The inverted T-beam system provides an accelerated bridge construction alternative. The system consists of adjacent precast inverted T-beams finished with a cast-in-place concrete topping. The system offers enhanced performance against reflective cracking and reduces the likelihood of cracking due to time dependent effects. Differential shrinkage is believed to be one of the causes of deck cracking in inverted T-beam systems. The objective of this study was to develop mix designs that exhibit lower shrinkage and higher creep compared to typical deck mixtures, recommend a prescriptive mix design and a performance criterion to VDOT that can be further investigated and used in the inverted T-beam system to combat effects of differential shrinkage. Ten different mix designs using different strategies to reduce shrinkage were tested for their compressive strength, splitting tensile strength, modulus of elasticity and unrestrained shrinkage. The four best performing mixes were selected for further study of their time dependent properties. The test data was compared against the data from various prediction models to determine the model that closely predicts the measured data. It was observed that ACI 209.2R-08 model best predicted the time dependent properties for the four mixes tested in this project. Tensile stresses in the composite cross-section of deck and girder, created due to difference in shrinkage and creep are quantified using an age adjusted effective modulus method. In this analysis, it was observed that mixes with normal weight coarse aggregate (NWCA) developed smaller stresses compared to those of mixes with lightweight coarse aggregate (LWCA). Mixes with fly ash as supplementary cementitious material (SCM) developed smaller stresses at the bottom of deck when compared to mixes with slag as the SCM. / Master of Science

Esta dissertação apresenta os resultados e análises do monitoramento de um recapeamento asfáltico executado com camada intermediária de geotêxtil. A pista experimental vem sendo solicitada desde 1999, em uma pesquisa que se encontra na sua terceira fase, atingindo 1.103.885 ciclos de carga de 100 kN aplicados. Nessa última fase de estudo o tráfego foi aplicado entre Setembro de 2008 e Fevereiro de 2009, totalizando 121.685 ciclos de carga de eixo de 100 kN. A pista foi dividida em três regiões, sendo empregado em duas delas geotêxteis impregnados com asfalto. Durante o período de estudo foram monitorados parâmetros de resposta estrutural, através de medidas de deflexões e bacias defletométricas, parâmetros de comportamento, através de medidas de deformações permanentes e mapeamento de trincas, e por fim parâmetros ambientais, através das medidas de temperatura do ar e precipitações. Foram também aplicados modelos de previsão de desempenho para o caso de reflexões de trincas. O monitoramento do trincamento na pista mostrou que as regiões com geotêxtil tiveram melhor desempenho quando comparadas à região sem camada intermediária. O comprimento de trincas no final do estudo foi de 764 cm na região sem camada intermediária, 328 cm na região com geotêxtil G150 e 554 cm na região com geotêxtil G150 TF. Foram extraídos corpos de prova da pista, sobre algumas trincas, de modo a se visualizar o modo de desenvolvimento do trincamento, e também para buscar se identificar onde ocorreu trincamento por reflexão. Não foi possível extrair CPs de todas as trincas face a proximidade das mesmas e das dimensões da sonda rotativa, porém do material retirado observou-se ocorrência de trincamento por reflexão, trincamento por fadiga e também trincamento conhecido como top-down cracking (TDC). Os resultados evidenciam que a inclusão de geotêxteis como camada de absorção de tensões aumenta significativamente a vida de recapeamentos asfálticos executados sobre pavimentos trincados. / This dissertation presents the results of the monitoring and analysis of an overlay executed with intermediate geotextile layer. The experimental track has been requested since 1999, in a research that is in its third phase, reaching 1.103.885 cycles of 100 kN axle load applied. In this last phase of the study, the traffic was applied between September 2008 and February 2009, totaling 121.685 cycles of 100 kN axle load. The track is divided into three regions, two of them uses geotextiles impregnated with asphalt. During the study period were monitored parameters of structural response, by means of deflections and basins, parameters of behavior, by means of permanent deformation and mapping of cracks, and finally environmental parameters, through the measures of air temperature and rainfall. Models were also applied to predict the performance of the overlay. The monitoring of cracking showed that regions with geotextile had improved performance when compared to the region without intermediate layer. The length of cracks at the end of the study was 764 cm in the region without intermediate layer, 328 cm in the region with geotextile G150 and 554 cm in the region with geotextile G150 TF. Samples were extracted from the track to see how the cracking was developed and also to identify where there was reflective cracking. On the material removed was observed occurrence of reflective cracking, fatigue cracking and also top-down cracking (TDC). The results show that geotextiles increases the life of concrete asphaltic overlays.

Esta dissertação apresenta os resultados e análises do monitoramento de um recapeamento asfáltico executado com camada intermediária de geotêxtil. A pista experimental vem sendo solicitada desde 1999, em uma pesquisa que se encontra na sua terceira fase, atingindo 1.103.885 ciclos de carga de 100 kN aplicados. Nessa última fase de estudo o tráfego foi aplicado entre Setembro de 2008 e Fevereiro de 2009, totalizando 121.685 ciclos de carga de eixo de 100 kN. A pista foi dividida em três regiões, sendo empregado em duas delas geotêxteis impregnados com asfalto. Durante o período de estudo foram monitorados parâmetros de resposta estrutural, através de medidas de deflexões e bacias defletométricas, parâmetros de comportamento, através de medidas de deformações permanentes e mapeamento de trincas, e por fim parâmetros ambientais, através das medidas de temperatura do ar e precipitações. Foram também aplicados modelos de previsão de desempenho para o caso de reflexões de trincas. O monitoramento do trincamento na pista mostrou que as regiões com geotêxtil tiveram melhor desempenho quando comparadas à região sem camada intermediária. O comprimento de trincas no final do estudo foi de 764 cm na região sem camada intermediária, 328 cm na região com geotêxtil G150 e 554 cm na região com geotêxtil G150 TF. Foram extraídos corpos de prova da pista, sobre algumas trincas, de modo a se visualizar o modo de desenvolvimento do trincamento, e também para buscar se identificar onde ocorreu trincamento por reflexão. Não foi possível extrair CPs de todas as trincas face a proximidade das mesmas e das dimensões da sonda rotativa, porém do material retirado observou-se ocorrência de trincamento por reflexão, trincamento por fadiga e também trincamento conhecido como top-down cracking (TDC). Os resultados evidenciam que a inclusão de geotêxteis como camada de absorção de tensões aumenta significativamente a vida de recapeamentos asfálticos executados sobre pavimentos trincados. / This dissertation presents the results of the monitoring and analysis of an overlay executed with intermediate geotextile layer. The experimental track has been requested since 1999, in a research that is in its third phase, reaching 1.103.885 cycles of 100 kN axle load applied. In this last phase of the study, the traffic was applied between September 2008 and February 2009, totaling 121.685 cycles of 100 kN axle load. The track is divided into three regions, two of them uses geotextiles impregnated with asphalt. During the study period were monitored parameters of structural response, by means of deflections and basins, parameters of behavior, by means of permanent deformation and mapping of cracks, and finally environmental parameters, through the measures of air temperature and rainfall. Models were also applied to predict the performance of the overlay. The monitoring of cracking showed that regions with geotextile had improved performance when compared to the region without intermediate layer. The length of cracks at the end of the study was 764 cm in the region without intermediate layer, 328 cm in the region with geotextile G150 and 554 cm in the region with geotextile G150 TF. Samples were extracted from the track to see how the cracking was developed and also to identify where there was reflective cracking. On the material removed was observed occurrence of reflective cracking, fatigue cracking and also top-down cracking (TDC). The results show that geotextiles increases the life of concrete asphaltic overlays.

Esta dissertação apresenta os resultados e análises do monitoramento de um recapeamento asfáltico executado com camada intermediária de geotêxtil. A pista experimental vem sendo solicitada desde 1999, em uma pesquisa que se encontra na sua terceira fase, atingindo 1.103.885 ciclos de carga de 100 kN aplicados. Nessa última fase de estudo o tráfego foi aplicado entre Setembro de 2008 e Fevereiro de 2009, totalizando 121.685 ciclos de carga de eixo de 100 kN. A pista foi dividida em três regiões, sendo empregado em duas delas geotêxteis impregnados com asfalto. Durante o período de estudo foram monitorados parâmetros de resposta estrutural, através de medidas de deflexões e bacias defletométricas, parâmetros de comportamento, através de medidas de deformações permanentes e mapeamento de trincas, e por fim parâmetros ambientais, através das medidas de temperatura do ar e precipitações. Foram também aplicados modelos de previsão de desempenho para o caso de reflexões de trincas. O monitoramento do trincamento na pista mostrou que as regiões com geotêxtil tiveram melhor desempenho quando comparadas à região sem camada intermediária. O comprimento de trincas no final do estudo foi de 764 cm na região sem camada intermediária, 328 cm na região com geotêxtil G150 e 554 cm na região com geotêxtil G150 TF. Foram extraídos corpos de prova da pista, sobre algumas trincas, de modo a se visualizar o modo de desenvolvimento do trincamento, e também para buscar se identificar onde ocorreu trincamento por reflexão. Não foi possível extrair CPs de todas as trincas face a proximidade das mesmas e das dimensões da sonda rotativa, porém do material retirado observou-se ocorrência de trincamento por reflexão, trincamento por fadiga e também trincamento conhecido como top-down cracking (TDC). Os resultados evidenciam que a inclusão de geotêxteis como camada de absorção de tensões aumenta significativamente a vida de recapeamentos asfálticos executados sobre pavimentos trincados. / This dissertation presents the results of the monitoring and analysis of an overlay executed with intermediate geotextile layer. The experimental track has been requested since 1999, in a research that is in its third phase, reaching 1.103.885 cycles of 100 kN axle load applied. In this last phase of the study, the traffic was applied between September 2008 and February 2009, totaling 121.685 cycles of 100 kN axle load. The track is divided into three regions, two of them uses geotextiles impregnated with asphalt. During the study period were monitored parameters of structural response, by means of deflections and basins, parameters of behavior, by means of permanent deformation and mapping of cracks, and finally environmental parameters, through the measures of air temperature and rainfall. Models were also applied to predict the performance of the overlay. The monitoring of cracking showed that regions with geotextile had improved performance when compared to the region without intermediate layer. The length of cracks at the end of the study was 764 cm in the region without intermediate layer, 328 cm in the region with geotextile G150 and 554 cm in the region with geotextile G150 TF. Samples were extracted from the track to see how the cracking was developed and also to identify where there was reflective cracking. On the material removed was observed occurrence of reflective cracking, fatigue cracking and also top-down cracking (TDC). The results show that geotextiles increases the life of concrete asphaltic overlays.

The inverted T-beam bridge system is a bridge construction technique that follows accelerated bridge construction processes. The system was discovered in France and first adopted in the U.S. by the Minnesota Department of Transportation. In 2012 the system was modified and adopted by Virginia, with research being carried out at Virginia Polytechnic Institute and State University (Virginia Tech). The research focused on multiple items involving the system, but the most relevant one is that regarding the transverse bending behavior of the system for different geometries, and joint types between adjacent precast beam members. The study found that using a joint system without any mechanical connection between adjacent beams was most efficient, and gave adequate performance under monotonic loading. The study recommended cyclic load testing be carried out on this joint type, as well as a welded joint similar to those found in decked bulb-T systems. The research contained herein presents the setup and results of this testing. From the work it was found that the no-connection joint behaves adequately under cyclic loading at service loads, however surface roughening between precast and cast-in-place concrete must be adequate. The welded connection behaves well, granted the surfaces to be welded are properly prepared. From these results it is recommended to evaluate different surface roughening techniques, and repeat the cyclic testing using the best. The surface roughening technique chosen should be used to provide guidance on this aspect of construction with inverted T-beams. / Master of Science

Hot Mix Asphalt (HMA) overlay is a major rehabilitation treatment for the existing deteriorated pavements (both flexible and rigid pavements). Reflective cracking (RC) is the most common distress type appearing in the HMA overlays which structurally and functionally degrades the whole pavement structure, especially under high traffic volume. Although many studies have been conducted to identify the best performing RC mitigation technique, the level of success varies from premature failure to good performance in the field. In Florida, Asphalt Rubber Membrane Interlayers (ARMIs) have been used as a RC mitigation technique but its field performance has not been successful. In this study, the best performing means to mitigate RC in the overlays considering Florida’s special conditions have been investigated. The research methodology includes (1) extensive literature reviews regarding the RC mechanism and introduced mitigation options, (2) nationwide survey for understanding the current practice of RC management in the U.S., and (3) the development of decision trees for the selection of the best performing RC mitigation method. Extensive literature reviews have been conducted to identify current available RC mitigation techniques and the advantages and disadvantages of each technique were compared. Lesson learned from the collected case studies were used as input for the selection of the best performing RC mitigation techniques for Florida’s roads. The key input parameters in selecting optimum mitigation techniques are: 1) overlay characterization, 2) existing pavement condition, 3) base and subgrade structural condition, 4) environmental condition and 5) traffic level. In addition, to understand the current iv practices how reflective cracking is managed in each state, a nationwide survey was conducted by distributing the survey questionnaire (with the emphasis on flexible pavement) to all other highway agencies. Based on the responses, the most successful method of treatment is to increase the thickness of HMA overlay. Crack arresting layer is considered to be in the second place among its users. Lack of cost analysis and low rate of successful practices raise the necessity of conducting more research on this subject. Considering Florida’s special conditions (climate, materials, distress type, and geological conditions) and the RC mechanism, two RC mitigation techniques have been proposed: 1) overlay reinforcement (i.e. geosynthetic reinforcement) for the existing flexible pavements and 2) Stress Absorbing Membrane Interlayer (SAMI) for the existing rigid pavements. As the final products of this study, decision trees to select an optimum RC mitigation technique for both flexible and rigid pavements were developed. The decision trees can provide a detailed guideline to pavement engineer how to consider the affecting parameters in the selection of RC mitigation technique.

This study quantifies the benefits of two interlayer systems (steel reinforcing netting and a newly-designed geocomposite membrane) in different pavement applications. Steel reinforcing netting and geocomposite membrane have been installed at the Virginia Smart Road in four different sections. Ground penetrating radar (GPR) surveys and time domain reflectometer (TDR) validated the effectiveness of the geocomposite membrane in preventing water from infiltrating to the underneath layers. In pavement rehabilitation applications, based on finite element (FE) analysis, it was found that the geocomposite membrane would create a protective compressive field around the crack tip and separate the criticality of the stress field in the cracked area from the bottom of the overlay. However, if the crack passes through the interlayer, a faster propagation rate than in a typical pavement is expected. These results emphasize the importance of proper field installation. As to steel reinforcing netting, this study found that this interlayer system would be effective in new pavement systems in both the crack initiation and propagation phases when the cracks start at the bottom of the HMA layers. For the considered pavement structures, steel reinforcing netting was found effective to delay the initiation of the cracks. This delay depends on the stiffness of the hot-mix asphalt (HMA) layers, the reinforcing pattern, and the direction of the strain at the bottom of the HMA layers. After initiation of the crack, steel reinforcement contribute by delaying the rate of crack propagation to the pavement surface. In pavement rehabilitations, however, the crack is already well established in the existing pavement, and steel reinforcement contribution is expected from the time of installation. In this case, steel reinforcement will delay the initiation of the crack in the overlay, and reduce the rate of crack propagation afterwards. Two models, to predict the overlay service life against reflective cracking from existing HMA layers, were developed. / Ph. D.

Les premiers recyclages d’enrobés bitumineux à 50% sont apparus sur autoroutes françaises dans les années 1990 – une charte de l’innovation spécifique aux enrobés drainants intégrant 50% de recyclés fut notamment délivrée début 2002 (SETRA - CSTR, 2002). Un nouveau cycle de recyclage à fort taux de ces tout premiers enrobés a été entrepris ici ou là, depuis quelques années. Le multirecyclage des agrégats d’en-robé (AE) dans les mélanges d’enrobés bitumineux est de ce fait une problématique actuelle, qui va se gé-néraliser dans l’avenir, lorsqu’il faudra recycler des enrobés contenant déjà des enrobés recyclés plusieurs fois. Le projet visant à étudier le MUlti-Recyclage des Enrobés tièdes a été labellisé projet national (PN MURE). Une part du projet MURE regroupant des aspects scientifiques particuliers a été regroupé au sein du projet « IMPROVMURE », financé par l’Agence Nationale de la Recherche, et qui a débuté en mars 2014. L’objectif du projet « Innovation en Matériaux et PROcédés pour la Valorisation du MUlti-Recyclage des En-robés » (IMPROVMURE) est de fournir des éléments de réponse raisonnés et quantifiés, en laboratoire et sur sites pilotes, afin de faire du multi-recyclage des enrobés fabriqués à chaud et tiède. Les questions sociétales, environnementales, règlementaires ou normatives sont également prises en compte dans le cadre du projet. Un des objectifs du projet IMPROVMURE est l’étude des propriétés thermomécaniques des enrobés. C’est dans le cadre de cet objectif que s’inscrit le travail de thèse présenté dans ce document. Cette thèse est le fruit d’une collaboration entre le Laboratoire Génie Civil et Bâtiment de l’ENTPE (LGCB)/Laboratoire de Tribologie et Dynamique des Systèmes (LTDS) et l’entreprise EIFFAGE Infrastructures. 15 types d’enrobés ont été testés pour l’étude des propriétés thermomécaniques des enrobés multi-recyclés. Les enrobés diffèrent par leur condition de fabrication (Laboratoire ou chantier), leur procédé de fabrication (chaud ou tiède mousse), le taux d’agrégat d’enrobé introduit (0%, 40%, 70% ou100%) et le nombre de cycles de recyclage (un, deux ou trois). Trois caractéristiques ont été communes à tous les types d’enrobés fabriqués, sauf pour l’enrobé contenant 100% d’agrégats d’enrobé. La première est la même courbe granulométrique des granulats, la troisième est la teneur en liant de 5.4% en masse et la troisième est le type d’enrobé « Béton Bitumineux Semi-Grenu » (BBSG) de type 03 selon la norme EN 13108-1. Trois domaines du comportement des enrobés bitumineux ont été étudies : Viscoélasticité linéaire (VEL), couplage thermomécanique à basse température et fissuration à froid. Pour le domaine de comportement VEL, les enrobés bitumineux ont été étudiés à l’aide des essais de module complexe en traction-compression réalisés sur une large gamme de températures et de fréquences sur éprouvette cylindrique à l’ENTPE. Les résultats sont modélisés à l’aide du modèle analogique 2S2P1D qui a été développé au laboratoire LGCB de l’ENTPE. Des essais de propagation d’ondes ont aussi été réalisés. La méthode de détermination du temps de vol des ondes « P » et des ondes « S » et la méthode Impact Résonance sont utilisées. Ces essais utilisent des méthodes non destructives et faciles à réaliser. On peut ainsi calculer les valeurs de modules et de coefficients de Poisson des matériaux. Puis, le couplage thermomécanique à basse température est caractérisé à l’aide de l’essai de retrait thermique empêché (TSRST), qui utilise le même dispositif que l’essai de module complexe mais les éprouvettes utilisées sont de géométrie différente. Finalement des essais de propagation de fissure ont été réalisés avec des sollicitations monotones. La propagation de la fissure suivie utilisant la méthode de corrélation des images. Des estimations de la hauteur de fissure ont été faites sur la basse de la méthode DRCL développée à l’ENTPE. / Reuse of Reclaimed Asphalt Pavement (RAP) is considered as one of the main solutions to cope with the objectives of worldwide sustainable development. In this way, the reuse of RAP in bituminous mixtures has been matter of study in previous papers (Chen et al., 2009; Kaur et al., 2013; Mogawer et al., 2012; Ru-bio et al., 2012; Sias Daniel et al., 2013; Valdés et al., 2011) and had concluded be economically profitable as well as had demonstrated the durability of the tested materials. Nowadays, new topics overcome dealing with how increase the RAP content and how many times RAP could be recycled. In France, a collaborative research and development project called “Multi-recycling of warm foam bitu-minous mixtures” (MURE) have brought together all the stakeholders involved in road construction. The pro-gram has run since March 2014. The scientific part of MURE project is IMPROVMURE project (Innovation for Materials and Processes for Improving the Multi-Recycling of Mixes). The overall budget of the project were €4.7M, €2.3M of which been provided by the ANR (National Re-search Agency) in the framework of the IMPROVMURE project, which has gotten under way in March 2014 and its main goal of characterizing the remobilization of the binder from recycled materials was the evalua-tion of the durability of mixes with the addition of binder. Thus, one objective of this project is to determine the thermomechanical properties of multi-recycled bi-tuminous mixtures, so in the context of this goal the current study was made. Likewise this investigation was a collaboration between the Tribology and System Dynamics Laboratory (LTDS) of the University of Lyon/ENTPE (“Ecole Nationale des Travaux Publics de l’Etat” ) and the French company EIFFAGE Infra-structures. For this study 15 types of bituminous mixtures were tested, the bituminous mixtures were produced in the laboratory and construction site, also two different techniques were studied for mixtures elaboration: hot and warm using foamed bitumen in both cases, the RAP content on these were 0%, 40%, 70% and even close to 100% produced after several recycling operations (up to 3 cycles). All bituminous mixtures have 3 invariants: the first is the same aggregate grading curves (except the bituminous mixture with 100% of RAP). The second one is the total binder content (5.4% in total weight). The last is classified as BBSG-03 0/10 bitu- 15 minous mixture, as is specified in the European standards for classification of bituminous mixtures (NF EN 13108-1 - 2007). Three domains of behaviour were studied: Linear Viscoelastic behaviour (LVE), cracking behaviour at low temperature and the fracture behaviour at low temperature. The LVE was studied considering complex modulus tests on bituminous mixtures and were performed in tension/compression on cylindrical samples, thus LVE behaviour was then modelled with 2S2P1D rheological model, developed at Uni. of Lyon / ENTPE, for the other hand cracking behaviour at low temperature was studied considering Thermal Stress Restrained Specimen Tests (TSRST), and finally fracture behaviour at low temperature was studied with the crack propagation tests as a monotonic loading.