Thesis (M.S. in civil engineering)--Washington State University, May 2010. / Title from PDF title page (viewed on June 16, 2010). "Department of Civil and Environmental Engineering." Includes bibliographical references (p. 82-89).

Thesis (M.S.)--University of Nevada, Reno, 2007. / "May, 2007." Includes bibliographical references (leaves 45-46). Online version available on the World Wide Web.

Dissertation (Ph.D.)--Auburn University, 2005. / Abstract. Includes bibliographic references (p.82-87).

No description available.

The increase and change in traffic loading in recent years has resulted in the introduction of a new range of high performance asphalt binders. These new binders known as modified asphalt binders, have a more complex behavior than traditional binders. A review of the current mathematical models shows that most of them suffer from different drawbacks that make them inadequate for their intended application. To describe the behavior of straight and modified binders in the thermorheologically simple linear viscoelastic region, two models are proposed. Models to characterize the absolute value of the complex shear modulus (|G*|) and the phase angle (d) were developed using the matching function approach and validated by an experimental program. The dynamic mechanical properties of two typical paving grade binders and three modified binders were tested at intermediate and high service temperatures. Short-term and long-term aging were simulated by the rolling thin film oven test and the pressure aging vessel test, respectively. A dynamic shear rheometer with parallel plate configuration was used to conduct the dynamic mechanical tests at frequencies between 0.06 to 188.5 rad/sec and temperatures ranging from 5 to 75°C. Prior to the frequency sweeps, strain sweeps were performed to establish the linear viscoelastic region. Results indicated a strong susceptibility to the defined strain at intermediate temperatures; however, strain susceptibility was less pronounced at high temperatures. Frequency sweeps were then conducted at a constant strain corresponding to greater than 95% of the initial complex shear modulus as established by AASHTO TP5 for straight asphalts. The Time-Temperature Superposition Principle was used to construct the master curves. The shift factors were determined based on the complex shear modulus master curves and verified for the phase angle, storage shear modulus and loss shear modulus. After construction of the master curves, non-linear regression was used to fit the proposed models to the experimental data. Comparison between the measured and predicted values indicated a good agreement for frequencies higher than 10⁵ rad/sec. The phase angle model was found to adequately describe unmodified binder with a small percentage of errors (less than 6%). On the other hand, the phase angle model was found unable to simulate the plateau region observed for polymer-modified binders. However, the error in this case was found to be relatively small (from zero to 10%). The ability of the models to estimate other viscoelastic functions, e.g. storage shear modulus (G'), loss shear modulus (G"), and relaxation spectrum (H(t)), was found to be adequate. / Master of Science

abstract: The application of fibers and other materials in asphalt mixes has been studied and applied over the past five decades in order to improve pavement performance around the world. This thesis highlights the characteristics and performance properties of modified asphalt mixes using a blend of polypropylene and aramid fibers, The main objective of this study was to evaluate the effect of adding different fiber dosages on the laboratory performance of both asphalt binder and mixture. The laboratory study was conducted on sixteen different dosages and blends of the fibers, with various combinations of polypropylene and aramid, using binder tests as well as hot mix asphalt tests. The binder tests included: penetration, softing point, and Brookfield viscosity tests. The asphalt mixture tests included the dynamic modulus, and indirect tensile strength. The binder test results indicated that the best viscosity - temperature susceptibility performance would be from the blend of three dosages of polypropylene and one dosage of aramid, the dynamic modulus test results also confirmed this finding. Overall, in almost every case, the addition of fibers resulted in an increase in mixture stiffness regardless of fiber content. From the indirect tensile strength results, the polypropylene fibers had less of an effect on post peak failure than the aramid fibers. Overall, the aramid fibers yielded better results than the polypropylene fibers. This study has important implications for the future of pavement design and the prospect of using optimal dosages of polypropylene and aramid fibers in further research to further determine their long-term performance and characteristics used in real world applications. / Dissertation/Thesis / M.S. Civil and Environmental Engineering 2012

Nesta dissertação de mestrado analisa-se e compara-se, através de ensaios laboratoriais, o comportamento mecânico e de adesividade de misturas em concreto asfáltico, confeccionadas a partir de ligantes asfálticos modificados e convencionais. O conhecimento e entendimento destas características são de extrema importância, pois refletem diretamente no desempenho do pavimento em serviço. Foram estudadas misturas elaboradas com um ligante convencional e três ligantes modificados por polímeros. Todas as misturas foram dosadas segundo a metodologia Marshall, e submetidas a ensaios laboratoriais de módulo de resiliência e resistência à tração por compressão diametral, resistência à fadiga com tensão controlada, fluência por compressão uniaxial dinâmico e dano por umidade induzida. Para uma avaliação combinada entre a rigidez e os modelos de fadiga das misturas, também realizou-se uma análise paramétrica de estruturas hipotéticas de pavimentos. Os resultados obtidos mostraram, na maioria dos casos, o melhor comportamento à fadiga das misturas elaboradas a partir de ligantes modificados. Embora pouco consistentes, os resultados de resistência à deformação permanente também indicam a superioridade das misturas modificadas. Entretanto, a mistura com ligante convencional foi a que se mostrou menos suscetível à temperatura nos ensaios de módulo de resiliência. Já os resultados do ensaio de dano por umidade induzida mostraram bom desempenho de todas as misturas, ainda que não se possa quantificar a influência do tipo de ligante sobre eles. / This research analyses and compares, trough laboratory tests, the mechanical and the stripping behavior of asphalt concrete mixtures, prepared with traditional and modified binders. The understanding of these characteristics is extremely important, since they reflect directly on pavements performance. Mixtures prepared with one traditional binder and three polymers modified binders. All mixtures were prepared following the Marshall methodology, and submitted to laboratory tests of resilient modulus, tensile strength, fatigue life (stress controlled), dynamic creep and resistance to moisture damage. In order to assess a combination of fatigue and stiffness modulus of the mixtures, a parametric analysis of hypothetical pavement structures was also done. The results obtained showed, in most cases, best behavior regarding fatigue of the mixtures prepared with modified binders. Although not very consistent, the results of permanent deformations resistance also indicate the superiority of the modified mixtures. However, the conventional binder mixture showed the lowest thermal susceptibility in the resilient modulus tests. The results of moisture damage resistance tests showed good performance for all mixtures, but it is not possible to quantify the influence of the binder type on then.

Nesta dissertação de mestrado analisa-se e compara-se, através de ensaios laboratoriais, o comportamento mecânico e de adesividade de misturas em concreto asfáltico, confeccionadas a partir de ligantes asfálticos modificados e convencionais. O conhecimento e entendimento destas características são de extrema importância, pois refletem diretamente no desempenho do pavimento em serviço. Foram estudadas misturas elaboradas com um ligante convencional e três ligantes modificados por polímeros. Todas as misturas foram dosadas segundo a metodologia Marshall, e submetidas a ensaios laboratoriais de módulo de resiliência e resistência à tração por compressão diametral, resistência à fadiga com tensão controlada, fluência por compressão uniaxial dinâmico e dano por umidade induzida. Para uma avaliação combinada entre a rigidez e os modelos de fadiga das misturas, também realizou-se uma análise paramétrica de estruturas hipotéticas de pavimentos. Os resultados obtidos mostraram, na maioria dos casos, o melhor comportamento à fadiga das misturas elaboradas a partir de ligantes modificados. Embora pouco consistentes, os resultados de resistência à deformação permanente também indicam a superioridade das misturas modificadas. Entretanto, a mistura com ligante convencional foi a que se mostrou menos suscetível à temperatura nos ensaios de módulo de resiliência. Já os resultados do ensaio de dano por umidade induzida mostraram bom desempenho de todas as misturas, ainda que não se possa quantificar a influência do tipo de ligante sobre eles. / This research analyses and compares, trough laboratory tests, the mechanical and the stripping behavior of asphalt concrete mixtures, prepared with traditional and modified binders. The understanding of these characteristics is extremely important, since they reflect directly on pavements performance. Mixtures prepared with one traditional binder and three polymers modified binders. All mixtures were prepared following the Marshall methodology, and submitted to laboratory tests of resilient modulus, tensile strength, fatigue life (stress controlled), dynamic creep and resistance to moisture damage. In order to assess a combination of fatigue and stiffness modulus of the mixtures, a parametric analysis of hypothetical pavement structures was also done. The results obtained showed, in most cases, best behavior regarding fatigue of the mixtures prepared with modified binders. Although not very consistent, the results of permanent deformations resistance also indicate the superiority of the modified mixtures. However, the conventional binder mixture showed the lowest thermal susceptibility in the resilient modulus tests. The results of moisture damage resistance tests showed good performance for all mixtures, but it is not possible to quantify the influence of the binder type on then.

Nesta dissertação de mestrado analisa-se e compara-se, através de ensaios laboratoriais, o comportamento mecânico e de adesividade de misturas em concreto asfáltico, confeccionadas a partir de ligantes asfálticos modificados e convencionais. O conhecimento e entendimento destas características são de extrema importância, pois refletem diretamente no desempenho do pavimento em serviço. Foram estudadas misturas elaboradas com um ligante convencional e três ligantes modificados por polímeros. Todas as misturas foram dosadas segundo a metodologia Marshall, e submetidas a ensaios laboratoriais de módulo de resiliência e resistência à tração por compressão diametral, resistência à fadiga com tensão controlada, fluência por compressão uniaxial dinâmico e dano por umidade induzida. Para uma avaliação combinada entre a rigidez e os modelos de fadiga das misturas, também realizou-se uma análise paramétrica de estruturas hipotéticas de pavimentos. Os resultados obtidos mostraram, na maioria dos casos, o melhor comportamento à fadiga das misturas elaboradas a partir de ligantes modificados. Embora pouco consistentes, os resultados de resistência à deformação permanente também indicam a superioridade das misturas modificadas. Entretanto, a mistura com ligante convencional foi a que se mostrou menos suscetível à temperatura nos ensaios de módulo de resiliência. Já os resultados do ensaio de dano por umidade induzida mostraram bom desempenho de todas as misturas, ainda que não se possa quantificar a influência do tipo de ligante sobre eles. / This research analyses and compares, trough laboratory tests, the mechanical and the stripping behavior of asphalt concrete mixtures, prepared with traditional and modified binders. The understanding of these characteristics is extremely important, since they reflect directly on pavements performance. Mixtures prepared with one traditional binder and three polymers modified binders. All mixtures were prepared following the Marshall methodology, and submitted to laboratory tests of resilient modulus, tensile strength, fatigue life (stress controlled), dynamic creep and resistance to moisture damage. In order to assess a combination of fatigue and stiffness modulus of the mixtures, a parametric analysis of hypothetical pavement structures was also done. The results obtained showed, in most cases, best behavior regarding fatigue of the mixtures prepared with modified binders. Although not very consistent, the results of permanent deformations resistance also indicate the superiority of the modified mixtures. However, the conventional binder mixture showed the lowest thermal susceptibility in the resilient modulus tests. The results of moisture damage resistance tests showed good performance for all mixtures, but it is not possible to quantify the influence of the binder type on then.

Finding innovative technologies for building our roads has always been of paramount importance. From moving to warm mix asphalt to decrease our indulgence in high energy consumption to substituting fly ash for asphalt binders to reduce dependence on pure asphalt binders from petroleum, engineers have painstakingly tried to develop new ways to improve the ways that flexible pavements are made. The major problem facing the next generation of civil engineers is sustainable practices on the field. Over the years, significant progress has been made in this regard on the impacts of building pavements on the environment. Characterizing these improvements tends to be difficult, and that is where Life Cycle Assessment (LCA) comes in. LCA is a technique used to analyze and quantify the environmental impacts of a product, system, or process. LCA shows where the significant impacts occur and how improvements can be made while recommending better practices. Even with its many advantages, its use is very constrained, especially in the United States, as it is still a very novel approach in design coupled with limited datasets and protocol for its operation. With modern technologies of substitute materials for binders like bio-oil from food waste, reclaimed asphalt pavement (RAP), and fly ash, there is a need to understand their environmental impacts. Furthermore, in this regard is where LCA can help using three significant areas: selection of materials, normalization, and characterization. Characterization refers to the identification and quantification of the relationships between the life cycle results and the environmental impacts. This research explores the environmental impacts of substituting other materials for asphalt binders using LCA. With variations in modifying levels of substitutes, results show promising levels in emissions of harmful gasses to both the air and water. This study explores ways used in normalizing this process as well as setting up a pathway for other asphalt binder substitutes. / Civil Engineering