Open-graded friction course (OGFC) is a porous mix primarily used to improve pavement safety. OGFC is characterized by air voids ranging from 15 to 20 percent which allows surface water to drain through its structure and then laterally from the pavement structure. The ability of OGFC to drain water quickly results in less water ponding on the pavement surface, thereby reducing hydroplaning, reducing vehicle spray, and providing improved skid resistance. Research objectives were to evaluate the use of OGFC mixes containing 100 percent gravel and 50 percent gravel/50 percent limestone and to determine specifications to be employed by the Mississippi Department of Transportation (MDOT). Specimens were prepared at design asphalt binder content and evaluated for permeability, durability, stability, and moisture resistance. Research findings show mixes containing 100 percent gravel and 50 percent gravel/50 percent limestone perform comparably in laboratory testing.

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Permeable friction course (PFC), or new generation open-graded friction course (OGFC) mixtures, are hot mix asphalt (HMA) characterized by high total air voids (AV) content (minimum 18 %) as compared to the most commonly used dense-graded HMA. The high AV content confers to PFC mixtures both high permeability and noise reduction effectiveness. These characteristics and the high values of surface friction exhibited by PFC mixtures, as compared to dense-graded HMA, lead to improvements in safety and the environment, which make PFC one of the safest, cleanest, and quietest alternatives currently available for surface paving. The main objective of this study was improving the current PFC mix design method and construction practices in terms of compaction control. Corresponding results were integrated in an improved mix design method that is based on the guidelines of the current mix design method used by the Texas Department of Transportation. The improved mix design included modified computation of the inputs required to determine mixture density (or corresponding total AV content). These changes led to a proposed modification of the density specification for mix design from 78-82 % to 76-80 %. In addition, the water-accessible AV content was proposed as a surrogate of the total AV content for mix design and evaluation. The improved mix design method also includes verification of drainability, durability, and stone-on-stone contact. Computation of the expected value of permeability (E[k]) and measurement of the water flow value were recommended, respectively, for verification of drainability in the laboratory (using specimens compacted in the Superpave Gyratory Compactor (SGC)) and in the field. The Cantabro loss test conducted in both dry- and wet-conditions was suggested for assessing mixture durability. Improved criteria were proposed for verification of stone-on-stone contact based on the evaluation of the AV content in the coarse aggregate fraction of the mixture. In addition, comparison of the internal structure of field-and laboratory-compacted mixtures supported recommendation of a field-compaction control. Recommendations to reduce the horizontal heterogeneity of AV encountered in PFC specimens included using road cores with a minimum 152.4 mm diameter and coring SGC specimens from 152.4 to 101.6 mm in diameter

Orientador: Cassio Eduardo Lima de Paiva / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Civil, Arquitetura e Urbanismo / Made available in DSpace on 2018-08-06T01:39:22Z (GMT). No. of bitstreams: 1 Silva_CarlosEduardoDelBenda_M.pdf: 2624680 bytes, checksum: 91c83d7e53e4678b23d6c80b5cb76bb5 (MD5) Previous issue date: 2005 / Resumo: A malha rodoviária brasileira tem grande importância para o desenvolvimento do País. Observando-se que esta malha é predominantemente de pavimento flexível, o estudo das propriedades de misturas betuminosas se toma indispensável. Com o desenvolvimento tecnológico de asfaltos, novas aplicações estão se mostrando viáveis e tecnicamente interessantes. Em algumas dessas aplicações, espera-se que estas misturas tenham uma permeabilidade adequada para o escoamento das águas precipitadas. Para caracterizar estas propriedades, desenvolveu-se, no Laboratório de Estradas de Engenharia Civil da Universidade de Campinas UNICAMP, um estudo da permeabilidade de 4 tipos de misturas betuminosas que pudessem caracterizar o amplo leque de misturas de graduação aberta. A partir dos resultados de permeabilidade obtidos, propõe-se a adoção do ensaio em novos projetos de misturas asfálticas durante a fase de elaboração e viabilização do mesmo, verificando se o tipo de mistura adotada é apropriado ou não com relação à precipitação característica do local e promovendo, acima de tudo, a segurança aos usuários. Propõe-se, ainda, a continuação do estudo para novos tipos de misturas asfálticas porosas, salientando-se que a utilização destas misturas ganha espaço no cenário nacional / Abstract: Brazilian highway network plays a huge importance for country development. Since most of this roads is formed by flexible pavement, a proper characterization of this bituminous mixture is indispensable. Following the development of new asphalt binders the altemative applications are becoming economic feasible. One of these applications is permeable wearing course that helps to drain off rainfall. In order of understand such bituminous mixtures a research was undergone in University of Campinas' Road Laboratory of Civil Engineering - UNICAMP where four different open coarse gradations were characterized, presenting a wide range of cases. As a result of this research new test methods for mixture design are proposed. It will be useful for selecting the right mixture for that place (amount of rain) in order to ensure user safety mainly. The continuation of this research includes other open graded mction coarse design since the adoption of this solution is growing nationwide / Mestrado / Transportes / Mestre em Engenharia Civil

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / Road transport is extremely important for the development of Brazil and the increasing vehicular traffic in the transport of people gives an excessive dependence on roads. The quality of the road network of the country requires improvements to both structural aspects (resilience to the efforts required by traffic) as the functional in driving the vehicle, especially in terms of safety and acoustics, requiring the construction of increasingly discerning pavement and improved. Among the various types of asphalt blends, the asphalt blends of open type graded friction course (OGFC), presents some characteristics that serve as an alternative to the functional improvement of a pavement. In the present study verified the mechanical and functional behavior of five types of blends of OGFC to be used in construction of federal highways in Rio Grande do Sul, comparing with data from two Asphalt Concrete blends (AC) - (Range B and C). To determine the mechanical properties were used the tests resilient modulus (RM), tensile strength (RT) and testing Cântabro abrasion (PM), to investigate the functional properties were used sound absorption testing and hydraulic conductivity and finally to evaluate the structural contribution of the OGFC in flexible pavements a mechanistic analysis was carried out. The five OGFC mixtures were designated OGFC1, OGFC2, OGFC3, OGFC4 (with lime) and OGFC5 (with lime) and the mixtures of AC designated in ACB (Range B) and ACC (Range C). Samples OGFC and AC was determined the density parameters along with the volumetric properties, voids, empty bitumen ratio and other properties, being prepared with asphalt cements oil (CAP) 60/85 and CAP 55/75 respectively. In the test PM Cantabro it was observed that increasing the binder content leads to a consequent improvement in wear resistance. In RT assays, it was found that no peak maximum variable resistance trends in different amounts of binders, blends OGFC. In the RT assays, it was found that there are variable maximum strength values, in the different binder contents, in the OGFC mixtures. The RM test showed that the deformability of the blends increases as the amount of binder increases, and consequently decreases the value of RM, it being understood that the asphalt binder decreases the rigidity of the blends. The increase of temperature and decrease of charging frequency increases the deformability for all mixes for making a termosusceptivel behavior. In the sound absorption assay, the five OGFC blends exhibited fairly high absorption values with variations in peak absorption values between 0.90 and 0.98 between the 500 and 800 Hz frequency band. OGFC presented values of sound absorption higher than the values of dense asphalt mixtures found in the literature. The hydraulic conductivity test showed that the asphalt content directly influences the value of the hydraulic conductivity coefficient. With regard to the determination of the design content of the CPA blends, the only content that met all the specifications of the DNER-ES-386/99 standard was the 4% binder content. The OGFC1 mixture presented the best mechanical performance and the OGFC5 blend presented the best results from a functional point of view, but did not achieve good results from the mechanical point of view, presenting limit values required by standard DNER-ES-386/99. In relation to the values of deflection, horizontal deformation of traction and vertical deformation of compression, the OGFC caused a small contribution to the structure of the pavement generating a small decrease of these parameters. For the N of fatigue, a small contribution of the OGFC in the results of N of fatigue in the pavement was realized which took into consideration its use. / O transporte rodoviário é de extrema importância para o desenvolvimento do Brasil e pelo crescente aumento do tráfego de veículos no trasporte de pessoas confere-se uma dependência excessiva em relação às rodovias. A qualidade da malha viária do país requer melhorias, tanto aos aspectos estruturais (capacidade de resistência aos esforços solicitados pelo tráfego) quanto aos funcionais na condução do veículo, especialmente em termos de segurança e acústica, exigindo a construção de pavimentos cada vez mais criteriosos e aprimorados. Entre os diversos tipos de misturas asfálticas, a mistura asfáltica do tipo Camada Porosa de Atrito (CPA), apresenta algumas características que servem como uma alternativa para a melhoria funcional de um pavimento. No presente trabalho verificado o comportamento mecânico e funcional de cinco tipos de misturas de CPA que serão utilizadas em obras de rodovias federais do Rio Grande do Sul BR 158 e BR 285, confrontando com dados de duas misturas de Concreto Asfáltico (CA) - (Faixa B e C). Para investigar as propriedades mecânicas foram usados os ensaios mecânicos Módulo de Resiliência (MR), Resistência a Tração (RT) e o ensaio de Perda de Massa Cântabro (PM), para avaliar as propriedades funcionais foram usados os ensaios de absorção sonora e de condutibilidade hidráulica e por fim para avaliar a contribuição estrutural da CPA em pavimentos flexíveis realizou-se uma análise mecanística. As cinco misturas de CPA foram designadas em CPA1, CPA2, CPA3, CPA4 (com cal) e CPA5 (com cal) e as misturas de CA designadas em CAB (Faixa B) e CAC (Faixa C). Nas amostras de CPA e CA determinou-se os parâmetros de densidade juntamente com as propriedades volumétricas, volume de vazios, relação betume vazio e outras propriedades, sendo preparadas com ligante CAP 60/85 e CAP 55/75, respectivamente. No ensaio de PM Cântabro observouse, que um aumento no teor de ligante leva a uma consequente melhoria da resistência ao desgaste. Nos ensaios de RT constatou-se que há valores de resistência máxima variáveis, nos diferentes teores de ligantes, nas misturas de CPA. O ensaio de MR demonstrou que a deformabilidade das misturas aumenta ao passo que a quantidade de ligante aumenta, e consequentemente o valor de MR diminui, ficando claro que o ligante asfáltico diminui a rigidez das misturas. O aumento da temperatura e redução da frequência de carregamento aumenta a deformabilidade para todas as misturas por apresentarem um comportamento termosusceptível. No ensaio de absorção sonora, as cinco misturas de CPA apresentaram valores de absorção bastante elevado, com variações de valores do pico de absorção entre 0,90 a 0,98, entre a faixa de frequência de 500 a 800 Hz. As misturas de CPA apresentaram valores de absorção sonora maior que os valores de misturas asfálticas densas encontradas nas literatura. O ensaio de condutividade hidráulica demonstrou que o teor de asfalto e o volume de vazios influenciam diretamente no valor do coeficiente de condutividade hidráulica. Com respeito à determinação do teor de projeto das misturas de CPA, o único teor que satisfez todas as especificações da norma DNER 386/99 foi o teor de ligante de 4%. A mistura de CPA1 apresentou o melhor desempenho mecânico e a mistura de CPA5 apresentou os melhores resultados no ponto de vista funcional, porém não atingiu bons resultados no ponto de vista mecânico, apresentando valores limites exigido pela norma DNER-ES- 386/99. Em relação aos valores de deflexão, deformação horizontal de tração e deformação vertical de compressão, a CPA originou uma pequena contribuição para a estrutura do pavimento gerando uma pequena diminuição desses parâmetros. Para o N de fadiga, percebeu-se uma pequena contribuição da CPA nos resultados encontrados de N de fadiga nos pavimento os quais levou-se em consideração sua utilização.

Urbanisation is characterised by mass migration of people to urban areas and conversion of land from rural to urban land uses. Changes in population dynamics have led to half the world’s population living in urban areas; in developed countries, urban dwellers account for three-quarters of the total population. Though populations have shifted from rural to urban areas, people continue to rely on their environment, and trees in particular, for tangible and intangible benefits alike. A great deal of factual and anecdotal knowledge supports the role of trees for ecological, social, and economic well-being. In spite of this, during urbanisation, previously vegetated land is converted to housing, roads, or utility corridors, all of which are necessary to support growing populations. This thesis investigates tree growth in these modified urban landscapes, in particular, the effects of pavements on urban trees. Pavements are truly pervasive, covering more than half of all land in highly developed urban areas. Their durability and strength are of great importance to transportation, but large-scale soil sealing is not without consequence. Pavements affect the hydrologic cycle, soil and air temperature, and nutrient cycling. Because of their effect on the surrounding environment, pavements inherently affect remnant or planted trees. They are believed to negatively affect tree growth and survival, thereby compromising the ecological, social, and economic benefits otherwise derived from the urban forest. In recent times, porous pavements have been increasingly installed in favour of impervious pavements. Porous pavements are perceived to be an environmentally-sound alternative to standard impervious pavements. This thesis begins by reviewing the literature concerning porous pavement’s effect on underlying soil and urban vegetation, thus illustrating the scarcity of empirical data describing the effect of porous pavement on tree growth. A greater understanding of porous pavement’s impact on the surrounding environment is needed, if its installation is to continue. With this aim in mind, this thesis describes an experiment in Christchurch, New Zealand, which monitored the impacts of porous and impervious pavement on underlying soil conditions, and subsequent tree growth. The experiment comprised 50 Platanus orientalis trees planted in an augmented factorial design, which consisted of controls and four treatments. Trees were split evenly amongst plots, such that ten replicates existed per treatment. The pavement treatments measured 2.3m by 2.3m, and were based on the combination of pavement type (2 levels: porous, impervious) and pavement profile design (2 levels: +/- subbase compaction and gravel base). The resulting four treatments were impervious concrete pavement (IP), impervious concrete pavement with compacted subbase and gravel base (IP+), porous concrete pavement (PP), and porous concrete pavement with compacted subbase and gravel base (PP+). From December 2007 to March 2009, data were collected to determine the effect of these treatments on soil moisture, aeration, pH, and nutrient concentration. Final tree height, stem diameter, shoot and root biomass, and root distribution were also measured at the conclusion of the experiment. Results of this experiment indicated that the effects of pavement porosity on soil moisture and aeration were dynamic, varying with season and soil depth. Increased soil moisture beneath porous pavements resulted from rapid infiltration following precipitation. This decreased the duration of plant stress resulting from drought. Relative to bare soil, paved plots had consistently greater soil moisture, likely because pavements reduced evaporation. The inclusion of a gravel base in the profile design limited capillary upflow, which resulted in lower soil moisture under pavements designed with a gravel base. Soil aeration was significantly lower beneath pavements relative to unpaved plots. This is likely related to greater soil moisture beneath pavements. Finally, soil pH increased beneath pavements, in particular beneath porous pavements. Though all growth parameters increased for trees surrounded by porous, rather than impervious pavement, this occurred only in the absence of a compacted subgrade and gravel base. Evidently, the impact of the compacted subgrade superseded the impact of pavement porosity. Furthermore, root growth was relatively shallow beneath pavements, likely due to favourable soil moisture directly beneath pavements. This research highlights (i) the dramatic effect of pavements on underlying soil conditions; (ii) that pavements do not inherently limit tree growth; (iii) that porous pavements can conditionally improve tree growth; and (iv) that soil compaction limits potential benefits resulting from porous pavements.

The thesis is aimed at deepening knowledge about the design and use of open-graded asphalt concrete filled with a special cement grout. The first part is the issue discussed theoretically with reference to the real possibility of practical application, a description of the various manufacturers and their patented technologies. The second part of this work is devoted to assess the resistance of this technology to chemical de-icing agents.

<p>Moisture can significantly affect flexible pavement performance. As such, it is crucial to remove moisture as quickly as possible from the pavements, mainly to avoid allowing moisture into the pavement subgrade. In the 1990s the Indiana Department of Transportation (INDOT) adopted an asphalt pavement drainage system consisting of an open-graded asphalt drainage layer connected to edge drains and collector pipes to remove moisture from the pavement system.</p> <p>Over the intervening two decades, asphalt pavement materials and designs have dramatically changed in Indiana, and the effectiveness of the pavements drainage system may have changed. Additionally, there are challenges involved in producing and placing open-graded asphalt drainage layers. They can potentially increase costs, and they tend to have lower strength than traditional dense-graded asphalt pavement layers. </p> <p>Given the potential difficulties, the overall objective of this research was to evaluate the effectiveness of the INDOT’s current flexible pavement drainage systems given the changes to pavement cross-sections and materials that have occurred since the open-graded drainage layer was adopted. Additionally, the effectiveness of the filter layer and edge drains were examined.</p><p><br>Laboratory experiments were performed to obtain the hydraulic properties of field-produced asphalt mixture specimens meeting INDOT’s current specifications. The results were used in finite element modeling of moisture flow through pavement sections. Modeling was also performed to investigate the rutting performance of the drainage layers under various traffic loads and subgrade moisture conditions in combination with typical Indiana subgrade soils. The modeling results were used to develop a design tool that can assist the pavement designer in more accurately assessing the need for pavement drainage systems in flexible pavements.<br></p>

Aim of this thesis is the usage of the open-graded asphalt concrete filled with a special cement grout in the road structures. Thesis defines the main concrete properties and explains related legislation and norms that apply. In addition, laboratory design of asfalt mixtures and a tree kind mortal filler and possibilities of mortal filler pigmentation are dealth with. Finally, thesis evaluates the results from various laboratory tests that were performed on the specimens made from final mixtures.