A Rolling Dynamic Deflectometer (RDD) is a nondestructive testing device for determining continuous deflection profiles of pavements. Theses deflection profiles can be used more effectively when combined with other data such as pavement thickness, variability in moisture and other subsurface conditions, void detection and pavement right-of-way conditions. Therefore, a new, multi-function pavement testing device has been developed by a joint effort between the Texas Department of Transportation (TxDOT), the Center for Transportation Research (CTR) at the University of Texas at Austin (UT) and the Texas A&M Transportation Institute (TTI) at Texas A&M University. This new device is called the Total Pavement Acceptance Device (TPAD). The objective of TPAD testing is to nondestructively and nonintrusively investigate the structural adequacy of the total pavement system. The multiple functions of the TPAD presently include the following measurement capabilities: (1) rolling dynamic deflectometer (RDD), (2) ground penetrating radar (GPR), (3) global positioning (GPS), (4) pavement surface temperature, (5) digital video imaging of pavement and right-of-way conditions and (6) longitudinal survey offsets from known points through distance measurement (DMI). The TPAD is currently designed to perform continuous measurements at speeds around 2 to 3 mph. The effort in this dissertation is directed at: (1) developing the fourth-generation rolling sensors for faster testing speeds with the TPAD, (2) developing the Jointed Concrete Pavement (JCP) testbed with known and well-documented conditions (3) developing and evaluating the TPAD mobile platform, (4) evaluating the performance of the fourth-generation rolling sensors and refining a field calibration procedure and (5) studying the influence of the longitudinal and transverse joints in Jointed Concrete Pavement on TPAD deflection profile measurements. The first part involved the study of previous research and preliminary testing using the second-generation rolling sensor. Key benefits of the fourth-generation rolling sensor are: (1) reduced rolling noise during the testing, (2) higher signal-to-noise ratio (SNR), and (3) better tracking of the sensor. The second part of this work involved the development of the JCP testbed at the Texas Department of Transportation (TxDOT), Flight Services Facility (FSF) adjacent to the Austin-Bergstrom International Airport (ABIA). The JCP testbed was developed to establish a pavement facility with known and well-documented conditions for use in future research dealing with rigid pavement testing. The third part of this work involved the acceptance testing of the TPAD mobile platform for the RDD deflection measurements. The mobile platform was the one of the key components to develop the new moving pavement testing device. The TPAD mobile platform was developed by modifying a small, off-road vibroseies built by Industrial Vehicle International, Inc. (IVI). Acceptance testing of each of the following components was performed: (1) automated speed control, (2) static loading system and (3) dynamic loading system. The fourth part of this work involved the TPAD deflection measurements at the testbed at the TxDOT FSF. The deflection profiles using the fourth-generation rolling sensors and TPAD were performed at the established testbed. During the performance evaluation testing, the new sensor positioning, towing and raising/lowering system was developed and installed in the TPAD. The fifth part of this study involved the deflection measurement using the TPAD-RDD system on the jointed concrete pavement. This study includes the repeatability of the TPAD deflection measurements, the influence of the proximity to the longitudinal and transverse joints in JCP on TPAD deflection measurements, deflection measurements under different pavement surface temperature, the characteristic of the TPAD-RDD deflections and the comparison between the Falling Weight Deflectometer and TPAD deflection measurement testing. / text

Motivado pela alteração do sistema construtivo de pavimentos de concreto de cimento Portland, na qual foi abolida a utilização da manta plástica entre placas e bases cimentadas, com conseqüente emprego de imprimação da base com emulsão asfáltica, este trabalho buscou responder algumas indagações surgidas durante este processo. Em laboratório, através de uma metodologia de ensaio especialmente adaptada para o estudo da resistência ao cisalhamento entre concreto de cimento Portland (CCP) e concreto compactado com rolo (CCR), inferiu-se, para diferentes tratamentos de interface, elevados níveis de resistência ao cisalhamento em interfaces sem emulsão asfáltica que potencializam o emprego de estruturas monolíticas de pavimentos. Quanto àquelas que continham material asfáltico, foram obtidos resultados muito inferiores aos anteriores, com caracterização de ruptura dúctil, por efeito de fluência do material betuminoso. Duas pistas experimentais instrumentadas, uma em whitetopping ultradelgado e outra em pavimento simples de concreto executado segundo a nova prática construtiva, capazes de mensurar as deformações específicas do CCP durante a execução de provas de carga dinâmica, associadas às modelagens por elementos finitos (MEF), realizadas com auxílio do programa ISLAB2000, propiciaram importantes inferências sobre o comportamento mecânico destes dois tipos de pavimentos de concreto. Verificou-se o trabalho mecânico composto (monolítico) das estruturas de whitetopping ultradelgado, com boas correlações entre as tensões medidas e numericamente calculadas; e entre os rebaixamentos da linha neutra (LN) determinados analítica, numérica e experimentalmente. No tocante ao pavimento simples de concreto sobreposto à base cimentada imprimada, apesar das ótimas correlações entre tensões medidas e determinadas numericamente, não se pode obter conclusões definitivas a despeito do trabalho mecânico desta estrutura, apesar da existência de indícios de comportamento não-monolítico. / This thesis intended to answer some inquiries, which arose during the alteration of the concrete pavement constructive process. This process substituted the plastic blanket by the asphalt emulsion, between the concrete slabs and the cemented bases. A laboratorial test methodology, specially adapted for the study of shear strength between the Portland cement concrete and the rolled concrete, inferred, for different types of interlayer treatments, high levels of shear strength, at the interfaces without asphalt emulsion. These shear strength levels enable the monolithic behavior of the pavement structure. When the asphalt emulsion was presented at the interlayer, the shear strength was much smaller than the former, with ductile rupture due to creep of the bituminous material. Two instrumented road tests, the first section in ultra-thin whitetopping pavement and de second one, in jointed plain concrete pavement (built according to new constructive process), and the finite element analyses led to important conclusions about the mechanical behavior of these pavement structures. This was possible because the strain-gages measured the specific concrete deformations during the dynamic load tests. The monolithic behavior of the ultra-thin whitetopping pavement was verified. There were good correlations between the measured stresses and theoretical stresses, which were calculated by the finite element method; and between the neutral axle displacements, estimated by analytical, numerical and experimental methods. With regard to the jointed plain concrete pavement, which was built over the cemented base (covered by the asphalt emulsion), great correlations between measured and simulated stresses were found, as well as it was found for ultra-thin whitetopping. However, it was not possible to conclude, definitively, concerning the mechanical behavior of this pavement structure, although there are clues that ndicated a non-monolithic behavior, that is, concrete slabs are unbounded up with the cemented base.

O gerenciamento de uma malha rodoviária engloba avaliações constantes das condições estruturais e, principalmente, funcionais. Assim sendo, uma forma de coleta automatizada, realizada em velocidades de tráfego, em que a influência humana possa ser desconsiderada, está em desenvolvimento na engenharia rodoviária brasileira, assim como é visto internacionalmente. O presente trabalho tem como objetivo a contribuição para o processo de avaliação funcional de pavimentos através do estudo sobre a aplicabilidade do processo de inventário funcional de pavimentos rígidos com o emprego do equipamento Pavement Scanner. Para tanto, após a revisão bibliográfica sobre a sistemática de inventário de pavimentos rígidos e também sobre o equipamento Pavement Scanner, seções testes foram definidas e avaliadas de acordo com o método tradicional de levantamento da superfície do pavimento (ICP - DNIT 062/PRO, DNIT 060/PRO), o método volumétrico tradicional de mancha de areia para avaliação de macrotextura (ASTM E 965/96), através de imageamento com análise de imagens obtidas no trecho e sob a utilização do equipamento Pavement Scanner. Com os resultados foi realizada uma análise estatística destas técnicas utilizadas, demonstrando a viabilidade de utilização do equipamento e do procedimento de análise adotado. / The management of a road network encompasses constant assessments of structural conditions and, above all, functional conditions. Thus, a form of automated survey, carried out at traffic speeds, in which human influence can be unconsidered, is under development in Brazilian road engineering, as it is seen internationally. This present work aims to contribute to the process of functional assessment of pavements through the study of applicability of the functional inventory process of rigid pavements with the use of Pavement Scanner equipment. In order to do so, after the literature review of rigid pavement inventory and Pavement Scanner equipment, test sections were defined and evaluated according to the traditional method of surface survey (ICP - DNIT 062 / PRO, DNIT 060 / PRO), the traditional sand patch volumetric method for the evaluation of macrotexture (ASTM E 965/96), through imaging analysis from the test sections and under the use of Pavement Scanner equipment. With the results, a statistical analysis of these techniques were performed, demonstrating the feasibility of using the equipment and the analysis procedure adopted.

Previous studies show that pavement condition properties are significant factors to enhance road safety and riding experience, and pavements with low quality might have inadequate performance in terms of safety and riding experience. Pavement Management System (PMS) databases include pavement properties for each segment of the road collected by the agencies. Understanding the impact of road characteristics on crash frequency is a key step to prevent crashes. Whereas other studies analyzed the effect of different characteristics such as International Roughness Index (IRI), Rutting Depth (RD), Annual Average Daily Traffic (AADT), this thesis analyzed the effect of Critical Condition Index (CCI) on crash frequency, in addition to the other factors identified in previous studies. Other characteristics such as Percentage of Heavy Vehicles, Road Surface Condition, Road Lighting Condition, and Driver Conditions are taken into the consideration. The scope of the study is the interstate highway system in Fairfax County, Virginia. Negative Binomial, Least Square and Nominal Logistic Models were developed, showing that the CCI value is a significant factor to predict the number of crashes, and that it has different effect for different values of AADT. The result of this study is a substantial step towards developing an integrated transportation control and infrastructure management framework. / Master of Science / Many factors cause crashes in the roads. Although there is a common sense that road characteristics such as asphalt quality are important in terms of road safety, there are few studies that scientifically prove that statement. In addition, asphalt maintenance decisions making process is mainly based on cost benefit optimization, and traffic safety is not considered at the process. The purpose of this study is to analyze crashes and road characteristics related to each crash to understand the effect of those characteristics on crash frequency, and eventually, to build a model to predict the number of crashes at each part of the road. The model can help transportation agencies to have a better understanding in terms of safety consequences of their infrastructure management plans. The scope of this study is the highway interstate system in Northern Virginia. Results suggest that pavement condition has a significant impact on crash frequency.

Η παρούσα εργασία μελετά αναλυτικά – αριθμητικά υπό συνθήκες επίπεδης παραμόρφωσης τη δυναμική απόκριση οδοστρώματος επί εδάφους δύο στρώσεων σε κινούμενα με σταθερή ταχύτητα φορτία. Η ανώτερη στρώση αποτελείται από ασφαλτικό σκυρόδεμα, η μεσαία στρώση από ποροελαστκό υλικό χωρίς νερό στους πόρους και το κατώτερο στρώμα με ποροελαστικό πλήρως κορεσμένο υλικό. Το όλο σύστημα υποστηρίζεται από απαραμόρφωτο βραχώδες υλικό. Στο σύστημα οδοστρώματος – εδάφους χρησιμοποιήθηκε η θεωρία του Biot με την τροποποίηση των Mei and Foda για το μεσαίο και το κατώτερο στρώμα και η θεωρία ιξωδοελαστικότητας των Sousa and Monismith για το ασφαλτικό σκυρόδεμα. Το φορτίο καθώς και η απόκριση προσομοιώνονται με σειρές Fourier. Έτσι οι εξισώσεις για κάθε στρώση καταλήγουν σε συνήθεις διαφορικές που επιλύονται αναλυτικά. Για τις συνοριακές συνθήκες του προβλήματος ισχύει η ισορροπία των ενεργών τάσεων και πιέσεων και η συνέχεια των μετακινήσεων και έτσι δημιουργείται ένα σύστημα 14 εξισώσεων με 14 αγνώστους. Η λύση του συστήματος δίνει τα διαγράμματα των τάσεων, των παραμορφώσεων και της πίεσης του νερού των πόρων σε οποιοδήποτε σημείο του εδαφικού όγκου, κάθε χρονική στιγμή. Τα αποτελέσματα παρουσιάζονται γραφικά και συγκρίνονται για διάφορες τιμές των παραμέτρων με αντίστοιχα άλλων εργασιών. Η παρούσα μέθοδος περιγράφει επαρκώς τόσοτην απόκριση ενός μέσου τριών στρώσεων που υπόκεινται σε κινούμενη φόρτιση, όσο και την εξάρτηση των παραμέτρων αυτών μεταξύ τους. / -

Asphalt’s fatigue and modulus characteristics play an important role in pavement design. Ultimately they govern the required thickness of asphalt to structurally support heavy vehicles. The thickness of the asphalt layer is a major contributor to the cost of construction. In New Zealand, the design of structural asphalt layers has been a problem for some time and gives rise to two areas of concern. First, the present fatigue failure criterion, the Shell fatigue transfer function, which has been adopted from overseas, not only underestimates the fatigue life of the country’s asphalts, but does not accurately characterise the fatigue behaviour of our local asphalt mixes. Consequently, asphalt thicknesses are overdesigned. Second, asphalt’s fatigue behaviour is influenced by numerous factors and therefore can be difficult to characterise. The primary objective of this thesis is to develop fatigue and modulus models, by carrying out fatigue and modulus tests, to characterise the behaviour of two typical New Zealand structural asphalts. Both resilient and stiffness moduli tests were performed at a range of temperatures and loading rates developing moduli master curves, which predict the asphalt’s modulus for any pavement temperature and vehicle speed. A general full factorial experiment was carried out utilising the four-point flexural beam fatigue test. Tests were carried out at different strain levels, temperatures, and loading rates. An analysis of variance showed that the impacts of strain amplitude, temperature, binder type, the interaction of strain amplitude and temperature, and the interaction of strain amplitude and binder type have a significant effect on fatigue behaviour. The developed models, which account for temperature effects give the pavement engineer the ability to undergo a more accurate assessment of fatigue damage than at present for different climatic temperatures demonstrated by using an incremental damage analysis approach. The research shows that with such characterisation for the given pavement’s design life, thinner and less expensive roads can be constructed in New Zealand.

O estudo da reciclagem de pavimentos de concreto para utilização em novos pavimentos tem se mostrado de grande importância haja vista a quantidade de materiais necessários para a reconstrução dessas vias. Além do ganho ambiental, devido a uma menor extração de agregados, obtém-se um ganho econômico, com menor custo de transporte e de aquisição de materiais. O agregado proveniente da britagem de antigas placas de concreto se mostrou, historicamente, apto a ser utilizado para a produção de um novo pavimento de concreto. Entretanto, existem certas limitações, pois o seu uso não resulta em um concreto com características totalmente idênticas àquelas do concreto convencional. O presente trabalho apresenta resultados da análise das características dos agregados produzidos através da britagem de antigas placas de pavimentos de concreto do Rodoanel Metropolitano Mário Covas em britador de mandíbula e em britador de impacto, bem como a influência do uso de agregados reciclados nas propriedades mecânicas do concreto. No estudo comparativo entre os tipos de britador foi verificado que agregados obtidos por britador de mandíbula e por britador de impacto possuem características muito semelhantes. No estudo das características mecânicas dos concretos a resistência à tração na flexão, a resistência à tração na compressão e o módulo de elasticidade diminuíram conforme se aumentou a absorção de água ponderada dos agregados. No que se refere à resistência à compressão, contudo, não foi observada queda ao se substituir somente a fração de agregados graúdos na mistura. Quando se procedeu com a substituição da fração miúda, porém, a resistência ficou abaixo daquela do concreto de convencional. / The study of concrete pavement recycling for its use in new pavements has shown to be of great importance considering the quantity of materials that are necessary to reconstruct these roads. Besides the environmental gain, due to a lesser extraction of aggregates, there is also an economic gain, with smaller transportation and material purchasing costs. The aggregate originated from the crushing of old concrete slabs has historically been shown to be able to be employed in the construction of a new concrete pavement. However, there are limitations, since its utilization does not result in a concrete with the exact same properties of the conventional concrete. The present work presents the results from the analysis of the characteristics from the aggregates produced through the crushing of old concrete slabs using a jaw crusher and an impact crusher, as well as the influence of the use of recycled aggregates on the concrete mechanical properties. The crusher type comparative study has shown that aggregates obtained from a jaw crusher and from an impact crusher have very similar characteristics. The concrete mechanical characteristic study reveals that flexural strength, indirect tensile strength and modulus of elasticity decrease as the aggregates water absorption increase. Concerning compressive strength, however, there was no observed decrease when only coarse recycled aggregates were used. Nevertheless, when fine recycled aggregates were employed besides coarse recycled aggregates, there was a decrease in compressive strength.

Relatam-se e discutem-se resultados obtidos em ações de uma tentativa para mostrar que o formato da seção transversal de rodovias pode ser usado para explicar uma parcela do comportamento de pavimentos e qualidade de viagens em estradas vicinais. Incluiu-se o uso de medidas sobre variáveis para explicação de estado de equipamentos para drenar água das vias. O tipo de variável usada para explicar o comportamento de pavimentos e qualidade de viagens foi a distribuição de notas atribuídas a viagens por segmentos de rodovias por um grupo de avaliadores treinados. A técnica estatística usada para análise dos dados foi a regressão linear múltipla passo a passo. Relata-se resultados de aplicação a um estudo de caso sobre um conjunto de rodovias vicinais próximo à Araraquara, estado de São Paulo. / lt is related and discussed the results from actions in an attempt to show that the format of the cross section of highways can be used to explain the behavior of the pavements and quality of trips in local highways. Measures on variables to explain the state of drainage equipments was taking into account. The variable used to explain the behavior of pavements and quality of trips was the distribution of scores attributed to the highway segments trips by a group of trained appraisers. The statistical technique used to analyze the data was the multiple linear step-by-step regressions. lt is told the application results to a case study on a set of local highway segments near the city of Araraquara, State of Sao Paulo.

Esse trabalho relata e discute resultados obtidos em uma tentativa para mostrar que séries temporais podem ser úteis e eficientes para identificar informações sobre características de comportamento de pavimento ao longo do tempo em que é submetido às solicitações de cargas provenientes de tráfego de eixos de veículos. Os dados e informações utilizadas foram obtidas por observações sobre o comportamento de um trecho experimental de via que liga o trevo de Assaí a Pau D\'Alho, no nordeste do estado do Paraná. Os dados foram manuseados em computador através do método para busca de funções para estimativa de valores de elementos de séries temporais \"Autoregressive lntegrated Moving Average\" para obter informações sobre o comportamento de índice para expressar o \"estado de pavimento\". / The results obtained on trying to show that time series should be useful and efficient in identifying information on the behavior of pavements submitted to vehicle axle load traffic were reported and discussed. The data and inputs used were obtained from observing the experimental road segment Assai to Pau D\'Alho in Northeast of Parana State (Brazil). The data were processed in computers using the \"Autoregressive lntegrated Moving Average\" method to search for estimating values functions for components of time series and obtain information on a pavement performance index.

A cinza pesada é um sub-produto gerado do processo da queima do carvão mineral pulverizado nas caldeiras das termelétricas para a produção de vapor aquecido que atuará na geração de energia elétrica. Não há um destino adequado para esse tipo de cinza, sendo que o volume gerado diariamente é depositado em bacias de sedimentação, causando, dessa forma, problemas ambientais. Principalmente nos Estados Unidos, muitas pesquisas têm evidenciado o sucesso do emprego deste resíduo na construção de rodovias. Contudo, no Brasil as pesquisas sobre cinza pesada estão mais voltadas para a área de edificações. Deste modo, a proposta da pesquisa foi investigar os efeitos da cinza pesada quando incorporada a solos, através de ensaios laboratoriais, visando o aproveitamento deste resíduo na construção de bases e sub-bases de pavimentos. Também foi avaliado o efeito da adição de cal às misturas solo-cinza. Os ensaios utilizados na etapa experimental foram os de mini-CBR, resistência à compressão simples e resistência à tração por compressão diametral. Complementarmente, realizaram-se ensaios de CBR e de resistência à compressão simples na condição imersa. Os resultados mostraram que as adições de cinza pesada aos solos não melhoram as propriedades mecânicas das misturas compactadas. Entretanto, a adição de 3% de cal às misturas de solo-cinza proporciona a melhora significativa no comportamento mecânico das misturas, oferecendo uma solução para aproveitamento da cinza pesada na construção rodoviária. / Bottom ash is a by-product from the burning of mineral coal. It is utilized as fuel in thermal power stations in order to produce electrical energy. The bottom ashes are deposited in the lagoons and are harmful to the environment. In the United States, several researches have indicated successful uses of this waste in the construction of roadways. However, in Brazil the researches have been accomplished to use the bottom ashes in the civil construction. Thus, the purpose of the present research was to investigate the results of the bottom ash additions to soil in order to utilization in bases and sub-bases of pavements. Afterward, the effects of lime additions to soil-bottom ash mixtures were evaluates. The tests employded were mini-CBR, unconfined compressive strength and indirect tensile strength. California bearing ratio and immersion unconfined compressive strength were accomplish such supplementary tests. The results indicated that bottom ash additions to soils does not improve the mechanical properties of the compacted mixtures. However, the addition of the 3% of the lime to soil-bottom ash mixtures provided better mechanical performance, offering a feasible solution for the use of this waste in road construction.