abstract: Recent research efforts have been directed to improve the quality of pavement design procedures by considering the transient nature of soil properties due to environmental and aging effects on pavement performance. The main purpose of this research study was to investigate the existence of subgrade soil moisture changes that may have arisen due to thermal and hydraulic gradients at the Atlantic City NAPTF and to evaluate their effect on the material stiffness and the California Bearing Ratio (CBR) strength parameter of the clay subgrade materials. Laboratory data showed that at the same water content, matric suction decreases with increasing temperature; and at the same suction, hydraulic conductivity increases with increasing temperature. Models developed, together with moisture/temperature data collected from 30 sensors installed in the test facility, yielded a maximum variation of suction in field of 155 psi and changes in hydraulic conductivity from 2.9E-9 m/s at 100% saturation to 8.1E-12 at 93% saturation. The maximum variation in temperature was found to be 20.8oC at the shallower depth and decreased with depth; while a maximum variation in moisture content was found to be 3.7% for Dupont clay and 4.4% for County clay. Models developed that predicts CBR as a function of dry density and moisture content yielded a maximum variation of CBR of 2.4 for Dupont clay and 2.9 for County clay. Additionally, models were developed relating the temperature with the bulk stress and octahedral stress applied on the subgrade for dual gear, dual tandem and triple tandem gear types for different tire loads. It was found that as the temperature increases the stresses increase. A Modified Cary and Zapata model was used for predicting the resilient modulus(Mr) of the subgrade. Using the models developed and the temperature/moisture changes observed in the field, the variation of suction, bulk and octahedral stresses were estimated, along with the resilient modulus for three different gear types. Results indicated that changes in Mr as large as 9 ksi occur in the soils studied due to the combined effect of external loads and environmental condition changes. / Dissertation/Thesis / Doctoral Dissertation Civil, Environmental and Sustainable Engineering 2017

abstract: Use of Recycled Asphalt Pavement (RAP) in newly designed asphalt mixtures is becoming a common practice. Depending on the percentage of RAP, the stiffness of the hot mix asphalt (HMA) increases by incorporating RAP in mixes. In a climatic area such as the City of Phoenix, RAP properties are expected to be more oxidized and aged compared to other regions across the US. Therefore, there are concerns about the cracking behavior and long-term performance of asphalt mixes with high percentage of RAP. The use of Organosilane (OS) in this study was hypothesized to reduce the additional cracking potential and improve resistance to moisture damage of the asphalt mixtures when using RAP. OS has also the potential to improve the bond between the aggregate and asphalt binder. The use of OS also reduces the mixing and compaction temperatures required for asphalt mixtures, making it similar to a warm mix asphalt (WMA), Six asphalt mixes were prepared with three RAP contents, 0%, 15% and 25%, with and without Organosilane. The mixing temperature was reduced by 10°C and the compaction temperature was reduced by 30°C. Mix designs were performed, and the volumetric properties were compared. The mixture laboratory performance was evaluated for all mixtures by conducting Dynamic Modulus, Flow Number and Tensile Strength Ratio tests. The study findings showed that mixtures achieved better compaction at a reduced temperature of 30°C. Mixtures modified with Organosilane generally exhibited softer behavior at the extreme ends of lower and higher temperatures. The lower moduli are to reduce the potential for cracking. For the Flow Number test, the RAP mixtures with OS passed the minimum required at all traffic levels. Tensile Strength Ratio results increased with the increase in RAP percentage, and further increase was observed when OS was used. The OS reduced the sticking nature of the binder to the molds and equipment, which reduced the efforts in cleaning them. Finally, the future use of RAP by the City of Phoenix would positively contributes to their sustainability aspiration and initiatives. The use of Organosilane may even facilitates higher percentage of RAP usage; it definitely improves the moisture resistance of asphalt mixtures, especially when lower mixing and compaction temperatures are desired or used. / Dissertation/Thesis / Masters Thesis Civil, Environmental and Sustainable Engineering 2018

Master of Science / Department of Civil Engineering / Mustaque A. Hossain / Based on a 2017 report on infrastructure by the American Society of Civil Engineers, 13% of Kansas public roads are in poor condition. Furthermore, reconstruction of a two-lane concrete pavement costs between $0.8 and $1.15 million dollars per lane mile. High early strength Portland cement concrete pavement (PCCP) patches are widely used in pavement preservation in Kansas due to the ability to open to traffic early. However, these repairs done by the Kansas Department of Transportation (KDOT) deteriorate faster than expected, though, prompting a need for inexpensive, durable high early strength concrete repair mixtures that meet KDOT standards (i.e., a 20-year service life). This study developed an experimental matrix consisting of six PCCP patching mixture designs with varying cement content and calcium chloride dosage. The mixtures were subjected to isothermal calorimetry, strength testing, drying shrinkage, and various durability tests. The effects of cement content and calcium chloride dosage on concrete strength and durability were then investigated. In addition, the compressive strength development with time, the split tensile versus compressive strength relationship, and the shrinkage strain of the PCCP patching mixtures were compared to established relationships provided by the American Concrete Institute (ACI). Results showed a maximum 3% increase in total heat generated by various concrete paste samples in isothermal calorimetry testing. The minimum compressive strength of 1,800 psi required by KDOT could likely be obtained using any of the PCCP mixtures, regardless of the cement content or calcium chloride dosage used in the study. Furthermore, surface resistivity tests for mixtures containing calcium chloride could result in erroneous measurements. Only one mixture satisfied the maximum expansion and minimum relative dynamic modulus of elasticity required by KDOT. Some ACI relationships for shrinkage and strength development do not appear to be valid for high early strength PCCP patching mixtures.

O ruído é uma forma de poluição que causa muitos problemas à saúde humana e à economia, sendo que o ruído gerado pelo tráfego de veículos é uma das principais fontes da poluição sonora. Assim, diversos países vêm esforçando-se para melhor compreender e, consequentemente, encontrar possíveis soluções à redução da poluição sonora. Contudo, tais esforços no Brasil ainda são parcos. De modo a contribuir para a compreensão e a busca de soluções à poluição sonora, este trabalho propõe-se a estudar o ruído gerado por veículos trafegando em diferentes revestimentos de pavimentos rodoviários, realizando-se medições e avaliando-se o ruído interno, que interfere no conforto do condutor e passageiros, bem como no ruído externo aos veículos, que pode incomodar os lindeiros à via - dependendo da pressão sonora. Apresenta-se um estudo de caso com medição e avaliação do ruído externo e interno em duas fases diferentes de estado de superfície de um trecho da Rodovia dos Bandeirantes (SP-348): antes e após a execução de um revestimento asfáltico denominado gap-graded com asfalto borracha, construído em substituição ao revestimento antigo de microrrevestimento asfáltico a frio. A análise dos resultados mostrou que a substituição do tipo de revestimento levou à redução de aproximadamente 2 dB(A) no ruído externo e que este diminuiu em escala logarítmica com a distância do receptor à fonte, corroborando a teoria do som propagado de uma fonte pontual, em forma esférica. A análise do ruído interno mostra que esta substituição do revestimento asfáltico do pavimento gera igualmente uma melhoria no conforto, reduzindo em aproximadamente 3 dB(A) o ruído, principalmente nas bandas de frequência de 200 Hz a 1000 Hz. Para comparação dos resultados com o Concreto Asfáltico, revestimento usinado de maior uso no Brasil, fez-se medições de ruído interno na pista de testes da Pirelli em Sumaré, avaliando-se, também, a intensidade e espectro do ruído com a variação da velocidade do veículo. De posse destes dados, pôde-se comparar o ruído interno do Concreto Asfáltico (CBUQ), com as demais soluções da Rodovia dos Bandeirantes. Constatou-se que o CBUQ tem o nível de ruído superior ao do gap-graded, e muito próximo ao do micro, nas condições de superfície em que estes três revestimentos se encontravam nos estudos em campo. Verificou-se, também, que o revestimento do pavimento pode auxiliar na redução do ruído, seja interno como externo. Por fim, constatou-se que os métodos atuais empregados na avaliação da macrotextura do pavimento não são suficientes para compreender a intensidade do ruído. / The noise is a form of pollution that causes diverse problems to the human health and the economy. One of the major sound pollutions forms is the noise generated by the traffic of vehicles. Several countries have been making efforts to better understand and, therefore, find possible solutions to mitigate the sound pollution. However, such efforts in Brazil are still incipient. This work proposes itself to measure and evaluate the noise, the internal noise, which disturbs the comfort of the driver and passenger, and the external vehicle noise, that can disturb the dwellings near by the highway depending on the sound pressure, generated by vehicles in different types of highway pavement surfaces. A case study at Bandeirantes Highway (SP 348) was run to evaluate the external and internal noise before and after the placement of a gap-graded prepared with rubber asphalt, above the of the old microsurfacing. The evaluation of the result shown that the substitution of the pavement surface led to the reduction of approximately 2dB(A) for external noise and that diminished in a logarithmic fashion, such as the theory of a sound propagating from a punctual source in a spherical manner. The analyses of the internal noise demonstrates that the substitution of the pavement surface generates an improvement in the comfort, reducing in approximately 3dB(A) the noise, especially in the frequency range of 200Hz to 1000Hz. The comparison with the Asphalt Concrete, pavement surface most used in Brazil, internal noise measurements were made at the Pirelli test track in Sumare/SP, evaluating, also, sound intensity and the noise frequencies with the variation of the vehicle speed. With this data, was possible to compare the asphalt concrete with the solutions made on Bandeirantes Highway. The research evidenced that the noise level of asphalt concrete is similar to the microsurfacing, and both are higher than the gap-graded prepared with asphalt rubber. The surface of the pavement can also contribute to the mitigation of the internal and the external noise. The present thesis also concluded that the current methods to evaluate the macrotexture of the pavement surface are incapable of fully understanding of the internal and external noise.

Orientador: Antonio Anderson da Silva Segantini / Banca: Marco Antonio Morais Alcantara / Banca: Paulo Jose Rocha de Albuquerque / Resumo: Neste trabalho, objetiva-se o estudo do aproveitamento de resíduos de concreto na confecção de novos concretos destinados à fabricação de peças pré-moldadas utilizadas na pavimentação intertravada. Inicialmente, por meio de realização do estudo de dosagem, a partir dos materiais, utilizados na composição do concreto, previamente caracterizados definiu-se o traço de referência, de modo a se otimizar o consumo de cimento para a resistência requerida de 35 MPa. Com base no traço de referência, procedeu-se a confecção de traços com emprego de teores crescentes de substituição do agregado miúdo natural, por agregado reciclado de concreto, com incremento de 20% até se atingir 100% de substituição, de modo a se definir o traço que apresentasse o teor ótimo de substituição. Tendo-se definido o traço com adição de agregado reciclado de concreto em substituição ao agregado miúdo natural, efetuou-se a confecção de peças pré-moldadas de concreto variando-se a geometria e espessura das mesmas, além de corpos-de-prova destinados aos ensaios de desgaste por abrasão e absorção de água por imersão, tanto para o traço de referência como para o traço com teor ótimo de substituição, a fim de se observar as interferências advindas da adição do agregado reciclado de concreto, quanto às propriedades físico-mecânicas dos novos concretos com estes produzidos, e ainda as influências das variações geométricas nas peças pré-moldadas de concreto / Abstract: This work, objective is to study the use of concrete wastes in new concretes manufacture destined to precast blocks production used in interlocking paving. In the beginning, through the mix-proportioning study accomplishment, from materials used in concrete composition, previously characterized, it was defined the reference trace, so much that to optimize the cement consume to the request strength of 35 MPa. Base in the reference, occurred the trace manufacture with employment of growing contents of natural small aggregated replacement for concrete recycled aggregated, with increase of 20% until reach 100% of replacement, so much that to define the trace that had presented the great content of replacement. It's having defined the trace if addition of recycled aggregated of concrete in replacement of natural small aggregated, effected the precast blocks manufacture of concrete varying the geometry and thickness from the same, beyond bodies-of-test designated the tests of wear for abrasion and absolved of water for immersion, as much to the reference trace as to the trace with great content of replacement, in order to observe the interference came from the addition of concrete recycled aggregated, as the physical mechanical properties from the new concrete with this produced, and still the influences from the geometric variations in the precast blocks of concrete / Mestre

O patrimônio de infraestrutura rodoviária brasileira através dos tempos está sobrevivendo com investimentos com grandeza de valor bem abaixo do que muitos outros países estão alocando. A questão de quanto investir em infraestrutura de transportes depende de múltiplas variáveis como a situação política e econômica do país, a característica da frota, sua dimensão territorial, sua matriz, os tipos de pavimentos utilizados e as condições climáticas. Portanto, estimar um valor a ser empregado em manutenção rodoviária de forma recomendável, deve ser resultado dos estudos que envolvam essas variáveis, como elas interagem entre si e como esse investimento retorna para a sociedade. Diante de tantas áreas precárias, administrar recursos para a infraestrutura de transportes é um desafio a ser ainda vencido no Brasil. É engajada nesse desafio, que essa dissertação é composta por três artigos que abordam os principais assuntos: (i) avaliação da gestão da manutenção rodoviária no Brasil, quanto a sua abrangência, investimentos e as experiências internacionais; (ii) os conceitos e etapas de um SGP (Sistema de Gerência de Pavimentos) e a sua importância no planejamento das intervenções de manutenção; (iii) aplicação prática com o software Highway Development and Management (HDM-4), avaliando os resultados econômicos com as variáveis International Roughness Index (IRI) e Volume Médio Diário (VDM) do tráfego iniciais de segmentos de uma rodovia federal, utilizando como alternativas de projeto programas usuais adotados pelos gestores da rodovia. A terceirização dos serviços de manutenção pelos departamentos rodoviários exige que tenham que planejar e administrar contratos de manutenção por pouco ou longo período. A aplicação prática do HDM-4 demonstra que, o planejamento, um componente de um SGP, deve ser considerado permanentemente pelos administradores públicos ou privados. A questão de quanto investir em manutenção nesse contexto depende de como se investiu em momento antecedente, tanto com os serviços de infraestrutura como nas etapas de inventário da malha, planejamento e elaboração de projetos. O sistema HDM-4 necessita de dados de entrada, tais como: características geométricas, mecânicas, dados históricos e de tráfego dos segmentos rodoviários; que devem ser preservados pelos gestores do sistema, de maneira que permita prever o desempenho do pavimento, os custos e benefícios para um período planejado. Durante a análise dos resultados de Valor Presente Líquido (VPL) com os IRI e VDM iniciais, verificouse que as maiores diferenças se encontravam nos segmentos com mesmo intervalo de IRI inicial mas com tráfego superior. As características da frota, seus custos operacionais bem como seus coeficientes de calibração devem ser considerados nas análises com o software HDM-4, visando uma boa gestão na manutenção rodoviária. Tendo em vista o fato do tráfego influenciar nos resultados e podendo alterar o planejamento da manutenção, se percebe como é importante o controle do gestor da rodovia nas cargas efetivas que estão sendo transportadas. / The patrimony of Brazilian highway infrastructure through the ages is surviving with investments of magnitude value well below of what many other countries are allocating. The question of how much to invest in transport infrastructure depends on multiple variables such as the political and economic situation of the country, the characteristic of the fleet, its territorial dimension, its matrix, the types of used pavements and weather conditions. Therefore, to estimate a value to be used in road maintenance of a recommended way should be the result of the studies involving these variables, how they interact and how this investment returns to society. In face of so many precarious areas, managing resources for transport infrastructure is a challenge yet to be overcome in Brazil. It is engaged in this challenge, that this thesis consists of three articles that discuss the main issues: (i) assess the management of road maintenance in Brazil, as its scope, investment and international experiences; (ii) the concepts and steps of a Pavement Management System (PMS) and its importance in the planning of maintenance operations; (iii) practical application with the software Highway Development and Management (HDM-4), evaluating the economic results with the variables International Roughness Index (IRI) and Annual Average Daily Traffic (AADT) of the initial traffic segments of a federal motorway, using as alternative project usual programs adopted by the highway managers. The outsourcing of the maintenance services by road departments requires that they have to plan and manage maintenance contracts for little or long period. The practical application of the HDM-4 shows that the planning, a component of the PMS should be considered permanently by public or private administrators. The question of how much to invest in maintenance in this context depends on how you invested in previous time, both with infrastructure services as with the inventory stages of the motorway network, planning and preparation of projects. The HDM-4 system requires input data, such as geometric and mechanical characteristics, historical data and traffic of road segments that should be preserved by system managers, in order to foresee the pavement performance, costs and benefits to a planned period. During the analysis of the results of Net Present Value (NPV) with the initial IRI and AADT, it was found that the greatest differences were in the same initial IRI segments range but with higher traffic. The fleet characteristics, their operating costs and their calibration coefficients should be considered in the analysis with the HDM-4 software, aiming at a good management in road maintenance. In view of the fact that traffic influences the results and can change the maintenance planning, one can perceive that the road manager control on actual loads being transported is important.

Nas últimas décadas os pavimentos rodoviários brasileiros têm tido seu desempenho comprometido devido a uma série de fatores, entre eles incluem-se não somente o crescente aumento do volume de tráfego de veículos pesados e aumento de sua capacidade de transporte, mas principalmente a circulação com cargas acima dos limites legais estabelecidos, configurando uma situação crítica para a sua adequada durabilidade da estrutura projetada. Paralelamente aos investimentos necessários, é importante também o desenvolvimento de métodos mais racionais de dimensionamento de pavimentos contemplando as especificidades dos materiais empregados e levando em consideração as condições climáticas e, principalmente uma completa e detalhada caracterização do tráfego solicitante. Neste contexto apresentado, a pesquisa insere-se em dois importantes estudos. O acompanhamento construtivo e monitoramento sistemático de desempenho de dois trechos na rodovia BR-448/RS e a continuidade do monitoramento de outros dois na BR-290/RS, trecho em concessão entre Osório e Porto Alegre (Freeway). Estas atividades inserem-se no “Projeto Integrado da Rede Temática de Tecnologia em Asfalto Petrobras/ANP", de abrangência nacional, para desenvolvimento de um novo método brasileiro de dimensionamento de pavimentos O segundo estudo trata-se de um completo monitoramento de cargas na Freeway, através da instalação e operacionalização inédita de um equipamento de pesagem dinâmica de alta velocidade (Hight Speed Weigh-in-Motion – HS-WIM) para determinação do espectro de cargas e posterior análise de sua influência no desempenho de pavimentos. Com ambos os estudos foi possível, além de determinar o espectro de cargas, os carregamentos médios e os níveis de sobrecargas praticados naquela rodovia, verificar como estas cargas influenciam o desempenho do pavimento e confrontar estes dados com as tendências observadas através do monitoramento sistemático dos trechos analisados. Por meio do desenvolvimento do presente trabalho pretende-se contribuir para melhorias na engenharia rodoviária e de tráfego através da inserção de novas tecnologias de monitoramento e fiscalização das cargas transportadas e contribuir com o desenvolvimento de um novo método de dimensionamento de pavimentos flexíveis proposto pela Rede Temática de Asfalto, através do levantamento de dados nos trechos experimentais para desenvolvimento de modelos de desempenho e sua posterior inserção nos modelos de calibração. / In recent decades the Brazilian road pavements have had their performance reduced due to a number of factors, not only the increasing volume of heavy vehicles and increased transport capacity, but mainly the flow with loads above the established legal limits, setting a critical situation for the durability of the designed structure. Alongside the necessary investment, it is also important to the development of more rational methods of pavement design, considering the specificities of the materials used and taking into account the climatic conditions and a complete and detailed characterization of the traffic. In this context, the research was developed to attain two main objectives: the construction monitoring and systematic assessment of performance of two test sections built in BR-448/RS highway and the continuity of assesment of two others previously built in BR-290/RS, between Osório and Porto Alegre (known as Freeway). These activities are part of the "Integrated Project Theme Technology Network Petrobras Asphalt/ANP", a nationwide project aimed at developing a new Brazilian method for pavement design The second objective was to conduct a comprehensive monitoring loads study on the Freeway, by installing and carrying on an unprecedented operation of a dynamic weighting equipment of high speed (High speed weigh-in-Motion - HS-WIM) to determine the loads spectrum and subsequent analysis of the influence on pavement performance. Both studies made possible to determine the loads spectrum, average loads and levels of overloads practiced on that highway, to estimate how these loads affect the pavement performance and to compare these data with the trends observed through the systematic assessment of the analyzed sections. This work aims to contribute to improvements in road and traffic engineering, by introducing new monitoring technologies, monitoring the transported cargo and contributing to the development of a new design method of flexible pavements, a major goal of the Thematic Network of Asphalt, to be achieved through experimental data collection in test sections, the development of performance models and their subsequent insertion in the calibration models.

As rodovias com revestimento primário constituem a imensa maioria da extensão da malha viária do Brasil e de muitos países. Sua manutenção em um nível mínimo aceitável de serventia consome parcelas importantes de orçamentos governamentais. Contudo, na maioria das vezes, as atividades de implantação e manutenção têm escasso sucesso, porque os agentes encarregados desconhecem a tecnologia específica. Visando contribuir para práticas mais efetivas, esta tese analisa os resultados de uma pesquisa realizada com o objetivo de identificar e discutir os mecanismos de degradação de rodovias com revestimento primário, à luz das Mecânicas dos Solos e dos Pavimentos. O projeto experimental incluiu ensaios laboratoriais, bem como a construção e monitoramento de desempenho, ao longo de 30 meses, de um pavimento experimental, em projeto de assentamento da Reforma Agrária, no Rio Grande do Sul. O revestimento primário foi construído em duas camadas (a superior constituída por 7 cm de saibro e a inferior por 17 cm de argila laterítica) assentes sobre um subleito estratificado, com camada superior arenosa. As formações geológicas são constituídas por depósitos aluvionares (subleito) e por siltito (jazida de argila) e gnaisse (jazida do saibro). A compactação das camadas foi verificada por meio de ensaios clássicos e com emprego do cone de penetração dinâmica (DCP). As deflexões foram medidas no topo do subleito e sobre cada camada de revestimento, com utilização de viga Benkelman. Amostras deformadas dos materiais do revestimento primário e da camada superior do subleito foram coletadas. Em laboratório realizaram-se ensaios de caracterização, bem como da classificação MCT; foram avaliadas a resistência ao desgaste e a durabilidade da fração graúda do saibro (abrasão Los Angeles e alteração de rochas água-estufa). Realizaram-se ensaios de compactação, Índice de Suporte Califórnia, Inderbitzen (erodibilidade), cisalhamento direto e triaxiais de carga repetida, para obtenção de módulos de resiliência e avaliação do comportamento quanto à deformação permanente. Complementarmente, foram obtidas curvas de retenção de água. Com base nos resultados laboratoriais foram realizadas previsões de desempenho do pavimento experimental, fundamentadas em conceitos, prescrições e em modelos matemáticos e estatísticos encontrados na literatura e no emprego do programa HDM 4. Durante o período de monitoramento do pavimento experimental foram realizados 3 levantamentos para a obtenção da Irregularidade Longitudinal (IRI), com o emprego de um perfilômetro inercial e 4 inspeções para a avaliação da evolução dos principais defeitos típicos de pavimento com revestimento primário. Os defeitos observados foram: afundamento de trilha de roda, buracos, perda de abaulamento, perda de espessura de revestimento e sulcos de erosão; identificando-se e discutindo-se os mecanismos de degradação a eles associados. Também foram comparadas as previsões de desempenho com a evolução da serventia do pavimento experimental, constatando-se que os modelos apresentados na literatura internacional nem sempre apresentam acurácia satisfatória. Isto mostra a necessidade de se desenvolverem novos modelos e calibrar os existentes, como condição indispensável para otimizar as atividades de manutenção das rodovias com revestimento primário. / Most of Brazilian and other countries’ roads networks mainly comprise unsurfaced gravel roads. The maintenance of such roads at a minimum acceptable level of serviceability consumes large percentages of governs budgets. In spite of that, the construction and maintenance activities are scarcely well-succeeded, since the personnel involved do not know the specific technology. Aiming at contributing for more effective practices, this thesis analyses the results of a research carried out with the objective of identifying and discussing distress mechanisms of unsurfaced gravel roads, based on Soil and Pavement Mechanics. Experimental procedures included laboratory tests, as well as the construction and performance monitoring, along 30 months, of a test section, in an agrarian reform settlement, in Rio Grande do Sul state, southern Brazil. The wearing course of the unsurfaced pavement consisted of two different layers (a 7-cm-thick upper layer, made of genuine residual soil and a lower one with 17 cm of lateritic clay), built over a stratified subgrade, with a sandy upper layer. Geological formations consisted of alluvial fans (the subgrade), siltstone (the clay site) and gneiss (genuine residual soil site). Layers compaction was quantified by means of classic tests and also using the dynamic cone penetrometer (DCP). Using a Benkelman beam, surface deflections were measured on the top of the subgrade and every layer. Samples were taken from the subgrade and from both materials that constitute the wearing course, in order to perform laboratory tests of characterization and those of a Brazilian soils classification system, known as MCT (miniature, compacted, tropical). Los Angeles abrasion and rock alteration by wetting and drying tests were done on samples of the genuine residual soil coarse fraction. Every material was subjected to compaction, CBR, Inderbitzen (erodibility), direct shear and repeated loading triaxial tests (these latter to compute resilient moduli and to evaluate the permanent deformation behaviour). Besides, water-retention curves were obtained. Based on laboratory results, the performance of the experimental pavement was predicted, founded on concepts, materials prescriptions and mathematical and statistical models and using HDM 4 program. During the monitoring period three roughness (IRI) surveys were carried out, using an inertial profilometer. Four distresses surveys were carried out to evaluate the evolution of the most important distresses typical of unsurfaced gravel roads. Distresses as rutting, potholes, cross-section deformation and thickness reduction and erosion channels were observed and the associated distress mechanisms were discussed. Pavement performance predictions were compared to the measured serviceability evolution. It was found out that the models available in the literature not always yield accurate results. Because of that, developing new models and calibrating the existing ones is mandatory to optimize maintenance activities in unsurfaced gravel roads.

A reciclagem profunda com adição de cimento Portland é uma técnica de recuperação estrutural e funcional de pavimentos empregada há muitos anos no país, devido a vantagens técnicas, econômicas e ambientais. Contudo, a difusão mais ampla da técnica esbarra na carência de normas e procedimentos nacionais, o que resulta na adoção de variados critérios nos projetos que incluem reciclagem com cimento, às vezes, comprometendo sua eficácia. A pesquisa relatada nesta dissertação teve por objetivo principal estabelecer as bases para a proposição de um método de dosagem para reciclagem de pavimentos com adição de cimento, considerando-se como referência o método de dosagem de materiais estabilizados com cimento da Austroads (2002). Para verificar a validade deste método para materiais de pavimentos brasileiros, desenvolveu-se um programa experimental no qual foram avaliadas propriedades mecânicas (resistência, rigidez e erodibilidade) e volumétricas (retração, absorção, expansão e ascensão capilar) de misturas constituídas por fresado asfáltico, brita graduada e cimento, variando-se a porcentagem de fresado (20% e 50%), o teor de cimento (2%, 4% e 6%), a energia de compactação (Intermediária e Modificada) e o tempo de cura dos corpos de prova (3, 7 e 14 dias). Os resultados dos ensaios mostraram que todas as variáveis analisadas afetam significativamente a resistência à compressão simples, a resistência à tração por compressão diametral e o módulo de resiliência das misturas, enquanto que a retração, a erodibilidade, a absorção, a expansão e a ascensão capilar são afetadas por algumas das variáveis independentes. Dentre outras conclusões, destaca-se que são obtidos elevados valores de resistência à compressão simples (1,61 MPa a 6,08 MPa), resistência à tração por compressão diametral (0,29 MPa a 1,00 MPa) e de módulo de resiliência (10390 MPa a 25719 MPa) com teores baixo (2%) e médio (4%) de cimento, sendo desnecessário e arriscado, pela elevada retração associada, o emprego de teor mais elevado (6%). Ainda, observou-se que o aumento da energia de compactação permite compensar a utilização de teores mais baixos de cimento no que se refere às resistências (à compressão, à tração e à erosão) e módulos obtidos. Globalmente, conclui-se que o método de dosagem de materiais estabilizados com cimento da Austroads (2002) pode ser usado como modelo para o desenvolvimento de um método de dosagem para reciclagem de pavimentos com adição de cimento, sendo necessárias pequenas complementações ou adaptações. O método de dosagem sugerido nesta Dissertação é, ao mesmo tempo, simples o suficiente para ser empregado em laboratórios de canteiros de obra e amplo o bastante para identificar as propriedades mecânicas e volumétricas que devem ser avaliadas ao elaborar-se um projeto de mistura reciclada com cimento. / Full-depth reclamation (FDR) with Portland cement is a technique used for structural and functional rehabilitation of pavements and has been used in Brazil for many years, especially because its technical, economical and environmental advantages. However, a larger diffusion of the technique has been inhibited by the lack of national standards and procedures, resulting in the adoption of different design criteria, which sometimes leads to a low efficiency of the FDR with cement. This research was carried out with the objective of setting the basis for a mix design method for FDR with cement, considering the Austroads (2002) mix design method for stabilized pavement materials as a model. In order to verify the applicability of the Austroads method to Brazilian pavement materials, an experimental program was carried out testing mechanical (strength, stiffness and durability) and volumetric (drying shrinkage, absorption, swell and capillary rise) properties of mixtures made of reclaimed asphalt pavement (RAP), graded crushed stone and cement. Specimens with different RAP contents (20% and 50%), cement contents (2%, 4% and 6%), compacted with two different efforts (Brazilian Intermediate and Modified) were cured for 3, 7 and 14 days. Test results showed that all the studied variables affect the unconfined compressive strength, indirect tensile strength and resilient modulus of the mixtures, while drying shrinkage, erodibility, absorption, swell and capillary rise are affected by some of the independent variables. Among other conclusions, it is pointed out that high values of unconfined compressive strength (1,61 MPa to 6,08 MPa), indirect tensile strength (0,29 MPa to 1,00 MPa) and resilient modulus (10390 MPa to 25719 MPa) may be achieved with low (2%) and intermediary (4%) cement contents, thus making the use of higher (6%) cement content unnecessary and unsafe, due to the higher costs and to the drying shrinkage associated. It was also observed that increases in the compaction effort may compensate the use of lower cement contents as regards to strengths and moduli obtained. Generally, can be concluded that the Austroads (2002) mix design method for stabilized pavement materials may be used as a model for the development of a mix design method for FDR with cement, being necessary only a few additions or adaptations. The suggested method is, simultaneously, simple enough to be used in field laboratories and comprehensive enough for including the mechanical and volumetric properties that must be evaluated when designing a mix for FDR with cement.

abstract: In recent years, an increase of environmental temperature in urban areas has raised many concerns. These areas are subjected to higher temperature compared to the rural surrounding areas. Modification of land surface and the use of materials such as concrete and/or asphalt are the main factors influencing the surface energy balance and therefore the environmental temperature in the urban areas. Engineered materials have relatively higher solar energy absorption and tend to trap a relatively higher incoming solar radiation. They also possess a higher heat storage capacity that allows them to retain heat during the day and then slowly release it back into the atmosphere as the sun goes down. This phenomenon is known as the Urban Heat Island (UHI) effect and causes an increase in the urban air temperature. Many researchers believe that albedo is the key pavement affecting the urban heat island. However, this research has shown that the problem is more complex and that solar reflectivity may not be the only important factor to evaluate the ability of a pavement to mitigate UHI. The main objective of this study was to analyze and research the influence of pavement materials on the near surface air temperature. In order to accomplish this effort, test sections consisting of Hot Mix Asphalt (HMA), Porous Hot Mix asphalt (PHMA), Portland Cement Concrete (PCC), Pervious Portland Cement Concrete (PPCC), artificial turf, and landscape gravels were constructed in the Phoenix, Arizona area. Air temperature, albedo, wind speed, solar radiation, and wind direction were recorded, analyzed and compared above each pavement material type. The results showed that there was no significant difference in the air temperature at 3-feet and above, regardless of the type of the pavement. Near surface pavement temperatures were also measured and modeled. The results indicated that for the UHI analysis, it is important to consider the interaction between pavement structure, material properties, and environmental factors. Overall, this study demonstrated the complexity of evaluating pavement structures for UHI mitigation; it provided great insight on the effects of material types and properties on surface temperatures and near surface air temperature. / Dissertation/Thesis / M.S. Civil and Environmental Engineering 2013