The X-ray computed tomography is a technology to investigate air void structure of drilled asphalt cores, which provides a non-destructive alternative to traditional laboratory methods, usually destructive testing.In this work, six in-situ specimens from a double layer porous asphalt pavement in Linköping, Sweden, were taken and analysed using both qualitative and quantitative methods of tomography. The qualitative study focused on identifying different features of the drilled cores, such as densification and air voids in the interface between the two porous layers. In the quantitative study, the air voids contents were quantified from processed tomography images. The tomography results of air voids content in all three directions (X, Y and Z), when increasing the calculated number of slices from 4 to 8, were compared to the measured air voids contents from a standardized laboratory method. Both t-test and F-test were applied to determine if a significant difference was found. Besides, the Evaluation Index (EI) was introduced to determine the most accurate combination slices and directions.The results shown here indicate that a reduced number of tomography slices can give enough accuracy in the determination of air voids content for the porous layers. The results also showed that air voids content determined with tomography gave no significant difference compared to the laboratory results. The most accurate combination found was, in this case, the Y+Z direction. Future development will focus on automatizing the determination of air voids, as well as mastic and aggregate phases using the same methodology of comparing tomography results with laboratory results.

O trabalho tem por objetivo apresentar procedimentos de projeto e execução de obras de pavimentos permeáveis visando sua aplicação prática como medidas compensatórias de drenagem urbana com a finalidade de retenção e amortecimento de picos de enchentes em cidades densamente urbanizadas. Os procedimentos propostos se baseiam na experiência adquirida para a implementação de dois tipos de pavimentos permeáveis; um com revestimento constituído de blocos intertravados de concreto e outro com revestimento de concreto asfáltico poroso, conhecido como camada porosa de atrito. Para subsidiar o trabalho uma pista experimental foi construída como área de estacionamento nas dependências do Centro Tecnológico de Hidráulica CTH na Universidade de São Paulo onde foi realizado o experimento. O local do estacionamento atua como um reservatório subsuperficial de águas pluviais sendo que sua estrutura, constituída de agregados granulares, abriga no interior de seus vazios a água infiltrada pelas camadas do pavimento. Recomenda-se, após os estudos, que os procedimentos e seqüências de atividades de projeto e execução de obras de pavimentos permeáveis sejam contemplados pelo poder público e privado como solução alternativa em diferentes empreendimentos urbanos como grandes áreas públicas ou particulares, estacionamentos, parques, quadras esportivas, passeios, calçamentos e ruas de pouca solicitação de tráfego entre outros. / The present work intents to show design and built procedures, of porous pavements; by paying attention on its practical appliances as compensatory option in urban drainage with purpose to retaining rainfall water by storage, reducing downstream flooding in cities with great urban density. The procedures here proposed are based in the know how acquired for the construction of two kinds of porous pavements: one built with interlocked concrete blocks and the other built with porous asphalt. In order to aid the present work, an experimental field was built as parking area inside the propriety of CTH Centro Tecnologico de Hidraulica in State University of Sao Paulo where the tests and experiments were made. The parking area is a reservoir structure where rain water is stored inside courses of aggregates. The storage volume is in the void space between particles of material that comes by infiltration trough the pavement layer. The commendation, after the studies, is that procedures and activities of design and build of porous pavements could be observed by government and private sector as alternative solution in many kinds of urban projects such as large public and private lots, parking areas sport fields side walks and streets, with low capacity of traffic loads, and so forth.

O trabalho tem por objetivo apresentar procedimentos de projeto e execução de obras de pavimentos permeáveis visando sua aplicação prática como medidas compensatórias de drenagem urbana com a finalidade de retenção e amortecimento de picos de enchentes em cidades densamente urbanizadas. Os procedimentos propostos se baseiam na experiência adquirida para a implementação de dois tipos de pavimentos permeáveis; um com revestimento constituído de blocos intertravados de concreto e outro com revestimento de concreto asfáltico poroso, conhecido como camada porosa de atrito. Para subsidiar o trabalho uma pista experimental foi construída como área de estacionamento nas dependências do Centro Tecnológico de Hidráulica CTH na Universidade de São Paulo onde foi realizado o experimento. O local do estacionamento atua como um reservatório subsuperficial de águas pluviais sendo que sua estrutura, constituída de agregados granulares, abriga no interior de seus vazios a água infiltrada pelas camadas do pavimento. Recomenda-se, após os estudos, que os procedimentos e seqüências de atividades de projeto e execução de obras de pavimentos permeáveis sejam contemplados pelo poder público e privado como solução alternativa em diferentes empreendimentos urbanos como grandes áreas públicas ou particulares, estacionamentos, parques, quadras esportivas, passeios, calçamentos e ruas de pouca solicitação de tráfego entre outros. / The present work intents to show design and built procedures, of porous pavements; by paying attention on its practical appliances as compensatory option in urban drainage with purpose to retaining rainfall water by storage, reducing downstream flooding in cities with great urban density. The procedures here proposed are based in the know how acquired for the construction of two kinds of porous pavements: one built with interlocked concrete blocks and the other built with porous asphalt. In order to aid the present work, an experimental field was built as parking area inside the propriety of CTH Centro Tecnologico de Hidraulica in State University of Sao Paulo where the tests and experiments were made. The parking area is a reservoir structure where rain water is stored inside courses of aggregates. The storage volume is in the void space between particles of material that comes by infiltration trough the pavement layer. The commendation, after the studies, is that procedures and activities of design and build of porous pavements could be observed by government and private sector as alternative solution in many kinds of urban projects such as large public and private lots, parking areas sport fields side walks and streets, with low capacity of traffic loads, and so forth.

Porous asphalt has gradually gained a lot of popularity in the past ten years for its ability to reduce traffic noise, especially noise generated between tire and road surface. The acoustical absorption properties are mainly due to the pore structure and the texture of the mixture. However, the percentage of these pores decrease during the lifetime. The main reason is that dirt and organic material get stuck in the air void structure and eventually cause clogging. In Nordic countries, particles from the road which get released due to the use of spiked tires accelerate clogging. To minimize wear and tear of these roads, larger aggregates are used. But, larger stone size diminishes the noise absorption ability of the mixture. Another reason that is attributed to void reduction is post-compaction. The fact that these mixtures damage prematurely and need more maintenance than conventional pavements is the main reason for its limited use. Given these problem, it is therefore important to understand how clogging can be minimized and/or reverted via operational maintenance actions. Different types of cleaning vehicles have been used previously to restore porosity. Unfortunately, these cleaning attempts have led to ambiguities and the effect of cleaning is widely debated. A method to look inside and to measure this effect is needed. This thesis has compared nine field core samples of porous asphalt from E4 Huskvarna, with the aim to conduct an in depth analysis of the air voids distribution before and after cleaning with a particular cleaning method. For this, the Skanska maintenance vehicle was selected, named VägRen  which is claimed to be optimized for porous asphalt under Nordic conditions has been used to clean a 100 m section. Cores were drilled before and after cleaning. The samples were scanned with high resolution X-ray computed tomography (CT) scanner in order to capture the entire morphology.  The digital image analysis program, AvizoFire® was used to characterize the 3D internal structure of air voids. Porosity evaluation as a function of depth of the asphalt layers has been studied to analyze the void distribution and cleaning effectiveness of the dirt with the investigated method. The results show that: (i) No visible damage induced by VägRen could be detected. (ii) Skanska's maintenance vehicles increased the air voids in the entire cleaned core and connected air voids increased by 83 %. The knowledge generated from this study can assist in the broader understanding of effectively utilizing porous asphalt under Nordic Conditions, though more research will be needed for conclusive results on the general effectiveness of the cleaning method and the effect of the life time of the pavement. / Intresset för att använda bullerreducerande beläggningar har gradvis ökat de senaste tio åren på grund av dess förmåga att reducera trafikbuller och i synnerhet det buller som genereras mellan däck och vägbana. Den bullerreducerande förmågan beror främst på beläggningens textur samt porstruktur. Dessutom minskar den procentuella andelen hålrum med tiden, det är främst partiklar och vägdamm som fastnar i porstrukturen och medverkar till igensättning av hålrummen. Denna igensättning accelereras i de nordiska länderna på grund av frekvent användande av dubbdäck. För att minska dubbdäcksslitaget används ofta beläggningar med större maximal stenstorlek, dessa större stenar genererar dock mer trafikbuller. En annan faktor som kan bidra till minskat hålrum är relaterat till efterpackning av beläggningen. Faktum att dessa typer av asfalt försämras i förtid och kräver mer underhåll generellt motverkar en bredare användning av bullerreducerande beläggningar. Ovannämnda problem belyser vikten att förstå till vilken grad igensättningsprocessen av beläggningens porstruktur kan minimeras samt återställas med riktade underhållsåtgärder. För att förbättra den akustiska livslängden har olika typer av rengöringsutrustningar testats. Utvärderingen från dessa tester har inte varit entydiga, vilket har lett till att effekterna av rengöring har ifrågasatts. Det finns således ett behov av att kunna utvärdera porstrukturen före och efter rengöring. Föreliggande avhandling har jämfört nio borrkärnor från en bullerreducerande beläggning från E4 utanför Huskvarna, med syftet att utföra en djupanalys av borrkärnornas porstruktur. Skanskas egenutvecklade underhållsfordon, VägRen (VR), optimerad för nordiska förhållanden användes för att rengöra en sträcka på ca 100 m av E4:an. Borrkärnorna togs före och efter rengöringen. Provkropparna analyserades med en högupplöst röntgen datortomograf (CT) skanner för att framställa hela morfologin. Bilderna erhållna från datortomografin bearbetades till 3D med bildanalysprogrammet, AvizoFire®. Porositeten som funktion av beläggningsdjup har studerats för att analysera effeketen av den valda rengöringsmetoden. Resultaten visar  att: (i) Inga synliga skador på den rengjorda sträckan, orsakade av  VägRen. (ii) Skanskas rengöringsfordon återställde en del av hålrummet på samtliga nivåer för de tvättade provkropparna. Andel sammanhängande porer ökade med 83 \%. Kunskap erhållen från denna studie kan bidra till en djupare förståelse om mer optimal användande av bullerreducerande beläggningar under nordiskt klimat. Dock behövs det mer forskning för att fastställa effektiviteten av rengöringsmetoden och hur den påverkar livslängen.

X-ray computed tomography is a technique that has been successfully utilized to characterize internal microstructure of asphalt mixtures. The city of Linköping (Sweden) developed an action plan to reduce noise; accordingly KTH and VTI developed a method to determine air void content in porous asphalt using x-ray computed tomography and an image processing software called ImageJ. The present study is a continuation of the previously mentioned work and focuses on the investigation of aggregate structure in porous asphalt by x-ray computed tomography. First the previously proposed method to estimate air void content was validated. Then, the assessment of aggregate structure including qualitative and quantitative analysis was completed. Qualitative evaluation was performed to determine the quality of slices in regard to establishing challenging areas, and the extent of beam hardening present in the X-ray images. This evaluation produced quality slices for each sample in Y-direction to work as a reference to establish general threshold ranges and image enhancement procedures, as well as identifying the interface between the top and bottom layer of the porous asphalt. The quantitative analysis consisted of analysing aggregate structures in the porous asphalt and developing a method to estimate the aggregate size distribution in porous asphalt layers. The gradation curves from the quantification of aggregate size distribution in all directions (X, Y, Z) were compared to the gradation curves from laboratory sieving tests previously performed on the drilled asphalt cores. To determine the accuracy of the method a perimeter analysis was performed to evaluate the suggested method to measure the aggregates. The results obtained indicate that to quantify the aggregates in porous asphalt, enhancement of the images is needed, as well as morphological operations to deal with beam hardening and overlapping stones due to unsuccessful separation of aggregates when thresholding. This further indicates that ImageJ Fiji is more suitable for complex cases, such as cases where aggregates and mastic are hard to distinguish from each other, rather than the original ImageJ software. This is due to the extended plugins available in ImageJ Fiji, where more options of for example filtering and enhancing of images are available. The results also suggest that the proposed method is a suitable method to determine the aggregate size distribution in porous asphalt pavements, as it allows to quantify the aggregate distribution and produces realistic results with slight inaccuracies due to the analysis being performed in 2D. Future development will be focused on automizing the determination of air void structure and aggregate size distribution, but also on the development of procedures to determine other relevant parameters such as mastic and binder content to establish a complete methodology to investigate the internal structure of a porous asphalt pavement, as well as 3D analysis to determine these parameters.

In this research study, a strategy was used for assigning stiffness values to various layers of the pavement system so that there are negligible tensile stresses in the subgrade and base layers. The stiffnesses of the aggregate base layers were assigned double the values of the corresponding subgrade materials. The layer thicknesses were designed to achieve surface deflection values within the acceptable limit. An innovative design procedure was developed for designing pavement sections covering various layer thicknesses, material and environmental variables. The designed sections were compared with the American Association of State Highway and Transportation Officials (AASHTO) procedure and the differences were critiqued. Porous asphalt layer was used as the surface course for all pavement sections. The calculations validated the general principle of pavement design, as the subgrade stiffness decreased the base thickness increased for the same surface course thickness and traffic. Structural design of 63 pavements sections was accomplished representing various temperature and materials including additives. Low Density Polyethylene, performance graded asphalt, different soils, aggregates, lime and cement were the component materials utilized in this research study. An explanation on the mechanics of the mixtures is given in the results and discussion section. / Civil Engineering

Permeable Friction Course (PFC) is a layer of porous asphalt pavement with a thickness of up to 50 millimeters overlain on a conventional impervious hot mix asphalt or Portland cement concrete roadway surface. PFC is used for its driver safety and improved stormwater quality benefits associated with its ability to drain rainfall runoff from the roadway surface. PFC has recently been approved as a stormwater best management practice in the State of Texas. The drainage properties of PFC are typically considered to be governed primarily by two hydraulic properties: porosity and hydraulic conductivity. Both of these hydraulic properties are expected to change over the life of the PFC layer due to clogging of the pore space by trapped sediment. Therefore, proper measurement of the hydraulic properties can be problematic. Laboratory and field tests are necessary for accurately determining the hydraulic conductivity of the PFC layer in order to ensure whether the driver safety and water quality benefits will persist in the future. During testing, PFC experiences a nonlinear flow relationship which can be modeled using the Forchheimer equation. Due to the two-dimensional flow patterns created during testing, the hydraulic conductivity cannot be directly measured. Therefore, numerical modeling of the two-dimensional nonlinear flow relationship is required to convert the measureable flow characteristics into the theoretical flow characteristics in order to properly determine the isotropic hydraulic conductivity. This numerical model utilizes a new scalar quantity, defined as the hydraulic conductivity ratio, to allow for proper modeling of nonlinear flow in two-dimensional cylindrical coordinates. PFC core specimens have been extracted from three different roadway locations around Austin, Texas for the past four years (2007 to 2010). Porosity values of the core specimens range from 12% to 23%, and the porosity data suggest a statistical decrease over time due to trapped sediment in the pore space. A series of constant head tests used in the laboratory and a falling head test used in the field are recommended for measurement of PFC hydraulic characteristics using a modified Forchheimer equation. Through numerical modeling, regressions equations are presented to estimate the hydraulic conductivity and nonlinear Forchheimer coefficient from the measureable hydraulic characteristics determined during experimental testing. Hydraulic conductivity values determined for laboratory core specimens range from 0.02 centimeters per second (cm/s) to nearly 3 cm/s. Field measurements of in-situ hydraulic conductivity vary over a range from 0.6 cm/s to 3.6 cm/s. The results of this research provide well-defined laboratory and field methods for measurement of the isotropic hydraulic conductivity of PFC experiencing two-dimensional nonlinear flow and characterized by the Forchheimer equation. This methodology utilizes a numerical model which presents a proper solution for nonlinear flow in two-dimensions. / text

För att permeabel asfalt skall vara ett bra sätt att ta hand om dagvatten i en stad med allt fler hårdgjorda ytor är det viktigt att den långsiktigt kan infiltrera dagvatten. Då det inte går att undvika att permeabel asfalt utsätts för små partiklar finns det en risk för att den skall sätta igen och förlora sin förmåga att infiltrera dagvatten. Som en skötselåtgärd för att förhindra att den sätter igen kan rengöring med högtryckstvätt och vakuumsugning göras. I detta examensarbete undersöktes det vilken effekt rengöring med högtryckstvätt och vakuumsugning har på permeabel asfalts infiltrationskapacitet. Vidare undersöktes även vilken typ av uppbyggnad av den permeabla asfalten som var mest lämplig för en effektiv infiltration. Litteraturstudie och intervjuer om permeabel asfalt samt infiltrationsförsök har utförts. För att uppbyggnaden av permeabel asfalt hydrologiskt sett skall fungera på ett bra sätt framkom det, i litteraturstudier och intervjuer, att det är viktigt att alla lager i uppbyggnaden verkligen är permeabla och att uppbyggnaden bör anpassas efter rådande förhållanden på anläggningsplatsen. Förhållanden som till exempel bör tas hänsyn till är underliggande jordart och närheten till grundvattenyta. I litteraturstudier och intervjuer framkom det att regelbunden skötsel av den permeabla asfalten är mycket viktig för dess långtidsfunktion att kunna infiltrera dagvatten. Infiltrationsförsöken skedde på två platser med permeabel asfalt i Uppsala; på en parkering vid ett köpcentrum i Gnista och på en lokalgata i Gränby backe. Infiltrationskapaciteten uppmättes innan och efter rengöring med högtryckstvätt och vakuumsugning på den permeabla asfalten. Vid Gnista kunde ingen infiltration uppmätas varken före eller efter rengöring. I Gränby backe ökade infiltrationskapaciteten från 0,47–0,71 mm/min till 1,24–12,23 mm/min efter rengöring. Denna infiltrationskapacitet visar på att den permeabla asfalten i Gränby backe kunde infiltrera dimensionerade regn med allt från 7 års återkomsttid till över 1000 års återkomsttid och med 10 minuters varaktighet. Det framkom i litteraturstudien att högtryckstvätt och vakuumsugning i olika studier har haft en positiv effekt på att upprätthålla och till viss del återskapa infiltrationskapaciteten hos permeabel asfalt. Vid infiltrationsförsöken i detta examensarbete påvisades även en positiv effekt, till viss del, av denna rengöringsmetod på infiltrationskapaciteten. Utifrån detta skulle rengöring med högtryckstvätt och vakuumsugning kunna rekommenderas som skötselmetod på permeabel asfalt.  Resultaten i Gnista skiljde sig från de i Gränby backe då det i Gnista varken före eller efter rengöring fanns någon infiltrationskapacitet. Det skiljer sig endast ett år i ålder mellan de båda försöksplatserna, de har skötts på liknande sätt sedan anläggning och litteratur visar på att rengöring med högtryckstvätt och vakuumsugning skall ha en effekt på infiltrationskapaciteten. Detta kan tyda på att bristen på infiltrationsförmåga i Gnista kan bero på något annat än igensättning av den permeabla asfalten. / It is important that permeable asphalt is able to infiltrate storm water in the long-term for it to be a viable alternative for handling storm water. Permeable asphalt will always, in some way, be exposed to fine particles and therefore there is a risk that clogging will occur and that the permeable asphalt will lose its ability to infiltrate storm water. As a mean of maintenance cleaning with high pressure washing and vacuum cleaning can be done to prevent clogging. In this master thesis the effect of high pressure washing and vacuum cleaning on the infiltration capacity of permeable asphalt was examined.  Also, the most suitable type of substructure for effective infiltration was examined. A literature study and interviews were conducted in combination with infiltration experiments on two locations with permeable asphalt in Uppsala. Literature studies and interviews state that for the substructure to be hydrologically well functioning it is important that every layer in the substructure really is permeable. The substructure should also be adapted to the conditions at the site where it is built. For example, conditions to take into consideration are soil type and highest level of groundwater. All through literature and interviews regular maintenance is said to be very important for the long-term functioning and infiltration of permeable asphalt. The infiltration experiments were conducted at a parking lot at a shopping center in Gnista and a small local street in Gränby backe. The infiltration capacity of the permeable asphalt was measured before and after maintenance with high pressure washing and vacuum suction. No infiltration capacity could be measured before or after maintenance at Gnista. In Gränby backe the infiltration capacity was 0,47-0,71 mm/min before maintenance and 1,24-12,23 mm/min after. According to this infiltration capacity the permeable asphalt in Gränby backe can infiltrate design rains with return periods of 7 years to over 1000 years and with a duration of 10 minutes. In research, high pressure washing, and vacuum suction were found to be able to maintain, and in some cases restore, infiltration capacity. In this master thesis’ infiltration experiments a positive effect on infiltration capacity by cleaning with high pressure washing and vacuum suction was partially found. According to this high pressure washing and vacuum suction can be recommended as a maintenance method on permeable pavement. The results from the two experiment sites stood apart from each other as Gnista had no infiltration capacity neither before nor after cleaning. In age, the two sites only differ by one year, and since they were built they have received similar maintenance and literature shows that high pressure washing and vacuums suction have an effect on infiltration capacity. This might indicate that the lack of infiltration capacity at Gnista might be due to something else than clogging.

Submitted by Viviane Lima da Cunha (viviane@biblioteca.ufpb.br) on 2017-07-18T12:00:27Z No. of bitstreams: 1 arquivototal.pdf: 3670112 bytes, checksum: d762a13cb07012ebb6bb3db0a6e3d4d6 (MD5) / Made available in DSpace on 2017-07-18T12:00:27Z (GMT). No. of bitstreams: 1 arquivototal.pdf: 3670112 bytes, checksum: d762a13cb07012ebb6bb3db0a6e3d4d6 (MD5) Previous issue date: 2016-09-30 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / The accumulated water on pavement surfaces is one of the factors responsible for the occurrence of traffic accidents, as it reduces the tire-pavement interface friction. The use of porous asphalt mixtures can increase road safety because it increases the adherence between a vehicle's tires and the pavement, especially in a wet highway, owing to its high drainage capacity. Accordingly, this research had the purpose of analyzing the use of polyethylene terephthalate (PET) waste as an alternative of additives to porous asphalt mixtures. The work method consisted of materials characterization, determination of the optimum binder content, production of three kinds of asphalt mixtures (conventional, with the addition of PET, and with polymer asphalt) and the performance of draindown tests, moisture susceptibility, resilient modulus, flow number, fatigue test, permeability to the asphalt mixtures, in their respective optimum binder contents. The PET was added to the mixtures by a dry process in the proportions of: 0; 0,33; 0,5; 0,75 e 1% regarding to the weight of the aggregates. The asphalt mixtures with polymer asphalt were taken as reference. Considering the mixtures design, additions of 0,75% PET up carried out the lowest optimum binder content. Besides that, the addition of PET contributed for a binder draindown inhibition and improved the mixtures performance regarding to moisture susceptibility. The PET additivated mixtures presented an increasing in the resilient modulus and a tendency of a longer fatigue life at low tension levels and high number of load applications. However, the mixtures are susceptible to rutting, even though presenting stiffening. Concerning to permeability, the execution of only one test became inconclusive. Although, it was verified that PET can present viability of being used as additive porous asphalt mixtures. / A água acumulada sobre a superfície do pavimento é uma das responsáveis pela ocorrência de acidentes em rodovias, por reduzir o atrito na interface pneu-pavimento. A adoção de misturas asfálticas porosas pode aumentar a segurança viária, pois seu uso favorece a aderência entre os pneus dos veículos e o pavimento, especialmente em pista molhada, tendo em vista a sua alta capacidade de drenagem. Diante disso, esta pesquisa objetivou analisar o uso de resíduos de politereftalato de etileno (PET) como aditivo para misturas asfálticas porosas. O método de trabalho consistiu na realização de ensaios de caracterização dos materiais utilizados, determinação do teor de projeto de ligante asfáltico, confecção de três tipos de misturas asfálticas (convencional, com adição de PET e com asfalto polímero) e realização de ensaios de escorrimento, dano por umidade induzida, módulo de resiliência, deformação permanente, vida de fadiga e permeabilidade para as misturas asfálticas, em seus respectivos teores de projeto de ligante asfáltico. A adição de PET nas misturas foi realizada via processo seco nas proporções 0,00; 0,33; 0,50; 0,75 e 1,00% em relação ao peso dos agregados. As misturas asfálticas com asfalto modificado por polímero foram tomadas como referência, tendo em vista a preferência do uso desse tipo de ligante em misturas porosas. Em termos de dosagem, adições de PET em até 0,75% resultaram na redução do teor de projeto de ligante asfáltico. Além disso, o PET contribuiu para a inibição do escorrimento do ligante e favoreceu o desempenho das misturas em relação ao dano por umidade induzida. As misturas aditivadas com PET apresentaram um aumento no módulo de resiliência e uma tendência de maior vida de fadiga para baixos níveis de tensões e elevadas repetições de carga. Porém, mostraram-se suscetíveis à deformação permanente, mesmo tendo apresentado um maior enrijecimento. Quanto a permeabilidade, é necessário a realização de mais ensaios de modo a garantir uma melhor confiabilidade nos resultados. De todo modo, pôde-se verificar que o PET pode apresentar viabilidade de ser utilizado como aditivos em misturas asfálticas porosas.

Les opérations de maintenance des routes en conditions hivernales sur réseaux routiers constituent un enjeu important pour maintenir l’offre de mobilité en situation dégradée. Elles génèrent des coûts d’exploitation directs et indirects élevés, liés en particulier à l’utilisation intensive de fondants routiers. Par ailleurs, leur impact environnemental doit être pris en considération. Nous étudions ici une structure de chaussée non soumise à ce type d’astreinte, grâce à la présence d’une couche de liaison drainante dans laquelle circule un fluide chaud, permettant ainsi d’éviter le dépôt de neige ou la formation de glace en surface. Dans le cadre d’une démarche en faveur de l’emploi d’énergie renouvelable, un tel dispositif pourrait permettre de récupérer l’énergie thermique disponible en surface de chaussée en période chaude, de l’acheminer vers un lieu de stockage (ex : géothermie) et de l’utiliser en période froide. Nous étudions ici la fonction d’échangeur de chaleur entre le fluide et la chaussée, la fonction de stockage externe à la chaussée n’étant pas abordée hormis dans la revue bibliographique. La structure de chaussée considérée comporte trois couches d’enrobés. La couche de roulement et la couche de base sont constituées de matériaux classiquement utilisés dans les chaussées, à base de liants hydrocarbonés. Le matériau de la couche de liaison possède une porosité supérieure à 20%. La structure de chaussée est supposée avoir un dévers de l’ordre de 2%. Une chaussée expérimentale instrumentée a été mise en oeuvre pour recueillir des grandeurs thermo-physiques de la chaussée. Un modèle thermo-hydrique 2D est d2veloppé numériquement pour calculer la distribution de température dans le corps de chaussée lorsque l’on injecte un fluide à température d’entrée donnée, en haut de dévers. Les paramètres du modèle sont identifiés à partir des données expérimentales recueillies sous diverses sollicitations climatiques. On analyse dans un premier temps la sensibilité de la distribution de température en surface de chaussée aux différents paramètres du modèle (conductivité hydraulique, dévers, conductivités thermiques, chaleurs massiques), afin d’optimiser les procédures nécessaires au contrôle sous contraintes de températures positives en tout point. Dans une deuxième partie, des données expérimentales recueillies durant une période estivale d’un mois ont servi à valider le modèle thermique 1D. Une maquette de laboratoire a également permis d’identifier des paramètres en milieu saturé et non saturé. La dernière partie de thèse est consacrée au calcul des quantités énergétiques récupérables pendant la période estivale à l’aide des données de la réglEmentation thermique RT2012. Elles sont comparées aux quantités énergétiques de chauffage nécessaires pendant la période hivernale en s’appuyant sur des données de la RT2012 et des données de la Direction Interdépartementale des Routes Massif (DIR MC) ; l’objectif final étant de déterminer les performances énergétiques du système. / Winter maintenance operations for road networks are an important issue for maintaining the mobility in degraded situations, but generate high direct and indirect exploitation costs, particularly related to the intensive use of road de-icing and environmental impact. We study a road structure free of this penalty, thanks to a bonding drainage asphalt layer, circulated by a hot fluid, to prevent the deposition of snow or ice formation on the road surface. As part of an integrated vision of promoting the use of renewable energy, such device could be used to recuperate the thermal energy available in the road surface during the hot period, to transport it to a storage location (e.g. geothermal) and use it during cold period. We study here the heat exchanger function between the fluid and the road, the external storage function to the road being not addressed. The considered pavement structure has three asphalt layers.The bearing layer and the base layer are formed of conventional materials with hydrocarbon-based binders. The material of the bonding layer has a porosity of 20% and based on the use of a binder resistant to a prolonged circulation of the coolant. The road structure is assumed to have a slope of about 2 to 3%. An instrumented experimental road is implemented to collect data on the thermo-hydraulic response of the pavement structure. A thermo-hydraulic 2D model is designed to simulate the temperature field in the road structure when the fluid is injected at the upslope side of the road with a target temperature. This model is calibrated from experimental data collected on the experimental road subjected to meteorological solicitations. Initially, the sensibility of the distribution of the surface temperature of the road toward various model parameters (hydraulic conductivity, transversal slope, thermal conductivities, heat capacities) is analysed, in order to study the optimization of control procedures allowing to keep positive the road surface temperature at any point (e.g. determination of the minimum fluid injection temperature, under given meteorological data). In a second time, pavement thermal parameters is identified using control optimal method in order to validated unidimensionnel thermal model applied on July experimental data. In third time, hydraulic model is validated experimentaly using a laboratory mockup in saturated and unsaturated conditions. In a fourth time, thermo-hydraulic bidimensionnal model is validated numerically using mesured data of experimental pavement. Finally, harvest energy in summer period using thermal reglementation RT2012 data and heating energy in winter period using RT2012 and Massif Interdepartmental Road Direction (DIR MC) are calculated in order to evaluate system performance.