute of Scientific and Technical Information of China (English)

    王彦明; 刘克; 孙纪正; 杨雯雯

    2011-01-01

    The fiber reinforced concrete with polypropylene fiber, nylon fiber and steel fiber respectively addedinto C30 plain concrete was used for flexural impact resistance performance experiment. The impact resistance property is evaluated by initial cracking times, final cracking times and impact toughness. The result shows that the impact toughness of steel fiber concrete, polypropylene fiber concrete and nylon fiber concrete is respectively 15.1, 3.4, 2.7 times of the plain concrete. Several energy absorbing mechanisms and toughness reinforcing mechanism were analyzed. The energy consumed by fiber pulling-out work of steel fiber concrete, polypropylene fiber concrete and nylon fiber concrete is respectively 25, 1.72, 0.93 times of the energy consumed by fiber fracture work. Sliding, pulling-out, fracture are major factors to improve the flexural impact resistance of polypropylene fiber, nylon fiber reinforced concrete. Besides sliding and pulling-out, the bridge-making to the crack of steel fiber is very important to improve the impact resistance property of steel fiber reinforced concrete greatly.%在C30素水泥混凝土中分别添加聚丙烯纤维、尼龙纤维、钢纤维配制纤维混凝土,进行抗弯曲冲击试验。以初裂次数、终裂次数、冲击韧性评价混凝土抗冲击性能的优劣。试验结果表明:添加钢纤维、聚丙烯纤维、尼龙纤维混凝土的冲击韧性分别是素混凝土冲击韧性的15.1倍、3.4倍、2.7倍。结合冲击破坏断裂特征,分析了纤维混凝土承受冲击载荷作用的几种能量吸收机制,对增韧机理进行了分析。钢纤维、聚丙烯纤维、尼龙纤维混凝土,纤维拔出功消耗能量分别是纤维断裂功消耗能量的25倍、1.72倍、0.93倍。纤维的滑移、拔出、断裂是聚丙烯纤维、尼龙纤维混凝土提高抗冲击性能的主要因素,钢纤维混凝土的抗冲击能力提高幅度最大除了纤维的滑移、拔出因素

  9. Polymer concrete patching materials

    Energy Technology Data Exchange (ETDEWEB)

    Fontana, J.J.

    1977-09-01

    The increased use of deicing salts is causing rapid deterioration of portland cement concrete bridge decks. Soluble chlorides cause corrosion of the steel reinforcing rods with a corresponding increase in volume of the rods. This expansion causes stresses in the concrete which result in delaminations and surface spalling. The repair of surface spalls with portland cement concrete can only be made if traffic can be avoided for several days. A patching material which would allow traffic to resume over the repaired area in a few hours was needed. Polymer concrete (PC) was developed to repair deteriorated portland cement concrete. Polymer concrete is defined as a composite material in which the aggregate is bound together in a dense matrix with a polymer binder. The aggregate is mixed with a monomer mixture and subsequently cured in place. Polymer concrete combines the premix characteristics of portland cement concrete with high strength, long term durability properties and fast cure times. PC placed at temperatures between 35/sup 0/F and 95/sup 0/F attains strengths greater than 5000 psi in 2 hours. The high early strength of PC is suitable for use in the repair of highway structures where traffic conditions allow closing of the area for only a few hours.

  10. Nutrient infiltrate concentrations from three permeable pavement types.

    Science.gov (United States)

    Brown, Robert A; Borst, Michael

    2015-12-01

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

  11. 绿色环保型高性能沥青混凝土排水铺装用防水材料应用研究%Application research on the green high-performance waterproof material for asphalt concrete drainage pavement

    Institute of Scientific and Technical Information of China (English)

    杨冲; 冉千平; 孙德文

    2013-01-01

    This article introduces a high-performance resin-based waterproof materials for drainage pavement with asphalt con-crete,and its performance advantages as waterproof layer. Its excellent performance includes:4.07 MPa of adhesion to asphalt concrete base surface, 3.51 MPa of adhesion to the concrete surface, low temperature flexibility of up to -20℃,no impervious after 24 h under 1.8 MPa pressure, excellent abrasion resistance. It can not only achieve good compatibility between the waterproof layer with the substrate, but also avoid the economic losses due to performance deficiencies in the waterproof layer exist in the real project.%介绍了一种沥青混凝土排水铺装用的高性能树脂型防水材料以及其作为防水层所具备的性能优势.其优异性能表现在与沥青混凝土基面的粘结强度达4.07 MPa,与混凝土基面的粘结强度达3.51 MPa,低温弯折性可达-20℃,同时在1.8 MPa的压力下24 h不透水,耐磨性优良.不仅能够实现防水层与基层之间良好的相容性,同时避免了在实际工程中存在的因防水层性能缺陷带来的经济损失.

  12. Fore and aft elastic response characteristics of 34 x 9.9, type 7, 14 ply-rating aircraft tires of bias-ply, bias-belted, and radial-belted design. M.S. Thesis - George Washington Univ., May 1973; [static and rolling tests on dry concrete pavements

    Science.gov (United States)

    Tanner, J. A.

    1974-01-01

    An investigation was conducted to determine the fore-and-aft elastic response characteristics of 34 x 9.9, type VII, 14 ply-rating aircraft tires of bias-ply, bias-belted, and radial-belted design. The investigation consisted of static and rolling tests on dry concrete pavements at the Langley aircraft landing loads and traction facility; statistical techniques which related the measured tire elastic characteristics to variations in the vertical load, inflation pressure, braking force and/or tire vertical deflection; and a semiempirical analysis which related the tire elastic behavior to measured wheel slippage during steady-state braking. The bias-belted tire developed the largest spring constant value for most loading conditions; the radial-belted tire, the smallest. The elastic response of the tire free periphery to static braking included both tread stretch and carcass torsional wind-up about the axle for the bias-ply and bias-belted tires and carcass wind-up alone for the radial-belted tire.

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

    Institute of Scientific and Technical Information of China (English)

    汪香莲

    2011-01-01

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

  14. 基于混凝土养护温度过低的分析研究%Analysis and Research on Too Low Concrete Curing Temperature

    Institute of Scientific and Technical Information of China (English)

    段江涛; 李志鹏

    2014-01-01

    At present, concrete winter construction becomes more and more common, but due to part of management personnel has some errors for winter construction techniques and the application of antifreeze, engineering accidents continue to emerge. Based on the quality accident in a residential building of Zhengzhou caused by cold, this paper analyzes the reasons and introduces the preventive measures.%目前,混凝土冬期施工越来越普遍,但是由于部分管理人员对冬施技术及防冻剂的应用存在一些误区,致使工程事故不断出现。下面仅就郑州某住宅楼工程质量因受冻而引发的质量事故进行原因分析和预防措施介绍。

  15. Determining the healing potential of asphalt concrete mixtures--a pragmatic approach

    NARCIS (Netherlands)

    Erkens, S.; Vliet, D. van; Dommelen, A. van; Leegwater, G.A.

    2012-01-01

    Most design methods for pavements use a factor explaining the difference between pavement life predictions from design models and performance in the road [1]. Part of this correction factor is healing, the natural capacity of asphalt concrete to recover in rest periods, which generally are not prese

  16. Tests on concrete containing cork powder admixtures

    OpenAIRE

    González, B.; Llamas, B; Juan, A.; Guerra, I.

    2007-01-01

    The present study aimed to determine the physical and mechanical properties of laboratory concrete made with different proportions of cork powder. While the resulting material lacked the mechanical strength characteristic of concrete, its properties may prove to be apt for certain hardscaping and agricultural uses, such as in the manufacture of pavement for playgrounds and parks, or certain kinds of structures used in livestock raising. These findings need to be analyzed and verified.

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

    Science.gov (United States)

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

    2013-06-01

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

  18. Fracture Behavior and Properties of Functionally Graded Fiber-Reinforced Concrete

    Science.gov (United States)

    Roesler, Jeffery; Bordelon, Amanda; Gaedicke, Cristian; Park, Kyoungsoo; Paulino, Glaucio

    2008-02-01

    In concrete pavements, a single concrete mixture design is selected to resist mechanical loading without attempting to adversely affect the concrete pavement shrinkage, ride quality, or noise attenuation. An alternative approach is to design distinct layers within the concrete pavement surface which have specific functions thus achieving higher performance at a lower cost. The objective of this research was to address the structural benefits of functionally graded concrete materials (FGCM) for rigid pavements by testing and modeling the fracture behavior of different combinations of layered plain and synthetic fiber-reinforced concrete materials. Fracture parameters and the post-peak softening behavior were obtained for each FGCM beam configuration by the three point bending beam test. The peak loads and initial fracture energy between the plain, fiber-reinforced, and FGCM signified similar crack initiation. The total fracture energy indicated improvements in fracture behavior of FGCM relative to full-depth plain concrete. The fracture behavior of FGCM depended on the position of the fiber-reinforced layer relative to the starter notch. The fracture parameters of both fiber-reinforced and plain concrete were embedded into a finite element-based cohesive zone model. The model successfully captured the experimental behavior of the FGCMs and predicted the fracture behavior of proposed FGCM configurations and structures. This integrated approach (testing and modeling) demonstrates the viability of FGCM for designing layered concrete pavements system.

  19. Early Property Development in Concrete

    DEFF Research Database (Denmark)

    Normann, Gitte; Munch-Petersen, Christian

    2014-01-01

    The Freiesleben Maturity function is widely used for planning of execution. We tested if for concrete with and without fly ash. The test showed surprisingly that the maturity function in general is not valid. We found that curing at high temperature gave a significant decrease in strength. Fly ash...... appears to reduce this decrease somewhat. We also examined the resistance against chloride penetration for the different concrete types. The resistance was reduced at high temperatures for concrete without fly ash. For concrete with fly ash, it was the opposite; concrete with fly ash obtained higher...

  20. How Concrete Is Concrete?

    Science.gov (United States)

    Gravemeijer, Koeno

    2011-01-01

    If we want to make something concrete in mathematics education, we are inclined introduce, what we call, "manipulatives", in the form of tactile objects or visual representations. If we want to make something concrete in a everyday-life conversation, we look for an example. In the former, we try to make a concrete model of our own,…

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

    Science.gov (United States)

    1984-08-01

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

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

    DEFF Research Database (Denmark)

    Pineda, Andres Felipe Valderrama

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

  3. Effect of curing conditions on water absorption ratio and electric -flux of concrete with mixed mineral ad mixture%养护条件对矿物掺和料混凝土吸水率和电通量的影响

    Institute of Scientific and Technical Information of China (English)

    刘宝举; 贺益田; 罗果; 梁东

    2015-01-01

    采用粉煤灰和矿渣粉复掺取代50%水泥,研究养护时间、养护湿度以及覆膜养护对混凝土吸水率和电通量的影响。试验结果表明:复掺矿物掺和料混凝土的标准养护时间越短、养护湿度越低、拆模前覆膜养护温度越高,混凝土吸水率越大,抗氯离子渗透性越差。在相同养护条件下,复掺粉煤灰-矿渣粉的混凝土吸水率比单掺煤灰的小,比单掺矿渣粉的大,抗氯离子渗透性能比单掺粉煤灰的好,但是比单掺矿渣粉的差。%In this paper,fly ash and slag power were used to replace 50 percent of cement to produce concrete. The water absorption rate and electric flux of the mineral admixture concrete were tested under different condi-tions,such as different curing time,different moisture and the impact of coated curing.The results of experiment show that the water -absorbing ability of the concrete become stronger and the property of resistance to chloride ion penetration resistance become weaker,in the condition of high temperature,shorter curing time and lower curing moisture.At the same curing process,the water absorption ratio of the concrete mixed with fly ash and slag powder is lower than the concrete only mixed with fly ash.However,the water absorption ratio of the con-crete mixed with fly ash and slag powder is higher than the concrete only mixed with slag powder.Moreover,the property of resistance to chloride ion permeability is opposite as the water absorption ratio.

  4. New methods for moisture control of high-performance concrete

    DEFF Research Database (Denmark)

    Kovler, Konstantin; Jensen, Ole Mejlhede; Falikman, Vyacheslav

    2005-01-01

    Curing of concrete by both external (conventional) and internal methods is reviewed and analyzed. The focus is given on the mitigation of autogenous shrinkage of low water-to-cementitious materials ratio concrete by means of internal curing. The concepts of internal curing are based on using pre-...

  5. New methods for moisture control of high-performance concrete

    DEFF Research Database (Denmark)

    Kovler, Konstantin; Jensen, Ole Mejlhede; Falikman, Vyacheslav

    2005-01-01

    Curing of concrete by both external (conventional) and internal methods is reviewed and analyzed. The focus is given on the mitigation of autogenous shrinkage of low water-to-cementitious materials ratio concrete by means of internal curing. The concepts of internal curing are based on using pre...... of professionals who work for them. The differences between conventional methods of external curing and novel methods of internal curing are described. It is concluded that proper curing is a key factor to achieve durable concrete....

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

    Science.gov (United States)

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

    2016-11-01

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

  7. Internal water curing with Liapor aggregates

    DEFF Research Database (Denmark)

    Lura, Pietro

    2005-01-01

    Internal water curing is a very efficient way to counteract self-desiccation and autogenous shrinkage in high performance concrete, thereby reducing the likelihood of early-age cracking. This paper deals with early-age volume changes and moisture transport in lightweight aggregate concrete realiz...

  8. 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

  9. A STUDY OF FATIGUE LIFE OF ASPHALT CONCRETE BASED ON SHUNGITE MINERAL POWDER

    OpenAIRE

    D. I. Chernousov; Vl. P. Podolsky; E. V. Trufanov; B. A. Bondarev

    2011-01-01

    Problem statement. Shortage of mineral powder stimulates seeking of new materials and technologiesby which traditional ones can be replaced without deterioration of their operating properties. Thatis why a study of mineral powder from shungite and development of new technologies of arrangementof high quality and durable asphalt concrete pavement based on shungite is an actual problem.Results. Bearing capacity and service life of asphalt concrete pavement is most completely characterizedby mod...

  10. 垃圾焚烧灰渣用于二灰碎石路面基层的试验研究%Experiment on Wastes Incineration Residues for Lime-Fly Ash Concrete Pavement Base

    Institute of Scientific and Technical Information of China (English)

    解建光; 陈金东; 曹兴国; 史进舟

    2011-01-01

    By replacing a part of macadam, wastes incineration residues used as aggregates to make lime-fly ash stabilized residues-macadam materials are conducted at nine different proportions. Compaction test , unconfined compressive strength test and shrinkage test are designed to evaluate the pavement performances of the material. Furthermore, the comparative trials are conducted between the new materials and traditional lime-fly ash macadam at the same proportions. Comparing with the traditional lime-fly ash macadam, the maximum dry density decreases by 8. 8% and the optimum water content increases by 38. 4% at the same content of lime and fly ash. Besides, the highest unconf ined compressive strength of lime-fly ash stabilized residues-macadam can reach 1-03 MPa, and the strengths of the new materials are significantly influenced by the content of fly ash. The strength decrease by 21%, if the content of fly ash decreases by 1%. The highest shrinkage coefficient is 67. 2 μ%, and if the content of lime and fly ash decreases by 2.55% the shrinkage coefficient reduces by 3. 1%. The performances of lime-fly ash stabilized residues-macadam can meet the requirements of highway pavement base, and combustion residues can be used as aggregates in road construction.%用城市生活垃圾焚烧灰渣替代部分集料,按照9种不同的配比制备二灰灰渣碎石路面基层材料,进行路用性能试验.结果表明:与普通二灰碎石对比,在相同的二灰含量下,灰渣碎石的最大干密度降低8.8%,而最佳含水量增大38.4%;无侧限抗压强度最高可达1.03 MPa;粉煤灰含量对材料强度影响较为显著,其中粉煤灰含量减少1%,无侧限抗压强度值降低21%;材料的干缩系数最大为67.2μ/%;石灰与粉煤灰含量越低,材料的干缩应变越小,平均干缩系数也越小,当二灰含量减少2.5%,平均干缩系数降低3.1%.二灰灰渣碎石材料满足基层的相关要求,灰渣可以为公路建设提供可持续的集料来源.

  11. The Albedo of Pervious Cement Concrete Linearly Decreases with Porosity

    Directory of Open Access Journals (Sweden)

    Rui Zhang

    2015-01-01

    Full Text Available Pervious pavements have been advocated as a potential countermeasure to the urban heat island effect. To understand if pervious pavements stay cooler than conventional pavements, the albedo of the pervious concrete must be understood. This study measured the albedo of pervious concrete with different porosity. Four Portland cement concrete mixes were casted, using designed amounts of sand to vary the porosity of the pervious concrete samples. The samples were sliced and the spectral reflectance and albedo of the sliced samples were measured and analyzed. It is found that the albedo of pervious concrete decreases linearly with the increase of the porosity. The albedo of a pervious Portland concrete varies from 0.25 to 0.35, which is 0.05~0.15 lower than the albedo of conventional cement concrete. Due to this lower albedo, it should be cautious to develop pervious concrete to battle with urban heat island unless the evaporation of pervious concrete is promoted to compensate the additional solar absorption caused by the low albedo.

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

    Science.gov (United States)

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

    2016-04-01

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

  13. Durable high strength cement concrete topping for asphalt roads

    Science.gov (United States)

    Vyrozhemskyi, Valerii; Krayushkina, Kateryna; Bidnenko, Nataliia

    2017-09-01

    Work on improving riding qualities of pavements by means of placing a thin cement layer with high roughness and strength properties on the existing asphalt pavement were conducted in Ukraine for the first time. Such pavement is called HPCM (High Performance Cementitious Material). This is a high-strength thin cement-layer pavement of 8-9 mm thickness reinforced with metal or polymer fiber of less than 5 mm length. Increased grip properties are caused by placement of stone material of 3-5 mm fraction on the concrete surface. As a result of the research, the preparation and placement technology of high-strength cement thin-layer pavement reinforced with fiber was developed to improve friction properties of existing asphalt pavements which ensures their roughness and durability. It must be emphasized that HPCM is a fundamentally new type of thin-layer pavement in which a rigid layer of 10 mm thickness is placed on a non-rigid base thereby improving riding qualities of asphalt pavement at any season of a year.

  14. RESEARCH ON THE HIGH PERFORMANCE COMPOSITE ROAD CONCRETE

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Ordinary concrete presents short service life when used for building and repairing high-grade road with heavy traffic due to its large brittleness, poor bending flexibility and serious shrinkage on drying. In this paper,a new kind of high performance concrete has been designed by means of combination of organic, inorganic material as well as metal material.The research and application have shown that this new concrete can significantly counteract the deficiency of ordinary concrete and give excellent mechanical properties and pavement performances. The application of this new kind of concrete is of great social and economic significance.

  15. Initiation and Propagation Mechanism of Blisters on the Epoxy Asphalt Concrete Paving Course of Steel Deck Bridge Pavement%钢桥面环氧沥青铺装层鼓泡形成扩展机理

    Institute of Scientific and Technical Information of China (English)

    张华; 郝培文; 张海伟

    2016-01-01

    In order to take effective steps to minimize the blistering problems on the epoxy asphalt overlays, the cause and propagation mechanism for blisters were studied systematically by means of field investigation, theoretical analysis and mathematical modeling. Based on the theory of thin plate and fracture mechanics,the deflection of blisters was studied under the pressure. Additionally, the energy principle in fracture mechanics was used to derive the energy relationship and the initiation and propagation mechanism was studied. The results indicate that the development of blisters includes three stages, namely, initiation, stale and unstable propagation. The deflection of blisters produced by the external force was related to the radius of blisters, depth and modulus of elasticity of pavement. The energy release rate was proposed as a criterion of the initiation and propagation of blisters. It provides the theory basis for further model experiment and simulation analysis.%为有效减少钢桥面环氧沥青铺装层出现鼓泡现象,采用现场调查、理论分析和数学建模的研究方法,系统地研究了鼓泡产生的原因和形成扩展机理。基于薄板理论,研究了鼓泡在竖向均布荷载作用下鼓泡挠度的变化规律。根据断裂力学中的能量原理,得到了鼓泡形成扩展过程中的能量关系,进而阐明了鼓泡形成扩展机理。研究结果表明:钢桥面环氧沥青铺装层鼓泡的形成扩展过程分为起裂、稳定扩展和失稳扩展3个阶段;鼓泡在外力作用下产生的挠度与鼓泡半径、铺装层厚度和弹性模量等因素有关,提出了以能量释放率为判定参数的扩展准则。

  16. Analysis of Instrumentation Selection and Placement to Monitor the Hydrologic Performance of Permeable Pavement Systems and Bioinfiltration Areas at the Edison Environmental Center in New Jersey

    Science.gov (United States)

    In 2009, the U.S. Environmental Protection Agency constructed a 0.4-ha (1-ac) parking lot surfaced with three different permeable pavement types (interlocking concrete pavers, porous concrete, and porous asphalt) and six bioinfiltration areas with three different drainage area to...

  17. 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

  18. Equivalent damage of loads on pavements

    CSIR Research Space (South Africa)

    Prozzi, JA

    2009-05-26

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

  19. Quantifying Evaporation in a Permeable Pavement System

    Science.gov (United States)

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

  20. G4高速公路湖南耒宜段大修工程路面结构方案设计%Pavement Structure Design of LeiYi Expressway Overhaul Engineering

    Institute of Scientific and Technical Information of China (English)

    吴超凡; 黄治湘; 张继森

    2014-01-01

    This paper introduces the original variety of Leiyi Expressway pavement structure,traf-fic flow and pavement damage.According to the pavement structure specific,traffic flow and axle load disparity of the road,using a technical and economical comparison,the original continuous reinforced concrete pavement overlay asphalt concrete pavement structure,the original ordinary cement concrete and reinforced concrete pavement overlay continuously reinforced concrete composite pavement,milling and overlay single or bunk asphalt pavement layer on the original asphalt pavement,the original asphalt pave-ment overlay situ thermal regeneration after single and double bituminous surface layer structure.%介绍了耒宜高速公路原路面的多种路面结构与交通流量及路面损害情况,针对具体的路面结构与左右幅交通流量与轴载的悬殊差异,经技术经济比较,采用了在原连续配筋混凝土路面上直接加铺沥青混凝土路面结构;在原普通水泥混凝土与钢筋混凝土路面上加铺连续配筋混凝土复合式路面;在原沥青路面上进行铣刨加铺单层沥青面层与双层沥青面层、对原沥青路面进行就地热再生后加铺单层与双层沥青面层结构。

  1. Criteria for the Use of Lime-Cement-Flyash on Airport Pavements

    Science.gov (United States)

    1989-12-01

    drainage of the pavement system. Performance of pavement with I.F as a base/subbase has been studied by the FAA2 2 and others. 6,8,15,21,27,28 They...conditions of soil classification, drainage and frost, a subbase is not required. The concrete surface must provide an acceptable nonskid surface...1965). 17. Callahan, J.P., Morrow, J., and Ahlberg, H.L., " Autogenous Healing in Lime-Pozzolan-Aggregate Mixtures," Report No. 631. Department of

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

    Science.gov (United States)

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

    2013-03-01

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

  3. Theoretical Solution for Temperature Profile in Multi-layered Pavement Systems Subjected to Transient Thermal Loads

    Science.gov (United States)

    2011-01-01

    kcal/mm s ◦C) Geopolymer paste 2.0x10−7 PCC slab 5.1x10−7 Thermal diffusivity, α (mm2/s) Geopolymer 0.2 PCC slab 1.3 for the surface layer of airfield...concrete pavements. Geopolymer materials have desirable properties for serving as an alternative binder to traditional Portland cement in producing...high thermal stability. Thus it is possible to construct paving concrete made from a geopolymer binder on top of the ordinary concrete slab to limit

  4. Vascular Cures

    Science.gov (United States)

    ... is Possible EVERY DOLLAR SAVES LIVES. Donate Now Vascular Cures innovates patient-centered research, catalyzes breakthrough collaborations and empowers people in their vascular health journey. what is vascular disease PATIENTS see ...

  5. Crumb rubber modified asphalt concrete in Oregon. Summary report. Report for 1985-94

    Energy Technology Data Exchange (ETDEWEB)

    Hunt, E.; Peters, W.

    1995-07-01

    Over the last nine years, the Oregon Department of Transportation (ODOT) has constructed 13 projects using crumb rubber modifiers (CRM) in asphalt concrete pavements using both the wet and dry process. State and federal legislation may require the use of recycled rubber in asphalt concrete, therefore, the Oregon Department of Transportation is interested in determining the most cost -effective crumb rubber modified asphalt concrete. The report includes a literature review on the use of crumb rubber modifiers in asphalt concrete pavement; a review on non-ODOT CRM paving projects constructed by Oregon counties and cities; and the Washington Department of Transportation. In additon, the report summarizes the data collected on all CRM hot mix asphalt concrete pavement projects constructed by ODOT. The ODOT information includes background constitution, cost, and performance data for each of the test and control sections. Finally, the future activities of the project are reviewed.

  6. THE FATIGUE DURABILITY OF THE MODIFIED ASPHALT CONCRETE UNDER THE EFFECT OF INTENSIVE TRAFFIC LOADS

    Directory of Open Access Journals (Sweden)

    Yuri KALGIN

    2016-06-01

    Full Text Available The problem of prediction of the service life of asphalt concrete surface constructed with modified asphalt concrete application onto a traffic lane is examined. Asphalt concrete behaviour in road surface under the traffic loads was analysed. There were shown The results of experiments and their mathematical analysis of the assessment of standard and modified cold asphalt concrete fatigue life on road surface were shown. The service life of an asphalt concrete surface covered with standard and modified cold asphalt concrete is examined. The prediction has been received with an account of stress relaxation processes in asphalt concrete pavement and unevenness of traffic load application.

  7. Impact of pavement conditions on crash severity.

    Science.gov (United States)

    Li, Yingfeng; Liu, Chunxiao; Ding, Liang

    2013-10-01

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

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

    Institute of Scientific and Technical Information of China (English)

    冯国龙

    2014-01-01

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

  9. Utilization of Electronic Waste Plastic in Concrete

    Directory of Open Access Journals (Sweden)

    Vivek S. Damal

    2015-04-01

    Full Text Available In India, bitumen pavements are commonly used for highways. Due to the increasing traffic intensity, distress such as rutting and cracking of pavements are very common in Indian roads. Under varying seasonal temperature, flexible pavements tend to become soft in summer and brittle in winter. Investigations revealed that properties of concrete can be better than bitumen roads. But now a day‟s concrete roads are used commonly because concrete roads have more life span than the bitumen roads. In large cities now a day‟s concrete roads are used because concrete roads are more durable, strengthen and having more life span than bitumen roads. Waste plastics and E-waste (electronic waste both by domestic and industrial sectors can be used in the production of asphalt mix. Waste plastic, mainly used for packing are made up of polyethylene, polypropylene, polystyrene. Electronic waste, abbreviated as e-waste, consists of discarded old computers, TVs, refrigerators; radios, etc are basically any electrical or electronic appliance that has reached its end of life. An experimental study is made on the utilization of E-waste particles as fine aggregates in concrete with a percentage replacement ranging from 0 % to 21.5% i.e. (7.5%, 15% and 21.5% on the strength criteria of M30 Concrete. Compressive strength Concrete with and without E- waste plastic as aggregates was observed which exhibits a good strength. The feasibility of utilizing E-waste plastic particles as partial replacement of fine aggregate has been presented. In the present study, compressive strength was investigated for Optimum Cement Content and 7.5% E-plastic content in mix yielded stability and very good in compressive strength of 43 grade cement.

  10. Discussion of the evolution of the chloride migration coefficient of Portland cement concrete tested by the rapid chloride migration (RCM) test at long-term curing periods up to 5 years

    NARCIS (Netherlands)

    Yu, Z.; Ye, G.; Hunger, M.; Noort, R.

    2013-01-01

    Chloride-induced corrosion of reinforced concrete is one of the main deterioration mechanisms leading to shortening of the service life of concrete structures. Therefore, assessment of the resistance of concrete to chloride ingress plays an important role in predicting the service life of such struc

  11. Comparisons of Faulting-Based Pavement Performance Prediction Models

    Directory of Open Access Journals (Sweden)

    Weina Wang

    2017-01-01

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

  12. Research on pavement performance of steel deck epoxy asphalt pouring concrete%钢桥面环氧沥青浇筑式混凝土铺装路用性能研究

    Institute of Scientific and Technical Information of China (English)

    崔晓波; 李超源; 邵强

    2014-01-01

    Through different binder contents flow detection selected suitable binder contents, and identified the suitable mixing time of mixture under the conditions of 10% binder content, the high and low temperature experiment results showed that, the low temperature performance of epoxy asphalt pouring asphalt mixture better than ordinary roller type epoxy asphalt concrete, and its low temperature properties little effect by mixing time, compared with common modified asphalt, epoxy asphalt could significantly improve the high temperature stability of pouring asphalt mixture.%通过不同结合料含量流动性检测选取了适宜的结合料用量,并确定了10%结合料用量条件下混合料适宜的拌和时间,高低温试验结果表明,环氧沥青浇筑式沥青混合料的低温性能优于普通碾压式环氧沥青混凝土,且其低温性能受拌和时间影响不大,与普通改性沥青相比,环氧沥青能够显著改善浇筑式沥青混合料的高温稳定性。

  13. How Concrete is Concrete

    OpenAIRE

    2010-01-01

    If we want to make something concrete in mathematics education, we are inclined introduce, what we call, ‘manipulatives’, in the form of tactile objects or visual representations. If we want to make something concrete in a everyday-life conversation, we look for an example. In the former, we try to make a concrete model of our own, abstract, knowledge; in the latter, we try to find an example that the others will be familiar with. This article first looks at the tension between these tw...

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

    Directory of Open Access Journals (Sweden)

    Cao Peng

    2013-01-01

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

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

    Institute of Scientific and Technical Information of China (English)

    车守忠

    2011-01-01

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

  16. How Concrete is Concrete

    Directory of Open Access Journals (Sweden)

    Koeno Gravemeijer

    2010-07-01

    Full Text Available If we want to make something concrete in mathematics education, we are inclined introduce, what we call, ‘manipulatives’, in the form of tactile objects or visual representations. If we want to make something concrete in a everyday-life conversation, we look for an example. In the former, we try to make a concrete model of our own, abstract, knowledge; in the latter, we try to find an example that the others will be familiar with. This article first looks at the tension between these two different ways of making things concrete. Next another role of manipulatives, will be discussed, namely that of means for scaffolding and communication. In this role, manipulatives may function as means of support in a process that aims at helping students to build on their own thinking while constructing more sophisticated mathematics

  17. 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.

  18. Conductive concrete wins Popular Science prize

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    1997-06-01

    A conductive concrete developed by a research team at IRC (Institute for Research in Construction, National Research Council of Canada) has won a prize in the home technology category because of its possible use in heating homes. Following the award, there have been a number of inquiries regarding possible applications for the concrete. Greatest interests in the concrete have been in its potential to heat buildings by using it as flooring. Other possible applications included de-icing pavements to building warming pads for parking aircraft. Essentially, carbon fibres and conductive particles are added to a concrete mix in such a quantity that they form a network within the mix, ensuring high electrical conductivity. A demonstration project is underway to build a 20 by 80 foot conductive concrete pad to test the material`s capability as a snow removal and de-icing tool.

  19. Examples of cooler reflective streets for urban heat-island mitigation : Portland cement concrete and chip seals

    Energy Technology Data Exchange (ETDEWEB)

    Pomerantz, M.; Akbari, H.; Chang, S.-C.; Levinson, R.; Pon, B.

    2003-04-30

    Part of the urban heat island effect can be attributed to dark pavements that are commonly used on streets and parking lots. In this paper we consider two light colored, hence cooler, alternative paving materials that are in actual use in cities today. These are Portland cement concrete (PCC) pavements and chip seals. We report measurements of the albedos of some PCC and chip sealed pavements in the San Francisco Bay Area. The albedos of the PCC pavements ranged from about 0.18 to 0.35. The temperatures of some PCC pavements are also measured and calculated. We then consider how the albedos of the constituent materials of the PCC (stone, sand and cement) contribute to the albedos of the resulting finished concrete. The albedos of a set of chip sealed pavements in San Jose, CA, were measured and correlated with the times of their placement. It is found that the albedos decrease with age (and use) but remain higher than that of standard asphalt concrete (AC) for about five years. After t hat, the albedos of the chip seals are about 0.12, similar to aged AC. The fact that many PCC pavements have albedos at least twice as high as aged AC suggests that it is possible to have pavement albedos that remain high for many years.

  20. 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,

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

    Science.gov (United States)

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

    2017-01-01

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

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

    Science.gov (United States)

    Castillo, Luis, Jr.

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

  3. Research on tensile strength characteristics of bridge deck pavement bonding layers

    Science.gov (United States)

    Wu, Shaopeng; Han, Jun

    2010-03-01

    As the development of the traffic in the world, the bridge deck pavement is playing a more and more important role in the whole traffic system. Big span bridge has become more and more especially cement concrete bridge, therefore the bridge deck pavement bonding layers are emphasized as an important part of bridge traffic system, which can mitigate travel impact to bridge and magnify stationary or traffic amenity. The quality and durability of deck pavement bonding layer has directly effect on traffic safety, comfort, durability and investment of bridge. It represents the first line of defence against the ingress of water, road de-icing salts and aggressive chemicals. In real project, many early age damage of bridge deck pavement has become serious disease that affecting the function of bridge. During the construction of the bridge deck, many types of asphalt binders were used, such as styrene-butadiene-styrene (SBS) modified asphalt, styrene-butadiene rubber (SBR) modified asphalt, neoprene latex asphalt, etc. In this paper UTM-25 was used to test the tensile strength of different bridge deck pavement bonding layers with the different treatment methods to inter-surface.

  4. 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.

  5. Significance of tests and properties of concrete and concrete-making materials

    CERN Document Server

    Pielert, James H

    2006-01-01

    Reflects a decade of technological changes in concrete industry! The newest edition of this popular ASTM publication reflects the latest technology in concrete and concrete-making materials. Six sections cover: (1) General information on the nature of concrete, sampling, variability, and testing laboratories. A new chapter deals with modeling cement and concrete properties. (2) Properties of freshly mixed concrete. (3) Properties of hardened concrete. (4) Concrete aggregates—this section has been revised and the chapters are presented in the order that most concerns concrete users: grading, density, soundness, degradation resistance, petrographic examination, reactivity, and thermal properties. (5) Materials other than aggregates—the chapter on curing materials now reflects the current technology of materials applied to new concrete surfaces. The chapter on mineral admixtures has been separated into two chapters: supplementary cementitious materials and ground slag. (6) Specialized concretes—contains a ...

  6. Monitoring water loss form fresh concrete

    DEFF Research Database (Denmark)

    Jensen, Ole Mejlhede

    2006-01-01

    . This paper concerns in particular a new method for site measurement of evaporation from concrete surfaces in the early hardening phase. Compared to the methods used today for determination of the desiccation process in the early hardening phase, the so-called Curing Meter permits a simple, safe and accurate...... determination of the evaporation loss from hardening concrete and thus better possibility for preventing curing problems, including detrimental crack damage due to plastic shrinkage....

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

    CSIR Research Space (South Africa)

    VdM Steyn, WJ

    2012-09-01

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

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

    CSIR Research Space (South Africa)

    Steyn, WJVDM

    2009-09-01

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

  9. Simplified Pavement Design for LPAs: Introduction to PaveXpress

    OpenAIRE

    2015-01-01

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

  10. Simplified Pavement Design for LPAs: Introduction to PaveXpress

    OpenAIRE

    Bonte, Dudley

    2015-01-01

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

  11. Crack repair of asphalt concrete with induction energy

    NARCIS (Netherlands)

    García, A.; Schlangen, E.; Ven, M. van de; Vliet, D. van

    2011-01-01

    It is well known that the healing rates of asphalt courses increase with the temperature. A new method, induction heating, is used in this paper to increase the lifetime of asphalt concrete pavements. Mastic will be first made electrically conductive by the addition of conductive fibers. Then it wil

  12. Crack repair of asphalt concrete with induction energy

    NARCIS (Netherlands)

    García, A.; Schlangen, E.; Van de Ven, M.; Van Vliet, D.

    It is well known that the healing rates of asphalt courses increase with the temperature. A new method, induction heating, is used in this paper to increase the lifetime of asphalt concrete pavements. Mastic will be first made electrically conductive by the addition of conductive fibers. Then it wil

  13. Investigation of perpetual pavement using finite element modelling

    Directory of Open Access Journals (Sweden)

    Monireh Zokaei

    2016-06-01

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

  14. Improving Data Quality for Pavement Management System

    OpenAIRE

    2015-01-01

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

  15. Removable Urban Pavements: An innovative, sustainable technology

    OpenAIRE

    2012-01-01

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

  16. Applications of observational techniques in pavement engineering

    CSIR Research Space (South Africa)

    Steyn, WJVDM

    2007-05-01

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

  17. Reliability Analysis of Temperature Influence on Stresses in Rigid Pavement Made from Recycled Materials

    Directory of Open Access Journals (Sweden)

    Aleš Florian

    2016-01-01

    Full Text Available Complex statistical and sensitivity analysis of principal stresses in concrete slabs of the real type of rigid pavement made from recycled materials is performed. The pavement is dominantly loaded by the temperature field acting on the upper and lower surface of concrete slabs. The computational model of the pavement is designed as a spatial (3D model, is based on a nonlinear variant of the finite element method that respects the structural nonlinearity, enables to model different arrangement of joints, and the entire model can be loaded by thermal load. Four concrete slabs separated by transverse and longitudinal joints and the additional structural layers including soil to the depth of about 3 m are modeled. The thickness of individual layers, physical and mechanical properties of materials, characteristics of joints, and the temperature of the upper and lower surface of slabs are supposed to be random variables. The simulation technique Updated Latin Hypercube Sampling with 20 simulations is used for the reliability analysis. As results of statistical analysis, the estimates of basic statistics of the principal stresses σ1 and σ3 in 106 points on the upper and lower surface of slabs are obtained. For sensitivity analysis the sensitivity coefficient based on the Spearman rank correlation coefficient is used. As results of sensitivity analysis, the estimates of influence of random variability of individual input variables on the random variability of principal stresses σ1 and σ3 are obtained.

  18. Structural Precast Concrete Handbook

    DEFF Research Database (Denmark)

    Kjærbye, Per Oluf H

    Structural concept for precast concrete systems. Design og precast reinforced concrete components. Design of precast concrete connections. Illustrations on design of precast concrete buildings. Precast concrete assembly....

  19. Green building handbook: Green pavement

    CSIR Research Space (South Africa)

    Van Wyk, Llewellyn V

    2010-11-01

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

  20. Enhancing pavements for thermal applications

    OpenAIRE

    Keikhaei Dehdezi, Pejman

    2012-01-01

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

  1. Rubberized Concrete Durability Against Abrasion

    Directory of Open Access Journals (Sweden)

    Md Noor Nurazuwa

    2016-01-01

    Full Text Available Durability performance of rubberized concrete against abrasion is presented in this paper. Surface depth loss was measured when abrasion load was constantly applied on concrete surface at each 500 interval rotation. Specimen with water-to cement ratio of 0.50 and 0.35 was prepared and tested at 28 days of curing age. In addition, 10% silica fume, SF was added to provide denser concrete and to understand its effectiveness against wear when added with crumb rubber. Results showed that crumb rubber shows good potential in providing abrasion resistance to concrete mix. However, in the case of rubberized concrete with silica fume, abrasion resistance was found to be slightly decreased with compressive strength more than 50N/mm2 due to the lack of low elastic modulus of CR particles to accommodate with denser cement matrix.

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

    Science.gov (United States)

    2014-01-01

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

  3. The Fatigue Behaviour of Asphaltic Concrete Made With Waste Shredded Tire Rubber Modified Bitumen

    OpenAIRE

    ÇELİK, Osman Nuri

    2001-01-01

    Pavement failure can be manifested by excessive cracking due to fatigue. Highway pavements are subjected to a repeated passage of wheel loading of varying magnitude and intensity. Fatigue has been defined as the phenomenon of fracture under repeated or fluctuating stress having a maximum value less than the tensile strength of the material. This paper examines a laboratory characterisation of the fatigue behaviour of rubberised asphaltic concrete and assesses the effect of waste shred...

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

    Directory of Open Access Journals (Sweden)

    Saud A. Sultan

    2016-10-01

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

  5. Effect of rapid set binder on early strength and permeability of HES latex modified road repair pre-packed concrete

    Science.gov (United States)

    Han, J. W.; Lee, S. K.; Yu, C.; Park, C. G.

    2015-12-01

    The early strength development characteristics and permeability resistance of high early strength (HES) pre-packed road repair concrete incorporating a rapid-set binder material were evaluated for emergency repairs to road pavement. The rapid-set binder is a mixture of rapid-set cement and silica sands whose fluidity improves with the addition of styrene butadiene latex (latex). The resulting mixture has a compressive strength of 21 MPa or higher and a flexural strength of greater than 3.5 MPa after 4 hours, the maximum curing age allowed for emergency repair materials. This study examines the strength development properties and permeability resistance of HES latex-modified pre-packed road repair concrete using a rapid- set binder as a function of the latex-to-binder mixing ratio at values of 0.40, 0.33, 0.29 and 0.25. Both early strength development properties and permeability resistance increased as the ratio of latex to rapid-set binder decreased. The mixture showed a compressive strength of 21 MPa or higher after 4 hours, which is the design standard of emergency repair concrete, only when this ratio was 0.29 or lower. A flexural strength of 3.5 MPa or greater was observed after hours only when this ratio was 0.33 or lower. The standard for permeability resistance, less than 2,000 C of chloride after 7 days of curing, was satisfied by all ratios. The ratio of latex to rapid-set binder satisfying all of the conditions for an emergency road repair material was 0.29 or less.

  6. Load Response Analysis of Asphalt Pavement

    Directory of Open Access Journals (Sweden)

    Xiao Zhijun

    2016-01-01

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

  7. 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

  8. EVALUATION OF TIRE RUBBER DISPOSAL IN CONCRETE FOR PAVEMENTS

    OpenAIRE

    Rosa Cristina Cecche Lintz; Maria Rachel Russo Seydell

    2009-01-01

    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...

  9. Experimental Relationships between Moduli For Soil Layers Beneath Concrete Pavements

    Science.gov (United States)

    1977-06-01

    Young’s Modulus with Overburden and Void Ratio for a Granular Soil ........... ...... .. ... 45 24 Measured Versus Calculated Deflections for Sand...values, to evaluate the validity of the material characteri,ations. By making comparisions between the "ideal" granular subgrade section and the...components C are dependent on the current total level of stress and strain. The variable modulus models represent materials of the so-called " hypoelastic

  10. Field cracking performance of airfield rigid pavements

    Directory of Open Access Journals (Sweden)

    Yusuf Mehta

    2017-08-01

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

  11. Structural Precast Concrete Handbook

    DEFF Research Database (Denmark)

    Kjærbye, Per Oluf H

    Structural concept for precast concrete systems. Design og precast reinforced concrete components. Design of precast concrete connections. Illustrations on design of precast concrete buildings. Precast concrete assembly.......Structural concept for precast concrete systems. Design og precast reinforced concrete components. Design of precast concrete connections. Illustrations on design of precast concrete buildings. Precast concrete assembly....

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

    Science.gov (United States)

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

    2014-01-01

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

  13. 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.

  14. 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.

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

    Institute of Scientific and Technical Information of China (English)

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

    2016-01-01

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

  16. Locating voids beneath pavement using pulsed electromagnetic waves

    Science.gov (United States)

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

    1981-11-01

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

  17. Glazed Concrete

    DEFF Research Database (Denmark)

    Bache, Anja Margrethe

    2010-01-01

    Why glazed concrete? Concrete hardens and finds its strength at room temperature whereas clay products must first be fired before they achieve this strength. They are stronger and three times as durable as clay products, which is a weighty reason for choosing concrete.5 Another reason, which....... If this succeeds, it will be possible to manufacture thin, large-scale glazed concrete panels comparable in size to concrete sandwich construction and larger which, with or without back-casting, can work as load-bearing construction elements....

  18. Glazed Concrete

    DEFF Research Database (Denmark)

    Bache, Anja Margrethe

    2010-01-01

    Why glazed concrete? Concrete hardens and finds its strength at room temperature whereas clay products must first be fired before they achieve this strength. They are stronger and three times as durable as clay products, which is a weighty reason for choosing concrete.5 Another reason, which....... If this succeeds, it will be possible to manufacture thin, large-scale glazed concrete panels comparable in size to concrete sandwich construction and larger which, with or without back-casting, can work as load-bearing construction elements....

  19. Assessment of the performance of rigid pavement back-calculation through finite element modeling

    Science.gov (United States)

    Shoukry, Samir N.; William, Gergis W.; Martinelli, David R.

    1999-02-01

    This study focuses on examining the behavior of rigid pavement layers during the Falling Weight Deflectometer (FWD) test. Factors affecting the design of a concrete slab, such as whether the joints are doweled or undoweled and the spacing between the transverse joints, were considered in this study. Explicit finite element analysis was employed to investigate pavement layers' responses to the action of the impulse of the FWD test. Models of various dimensions were developed to satisfy the factors under consideration. The accuracy of the finite element models developed in this investigation was verified by comparing the finite element- generated deflection basin with that experimentally measured during an actual test. The results showed that the measured deflection basin can be reproduced through finite element modeling of the pavement structure. The resulting deflection basins from the use FE modeling was processed in order to backcalculate pavement layer moduli. This approach provides a method for the evaluation of the performance of existing backcalculation programs which are based on static elastic layer analysis. Based upon the previous studies conducted for the selection of software, three different backcalculation programs were chosen for the evaluation: MODULUS5.0, EVERCALC4.0, and MODCOMP3. The results indicate that ignoring the dynamic nature of the load may lead to crude results, especially during backcalculation procedures.

  20. Experimental Study on Electric Properties of Carbon Fiber Reinforced Concrete

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    According to the phenomenon that the physical properties have a great effect on the electric capability of carbon fiber reinforced concrete, the author researched the relationship between DC resistance of carbon fiber reinforced concrete and curing age using the two-probe method. Then the effect of insulative area,location and quantity on DC resistance of carbon fiber reinforced concrete was investigated at different curing age with analysis of hydration. The results suggest that DC resistance increases greatly with its curing age, which illustrates the relationship like Gaussian curve. In every curing ages the electric capability of carbon fiber reinforced concrete weakenes with the increase of insulative area. In same curing ages, section and insulative area, the more the quantity of insulation, the stronger the conductibility. The insulative location in optimal position can only result in optimal conductibility.

  1. Concrete Hinges

    DEFF Research Database (Denmark)

    Halding, Philip Skov; Hertz, Kristian Dahl; Schmidt, Jacob Wittrup

    2014-01-01

    In the first part of the 20th century concrete hinges developed by Freyssinet and Mesnager were widely tested and implemented in concrete structures. The concrete hinges were used a great deal in closed-spandrel arch bridges. Since such a bridge type has not been competitive for the past 40 years......, the research in concrete hinges has not evolved significantly in that period. But introducing a new state-of-the-art concrete arch bridge solution (Pearl-Chain arches invented at the Technical University of Denmark) creates a necessity of a concrete hinge research based on modern standards. Back when research...... in concrete hinges was more common different designs were proposed for the geometry and reinforcement. Previous research focused on fatigue, multi-axial stresses around the hinge throat, and the relation between rotation- and moment. But many different test-setups were proposed by different researchers...

  2. Concrete structures

    CERN Document Server

    Setareh, Mehdi

    2017-01-01

    This revised, fully updated second edition covers the analysis, design, and construction of reinforced concrete structures from a real-world perspective. It examines different reinforced concrete elements such as slabs, beams, columns, foundations, basement and retaining walls and pre-stressed concrete incorporating the most up-to-date edition of the American Concrete Institute Code (ACI 318-14) requirements for the design of concrete structures. It includes a chapter on metric system in reinforced concrete design and construction. A new chapter on the design of formworks has been added which is of great value to students in the construction engineering programs along with practicing engineers and architects. This second edition also includes a new appendix with color images illustrating various concrete construction practices, and well-designed buildings. The ACI 318-14 constitutes the most extensive reorganization of the code in the past 40 years. References to the various sections of the ACI 318-14 are pro...

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

    Science.gov (United States)

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

    2014-01-01

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

  4. Wood slabs as a proposed solution to the design and construction of pavement

    Directory of Open Access Journals (Sweden)

    Carlos Alfonso Devia Castillo

    2016-01-01

    Full Text Available Alternatives to replace concrete slabs for prefabricated wood as structure of pavement with wearing course was evaluated, ensuring that these prefabrications work as a single element using finger joints. The mechanical behavior of two types of wood identified through simulations implementing a method of finite elements was evaluated, to subsequently determined optimal configuration for the alternative design with wood pavements and finally verified in the laboratory with the optimal configuration determined with simulation for a design of 440 000 vehicles shafts, with the use of the MTS machine and a load of 6.50 tons equivalent to a load of a single axle shaft with two wheels, found that for different traffic design the thickness of the slab of wood to resist this load varies between 0.125 and 0.24 meters. This research shows that prefabricated wood building systems are a viable alternative in the market for pavement construction in the structural sense; additionally, they are an innovation since they modify the structural system of slabs, conventionally built on concrete slabs and reduce environmental impact.

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

    Directory of Open Access Journals (Sweden)

    O. S. Aderinola

    2016-08-01

    Full Text Available A mechanistic-empirical pavement design method is developed characterising cement-treated base layers for pavement design in Nigeria or other similar tropical and subtropical countries. Asphalt Concrete surface, Subbase and Aggregate base were characterised based on back calculation data from Claros et al (1986 while cement-treated base layer was based on modulus tests that had been conducted by past researchers. Failure criteria for the Asphalt Concrete fatigue failure and the subgrade rutting failure were based on those by Claros and Ijeh (1987 for Nigerian pavements. Cracking criterion used for the cement-treated layer was that developed by Otee et al. (1982. The comparison between the Soil-Cement and Aggregate base showed that at a low Equivalent Single Axle Load (ESAL (0.5 million repetitions was considered, the use of Aggregate base was better than Soil-Cement base. That for Aggregate base and Cement-Treated Gravel Base showed that the Cement-Treated Gravel Base was better than the Aggregate base at high ESAL (2.5 million repetitions was considered

  6. Temporal evolution modeling of hydraulic and water quality performance of permeable pavements

    Science.gov (United States)

    Huang, Jian; He, Jianxun; Valeo, Caterina; Chu, Angus

    2016-02-01

    A mathematical model for predicting hydraulic and water quality performance in both the short- and long-term is proposed based on field measurements for three types of permeable pavements: porous asphalt (PA), porous concrete (PC), and permeable inter-locking concrete pavers (PICP). The model was applied to three field-scale test sites in Calgary, Alberta, Canada. The model performance was assessed in terms of hydraulic parameters including time to peak, peak flow and water balance and a water quality variable (the removal rate of total suspended solids). A total of 20 simulated storm events were used for model calibration and verification processes. The proposed model can simulate the outflow hydrographs with a coefficient of determination (R2) ranging from 0.762 to 0.907, and normalized root-mean-square deviation (NRMSD) ranging from 13.78% to 17.83%. Comparison of the time to peak flow, peak flow, runoff volume and TSS removal rates between the measured and modeled values in model verification phase had a maximum difference of 11%. The results demonstrate that the proposed model is capable of capturing the temporal dynamics of the pavement performance. Therefore, the model has great potential as a practical modeling tool for permeable pavement design and performance assessment.

  7. Possibilities of ground penetrating radar usage within acceptance tests of rigid pavements

    Science.gov (United States)

    Stryk, Josef; Matula, Radek; Pospisil, Karel

    2013-10-01

    Within the road pavement acceptance tests, destructive as well as non-destructive tests of individual road layers are performed to verify the standard requirements. The article describes a method for providing quick, effective and sufficiently accurate measurements of both dowel and tie bar positions in concrete pavements, using a two-channel ground penetrating radar (GPR). Measurements were carried out in laboratory and in-situ conditions. A special hand cart for field measurements, set for the testing requirements, was designed. It was verified that following the correct measuring and assessment method, it is possible to reach accuracy of determining the in-built rebar up to 1 cm in vertical direction and up to 1.5 cm per 11.5 m of measured length in horizontal direction. In the in-situ tests, GPR identification of possible anomalies due to the phase of concrete pavement laying was presented. In the conclusion, a measurement report is mentioned. The standard requirements for the position of dowels and tie bars cover maximum possible deviation of the rebar position from the project documentation in vertical and horizontal direction, maximum deflection of rebar ends to each other, and maximum translation of rebar in the direction of its longitudinal axis.

  8. Effective flow resistivity of highway pavements.

    Science.gov (United States)

    Rochat, Judith L; Read, David R

    2013-12-01

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

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

    CSIR Research Space (South Africa)

    Steyn, WJVDM

    2007-07-01

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

  10. Cost-benefit analysis of the construction of different flexible pavement structures considering the axle load and type of binder

    Directory of Open Access Journals (Sweden)

    Lucas Dotto Bueno

    2016-08-01

    Full Text Available The status of Brazilian highways reflects a deficient pavement performance when they are subjected to loadings imposed by heavy traffic. Current legislation, as enacted by Contran (National Traffic Council, has increased the axle weight limit for cargo vehicles by up to 10%. Therefore, the aim of this study was to determine a cost-benefit ratio by using different types of structures, asphalt binders and load intensities. Typical pavements were determined and then analyzed by the software AEMC (SisPav to obtain the horizontal tensile strain (εt values at the bottom of the asphalt concrete layer and, later, the NFATIGUE value. It was found that the increase in weight, within values covered by legislation, might result in a reduction of approximately 50% in the NFATIGUE value for the pavement structures analyzed. As for economic impact, the same weight increase caused a mean increase of 120% in the cost of repeated loading on pavement structures (R$ NFATIGUE-1. It was also observed that structures with more robust asphalt concrete layers can provide the best R$ NFATIGUE-1 ratios. The best results for granular materials were found with thinner layers, associated with a thicker coating. The benefits of modified binders were shown by the analyses of the best structural options: both the polymer-modified binder and the rubber asphalt binder offer significant structural and economic improvements to the structure.

  11. 养护龄期对混凝土氯离子扩散系数时间依赖性的影响%Influence of curing age on time dependence of chloride diffusion coefficient of concrete

    Institute of Scientific and Technical Information of China (English)

    宋鲁光; 孙伟; 高建明

    2015-01-01

    The chloride apparent diffusion coefficients at different immersion time in slag with differ-ent curing ages were studied through natural immersion tests.The influence of the curing age on chlo-ride apparent diffusion coefficients was analyzed.And the apparent diffusion coefficient was consid-ered as the integral mean of the instantaneous diffusion coefficients during the testing period,and the obtained apparent diffusion coefficient was transferred to the instantaneous diffusion coefficients.The relationship between the curing age and the constant of time dependence of the instantaneous diffusion coefficient was derived.The experimental results show that the chloride apparent diffusion coefficient decreases with the increase of the curing age and the decrease rate slows down gradually.There is a power function relationship between the apparent diffusion coefficient and the curing age.The constant of time dependency of the instantaneous diffusion coefficient increases with the increase of the curing age and the increase rate slows down gradually.There is a square root relationship between the con-stant of time dependency of the instantaneous diffusion coefficient and the curing age.%利用自然浸泡试验,研究了不同养护龄期的矿渣混凝土在不同暴露时间下的氯离子表观扩散系数,分析了养护龄期对氯离子表观扩散系数的影响。将表观扩散系数看作暴露时间内即时扩散系数的积分平均值,将得到的表观扩散系数转换为即时扩散系数,推导出养护龄期与即时扩散系数时间依赖性常数的关系。结果表明,混凝土中氯离子表观扩散系数随着养护龄期的增加而减小,且减小幅度逐渐减缓;养护龄期与表观扩散系数成幂函数关系。即时扩散系数的时间依赖性常数随着养护龄期的增加而增加,且增加幅度逐渐减小;即时扩散系数时间依赖性常数与养护龄期符合平方根关系。

  12. Effect of curing way on brittleness and durability of prestress high concrete pipe piles%养护制度对预应力高强度混凝土管桩脆性及耐久性的影响

    Institute of Scientific and Technical Information of China (English)

    王成启; 王春明; 周郁兵; 张宜兵

    2014-01-01

    The brittleness and durability of prestress high concrete pipe piles on non-steam autoclaved and steam autoclaved were exper-imentally studied.Experimental results showed that the brittleness of non-steam autoclaved concrete was less than steam autoclaved con-crete's.Moreover,the chlorine-resistant and frost-resistance properties of non-steam autoclaved concrete were better than steam autoclaved concrete's.prestress high concrete pipe piles on non-steam autoclaved excels in anti hammer ,it was applicable in freeze-thaw and chlorine circumstance.%试验研究了常压蒸养护和高压蒸汽养护工艺生产的预应力高强度混凝土管桩混凝土的脆性和耐久性。研究结果表明,常压蒸养预应力高强度混凝土管桩混凝土的脆性小于高压蒸养混凝土;常压蒸养预应力高强度混凝土管桩混凝土抗氯盐侵蚀性能和抗冻性等耐久性高于高压蒸养混凝土。采用常压蒸养生产预应力高强度混凝土管桩有利于预应力高强度混凝土管桩的抗锤击性能,适用于北方冻融和海洋环境。

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

    Science.gov (United States)

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

    2017-07-01

    Soil sealing is one of the most pervasive forms of soil degradation that follows urbanization and, despite innovative pavements (i.e. pervious) are being installed in urban areas to mitigate it, there is little research on the effects of pervious pavements on soil water and carbon cycle and on the physiology of urban trees. The aim of this 4-year experiment was to assess the effects of three pavements, differing in permeability to water and gases, on some soil physical parameters, and on growth and physiology of newly planted Celtis australis and Fraxinus ornus. Treatments were: 1) impermeable pavement (asphalt on concrete sub-base); 2) permeable pavement (pavers on crushed rock sub-base); 3) porous design (porous pavement on crushed rock sub-base); 4) control (unpaved soil, kept free of weed by chemical control). Soil (temperature, moisture, oxygen content and CO2 efflux) and plant (above- and below-ground growth, leaf gas exchange, chlorophyll fluorescence, water relations) parameters were measured. All types of pavements altered the water cycle compared to unpaved soil plots, but this disturbance was less intense in porous pavements than in other soil cover types. Porous pavements allowed both higher infiltration and evaporation of water than both pavers and asphalt. Reduction of evaporative cooling from soil paved with permeable and impermeable pavements contributed to significant soil warming: at 20cm depth, soils under concrete pavers and asphalt were 4 and 5°C warmer than soil covered by porous pavements and unpaved soils, respectively. Thus, enhancing evaporation from paved soil by the use of porous pavements may contribute to mitigating urban heat islands. CO2 greatly accumulated under impermeable and permeable pavements, but not under porous pavements, which showed CO2 efflux rates similar to control. Soil oxygen slightly decreased only beneath asphalt. Growth of newly planted C. australis and F. ornus was little affected by pavement type. Tree

  14. On-road Bicycle Pavement Markings

    Data.gov (United States)

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

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

    Science.gov (United States)

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

    2012-01-01

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

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

    Science.gov (United States)

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

    2012-06-01

    Coal-tar-based pavement sealants, a major source of PAHs to urban water bodies, are a potential source of volatile PAHs to the atmosphere. An initial assessment of volatilization of PAHs from coal-tar-sealed pavement is presented here in which we measured summertime gas-phase PAH concentrations 0.03 m and 1.28 m above the pavement surface of seven sealed (six with coal-tar-based sealant and one with asphalt-based sealant) and three unsealed (two asphalt and one concrete) parking lots in central Texas. PAHs also were measured in parking lot dust. The geometric mean concentration of the sum of eight frequently detected PAHs (ΣPAH(8)) in the 0.03-m samples above sealed lots (1320 ng m(-3)) during the hottest part of the day was 20 times greater than that above unsealed lots (66.5 ng m(-3)). The geometric mean concentration in the 1.28-m samples above sealed lots (138 ng m(-3)) was five times greater than above unsealed lots (26.0 ng m(-3)). Estimated PAH flux from the sealed lots was 60 times greater than that from unsealed lots (geometric means of 88 and 1.4 μg m(-2) h(-1), respectively). Although the data set presented here is small, the much higher estimated fluxes from sealed pavement than from unsealed pavement indicate that coal-tar-based sealants are emitting PAHs to urban air at high rates compared to other paved surfaces. Published by Elsevier Ltd.

  17. Mobile acoustic system for the detection of surface-breaking cracks in pavement

    Science.gov (United States)

    Marzani, Alessandro; Rizzo, Piervincenzo; Lanza di Scalea, Francesco; Benzoni, Gianmario

    2004-07-01

    Monitoring the structural condition of road and airport pavement is an extremely critical task to ensure the safety and efficiency of teh transportation. The topic is relevant to both civil and military transportation infrastructure. The presence of damage in pavement, including surface cracking, depressions, swells, and wear, is inevitable due to the sever environmental and service loads that these structures must be subject to. Existing NDE techniques aimed at assessing the structural condition of pavement include Falling Weight Deflectometer, Ground Penetrating Radar, and acoustic methods based on surface waves. This paper presents improvements to the traditional surface-wave method for the detection of surface-breaking cracks in pavement. The advances include 1) the modeling of the problem as dipsersive waves propagating in a multilayer system, 2) the inclusion of post-processing algorithms based on the Wavelet Transform to improve the sensitivity and accuracy of the inspection, and 3) the use of non-contact, air-coupled acoustic detectors to enhance the mobility of the inspection unit. The crack detection procedure consists of first generating a dispersive wave with an impulse hammer, and then measuring the changes in velocity, amplitude and/or frequency content as the wave travels across the flaw with the aid of the Continuous Wavelet Transform. Multilayer wave propagation modeling provides a better understanding of the experimental results by predicting how the various frequencies interact with cracks of different depths. The results of field tests will be presented for both rigid (concrete-based) and flexible (bitumen-based) pavement with surface cracks.

  18. Open-Graded Bases for Airfield Pavements.

    Science.gov (United States)

    1987-07-01

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

  19. Comparing Production and Placement of Warm-Mix Asphalt to Traditional Hot-Mix Asphalt for Constructing Airfield Pavements

    Science.gov (United States)

    2013-08-01

    pressure cells ( EPC ), single depth deflectometers (SDD), and asphalt strain gauges (ASG) are indicated by symbols denoted on the figures. Further...gauges, I-buttons, ASGs, SDDs, and EPCs to measure the pavement response to simulated aircraft loading. The asphalt concrete strain gauges (Figure 55...gauge in backscatter mode. The type of roller used for each pass is indicated on each figure. The contractor determined how many roller passes to use

  20. SIMULATION OF TEMPERATURE AND TRANSPORT LOAD IMPACT ON FORMATION AND DEVELOPMENT OF CRACKS ON ASPHALT-CONCRETE ROAD SURFACES

    Directory of Open Access Journals (Sweden)

    I. Melnikova

    2012-01-01

    Full Text Available An analysis of statistical data has shown that about 60 % of all types of road surface destructions and damages in the Republic of Belarus are attributed to cracks (separate, frequent and cracks network. The process of cracks formation in the asphalt concrete pavement is rather complicated and it is affected by a number of factors. The most important and determining factors are character and value of traffic loads, temperature action, road pavement structure, properties of materials used for its layers. Some regularities of the cracks formation and development in the asphalt-concrete layers of the pavement have been established on the basis of the physical and mathematical modeling. Application of a finite  element  method for  calculations  has made it possible to determine  numerical values of compressive and tensile stresses arising due to temperature action and traffic load, deflection of road pavement constructive layers. The paper contains recommendations for a road pavement design and repair of asphalt-concrete pavements which have been made on the basis of the obtained data analysis.

  1. Pavement Performance Index for Indian rural roads

    Directory of Open Access Journals (Sweden)

    Abhay Tawalare

    2016-09-01

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

  2. Fracture of highway and airport pavements

    Science.gov (United States)

    Ramsamooj, D. V.

    1993-03-01

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

  3. Optimal Composite Curing System

    Science.gov (United States)

    Handel, Paul; Guerin, Daniel

    The Optimal Composite Curing System (OCCS) is an intelligent control system which incorporates heat transfer and resin kinetic models coupled with expert knowledge. It controls the curing of epoxy impregnated composites, preventing part overheating while maintaining maximum cure heatup rate. This results in a significant reduction in total cure time over standard methods. The system uses a cure process model, operating in real-time, to determine optimal cure profiles for tool/part configurations of varying thermal characteristics. These profiles indicate the heating and cooling necessary to insure a complete cure of each part in the autoclave in the minimum amount of time. The system coordinates these profiles to determine an optimal cure profile for a batch of thermally variant parts. Using process specified rules for proper autoclave operation, OCCS automatically controls the cure process, implementing the prescribed cure while monitoring the operation of the autoclave equipment.

  4. The Use Of Permeable Concrete For Ground Water Recharge

    Directory of Open Access Journals (Sweden)

    Akshay Tejankar

    2016-09-01

    Full Text Available In order to develop Smart Cities in India, we need to develop smart technologies and smart construction materials. Permeable concrete an innovative material is environment friendly and a smart material which can be used for construction of several structures. In India, the ground water table is decreasing at a faster rate due to reduction in ground water recharge. These days, the vegetation cover is replaced by infrastructure hence the water gets very less opportunity to infiltrate itself into the soil. If the permeable concrete which has a high porosity is used for the construction of pavements, walking tracks, parking lots, well lining, etc. then it can reduce the runoff from the site and help in the ground water recharge. Such type of smart materials will play an important role for Indian conditions where government is putting lot of efforts to implement ground water recharging techniques. During the research work, the runoff for a particular storm was calculated for a bitumen pavement on a sloping ground. Later after studying the various topographical features, the traffic intensity and the rainfall for that particular area, the concrete was designed and tested for the different proportion and thus the mix design for the permeable concrete was finalized based upon its permeability and strength characteristics. Later by using this permeable concrete the infiltration and runoff for the same storm was compared and studied. The research paper will thus give an account of the properties of permeable concrete where it can be used over an existing road.

  5. How can we make good concrete even better?

    DEFF Research Database (Denmark)

    Kovler, Konstantin; Jensen, Ole Mejlhede; Falikman, Vyacheslav

    2005-01-01

    It is known that some high-strength/high-performance concretes are prone to cracking at an early age unless special precautions are used. The paper deals with the methods of curing as one of the main strategies to provide both strength and performance. Curing by both external (conventional......) and internal methods is reviewed and analyzed, among other methods of mitigating shrinkage and cracking of concrete. The focus is given on the mitigation of autogenous shrinkage of low water to binder ratio concrete by means of internal curing. The concepts of internal curing are based on using pre......-soaked lightweight aggregate, super-absorbent polymers or water-soluble chemicals, which reduce water evaporation (so called "internal sealing"). These concepts have been suggested in the 90s, but still are not popular among users, engineers, contractors, concrete suppliers, researchers, and the rest...

  6. 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.

  7. Chloride migration in concrete with superabsorbent polymers

    DEFF Research Database (Denmark)

    Hasholt, Marianne Tange; Jensen, Ole Mejlhede

    2015-01-01

    Superabsorbent polymers (SAP) can be used as a means for internal curing of concrete. In the present study, the development of transport properties of concrete with SAP is investigated. The chloride migration coefficient according to NT BUILD 492 is used as a measure of this. Twenty concrete...... mixtures are tested 7, 14, and 28 days after casting. The development of degree of hydration is followed for 20 corresponding paste mixtures. Both when SAP is added with extra water to compensate the SAP water absorption in fresh concrete and without extra water, the internal curing water held by SAP may...... contribute to increase the degree of hydration. No matter if SAP is added with or without extra water, it appears that the so-called gel space ratio can be used as a key parameter to link age and mixture proportions (water-to-cement ratio and SAP dosage) to the resulting chloride migration coefficient...

  8. Flexural fatigue characteristics of steel fiber reinforced recycled aggregate concrete (SFRRAC

    Directory of Open Access Journals (Sweden)

    Heeralal M.

    2009-01-01

    Full Text Available This research work is aimed at investigating the flexural fatigue behavior of Steel Fiber Reinforced Recycled Aggregate Concrete (SFRRAC. This study gains importance in view of the wide potential for demolished concrete to serve as a source of quality aggregate feed stock in a variety of structural and non-structural applications. This is a continuation of a series of investigations being conducted aimed at optimizing the utilization of recycled aggregate concrete in rigid pavements. A total of 72 standard flexure specimens of 100mm x 100mm x 450mm were cast and tested for flexure under both static and fatigue loading. The parameters of the investigation included the different replacements of recycled aggregate in natural aggregate, presence of steel fiber and different stress levels. The study showed that the recycled aggregates can be used in rigid pavements also and the inclusion of fibers can benefit the fatigue performance of recycled aggregate concrete.

  9. Precision and accuracy of mechanistic-empirical pavement design

    CSIR Research Space (South Africa)

    Theyse, HL

    2006-09-01

    Full Text Available The availability of mechanistic-empirical pavement design methods is increasing internationally. Although mechanistic-empirical design does offer some insight into pavement behaviour and performance, at least more so than empirical design methods...

  10. Experimental Studies on the M elting Snow Effect of Asphalt Concrete Pavement Reinforced with Carbon Fiber-glass Fiber Grating%铺设碳纤维-玻璃纤维格栅的沥青混凝土路面融雪试验研究

    Institute of Scientific and Technical Information of China (English)

    祁显宽; 孙明清; 李红; 张谢东; 孙文明

    2014-01-01

    Snow accumulation and ice in winter produce serious obstacles for traffic all over the world . In order to remove snow and ice as quickly as possible ,one type of convenient and efficient conductive grating material -carbon fiber-glass fiber grating is laid into the pavement as electric heating element , which can be powered on and produces quantity of heat ,and then the temperature of the road rises and snow is melted .Two different pavement models are tested in a testing chamber with the air tempera-ture of-6 .5℃ and the electricity power of about 300W/m2 .It is found that the reasonable arrange-ment of carbon fiber-glass fiber grating inside the pavement is 5cm below the surface of pavement . Field tests have also been performed to melt snow .Results show this method can be worked .%冬季冰雪天气严重影响着城市交通和道路交通,为了尽快的使道路上的积雪融化,研究一种既方便又快捷的材料---碳纤维-玻璃纤维格栅,将这种材料作为导电发热体铺设在路表面下,在冰雪天气对导电发热体进行通电、产生热量,通过热传递的方式使路表面温度升高.文中对铺设了碳纤维-玻璃纤维格栅的沥青混凝土路面进行升温和融雪模拟试验,研究了2种不同铺设方案下,在温度为-6.5℃、发热通电功率控制在300 W/m2时路面结构模型的升温情况,表明将格栅铺设在路面表层5 cm以下较为合理.通过现场的融雪试验表明,这种路面能实现融化积雪的功能.

  11. 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...

  12. A multiscale model for predicting the viscoelastic properties of asphalt concrete

    Science.gov (United States)

    Garcia Cucalon, Lorena; Rahmani, Eisa; Little, Dallas N.; Allen, David H.

    2016-08-01

    It is well known that the accurate prediction of long term performance of asphalt concrete pavement requires modeling to account for viscoelasticity within the mastic. However, accounting for viscoelasticity can be costly when the material properties are measured at the scale of asphalt concrete. This is due to the fact that the material testing protocols must be performed recursively for each mixture considered for use in the final design.

  13. Evaluation of Fatigue Resistance for Modified Asphalt Concrete Mixtures Based on Dissipated Energy Concept

    OpenAIRE

    Khodary Moalla Hamed, Farag

    2010-01-01

    The performance of asphalt concrete pavement depends on the bitumen properties, asphalt concrete mixtures volumetric properties and external factors such as traffic volume and environment. Bitumen is a visco-elastic material where temperature and rate of load application have a great influence on its behavior. Conventional bitumen is exposed to a wide range of loading and weather conditions; it is soft in a hot environment and brittle in cold weather. Higher traffic volume produces high stres...

  14. Example of using small falling weight deflectomer (FWD) for Earth structures and low cost road pavement in Japan

    Science.gov (United States)

    Shibata, Hideaki; Tanaka, Yasutomo; Ono, Isamu; Okano, Tsuyoshi

    2007-01-01

    The FWD (Falling Weight Deflectometer) is an instrument which makes the weight fall freely on its loading plate to apply impact load and measures the displacement caused by the fall at the center of impact load and also at the points in radial direction from the center of impact load. A kind of instrument which is mounted on or drawn by a vehicle used for construction of concrete pavement or asphalt pavement of a runway is usually called FWD. The impact load of FWD is 49KN to 196kN and it can obtain the modulus of elasticity of each pavement layer by back analysis based on the theory of multi-layer elasticity using 6 to 8 of extemal displacement sensors. On the other hand, the small FWD is an FWD which is constructed small and easy and is applicable for hand carry. It makes the weight fall freely on the loading plate to apply impact load and measures the load and displacement caused by the fall. It was developed for mainly assessing the rigidity and bearing capacity of the subgrade easily and promptly. It can measure many points in short term and obtain coefficient of subgrade reaction and modulus of subgrade elasticity without using reaction facilities like as plate bearing test or CBR test. It has also been tried to apply the small FWD to low cost asphalt road pavement (later called as low cost road pavement). Application examples of small FWD test for earth structure and low cost load pavement in Japan are shown and the methods and test results are stated in this report.

  15. Knowledge Discovery and Pavement Performance: Intelligent Data Mining

    NARCIS (Netherlands)

    Miradi, M.

    2009-01-01

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

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

    Science.gov (United States)

    2013-03-01

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

  17. Evaluation of Procedures for Backcalculation of Airfield Pavement Moduli

    Science.gov (United States)

    2015-08-01

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

  18. Damage development in the adhesive zone and mortar of porous asphalt concrete

    NARCIS (Netherlands)

    Mo, L.T.

    2010-01-01

    This research is focused on damage development in the adhesive zone and the mortar of porous asphalt concrete. The motive of this research is the loss of stone from the pavement surface, the so-called ravelling of noise reducing surface wearing courses. Ravelling is the dominant defect of porous asp

  19. Bending characteristics of resin concretes

    Directory of Open Access Journals (Sweden)

    Ribeiro Maria Cristina Santos

    2003-01-01

    Full Text Available In this research work the influence of composition and curing conditions in bending strength of polyester and epoxy concrete is analyzed. Various mixtures of resin and aggregates were considered in view of an optimal combination. The Taguchi methodology was applied in order to reduce the number of tests, and in order to evaluate the influence of various parameters in concrete properties. This methodology is very useful for the planning of experiments. Test results, analyzed by this methodology, shown that the most significant factors affecting bending strength properties of resin concretes are the type of resin, resin content and charge content. An optimal formulation leading to a maximum bending strength was achieved in terms of material parameters.

  20. Pavement Sealcoat, PAHs, and the Environment

    Science.gov (United States)

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

    2011-12-01

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

  1. Photocatalyticpaving concrete

    OpenAIRE

    2014-01-01

    Today bituminous concrete is a conventional paving material. Among its advantages one can name dustlessness and noiselessness, fine wear (up to 1 mm a year) and fine maintainability. As the main disadvantages of this material one can name high slipperiness under humidification, low durability and weather resistance. Besides that, during placement of the bituminous concrete a lot of different air pollutants are emitted, which are harmful for environment and human’s health (they are listed in t...

  2. 呼和浩特市综合性公园道路景观铺装设计浅析%Hohhot comprehensive park road landscape design of pavement

    Institute of Scientific and Technical Information of China (English)

    高晓矫

    2015-01-01

    随着我国园林建设的迅猛发展,人们已经对园林道路中灰色的沥青路面和单调的混凝土地面失去了兴趣,因此,园林道路的美化铺装设计已经越来越受到重视。本文结合呼和浩特市内综合性公园道路景观铺装情况,对道路铺装的功能、铺装要素和设计理念以及园林道路铺装常见问题等进行了探讨,以期对园路设计和施工提供一定的参考。%With the rapid development of China's Landscape Construction, people have been lost interest on the garden road of the asphalt pavement and the dul gray concrete floor. Therefore, the garden road pavement design has been receiving increasing attention., This paper takes comprehensive park road pavement conditions of Hohhot for example, discussing the function of the road pavement, pavement design, landscape elements and the problems frequently encountered of road pavement, to provide a reference of road pavement on landscape design and construction.

  3. marine water effect on compressive strength of concrete

    African Journals Online (AJOL)

    hp

    Concrete cubes cast and cured with seawater were observed to have a higher strength at 28 ... However, in the case of reinforced concrete, it is recommended that reinforcement be prevented from corrosion by ... Cracking facilitate the entry of de-icing salt solution that may .... From Table 2, it can be seen that the value of the.

  4. Study on the curing methods of reactive powder concrete with steel fibre%钢纤维活性粉末混凝土的养护方法研究

    Institute of Scientific and Technical Information of China (English)

    徐晓; 郝文秀; 白永兵

    2010-01-01

    活性粉末混凝土(Reactive Powder Concrete,简称RPC)是一种具有超高性能和超高强度的水泥基复合材料.通过研究热养护温度(70、80、90 ℃) 、热养护时间(48、72、96 h)及标准养护等养护方法对活性粉末混凝土立方体试块抗压和劈裂抗拉强度的影响,依据强度指标及考虑养护简便、经济,确定适合工程实践的养护方法.

  5. Patología de pavimentos articulados Pathology of interlocking pavements

    Directory of Open Access Journals (Sweden)

    Carlos Hernando Higuera Sandoval

    2010-07-01

    Full Text Available Este artículo presenta los resultados de un proyecto de grado sobre patología de pavimentos articulados, el cual fue elaborado con el propósito de hacer una recolección de los deterioros típicos de los pavimentos articulados construidos con adoquines de concreto o de ladrillo; y de esta forma, elaborar un catálogo de deterioros para este tipo de estructuras que facilitará la identificación y cuantificación de los deterioros en una inspección visual. El segundo propósito de este proyecto, es la formulación para Colombia de una metodología que permita determinar el Índice de Condición de las estructuras de pavimentos articulados.This article presents the results of a thesis on pathology of interlocking pavements, which objective was to make a compilation of typical damages of interlocking pavements constructed with concrete or brick pavers and, in this way, to elaborate a catalogue of damages for this kind of structures which will make the identification and quantification of deteriorations possible in a visual inspection. The second purpose of this project is the formulation of a methodology which allows determining the Index of pavement conditions for Colombia.

  6. Exploration under pavement by electromagnetic subsurface profiling. Hosoka ni okeru roban rosho heno haaku

    Energy Technology Data Exchange (ETDEWEB)

    Kaneko, C.; Miyatsu, Y.; Seki, M. (Construction Project Consultant Co. Ltd., Osaka (Japan))

    1994-05-01

    This paper reports explorations on change in roadbeds and subgrades under pavement by means of an electromagnetic wave method (underground radar method). The paper summarizes the measurement principle of this exploration method, the measurement equipment (consisting of a control unit, an antenna unit, and an image output unit), and data analysis and processing. It is indicated that the quality of the exploration result is governed by the antenna used, whereas a reference is shown for selecting antennas according to the exploration objects (embedded pipes, underground cavities, and pavement thickness) and depths of the explorations. The paper then lists examples of explorations conducted by using antennas with a frequency of 500 MHz. The explorations include the following cases: cavities directly below concrete seals (with a thickness of 10 cm), hume pipes (with a diameter of 10 cm) embedded in a depth of 1.1 m under asphalt pavement, clearances existing in subgrades, loosened ground bed believed to have been caused by immersion, and clearances (depth of 70 cm) existing in ground beds behind bridge piers. 5 refs., 9 figs., 2 tabs.

  7. A fiber-reinforced composite structure for the repair of thermally cracked bituminous pavements

    Science.gov (United States)

    Frantzen, Jeffrey Alan

    1998-10-01

    The apparatus under development in this project is a structural component or beam fabricated from a fiber reinforced plastic composite (FRPC). The FRPC beam is a structural repair component intended to bridge a deteriorated thermal crack in full depth bituminous pavements or partial depth bituminous pavements over portland cement concrete. The bridging action provided by the FRPC beam is intended to minimize roughness through the repaired area for up to five years, eliminate reappearance of the deteriorated crack, and provide a controlled expansion crack that can be treated with standard sealing techniques. This apparatus is designed for maintenance use as a field expedient, semi-permanent repair using tools that are commonly available at the Area Maintenance level. Three FRPC beams were constructed for field trial in a thermally cracked, full depth bituminous pavement on US-36 east of Hiawatha, Kansas. Each of the beams were instrumented with bonded metal foil strain gages and field installation by KDOT Maintenance forces was done in August and September of 1997. The FRPC beams have been evaluated since installation and this evaluation will continue for up to five years. Evaluation of the beams has been accomplished through static load tests using the strain gage instrumentation and Falling Weight Deflectometer measurements. The FRPC beams have performed satisfactorily as of the date of writing.

  8. Self-Placing Concrete

    OpenAIRE

    ECT Team, Purdue

    2007-01-01

    Certain concrete pours have areas where the congestion of reinforcing bars make placement of concrete almost impossible. Using conventional placing and vibration techniques, the resulting concrete can have considerable honeycombing due to the development of voids. Self-placing concrete is a possible solution to the problem. Also known as self-compactable concrete, self-consolidating concrete, flowable concrete, and non-vibration concrete. These concretes eliminate the need for vibration in a ...

  9. Pavement thickness and stabilised foundation layer assessment using ground-coupled GPR

    Science.gov (United States)

    Hu, Jinhui; Vennapusa, Pavana K. R.; White, David J.; Beresnev, Igor

    2016-07-01

    Experimental results from field and laboratory investigations using a ground-coupled ground penetrating radar (GPR), dielectric measurement, magnetic imaging tomography (MIT) and dynamic cone penetrometer (DCP) tests are presented. Dielectric properties of asphalt pavement and stabilised and unstabilised pavement foundation materials were evaluated in the laboratory in frozen and unfrozen conditions. Laboratory test results showed that dielectric properties of materials back-calculated from GPR in comparison to dielectric gauge measurements are strongly correlated and repeatable. For chemically stabilised materials, curing time affected the dielectric properties of the materials. Field tests were conducted on asphalt pavement test sections with different foundation materials (stabilised and unstabilised layers), drainage conditions and layer thicknesses. GPR and MIT results were used to determine asphalt layer thicknesses and were compared with measured core thicknesses, while GPR and DCP were used to assess foundation layer profiles. Asphalt thicknesses estimated from GPR showed an average error of about 11% using the dielectric gauge values as input. The average error reduced to about 4% when calibrated with cores thicknesses. MIT results showed thicknesses that are about 9% higher than estimated using GPR. Foundation layer thicknesses could not be measured using GPR due to variations in moisture conditions between the test sections, which is partly attributed to variations in gradation and drainage characteristics of the subbase layer.

  10. Characterization of cementitiously stabilized subgrades for mechanistic-empirical pavement design

    Science.gov (United States)

    Solanki, Pranshoo

    Pavements are vulnerable to subgrade layer performance because it acts as a foundation. Due to increase in the truck traffic, pavement engineers are challenged to build more strong and long-lasting pavements. To increase the load-bearing capacity of pavements, subgrade layer is often stabilized with cementitious additives. Thus, an overall characterization of stabilized subgrade layer is important for enhanced short- and long-term pavement performance. In this study, the effect of type and amount of additive on the short-term performance in terms of material properties recommended by the new Mechanistic-Empirical Pavement Design Guide (MEPDG) is examined. A total of four soils commonly encountered as subgrades in Oklahoma are utilized. Results show that the changes in the Mr, ME and UCS values stabilized specimens depend on the soil type and properties of additives. The long-term performance (or durability) of stabilized soil specimens is investigated by conducting freeze-thaw (F-T) cycling, vacuum saturation and tube suction tests on 7-day cured P-, K- and C-soil specimens stabilized with 6% lime, 10% CFA and 10% CKD. This study is motivated by the fact that during the service life of pavement stabilized layers are subjected to F-T cycles and moisture variations. It is found that that UCS value of all the stabilized specimens decreased with increase in the number of F-T cycles. A strong correlation was observed between UCS values retained after vacuum saturation and F-T cycles indicating that vacuum saturation could be used as a time-efficient and inexpensive method for evaluating durability of stabilized soils. In this study, short- and long-term observations from stabilization of sulfate bearing soil with locally available low (CFA), moderate (CKD) and high (lime) calcium-based stabilizers are determined to evaluate and compare the effect of additive type on the phenomenon of sulfate-induced heave. The impact of different factors on the development of the

  11. Effects of composition and exposure on the solar reflectance of Portland cement concrete

    Energy Technology Data Exchange (ETDEWEB)

    Levinson, Ronnen; Akbari, Hashem

    2001-12-21

    Increasing the solar reflectance (albedo) of a paved surface keeps it cooler in the sun, reducing convection of heat from pavement to air and thereby decreasing the ambient air temperature. Simulations of the influence of pavement albedo on air temperature in Los Angeles predict that increasing the albedo of 1,250 km2 of pavement by 0.25 would save cooling energy worth $15M yr-1, and reduce smog-related medical and lost-work expenses by $76M yr-1. Most sidewalks and a small fraction of roads and parking areas are paved with portland cement concrete, which can be made quite reflective through suitable choice of cement and aggregate. Variations with composition and environmental exposure of the albedos of portland cement concrete pavements were investigated through laboratory fabrication and exposure of 32 mixes of concrete. Twenty-four mixes yielded substandard, ''rough'' concretes due to high, unmet aggregate water demand. The albedos of the remaining eight ''smooth'' concrete mixes ranged from 0.41 to 0.77 (mean 0.59). Simulated weathering, soiling, and abrasion each reduced average concrete albedo (mean decreases 0.06, 0.05, and 0.19, respectively), though some samples became slightly more reflective through weathering or soiling. Simulated rain (wetting) strongly depressed the albedos of concretes (mean decrease 0.23) until their surfaces were dried. Concrete albedo grew as the cement hydration reaction progressed (mean increase 0.08), but stabilized within six weeks of casting. White-cement concretes were on average significantly more reflective than gray-cement concretes. The albedo of the most-reflective white-cement concrete was 0.18 to 0.39 higher than that of the most-reflective gray-cement concrete, depending on state of exposure. Concrete albedo generally correlated with cement albedo and sand albedo, and, after abrasion, with rock albedo. Cement albedo had a disproportionately strong influence on the reflectance

  12. Effect of Metakaolin on Compressive Strength of Concrete

    Directory of Open Access Journals (Sweden)

    Satyendra Dubey

    2015-06-01

    Full Text Available Metakaolin is a cementitious materials used as an admixture to produce high strength concrete and is used for maintaining the consistency of concrete. In the case where insufficient or poor curing concrete structure like the underground structure which undergo serve loss of compressive strength, use of metakaolin proves to be very useful to modify the properties of concrete. This paper deals with the properties of concrete with varying percentage replacement of metakaolin in M-25 greade of concrete. The mix M1,M2,M3 and M4 were obtained by replacing 0,5,10 and 15 percent mass of cement by Metakaolin. The test results indicated that admixture metakaolin when used at optimum quantity tend to increase the strength of the concrete mix when compared with conventional concrete.

  13. Fly ash for durable concrete construction

    Energy Technology Data Exchange (ETDEWEB)

    Dhir, R.K. [University of Dundee, Dundee (United Kingdom). Dept. of Civil Engineering

    1994-12-31

    This is essentially a review paper, bringing together the various studies undertaken at the University of Dundee as well as many others selected from published work. A full range of durability properties have been considered dealing with the effects of fly ash (FA) in concrete. It is shown that the use of FA generally effects improvement in the resistance of concrete to various forms of attack. FA is shown to greatly improve concrete resistance to chloride ingress and to reduce expansion caused by ASR. In the case of sulphate attack the use of FA is recommended. With regard to carbonation, FA can slightly reduce the resistance. It is also shown that FA concrete will benefit more from curing than OPC concrete in developing its resistance to deterioration with age. 78 refs., 8 figs., 5 tabs.

  14. FLEXURAL TOUGHNESS OF STEEL FIBER REINFORCED CONCRETE

    Directory of Open Access Journals (Sweden)

    Fehmi ÇİVİCİ

    2006-02-01

    Full Text Available Fiber concrete is a composite material which has mechanical and physical characteristics unlike plain concrete. One of the important mechanical characteristics of fiber concrete is its energy absorbing capability. This characteristics which is also called toughness, is defined as the total area under the load-deflection curve. A number of composite characteristics such as crack resistance, ductility and impact resistance are related to the energy absorbtion capacity. According to ASTM C 1018 and JSCE SF-4 the calculation of toughness is determined by uniaxial flexural testing. Fiber concrete is often used in plates such as bridge decks, airport pavements, parking areas, subjected to cavitation and erosion. In this paper, toughness has been determined according to ASTM C 1018 and JSCE SF-4 methods by testing beam specimens. Energy absorbing capacities of plain and steel fiber reinforced concrete has been compared by evaluating the results of two methods. Also plain and steel fiber reinforced plate specimens behaviors subjected to biaxial flexure are compared by the loaddeflection curves of each specimen.

  15. Use of leaching tests to quantify trace element release from waste to energy bottom ash amended pavements.

    Science.gov (United States)

    Roessler, Justin G; Townsend, Timothy G; Ferraro, Christopher C

    2015-12-30

    A series of roadway tests strips were paved on-site at a landfill in Florida, U.S. Waste to energy (WTE) bottom ash was used as a partial course aggregate replacement in a hot mix asphalt (HMA) and a Portland cement concrete (PCC) pavement, along with control HMA and PCC sections. This allowed for a comparison of the relative degree of leaching between both materials (HMA and PCC) as well as between the ash-amended and control pavements. Batch and monolithic tank leaching tests were conducted on the pavements. Testing of the PCC samples demonstrated that Mo and Al were elevated above regulatory thresholds for both the control and ash amended samples. Further leach testing demonstrated that the release of Mo was likely from the PCC and not a result of the inclusion of the BA into pavement. Batch leach testing of ash-amended HMA samples revealed Sb as a constituent of potential concern. The results of the monolith leaching test displayed leaching of Sb within the same order of magnitude as the regulatory threshold. Calculation of the leachability index (LI) for Sb found that it would have limited mobility when incorporated in the HMA matrix. Copyright © 2015 Elsevier B.V. All rights reserved.

  16. 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.

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

    Science.gov (United States)

    Diniz, E. V.

    1980-08-01

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

  18. Concentrations of polycyclic aromatic hydrocarbons (PAHs) and azaarenes in runoff from coal-tar- and asphalt-sealcoated pavement.

    Science.gov (United States)

    Mahler, Barbara J; Van Metre, Peter C; Foreman, William T

    2014-05-01

    Coal-tar-based sealcoat, used extensively on parking lots and driveways in North America, is a potent source of PAHs. We investigated how concentrations and assemblages of PAHs and azaarenes in runoff from pavement newly sealed with coal-tar-based (CT) or asphalt-based (AS) sealcoat changed over time. Samples of simulated runoff were collected from pavement 5 h to 111 d following application of AS or CT sealcoat. Concentrations of the sum of 16 PAHs (median concentrations of 328 and 35 μg/L for CT and AS runoff, respectively) in runoff varied relatively little, but rapid decreases in concentrations of azaarenes and low molecular weight PAHs were offset by increases in high molecular weight PAHs. The results demonstrate that runoff from CT-sealcoated pavement, in particular, continues to contain elevated concentrations of PAHs long after a 24-h curing time, with implications for the fate, transport, and ecotoxicological effects of contaminants in runoff from CT-sealcoated pavement.

  19. Concentrations of polycyclic aromatic hydrocarbons (PAHs) and azaarenes in runoff from coal-tar- and asphalt-sealcoated pavement

    Science.gov (United States)

    Mahler, Barbara J.; Van Metre, Peter C.; Foreman, William T.

    2014-01-01

    Coal-tar-based sealcoat, used extensively on parking lots and driveways in North America, is a potent source of PAHs. We investigated how concentrations and assemblages of PAHs and azaarenes in runoff from pavement newly sealed with coal-tar-based (CT) or asphalt-based (AS) sealcoat changed over time. Samples of simulated runoff were collected from pavement 5 h to 111 d following application of AS or CT sealcoat. Concentrations of the sum of 16 PAHs (median concentrations of 328 and 35 μg/L for CT and AS runoff, respectively) in runoff varied relatively little, but rapid decreases in concentrations of azaarenes and low molecular weight PAHs were offset by increases in high molecular weight PAHs. The results demonstrate that runoff from CT-sealcoated pavement, in particular, continues to contain elevated concentrations of PAHs long after a 24-h curing time, with implications for the fate, transport, and ecotoxicological effects of contaminants in runoff from CT-sealcoated pavement.

  20. Retrofitting of Reinforced Concrete Beams using Reactive Powder Concrete (RPC)

    Science.gov (United States)

    Karthik, S.; Sundaravadivelu, Karthik

    2017-07-01

    Strengthening of existing damaged structures is one of the leading studies in civil engineering. The purpose of retrofitting is to structurally treat the member with an aim to restore the structure to its original strength. The focus of this project is to study the behaviour of damaged Reinforced Concrete beam retrofitted with Reactive Powder Concrete (RPC) Overlay. Reinforced concrete beams of length 1200 mm, width 100 mm and depth 200 mm were casted with M30 grade of concrete in the laboratory and cured for 28 days. One beam is taken as control and are tested under two point loading to find out ultimate load. Remaining beams are subjected to 90 % ultimate load of control beams. The partially damaged beams are retrofitted with Reactive Powder Concrete Overlay at the full tension face of the beam and side overlay depends upon the respectable retrofitting techniques with 10 mm and 20 mm thick layer to find optimum. Materials like steel fibres are added to enhance the ductility by eliminating coarse particle for homogeneity of the structure. Finally, the modes of failure for retrofitted beams are analysed experimentally under two point loading & compared the results with Control beam.

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

    CSIR Research Space (South Africa)

    Theyse, HL

    2011-09-01

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

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

    Science.gov (United States)

    Arnaud, L.; Houel, A.

    2010-06-01

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

  3. 重载交通下不同基层类型沥青路面结构应力分析%Analysis for Structural Stress of Asphalt Pavement of Different Types of Basecourses under Heavy Load Traffic

    Institute of Scientific and Technical Information of China (English)

    伍祥松

    2012-01-01

    基于我国沥青路面设计理论及标准,参考实际沥青路面结构,选取不同的沥青路面结构与材料参数,如结构层厚度、模量和泊松比等,采用BISAR3.0路面力学计算程序计算分析不同基层类型对沥青混凝土路面结构内部应力状态的影响.结果表明,柔性基层路面与半刚性基层路面的破坏机理存在明显差异,为了实现2种路面的优势互补,应将柔性基层与半刚性基层的结构进行合理的优化组合,以弥补柔性基层和半刚性基层沥青路面的缺陷.%Based on design theories and standards for asphalt pavement in China and by reference to actual structures of asphalt pavement, this paper selects different structure and material parameters of asphalt pavement, such as thickness, modulus and Poisson' s Ratio of structural layers, etc. , calculates and analyzes influences of different basecourse types on internal stress states of asphalt concrete pavement structures by means of BISAR3. 0 mechanical calculation program for pavement. The results show that significant differences exist in failure mechanisms of flexible basecourse pavement and semi - rigid basecourse pavement, to realize complementary advantages of two pavements, the structures of flexible basecourse and semi - rigid basecourse should be optimized and combined in a reasonable way to make up defects of flexible basecourse and semi - rigid basecourse pavements.

  4. Investigation of modified asphalt concrete

    Science.gov (United States)

    Zimich, Vita

    2016-01-01

    Currently the problem of improving the asphalt quality is very urgent. It is used primarily as topcoats exposed to the greatest relative to the other layers of the road, dynamic load - impact and shear. The number of cars on the road, the speed of their movement, as well as the traffic intensity increase day by day. We have to upgrade motor roads, which entails a huge cost. World experience shows that the issue is urgent not only in Russia, but also in many countries in Europe, USA and Asia. Thus, the subject of research is the resistance of asphalt concrete to water and its influence on the strength of the material at different temperatures, and resistance of pavement to deformation. It is appropriate to search for new modifiers for asphaltic binder and mineral additives for asphalt mix to form in complex the skeleton of the future asphalt concrete, resistant to atmospheric condensation, soil characteristics of the road construction area, as well as the growing road transport load. The important task of the work is searching special modifying additives for bitumen binder and asphalt mixture as a whole, which will improve the quality of highways, increasing the period between repairs. The methods described in the normative-technical documentation were used for the research. The conducted research allowed reducing the frequency of road maintenance for 7 years, increasing it from 17 to 25 years.

  5. Ultrasound data for laboratory calibration of an analytical model to calculate crack depth on asphalt pavements

    Directory of Open Access Journals (Sweden)

    Miguel A. Franesqui

    2017-08-01

    Full Text Available This article outlines the ultrasound data employed to calibrate in the laboratory an analytical model that permits the calculation of the depth of partial-depth surface-initiated cracks on bituminous pavements using this non-destructive technique. This initial calibration is required so that the model provides sufficient precision during practical application. The ultrasonic pulse transit times were measured on beam samples of different asphalt mixtures (semi-dense asphalt concrete AC-S; asphalt concrete for very thin layers BBTM; and porous asphalt PA. The cracks on the laboratory samples were simulated by means of notches of variable depths. With the data of ultrasound transmission time ratios, curve-fittings were carried out on the analytical model, thus determining the regression parameters and their statistical dispersion. The calibrated models obtained from laboratory datasets were subsequently applied to auscultate the evolution of the crack depth after microwaves exposure in the research article entitled “Top-down cracking self-healing of asphalt pavements with steel filler from industrial waste applying microwaves” (Franesqui et al., 2017 [1].

  6. Ultrasound data for laboratory calibration of an analytical model to calculate crack depth on asphalt pavements.

    Science.gov (United States)

    Franesqui, Miguel A; Yepes, Jorge; García-González, Cándida

    2017-08-01

    This article outlines the ultrasound data employed to calibrate in the laboratory an analytical model that permits the calculation of the depth of partial-depth surface-initiated cracks on bituminous pavements using this non-destructive technique. This initial calibration is required so that the model provides sufficient precision during practical application. The ultrasonic pulse transit times were measured on beam samples of different asphalt mixtures (semi-dense asphalt concrete AC-S; asphalt concrete for very thin layers BBTM; and porous asphalt PA). The cracks on the laboratory samples were simulated by means of notches of variable depths. With the data of ultrasound transmission time ratios, curve-fittings were carried out on the analytical model, thus determining the regression parameters and their statistical dispersion. The calibrated models obtained from laboratory datasets were subsequently applied to auscultate the evolution of the crack depth after microwaves exposure in the research article entitled "Top-down cracking self-healing of asphalt pavements with steel filler from industrial waste applying microwaves" (Franesqui et al., 2017) [1].

  7. Historic Concrete: From Concrete Repair to Concrete Conservation

    NARCIS (Netherlands)

    Heinemann, H.A.

    2013-01-01

    Concrete like materials were already applied during the Roman Empire. After the decline of the Roman Empire, a wide scale application of concrete only reappeared in the 19th century. Here lies also the origin of modern (reinforced) concrete. Since then, both concrete application and composition have

  8. Curing Behavior of Epoxy Asphalt

    Institute of Scientific and Technical Information of China (English)

    YU Jianying; CONG Peiliang; WU Shaopeng; CHENG Songbo

    2009-01-01

    The curing process of epoxy asphalt was analyzed by Fourier transform infrared (FT-IR)spectroscopy.Effect of curing temperature on viscosity of epoxy asphalt,and changes of mechanical properties with curing time were investigated.The evolution of concentration of epoxy band was followed as a function of the applied curing process.The experimental results indicate that the curing reaction rate of epoxy asphalt is invariable before 70 min at 120℃,and it decreases when curing time exceeds 70 min.The viscosity of epoxy asphalt increases slowly with curing time at initial curing stage.But it increases quickly after initial curing stage and the initial curing time decreases as the curing temperature increases.The tensile strength increases slowly at incipient curing stage and increases rapidly when curing time is form 20 min to 70 min.The elongation at break shows a decrease with curing time,but it exceeds 200%after cured.

  9. Asphalt for draining pavement; Haisuisei hosoyo asphalt

    Energy Technology Data Exchange (ETDEWEB)

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

    1994-12-28

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

  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...

  11. Pavement behaviour under the super single tyre

    CSIR Research Space (South Africa)

    Viljoen, AW

    1982-06-01

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

  12. "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...

  13. Design and construction of tunnel pavement on Guangxi highway%广西高速公路隧道路面的设计与施工

    Institute of Scientific and Technical Information of China (English)

    肖锋

    2011-01-01

    介绍了广西高速公路隧道中所采用的基于永久性路面或长寿命设计理念的隧道路面结构形式,以及隧道路面中所采用的新结构、新材料与新工艺;并对连续配筋混凝土路面结构层的设计与施工进行了简要介绍,对今后同类隧道路面施工具有一定指导意义。%This thesis introduces the tunnel pavement structure form on Guangxi highway tunnel based on eternal pavement and long life design concept, and new structure, new material, and new technology used in tunnel pavement as well, and briefly expounds the design and construction of continuous reinforcement concrete pavement structure, which has certain guiding significance for future similar tunnel pavement construction.

  14. Self-assembling particle-siloxane coatings for superhydrophobic concrete.

    Science.gov (United States)

    Flores-Vivian, Ismael; Hejazi, Vahid; Kozhukhova, Marina I; Nosonovsky, Michael; Sobolev, Konstantin

    2013-12-26

    We report here, for the first time in the literature, a method to synthesize hydrophobic and superhydrophobic concrete. Concrete is normally a hydrophilic material, which significantly reduces the durability of concrete structures and pavements. To synthesize water-repellent concrete, hydrophobic emulsions were fabricated and applied on portland cement mortar tiles. The emulsion was enriched with the polymethyl-hydrogen siloxane oil hydrophobic agent as well as metakaolin (MK) or silica fume (SF) to induce the microroughness and polyvinyl alcohol (PVA) fibers to create hierarchical surfaces. Various emulsion types were investigated by using different mixing procedures, and single- and double-layer hydrophobic coatings were applied. The emulsions and coatings were characterized with optical microscope and scanning electron microscope (SEM), and their wetting properties, including the water contact angle (CA) and roll-off angle, were measured. A theoretical model for coated and non-coated concrete, which can be generalized for other types of materials, was developed to predict the effect of surface roughness and composition on the CA. An optimized distance between the aggregates was found where the CA has the highest value. The maximal CA measured was 156° for the specimen with PVA fibers treated with MK based emulsion. Since water penetration is the main factor leading to concrete deterioration, hydrophobic water-repellent concretes have much longer durability then regular concretes and can have a broad range of applications in civil and materials engineering.

  15. Maintenance measures for preservation and recovery of permeable pavement surface infiltration rate--The effects of street sweeping, vacuum cleaning, high pressure washing, and milling.

    Science.gov (United States)

    Winston, Ryan J; Al-Rubaei, Ahmed M; Blecken, Godecke T; Viklander, Maria; Hunt, William F

    2016-03-15

    The surface infiltration rates (SIR) of permeable pavements decline with time as sediment and debris clog pore spaces. Effective maintenance techniques are needed to ensure the hydraulic functionality and water quality benefits of this stormwater control. Eight different small-scale and full-scale maintenance techniques aimed at recovering pavement permeability were evaluated at ten different permeable pavement sites in the USA and Sweden. Maintenance techniques included manual removal of the upper 2 cm of fill material, mechanical street sweeping, regenerative-air street sweeping, vacuum street sweeping, hand-held vacuuming, high pressure washing, and milling of porous asphalt. The removal of the upper 2 cm of clogging material did not significantly improve the SIR of concrete grid paves (CGP) and permeable interlocking concrete pavers (PICP) due to the inclusion of fines in the joint and bedding stone during construction, suggesting routine maintenance cannot overcome improper construction. For porous asphalt maintenance, industrial hand-held vacuum cleaning, pressure washing, and milling were increasingly successful at recovering the SIR. Milling to a depth of 2.5 cm nearly restored the SIR for a 21-year old porous asphalt pavement to like-new conditions. For PICP, street sweepers employing suction were shown to be preferable to mechanical sweepers; additionally, maintenance efforts may become more intensive over time to maintain a threshold SIR, as maintenance was not 100% effective at removing clogging material.

  16. Rendering the loss of strength in dry concretes with addition of milled asphalt through microscopic analysis

    Directory of Open Access Journals (Sweden)

    T. Sachet

    Full Text Available Milled asphalt removed from old pavement carpets requires tenable handling easily reachable through its incorporation within other paving materials. This work deals with the effects of such incorporation to dry compacted concretes. Fine, intermediate, coarse and whole portions of milled asphalts were blended to a reference concrete. Mechanical tests disclosed remarkable losses on its strengths and modulus of elasticity; for the stereoscope and scanning microscopy pointed out impaired transition zones between the cement paste and the milled aggregates involved by thin asphalt films. Nevertheless, the mechanical results shown that the concretes with incorporated milled asphalt aggregates are suitable for use in pavement layers as bases and sub-bases even with reduced mechanical parameters.

  17. The shakeout scenario: Meeting the needs for construction aggregates, asphalt, and concrete

    Science.gov (United States)

    Langer, W.H.

    2011-01-01

    An Mw 7.8 earthquake as described in the ShakeOut Scenario would cause significantdamage to buildings and infrastructure. Over 6 million tons of newly mined aggregate would be used for emergency repairs and for reconstruction in the five years following the event. This aggregate would be applied mostly in the form of concrete for buildings and bridges, asphalt or concrete for pavement, and unbound gravel for applications such as base course that goes under highway pavement and backfilling for foundations and pipelines. There are over 450 aggregate, concrete, and asphalt plants in the affected area, some of which would be heavily damaged. Meeting the increased demand for construction materials would require readily available permitted reserves, functioning production facilities, a supply of cement and asphalt, a source of water, gas, and electricity, and a trained workforce. Prudent advance preparations would facilitate a timely emergency response and reconstruction following such an earthquake. ?? 2011, Earthquake Engineering Research Institute.

  18. Use of Crushed Granite Fine as Replacement to River Sand in Concrete Production

    Directory of Open Access Journals (Sweden)

    Manasseh JOEL

    2010-12-01

    Full Text Available The suitability of Crushed granite fine (CGF to replace river sand in concrete production for use in rigid pavement was investigated. Slump, compressive and indirect tensile strength tests were performed on fresh and hardened concrete.28 days Peak compressive and indirect tensile strength values of 40.70N/mm2 and 2.30N/mm2 respectively was obtained, with the partial replacement of river sand with 20% CGF, as against values of 35.00N/mm2 and 1.75N/mm2, obtained with the use of river sand as fine aggregate. Based on economic analysis and results of tests, river sand replaced with 20% CGF is recommended for use in the production of concrete for use in rigid pavement. Conservation of river sand in addition to better ways of disposing wastes from the quarry sites are some of the merits of using CGF.

  19. Stabilized fiber-reinforced pavement base course with recycled aggregate

    Science.gov (United States)

    Sobhan, Khaled

    's assumptions for rigid pavements), which has been found to explain reasonably well the field behavior of unreinforced and fiber-reinforced concrete slabs on grade. Finally, a preliminary cost analysis demonstrated that the use of stabilized recycled aggregate instead of a standard crushed stone base course can result in a meaningful economic savings.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1987-01-01

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