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Civil engineering, Génie civil, Transportation, Transports, Sciences exactes et technologie, Exact sciences and technology, Sciences appliquees, Applied sciences, Batiment. Travaux publics, Buildings. Public works, Calcul des constructions. Sollicitations, Structural analysis. Stresses, Méthodes de calcul. Tables. Abaques, Computation methods. Tables. Charts, Durabilité. Pathologie. Réparation. Entretien, Durability. Pathology. Repairing. Maintenance, Réparation (renforcement, consolidation), Repair (reinforcement, strenthening), Infrastructure des transports, Transportation infrastructure, Construction routière. Chaussées. Entretien, Road construction. Pavements. Maintenance, Revêtements, Surfacing, Analyse surface, Surface analysis, Análisis superficie, Chaussée souple, Flexible pavement, Calzada elástica, Etude comparative, Comparative study, Estudio comparativo, Evaluation projet, Project evaluation, Evaluación proyecto, Fissuration, Cracking, Agrietamiento, Modélisation, Modeling, Modelización, Ornière, Pavement rut, Carríl, Probabilité, Probability, Probabilidad, Préservation, Preservation, Preservación, Recouvrement, Overlay, Recubrimiento, Réhabilitation, Rehabilitation, Rehabilitación, Réseau routier, Road network, Red carretera, Résultat mesure, Measurement result, Resultado medición, Traitement surface, Surface treatment, Tratamiento superficie, Etude avant après, Before and after study, and Estudio previo posterior

When a pavement section is subjected to preservation or rehabilitation treatment, its surface condition is transformed from one set of condition states—those before treatment—to another set—those after treatment. This transformation is a function of the pavement condition before treatment, the type and timing of treatment, the project boundaries, and the quality of construction. For most pavement sections, the surface condition before and after treatment varies substantially along the section and over time. This study sponsored by FHWA analyzed the distribution of pavement surface condition and distress before and after treatment along several flexible pavement projects in the state of Louisiana. The study showed that current practices regarding the selection of pavement treatment type, treatment time, and project boundaries were independent of pavement surface condition and distress before treatment. For all pavement projects that received certain types of treatment in the past, knowledge of the relationships between the before- and after-treatment distributions of the pavement's surface condition and distress was crucial to the establishment of a future cost-effective strategy for pavement treatment. This paper shows that such relationships can be expressed by the probabilities of transforming before-treatment condition states to after-treatment condition states. These probabilities can be housed in one matrix format called the treatment transition matrix (TTM). For each treatment type, the TTM presents a snapshot of the state of the practice.

Civil engineering, Génie civil, Transportation, Transports, Sciences exactes et technologie, Exact sciences and technology, Sciences appliquees, Applied sciences, Batiment. Travaux publics, Buildings. Public works, Durabilité. Pathologie. Réparation. Entretien, Durability. Pathology. Repairing. Maintenance, Réparation (renforcement, consolidation), Repair (reinforcement, strenthening), Matériaux, Materials, Bitumes. Goudrons. Liants et bétons hydrocarbonés, Bitumen. Tars. Bituminous binders and bituminous concretes, Infrastructure des transports, Transportation infrastructure, Construction routière. Chaussées. Entretien, Road construction. Pavements. Maintenance, Revêtements, Surfacing, A chaud, Hot process, En caliente, Analyse dommage, Failure analysis, Análisis avería, Analyse donnée, Data analysis, Análisis datos, Chaussée, Pavement, Calzada, Efficacité, Efficiency, Eficacia, Enrobé hydrocarboné, Bituminous mixture, Mezcla bituminosa, Fouille donnée, Data mining, Busca dato, Modélisation, Modeling, Modelización, Recommandation, Recommendation, Recomendación, Revêtement routier, Carriageway surfacing, Revestimiento carretera, Traitement surface, Surface treatment, and Tratamiento superficie

The effectiveness of pavement treatments is a function of several factors, including material quality, design, distribution of pavement condition states (conditions and rates of deterioration) before treatment, and construction quality. Because of these factors, state highway agencies have established estimates of treatment service lives with significantly wide ranges. These wide ranges make the calculation of treatment benefits or effectiveness a difficult task unless the role of each factor that affects service life is well understood. This study analyzed the impacts of the state of the practice of Colorado, Louisiana, and Washington on the effectiveness of thin (< 2.5 in.) hot-mix asphalt (HMA) overlay treatment. This paper reports that analysis of time-series pavement condition and distress data of previously treated pavement sections can be tabulated in a matrix format to demonstrate a snapshot examination of past practice. Such matrices are called treatment transition matrices (T2Ms). The data in the matrices express the probability that a pavement treatment will have certain effectiveness. T2Ms for pavement projects subjected to thin HMA overlays by three state highway agencies are discussed. Differences in treatment effectiveness were related to differences in the state of the practice in the three states. Selection of treatment timing and project boundaries significantly affected treatment effectiveness, and similar states of the practice yielded similar treatment effectiveness.

Ecology, Ecologie, Forestry, silviculture, Foresterie, sylviculture, Sciences biologiques et medicales, Biological and medical sciences, Sciences biologiques fondamentales et appliquees. Psychologie, Fundamental and applied biological sciences. Psychology, Ecologie animale, vegetale et microbienne, Animal, plant and microbial ecology, Ecologie animale et végétale, Animal and plant ecology, Synécologie, Synecology, Ecosystèmes terrestres, Terrestrial ecosystems, Sylviculture, Forestry, Aménagement forestier. Types de peuplements. Dynamique des peuplements. Traitements sylvicoles. Entretien des peuplements. Régénération naturelle, Forest management. Stand types and stand dynamics. Silvicultural treatments. Tending of stands. Natural regeneration, Types de peuplements. Dynamique des peuplements. Traitements sylvicoles. Entretien des peuplements. Régénération naturelle, Stand types and stand dynamics. Silvicultural treatments. Tending of stands. Natural regeneration, Environnement physique, Physical environment, Medio ambiente físico, Peuplement forestier, Forest stand, Rodal forestal, Arbre forestier résineux, Softwood forest tree, Arbol forestal resinoso, Combustible, Fuel, Feu végétation, Vegetation fire, Fuego vegetación, Foresterie, Forestry, Ciencias forestales, Forêt résineuse, Coniferous forest, Bosque resinoso, Incendie spontané, Wildfire, Fuego griego, Montagne, Mountain, Montaña, Peuplement forestier mélangé, Mixed forest stand, Rodal forestal mixto, Régénération, Regeneration, Regeneración, Traitement surface, Surface treatment, Tratamiento superficie, Chaîne Cascades, Cascade Range, Ecologie forestière, Forest ecology, Ecología forestal, Préparation site, Site preparation, Preparación sitio, Fire severity, Plantations, Surface fuel, Tripod Fire, and Washington

Previous studies have debated the flammability of young regenerating stands, especially those in a matrix of mature forest, and no consensus has emerged as to whether young stands are inherently prone to high-severity wildfire. This topic has recently been addressed using spatial imagery, and weak inferences were made given the scale mismatch between the coarse resolution of spatial imagery and the fine resolution of mechanisms driving fire severity. We collected empirical stand and fire-severity data from 44 regenerating stands that are interspersed in mature, mid-elevation forests in the Okanogan-Wenatchee National Forest (OWNF) on the eastside of the Cascade Range in Washington, USA. These stands are mixed-species plantations that were established to promote regeneration of seral to late-seral tree species (Douglas-fir, subalpine fir, Engelmann spruce, western larch) in small patches within a larger lodgepole pine forest. In 2006, the 70,925 ha Tripod Fire burned through all the plantations and the surrounding lodgepole pine matrix. To understand what drives fire effects in plantations, especially those that exist in spatially heterogeneous forests, we compared fire severity in plantations with and without fuels-reducing site preparation (i.e., fuel treatments), using three metrics to quantify severity: mortality (%), exposed mineral soil (%), and char height (m). We built generalized linear models for each severity metric and tested for a difference in all severity metrics between treated and untreated units using Permutational Multivariate Analysis of Variance. Units without fuel treatments have more severe fire effects: mortality is 77% in untreated units and 37% in treated units (p = 0.0005). Other variables contribute to differences in fire severity, including species composition, canopy closure, and canopy base height. Canopy base height and canopy closure both exhibit a reverse relationship with mortality from what was expected: the higher the canopy closure and the lower the canopy base height, the lower the mortality. In other words, stands that have trees closer together with crowns near the ground are more likely to have lower mortality. Overall, the results suggest that young stands in some dry mixed conifer forests can be resilient to wildfire if surface fuel loading is low upon stand establishment.

Civil engineering, Génie civil, Sciences exactes et technologie, Exact sciences and technology, Sciences appliquees, Applied sciences, Batiment. Travaux publics, Buildings. Public works, Infrastructure des transports, Transportation infrastructure, Exploitation routière (signalisation, éclairage, sécurité et accessoires, déneigement, écran antibruit, etc.), Road operations (signalization, lighting, safety and accessories, snow clearance, acoustical panel, etc.), Transports terrestres, transports aeriens, transports maritimes, constructions navales, Ground, air and sea transportation, marine construction, Transports et trafic routiers, Road transportation and traffic, Accident circulation, Traffic accident, Accidente tráfico, Analyse factorielle, Factor analysis, Análisis factorial, Apprentissage, Learning, Aprendizaje, Chaussée, Pavement, Calzada, Mesure sécurité, Safety measure, Medida seguridad, Modification, Modificación, Signalisation horizontale, Horizontal signalling, Señalización horizontal, Sécurité trafic, Traffic safety, Seguridad tráfico, Trafic routier, Road traffic, Tráfico carretera, Traitement surface, Surface treatment, and Tratamiento superficie

Crash modification factors, when used properly, can help transportation engineers identify and apply the most appropriate countermeasures for increasing roadway safety.

General chemistry, physical chemistry, Chimie générale, chimie physique, Energy, Énergie, Sciences exactes et technologie, Exact sciences and technology, Sciences appliquees, Applied sciences, Energie, Energy, Combustibles, Fuels, Combustibles de remplacement. Production et utilisation, Alternative fuels. Production and utilization, Hydrogène, Hydrogen, Acier inoxydable, Stainless steel, Acero inoxidable, Corrosion, Corrosión, Fabrication, Manufacturing, Fabricación, Géométrie, Geometry, Geometría, Hydrogène, Hydrogen, Hidrógeno, Pile combustible, Fuel cell, Pila combustión, Procédé fabrication, Manufacturing process, Procedimiento fabricación, Revêtement protecteur, Protective coatings, Revestimiento protector, Résistivité électrique, Electric resistivity, Resistividad eléctrica, Traitement surface, Surface treatment, Tratamiento superficie, Contact resistance, Hydroforming, Metallic bipolar plates, Micro-channel, PEMFC, and Stamping

In this study, metallic bipolar plate (BPP) samples manufactured with stamping and hydroforming under different process conditions were tested for their electrical contact resistance characteristics to reveal the effect of manufacturing type and conditions. Punch speed and force in stamping, and pressure and pressure rate in hydroforming were selected as variable process parameters. In addition, two different channel sizes were tested to expose the effect of BPP micro-channel geometry and its consequences on the contact resistance. As a general conclusion, stamped BPPs showed higher contact conductivity than the hydroformed BPPs. Moreover, pressure in hydroforming and geometry had significant effects on the contact resistance behavior of BPPs. Short term corrosion exposure was found to decrease the contact resistance of bipolar plates. Results also indicated that contact resistance values of uncoated stainless steel BPPs are significantly higher than the respective target set by U.S. Department of Energy. Conforming to literature, proper coating or surface treatments are necessary to satisfy the requirements.

Civil engineering, Génie civil, Transportation, Transports, Sciences exactes et technologie, Exact sciences and technology, Sciences appliquees, Applied sciences, Batiment. Travaux publics, Buildings. Public works, Economie de la construction. Coût, Building economics. Cost, Durabilité. Pathologie. Réparation. Entretien, Durability. Pathology. Repairing. Maintenance, Réparation (renforcement, consolidation), Repair (reinforcement, strenthening), Infrastructure des transports, Transportation infrastructure, Construction routière. Chaussées. Entretien, Road construction. Pavements. Maintenance, Généralités, General, Analyse avantage coût, Cost benefit analysis, Análisis coste beneficio, Analyse coût, Cost analysis, Análisis costo, Caractéristique, Characteristic, Característica, Chaussée, Pavement, Calzada, Collecte donnée, Data gathering, Recolección dato, Durée service, Service life, Duración servicio, Endommagement, Damaging, Deterioración, Enrobé hydrocarboné, Bituminous mixture, Mezcla bituminosa, Infrastructure routière, Road infrastructure, Infraestructura de carreteras, Maintenance, Mantenimiento, Traitement surface, Surface treatment, and Tratamiento superficie

This study investigated the benefits and costs of commonly used thin surface treatments for maintenance of bituminous pavements in Kansas. Cost and performance data were collected from the Kansas Pavement Management Information System for all treatments applied from 1992 to 2006. Results show that seal coats have a short average service life on Interstate highways. The average life on non-Interstate highways is about 4 years. This life is slightly lower than that for other thin surface treatments, including hot-mix asphalt (HMA) overlays. Seal coats also have a significantly lower equivalent uniform annual cost than do all other thin surface treatments in Kansas. A comparison of pavement benefit values before and after application showed that seal coat could not mitigate distresses better than other methods, especially thin HMA overlays. However, its performance is quite similar to that of the modified slurry seal.

Civil engineering, Génie civil, Transportation, Transports, Sciences exactes et technologie, Exact sciences and technology, Sciences appliquees, Applied sciences, Batiment. Travaux publics, Buildings. Public works, Matériaux, Materials, Bitumes. Goudrons. Liants et bétons hydrocarbonés, Bitumen. Tars. Bituminous binders and bituminous concretes, Infrastructure des transports, Transportation infrastructure, Construction routière. Chaussées. Entretien, Road construction. Pavements. Maintenance, Revêtements, Surfacing, Chaussée, Pavement, Calzada, Conception système, System design, Concepción sistema, Enrobé hydrocarboné, Bituminous mixture, Mezcla bituminosa, Gestion, Management, Gestión, Maintenance, Mantenimiento, Modélisation, Modeling, Modelización, Préservation, Preservation, Preservación, Rugosité, Roughness, Rugosidad, Réseau routier, Road network, Red carretera, Stratégie, Strategy, Estrategia, Traitement surface, Surface treatment, and Tratamiento superficie

To help the Washington State Department of Transportation (WSDOT) enhance its pavement preservation program through an improved understanding of the use of bituminous surface treatment (BST), the Highway Development and Management System was used as an analytical tool to test the average annual daily traffic and equivalent single-axle load levels appropriate as criteria for selecting the application of BST resurfacings to WSDOT pavements. It verified the feasibility of using BSTs to maintain pavements with higher traffic levels than have been applied in the past. Results also suggested that alternating the application of BST resurfacings and 45-mm hot-mix asphalt overlays is an effective rehabilitation strategy. Finally, the study results were used to estimate the impacts that increased use of BST surfaces would have on the performance of the state-owned route system.

Civil engineering, Génie civil, Sciences exactes et technologie, Exact sciences and technology, Sciences appliquees, Applied sciences, Batiment. Travaux publics, Buildings. Public works, Infrastructure des transports, Transportation infrastructure, Construction routière. Chaussées. Entretien, Road construction. Pavements. Maintenance, Revêtements, Surfacing, Transports terrestres, transports aeriens, transports maritimes, constructions navales, Ground, air and sea transportation, marine construction, Transports et trafic routiers, Road transportation and traffic, Amélioration, Improvement, Mejora, Chaussée, Pavement, Calzada, Construction routière, Road construction, Construcción carretera, Procédé pose, Laying process, Método colocación, Rechargement par friction, Friction surfacing, Recargue por fricción, Surfaçage, Surfacing, Acabado superficie, Sécurité trafic, Traffic safety, Seguridad tráfico, Technologie construction, Construction technology, Tecnología construcción, Temps météorologique, Weather, Tiempo meteorológico, Traitement surface, Surface treatment, and Tratamiento superficie

High-friction surfacting systems show promise in helping transportation agencies improve skid resistance on wet pavement and hazardous curves and grades.

Civil engineering, Génie civil, Transportation, Transports, Sciences exactes et technologie, Exact sciences and technology, Sciences appliquees, Applied sciences, Batiment. Travaux publics, Buildings. Public works, Durabilité. Pathologie. Réparation. Entretien, Durability. Pathology. Repairing. Maintenance, Réparation (renforcement, consolidation), Repair (reinforcement, strenthening), Infrastructure des transports, Transportation infrastructure, Construction routière. Chaussées. Entretien, Road construction. Pavements. Maintenance, Revêtements, Surfacing, Analyse coût, Cost analysis, Análisis costo, Déformation superficielle, Surface deformation, Deformación superficial, Etude cas, Case study, Estudio caso, Evaluation performance, Performance evaluation, Evaluación prestación, Evaluation projet, Project evaluation, Evaluación proyecto, Innovation, Innovación, Maintenance, Mantenimiento, Polymère, Polymer, Polímero, Poussière, Dust, Polvo, Procédé pose, Laying process, Método colocación, Route, Highway, Carretera, Stabilisant, Stabilizer agent, Estabilizante, Traitement surface, Surface treatment, Tratamiento superficie, Route non revêtue, Unpaved road, Terracería, Route à faible volume, and Low volume road

Maintenance of unpaved roads in Arizona has become a challenge. With strict environmental compliance issues, historical considerations, lack of surfacing materials, cost increases, an extremely dry climate, and other safety concerns, the task of maintaining these roads is increasingly difficult. The Arizona Department of Transportation Globe District has investigated and implemented various techniques to address the maintenance of unpaved roads in an efficient, cost-effective manner. Options are presented, and two case studies of the most successful techniques are outlined. Construction costs and performance of these road treatment strategies are discussed.

Civil engineering, Génie civil, Transportation, Transports, Sciences exactes et technologie, Exact sciences and technology, Sciences appliquees, Applied sciences, Batiment. Travaux publics, Buildings. Public works, Durabilité. Pathologie. Réparation. Entretien, Durability. Pathology. Repairing. Maintenance, Réparation (renforcement, consolidation), Repair (reinforcement, strenthening), Infrastructure des transports, Transportation infrastructure, Construction routière. Chaussées. Entretien, Road construction. Pavements. Maintenance, Chaussée, Pavement, Calzada, Construction routière, Road construction, Construcción carretera, Coût global, Life cycle cost, Costo global, Etude méthode, Method study, Estudio método, Evaluation performance, Performance evaluation, Evaluación prestación, Méthode alternative, Alternative method, Método alternativo, Réhabilitation, Rehabilitation, Rehabilitación, Stratégie, Strategy, Estrategia, Traitement surface, Surface treatment, Tratamiento superficie, Route à faible trafic, and Low volume road

An overview of the attempt by the Nevada Department of Transportation (NDOT) to find alternative rehabilitation strategies to rehabilitate its low-volume road network effectively is provided. Because of Nevada's continuing growth, NDOT is faced with the challenge of how to balance its available funding between pavement preservation and capacity improvement projects. NDOT is responsible for 13,000 lane miles of roadway, of which 3,385 lane miles (26%) qualify as low-volume roads. The low-volume roads have a two-directional average daily traffic of 400 or less. Five roadway projects with a combined total of 111 centerline miles were rehabilitated with 29 combinations of structural and surface strategies. The rehabilitation strategies investigated included full-depth reclamation with lime, cement, asphalts, and foamed asphalt. Various cold-mix, cold-in-place recycling with millings and different rejuvenating agents, and surface treatment test sections were constructed. The constructability issues that were reported during construction are discussed. In addition, pavement condition is examined and laboratory testing is reviewed. Results suggest that NDOT can use alternative rehabilitation strategies in place of its conventional method of 2-in. plant-mix bituminous surface overlay and chip seal to rejuvenate its low-volume roadway network. A cost saving of approximately $100,000 per centerline mile is anticipated.

Civil engineering, Génie civil, Transportation, Transports, Sciences exactes et technologie, Exact sciences and technology, Sciences appliquees, Applied sciences, Batiment. Travaux publics, Buildings. Public works, Infrastructure des transports, Transportation infrastructure, Construction routière. Chaussées. Entretien, Road construction. Pavements. Maintenance, Asphalte, Asphalt, Asfalto, Chaussée, Pavement, Calzada, Conception, Design, Diseño, Construction routière, Road construction, Construcción carretera, Dépendance du temps, Time dependence, Dependencia del tiempo, Enrobé hydrocarboné, Bituminous mixture, Mezcla bituminosa, Essai laboratoire, Laboratory test, Ensayo laboratorio, Etude expérimentale, Experimental study, Estudio experimental, Mélange, Mixture, Mezcla, Traitement surface, Surface treatment, Tratamiento superficie, Route à faible trafic, and Low volume road

Asphalt surface treatment (AST) pavements using high-float (HF) emulsions and dense-graded aggregates have been constructed on Alaska's low-volume roads for more than 20 years. These HF ASTs proved to be relatively inexpensive, were easy to construct, and provided good service for low-volume roads. However, the normally positive economics of these pavements have sometimes been offset by problems during or after construction. It was argued that most problems could be solved if a mix design method was devised to ensure optimum application rates of emulsion and aggregate. This paper presents a standardized laboratory mix design method for HF emulsion and dense-graded aggregates based on simple volumetric calculations. The method accounts specifically for aggregate maximum size, compaction characteristics, moisture content, and air voids. An outline of the design method and an example numerical application are presented, and reasons supporting each element of the design method are discussed. The paper addresses the variables that control the emulsion and aggregate contents of these mixes. New laboratory test methods are proposed for determining aggregate density. The proposed mix design method requires that 15 % additional aggregate be added to the design amount determined through voids calculations. The paper also presents information that improves the constructability and long-term performance of HF pavements.

Civil engineering, Génie civil, Transportation, Transports, Sciences exactes et technologie, Exact sciences and technology, Sciences appliquees, Applied sciences, Batiment. Travaux publics, Buildings. Public works, Matériaux, Materials, Constituants du béton de ciment, Cement concrete constituents, Granulats et autres constituants du béton, Aggregates and other concrete constituents, Généralités, General, Infrastructure des transports, Transportation infrastructure, Construction routière. Chaussées. Entretien, Road construction. Pavements. Maintenance, Chemin forestier, Forest road, Camino forestal, Conception, Design, Diseño, Construction routière, Road construction, Construcción carretera, Essai sol, Soil test, Ensayo suelo, Evaluation performance, Performance evaluation, Evaluación prestación, Granulat, Aggregate(materials), Agregado, Montagne, Mountain, Montaña, Resurfaçage, Resurfacing, Résistance mécanique, Strength, Resistencia mecánica, Sol fondation, Subgrade, Suelo fundación, Traitement surface, Surface treatment, Tratamiento superficie, Route à faible trafic, and Low volume road

An integrated aggregate design and management system for forest roads in wet, mountainous terrain requires special considerations. Typically, subgrade soils, drainage conditions, and compactive effort vary along the length of new and existing roads. There are fewer testing opportunities for obtaining design parameters in these remote areas. Nevertheless, relatively small depths of aggregate can provide high performance. This design requires characterization of subgrade materials before or during construction. It uses steep road grades to advantage for effective drainage of the subgrade and aggregate. The design is used in conjunction with drainage practices that minimize erosion from reaching streams. Compaction effectiveness can be limited by soil moisture that is wet of optimum for compaction during the short construction period, requiring that aggregate depths be adjusted accordingly. To be used by practitioners, the design must be simple and not very conservative. Aggregate properties vary widely, and gradation specifications must be adjusted on the basis of these properties. Aggregate roads require timely inspection and should be graded only when they are rutted or major defects are present. Drainage and subgrade problems also need to be addressed during maintenance of the surface.

Mechanical engineering, Génie mécanique, Transportation, Transports, Sciences exactes et technologie, Exact sciences and technology, Sciences appliquees, Applied sciences, Transports terrestres, transports aeriens, transports maritimes, constructions navales, Ground, air and sea transportation, marine construction, Constructions navales, Marine construction, Adhérence, Adhesion, Adherencia, Construction navale, Shipbuilding, Construcción naval, Etude théorique, Theoretical study, Estudio teórico, Joint construction, Construction joint, Junta construcción, Matériau composite, Composite material, Material compuesto, Métal, Metal, Méthode expérimentale, Experimental method, Método experimental, Nettoyage, Cleaning, Limpieza, Recommandation, Recommendation, Recomendación, Traitement surface, Surface treatment, and Tratamiento superficie

Recently, many nations along with private shipbuilders have begun developing large maritime vessels using composite materials structurally. Concurrently, the US Navy has a need for research on bonded metal-composite joints. For these reasons, a literature review was conducted to establish a fundamental knowledge base of adhesive bonding and failure theories along with surface cleaning and engineering processes that would be valuable for metal-composite joint designs. It is believed that by understanding bonding and failure fundamentals, optimal surface characteristics can be targeted. Furthermore, by knowing the available cleaning and surface engineering processes, in conjunction with understanding their resulting surface topographies and compositions, creative and novel joints can be designed. This report provides the results of the literature review performed, which serves as a platform for future research aimed at optimizing bonded joints for use in naval applications.

Polymers, paint and wood industries, Polymères, industries des peintures et bois, Sciences exactes et technologie, Exact sciences and technology, Sciences appliquees, Applied sciences, Industrie des polymeres, peintures, bois, Polymer industry, paints, wood, Technologie des polymères, Technology of polymers, Formes d'application et semiproduits, Forms of application and semi-finished materials, Matériaux composites, Composites, Agent surface cationique, Cationic surfactant, Agente superficie catiónico, Ammonium quaternaire composé, Quaternary ammonium compound, Amonio cuaternario compuesto, Argile organique, Organic clay, Arcilla orgánica, Bentonite, Bentonita, Capacité échange cation, Cation exchange capacity, Capacidad intercambio catión, Degré dispersion, Dispersion degree, Grado dispersión, Etude expérimentale, Experimental study, Estudio experimental, In situ, Matériau composite, Composite material, Material compuesto, Matériau renforcé dispersion, Dispersion reinforced material, Material renforzado dispersión, Morphologie, Morphology, Morfología, Nanocomposite, Nanocompuesto, Polymérisation radicalaire, Free radical polymerization, Polimerización radicalar, Relation mise en oeuvre structure, Structure processing relationship, Relación puesta en marcha estructura, Styrène polymère, Styrene polymer, Estireno polímero, Traitement surface, Surface treatment, Tratamiento superficie, Silicate lamellaire, nanocomposites, polystyrene, and surfactants

An effect of the cation-exchange capacity (CEC) on the formation of polystyrene-clay nanocomposites is reported. Two types of 2:1 layered silicates with different CECs, Wyoming (97 mequiv/100 g of clay) and bentonite H (BNH; 131 mequiv/100 g of clay) were investigated. The organoclay was prepared through the mixing of purified clay and octadecyldimethylammonium chloride (ODA) in an aqueous solution. The packing of the intercalated ODA surfactant depended on the CEC and the degree of solvent extraction. Two possible phases of the interlayer packing, solidlike and liquidlike, were detected for the extracted BNH because of the charge heterogeneity of the clay. The liquidlike phase showed a good affinity toward the styrene monomer, which promoted the formation of exfoliated nanocomposites. On the other hand, the solidlike phase showed a restricted dispersion in the styrene monomer. The organoclay interlayer showed limited expansion by the styrene monomer. This led to the formation of intercalated nanocomposites. An increase in the organoclay loading hindered the formation of the exfoliated nanocomposites.

Civil engineering, Génie civil, Transportation, Transports, Sciences exactes et technologie, Exact sciences and technology, Sciences appliquees, Applied sciences, Batiment. Travaux publics, Buildings. Public works, Matériaux, Materials, Bitumes. Goudrons. Liants et bétons hydrocarbonés, Bitumen. Tars. Bituminous binders and bituminous concretes, Infrastructure des transports, Transportation infrastructure, Construction routière. Chaussées. Entretien, Road construction. Pavements. Maintenance, Généralités, General, A chaud, Hot process, En caliente, Analyse quantitative, Quantitative analysis, Análisis cuantitativo, Asphalte, Asphalt, Asfalto, Chaussée, Pavement, Calzada, Ciment, Cement, Cemento, Emulsion, Emulsión, Etude comparative, Comparative study, Estudio comparativo, Evaluation performance, Performance evaluation, Evaluación prestación, Granulat léger, Lightweight aggregate, Granulado liviano, Liant, Binders, Ligante, Procédé pose, Laying process, Método colocación, Projet, Project, Proyecto, Scellage, Sealing, Sellado, Traitement surface, Surface treatment, Tratamiento superficie, Asphalt cement, CE Database Subject headings: Asphalt pavements, Emulsions, and Pavement management

The study collected both design and performance data on 342 chip seal projects worth nearly $30 million that had been completed in the Texas Department of Transportation's Atlanta District since 1996. One hundred sixty five of these projects were emulsion projects utilizing CRS-2P as the binder and 177 were asphalt cement projects using AC15-5TR binders. The external variables were minimized as Atlanta District had used the same seal coat contractor, Area Office, construction season, asphalt suppliers, and aggregate on all its districts chip seal projects for the past 12 years. The one difference in the aggregate was that the AC15-5TR used a lightweight aggregate that was precoated unlike the emulsion seals' lightweight aggregate that was not precoated. Thus, the comparison of the two binders can be made in a very direct manner, and the results can be viewed as specific to the engineering properties of the binders themselves without the need to qualify the conclusions based on independent parameters that could not be mathematically removed from the data. The study found that the emulsion chip seals performed as well as the hot asphalt cement seals and were the more cost effective of the two alternatives. Emulsion chip seals also furnished a better long-term friction course as measured by the skid number.

Civil engineering, Génie civil, Transportation, Transports, Sciences exactes et technologie, Exact sciences and technology, Sciences appliquees, Applied sciences, Batiment. Travaux publics, Buildings. Public works, Durabilité. Pathologie. Réparation. Entretien, Durability. Pathology. Repairing. Maintenance, Réparation (renforcement, consolidation), Repair (reinforcement, strenthening), Infrastructure des transports, Transportation infrastructure, Construction routière. Chaussées. Entretien, Road construction. Pavements. Maintenance, Généralités, General, Essais routiers: méthodes, matériels et résultats, Road test: methods, equipments and results, Chaussée, Pavement, Calzada, Essai routier, Road test, Ensayo carretera, Etude comparative, Comparative study, Estudio comparativo, Maintenance, Mantenimiento, Méthodologie, Methodology, Metodología, Prévention, Prevention, Prevención, Route, Highway, Carretera, Réhabilitation, Rehabilitation, Rehabilitación, Résultat, Result, Resultado, Traitement surface, Surface treatment, Tratamiento superficie, Zone rurale, Rural area, and Zona rural

Thin maintenance surfaces (TMSs) provide an economical method of extending pavement life for asphaltic concrete or bituminous roads. Two phases of research were undertaken to demonstrate TMSs and establish guidelines for their use in Iowa. The project involved the construction and observation of multiple test sections on four rural U.S. highways in Iowa over a 3-year period. Average annual daily traffic on these highways ranged from approximately 1,000 to 5,000. Test sections included single and double chip seals with various types and sizes of aggregates and two types of binder: cationic emulsion and high-float emulsion. Test sections of microsurfacing, microsurfacing cape seal, and thin-lift hot-mix overlay were also placed. These TMS treatments were compared with control sections. Researchers designed the chip seal test sections, monitored the construction process, and collected quality-control information on materials. The pavement condition index (PCI) and skid resistance were measured and compared for each test section before and after construction. TMSs improved PCI when materials were selected properly and quality construction techniques were used. Success was achieved with chip seal that used graded cover aggregates and small cover aggregates and also with various thin-lift overlays. Difficulties were experienced with microsurfacing aggregates that had few fines. The results of the study reinforce the importance of selecting the right type of TMS, ensuring construction quality, and having favorable weather during and after construction.