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Canadian Solar Road Panel Design: A Structural and Environmental AnalysisNorthmore, Andrew 05 February 2014 (has links)
Solar road panels are a technology that have the ability to revolutionize the way that roads are built and how electricity is generated. Strong incentives towards sustainable solutions in both of these fields have led to the design of innovative, multifaceted solutions, of which solar road panels are one of the most recent entrants. This research presents some initial analysis into the design of solar road panels from the perspective of Canadian pavement engineering. The hypothesis of this research was as follows:
A specially designed modular panel can be constructed to withstand the structural and environmental loads on Canadian pavement structures while simultaneously generating electricity through embedded photovoltaic cells.
Through a process that covers the design, construction, and analysis of the structural elements of a solar road panel prototype, this research evaluated the impact that solar road panels can have for Canada???s pavement infrastructure. Specific elements researched include the material selection for such a panel, the flexural response of the composite structure, how the panel will interact with traditional pavement and geotechnical materials while in use, and the change in performance of transparent layer materials as they are subjected to freeze-thaw cycling and scaling.
The research found that the initial prototype design included a two 10-mm tempered glass pane transparent layers with a 12.7-mm GPO-3 optical layer and 19.1-mm GPO-3 base layer. The concept being that the glass would provide the rigidity required to protect the fragile solar cells while the fiberglass laminate has demonstrated performance as a traffic-supporting material in adverse conditions.
Testing of this structure found that the performance was easily duplicated through finite element analysis, given that the material properties were assumed to be more rigid than the averages for tempered glass and GPO-3. Further finite element analysis demonstrated that the prototype solar road panel would not fail through traditional fatiguing methods, and in all cases on concrete, asphalt, granular, and subgrade bases the panels improved the performance characteristics of the structural base.
The environmental conditioning of acrylic, glass, and polycarbonate specimens demonstrated that glass is the ideal material choice for the transparent layer for Canadian solar road panels. It proved to have the greatest freeze-thaw and scaling resistance of the three materials, and while the friction characteristic of the flat glass samples would not be suitable for driving on, avenues of research were identified that could improve this characteristic.
In summary, the research conducted clearly proved the hypothesis; it is possible to build a structure that can house a photovoltaic system while supporting the structural and environmental loads that Canadian pavement are exposed to. The ideal panel would be constructed with a tempered glass transparent layer, GPO-3 optical and base layers, and the structure would be installed on a concrete structural base. The refinement of this design will be the scope for future research.
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A methodology for characterizing pavement rutting condition using emerging 3D line laser imaging technologyLi, Feng 12 November 2012 (has links)
Pavement rutting is one of the major asphalt pavement surface distresses affecting pavement structure integrity and driving safety and is also a required performance measure specified in the Highway Performance Monitoring System (HPMS). Manual rutting measurement is still conducted by many state Departments of Transportation (DOTs), like Georgia DOT; however, it is time-consuming, labor-intensive, and dangerous. Although point-based rut bar systems have been developed and utilized by state DOTs to measure rutting conditions, they often underestimate rut depth measurements. There is an urgent need to develop an automated method to accurately and reliably measure rutting conditions. With the advance of sensing technology, emerging 3D line laser imaging technology is capable of collecting high-resolution 3D range data at highway speed (e.g., 100 km/h) and, therefore, holds a great potential for accurately and repeatedly measuring pavement rutting condition. The main contribution of this research includes a methodology, along with a series of methods and procedures, for the first time, developed utilizing emerging 3D line laser imaging technology to improve existing 1D rut depth measurement accuracy and repeatability and to measure additional 2D and 3D rutting characteristics. These methods and procedures include: (1) a threshold-based outlier removal method employing the multivariate adaptive regression splines (MARS) technique to remove outliers caused by non-rutting features, such as wide transverse cracks and potholes; (2) a modified topological-ordering-based segment clustering (MTOSC) method to optimally partition the continuous roadway network into segments with uniform rutting condition; (3) an overlapping-reducing heuristic method to solve large-scale segmentation problems; (4) a network-level rutting condition assessment procedure for analyzing 3D range data to statistically interpret the pavement rutting condition in support of network-level pavement management decisions; (5) an isolated rut detection method to determine the termini, maximum depth, and volume of isolated ruts in support of project-level maintenance operations. Comprehensive experimental tests were conducted in the laboratory and the field to validate the accuracy and repeatability of 1D rut depth obtained using the 3D range data. Experimental tests were also conducted in the laboratory to validate the accuracy of 3D rut volume. Case studies were conducted on one interstate highway (I-95), two state routes (SR 275 and SR 67), and one local road (Benton Blvd.) to demonstrate the capability of the developed methods and procedures. The results of experimental tests and case studies show that the proposed methodology is promising for improving the rutting measurement accuracy and reliability. This research is one of the initial effort in studying the applicability of this emerging sensing technology in pavement management. And the outcomes of this research will play a key role in advancing state DOTs’ existing pavement rutting condition assessment practices.
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Evaluation of thermal variations on concrete pavement using three dimensional line laser imaging technologyLewis, Zachary Ludon 13 January 2014 (has links)
Jointed Plain Concrete Pavements (JPCP) are some the most popular forms of concrete pavement that are used in the state of Georgia. Each year the Georgia Department of Transportation (GDOT) inspects and surveys their highways to determine what condition the pavement is in and if any rehabilitation is required to maintain the integrity of the highway. These annual surveys include the JPCP and the key concrete pavement characteristics that are used to determine the condition of the JPCP are the faulting at the joints and the roughness of the section. Since it is well known that concrete will exhibit slight movement when subjected to thermal variations it is possible that the these minor movements could have an impact on the measured slab properties used to rate the JPCP section. The focus of this research is to develop a methodology to use three dimensional technologies to capture JPCP surface data under a variety of thermal conditions, to develop a procedure to collect and analyze concrete temperature data, to develop a method to analyze the surface data and how to correlate all of the data that was collected. Three test sites were chosen that covered a total of 6 test sections that were composed of 25 slabs and 26 joints each. This provided a total of 150 slabs and 156 joints that were used for analysis.
A single slab was selected as a test specimen to install thermal logging devices into so that the temperature distributions through the slab could be investigated. Three positions were monitored to determine if the position that the temperature gradient was measured was critical. It was found that the temperature followed a similar trend for all of the positions with the profiles being slightly shifted from each other. It was also concluded that the temperature in the bottom of the slab was approximately the same as the temperature in the base. It was discovered that the maximum positive temperature gradient occurred simultaneously with the maximum ambient air temperature and the maximum surface temperature. The results showed that the surface temperature followed a trend similar to the ambient air temperature. However the surface temperature was greater throughout the day.
The faulting analysis results indicated that out of the 156 joints inspected only 15 showed a variation in the average faulting that was greater than the 0.5 mm (0.02 in) accuracy of the sensors used to collect the JPCP surface data. Further investigation revealed that there was no clear trend between the temperature change and the average faulting variation. It was concluded that if there was a change in the average faulting due to temperature it is smaller than what can be depicted by the sensing vehicle and it is less than the 1 mm (0.04 in) measurement accuracy that is specified in the American Association of State Highway and Transportation Officials (AASHTO) R36-04 specification which governs the accuracy requirements for automated faulting measurement methods.
The International Roughness Index (IRI) was the method used to measure the roughness on each test site for each data collection run. This resulted in 336 IRI values that were inspected to determine whether there was an impact from the temperature variations. The IRI results showed that the roughness of the test sections did vary through the day. After it was found that the IRI did vary through the day the IRI distributions were compared to the temperature distribution and 7 out of the 12 distributions studied showed a weak correlation between the temperature and the IRI. The amount of variation in the IRI was not quantified because the exact accuracy of the IRI values attained from the sensing vehicle was unknown. However it was attempted to validate the system and determine the accuracy but one of the validation test sections showed disappointing results while the other two showed promising results. Further research is required to fully evaluate the sensing vehicles ability and accuracy when measuring the IRI.
A procedure was also developed to extract the longitudinal and transverse curvature of the concrete pavement slabs. Three test slabs were selected at one of the test sites and curvature results were generated using the developed procedure. The curvature results were visually and quantitatively assessed. The visual analysis indicated that the curvature profiles measured by the 3D line lasers did change throughout the data collection, but the patterns did not follow what was expected and a correlation could not be created with the temperature. The quantitative results for the longitudinal curvature revealed that one of the slabs did show a pattern that followed the temperature changes during the data collection, but it did show as much as 4.65 mm (0.183 in) of change between consecutive data collection runs. The longitudinal curvature results for the other two slabs did not show a trend and exhibited unlikely changes in the curvature measured between consecutive data collection runs, which in some instances the deviation was as much as 12.09 mm (0.480 in). For the transverse curvature one of the slabs indicated that the curvature did not change during the data collection, while the other two showed sudden changes as high as 2.16 mm (0.085 in) between consecutive data collection runs. The developed procedure is only preliminary and needs to be further evaluated and refined for it to be able to adequately measure the curvature of as slab. The results also need to be verified using actual measured ground truth curvatures to determine the validity of using the developed procedure and the 3D line laser data to measure the curvature of concrete slabs. Once the procedure is proven to produce reliable results it should be compared to other curvature computation methods, such as those that utilize road profilers or LIDARs, to determine which method is the best.
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Laboratory characterisation of cementitiously stabilised pavement materialsWhite, Gregory William, Aerospace, Civil & Mechanical Engineering, Australian Defence Force Academy, UNSW January 2007 (has links)
Insitu cementitious stabilisation is an economical, environmentally sustainable and socially advantageous means of rehabilitating pavements. With the recent availability of a wide range of binders and advanced construction equipment, the characterisation of cementitiously stabilised pavement materials has become the focus of further advancement of this technology. Australian practice has moved towards the use of Indirect Diametric Tensile (IDT) methods for the characterisation of these materials. A draft protocol for the IDT test has been prepared and specifies samples to be compacted by gyratory compactor. This procedure provides for both monotonic and repeated load testing, which aims to measure the material???s strength, modulus and fatigue life. A range of host materials, including a new crushed rock and a reclaimed existing pavement base course, were assessed when stabilised with a General Purpose cement binder as well as with a slag-lime blended binder. Materials were assess for their inherent material properties, Unconfined Compression Strength (UCS), Unconfined Compression modulus, IDT strength and modulus under both monotonic and repeated load. A number of amendments and refinements to the testing protocol were recommended. These included the use of minimum binder contents to ensure the binder was uniformly distributed and to promote heavy binding of the materials to ensure they behaved elastically. It was also recommended that samples be gyratory compacted to a pre-determined sample height to allow a constant density to be achieved. The variability of the test results was examined. UCS results were found to be comparatively as variable as other researchers had reported. IDT strength results contained a similar level of variability, which was considered to be acceptable. Modulus results, both monotonic and repeated load, were found to be five to ten times more variable than strength results, which is a generally accepted trend for modulus testing. Under repeated loading, some challenges with the test protocol were encountered. The primary challenge was obtaining reliable and repeatable diametrical displacement data for modulus calculation. This was partially overcome by the insertion of smooth spacers to prevent the Linear Voltage Displacement Transformer (LVDTs) becoming caught on the sample sides. The achievement of reliable and repeatable IDT modulus results through improved displacement measurements should be the focus of future research efforts in this area.
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Infrastructure, separation, and inequality the streets of Indianapolis between 1890 and 1930 /Reichard, Ruth Diane. January 2008 (has links)
Thesis (M.A.)--Indiana University, 2008. / Title from screen (viewed on June 1, 2009). Department of History, Indiana University-Purdue University Indianapolis (IUPUI). Advisor(s): Annie Gilbert Coleman, Robert G. Barrows, Jason M. Kelly. Includes bibliographical references (leaves 152-165).
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Three-dimensional pavement surface texture measurement and statistical analysisLiu, Qingfan 09 January 2016 (has links)
Pavement texture has been measured predominantly by using two-dimensional (2D) profile methods. The 2D profile based mean profile depth (MPD) is still the well accepted texture index which has been found inadequate to characterize pavement texture especially when tire/pavement friction and noise are involved.
There is a lack of standard 3D texture indices which show strong correlation with pavement friction and noise. There is a need to use 3D texture measurement for more comprehensive understanding of texture.
The objectives of this thesis are to characterize pavement surfaces using 3D texture parameters based on 3D texture measurement and to explore the relationship between 3D texture parameters, pavement friction, and pavement noise.
Field tests are conducted at various pavement sections for the measurements of texture, friction, and noise. The tested pavements include Interstate highway, MnROAD test facilities, airport runway, and municipal streets.
The findings and contributions of this thesis are:
• The pavement surface texture is measured in a 3D manner by using a line-laser scanner with both horizontal sample interval and vertical accuracy better than 0.05 mm.
• A 3D texture analysis procedure with discrete wavelet transform (DWT) is proposed to separate macrotexture from microtexture and to define texture indices independently.
• 3D parameters for macrotextures and microtexture are proposed and verified by field tests.
• The relationship between 3D and 2D macrotexture indices [i.e. SMTD and MPD; Sq and root mean square roughness (RMSR)] are established, which is useful for the purposes of data comparison between 3D and 2D methods.
• The relationship is investigated between 3D macrotexture parameters (SMTD and Sq) and pavement friction and noise.
• It is found that texture distribution indices (i.e. Ssk and Sku) are significant contributors to pavement friction and noise.
The new 3D texture analysis procedure and texture indices proposed in this thesis can be used to characterize various pavement textures (concrete pavement, asphalt pavement, and pavement contains recycled materials) in 3D manner, to compare 3D with 2D texture measurement/indices for quality control purposes, and to evaluate and predict pavement friction and noise. / February 2016
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Avaliação de misturas mornas com emprego de simulador de tráfego linear / Evaluation of warm asphalt mixtures with the use of linear traffic simulatorRivoire Junior, Larry January 2014 (has links)
Esta pesquisa relata o estudo da elaboração e avaliação de desempenho de misturas asfálticas mornas com uso de zeólitas naturais. Ela foi dividida em três etapas. A primeira consistiu na execução de ensaios de laboratório que buscaram conhecer algumas propriedades e o funcionamento da mistura asfáltica morna com utilização de zeólitas naturais através da determinação do projeto da mistura e da elaboração em diferentes temperaturas. A segunda etapa consistiu na preparação da usina de asfalto para misturas à quente para a fabricação de misturas a temperaturas inferiores, nas regulagens de temperatura e na verificação dos procedimentos necessários para adequar uma usina padrão para elaborar misturas mornas nas temperaturas de projeto. Na última etapa, foi feito o acompanhamento do transporte, espalhamento, compactação das misturas mornas e posterior avaliação de desempenho dos pavimentos, com o emprego de simulador de tráfego linear, em três testes, realizados em duas pistas experimentais, localizadas na Área de Testes de Pavimentos, no Campus do Vale da Universidade Federal do Rio Grande do Sul. / This research reports the study of the production, implementation and performance evaluation of warm asphalt mixtures prepared by adding natural zeolites. It was divided into three stages. The first consisted of performing laboratory tests that get to know some properties and the functioning of warm mix asphalt, determining the projects of mixtures which were used in accelerated tests after analysis of specimens produced by different temperatures of manufacturing and compression. The second step consisted of preparing an asphalt plant for conventional mixtures for the manufacture of mixtures at lower temperatures, in temperature settings, and checking the necessary procedures to tailor a pilot plant to produce warm mixtures according to the temperatures of the project. In the last step, the transport, spreading and compaction of warm mixtures and subsequent performance evaluation of pavements were checked, with the use of linear traffic simulator in three tests conducted on two experimental tracks, located in Testing Pavement Area, on Valley Campus of the Federal University of Rio Grande do Sul.
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Avaliação da aderência pneu-pavimento e tendências de desempenho para a rodovia BR-290/RS / Evaluation and modeling of tire-road friction in brazilian federal road BR-290/RSMattos, João Rodrigo Guerreiro January 2009 (has links)
A aderência pneu-pavimento é um dos parâmetros mais importantes da segurança viária e deve ser avaliada em duas escalas: microtextura e macrotextura. As medidas de textura da superfície de pavimentos podem ser obtidas por diversos equipamentos, sendo que os mais difundidos são o Pêndulo Britânico e a Mancha de Areia. Dessa forma, esta pesquisa pretende utilizar esses dois equipamentos para verificar o comportamento da textura em função do tempo/tráfego para diferentes tipos de revestimentos. Para tanto, foram realizados levantamentos dos valores de micro e macrotextura em pavimentos da rodovia BR-290/RS, trecho Osório-Porto Alegre, com uma freqüência aproximadamente mensal durante um período inferior a um ano. Com base nos dados coletados, foi possível desenvolver tendências de desempenho da micro e macrotextura para pavimentos flexíveis e rígidos dessa rodovia. Os modelos propostos para a estimativa da textura podem ser usados como ferramentas auxiliares no Sistema de Gerência de Pavimentos (SGP), prevendo o momento oportuno para intervenções na superfície dos pavimentos de modo a garantir a segurança dos usuários. Após a análise dos resultados, constatou-se que, no geral, os pontos de monitoração da rodovia BR- 290/RS apresentam boas condições de aderência pneu-pavimento quando avaliados pelo International Friction Index (IFI), que é um índice representativo da combinação entre a macro e microtextura do pavimento. Além dos modelos para estimativa da textura, desenvolveu-se nesta pesquisa um modelo de correlação entre os resultados dos ensaios de Mancha de Areia e de Drenabilidade, possibilitando, assim, a estimativa do IFI através do valor da vazão de água na superfície do pavimento. / Tire-road friction is one of the most important parameters regarding the safety of vehicles under slippery road conditions. Road surface texture is currently evaluated using several devices. In Brazil, the British Pendulum and the sand-patch method are most frequently used to measure microtexture and macrotexture, respectively. They were used in the research reported in this dissertation that aimed at verifying texture evolution with time/traffic on different types of pavement wearing courses. Thus, micro and macrotexture values were monthly measured in surveys carried out during one year in Brazilian Federal Road BR- 290/RS. Collected data allowed defining performance trends regarding micro and macrotexture of asphalt and Portland Cement Concrete (PCC) pavements. The models here proposed might be used as auxiliary tools in Pavement Management Systems (PMS) to estimate the time when a given rehabilitation action is necessary to assure vehicle and drivers safety. Results analysis showed that the surveyed pavements present adequate tire-road friction, when evaluated by the International Friction Index (IFI) which combines pavements macro and microtexture. In addition, a model relating results of the sand-patch method to drainability results is proposed. Such model allows the estimation of the IFI based on values of water inflow through the pavements wearing courses.
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Qualificando solos para revestimentos primários de rodovias : uma abordagem baseada nas mecânicas dos solos e dos pavimentos / Qualifying soils for road wearing courses : an approach based on mechanics of pavements and soil mechanicsPeraça, Vinícius January 2007 (has links)
Esta dissertação apresenta os resultados do estudo de dois solos saprolíticos de rochas vulcânicas, localizados em jazidas próximas às cidades de São Martinho da Serra e Silveira Martins (região central do RS), para aplicação como revestimento primário em estradas não pavimentadas da região ou como camada de pavimentos delgados. A análise dos materiais procura valer-se dos conhecimentos da Mecânica dos Pavimentos à luz dos conceitos da Mecânica dos Solos. Esta abordagem se justifica porque solos aplicados em revestimento primário estão sujeitos à ação do tráfego, porém seu comportamento será comandado pelos princípios da Mecânica dos Solos. O programa experimental incluiu ensaios de caracterização e classificação dos materiais, além de ensaios para a determinação do ISC e curva de compactação, difratometria de raios X, ensaios de cisalhamento direto na condição inundada, ensaios triaxiais de carga repetida para a obtenção dos módulos resilientes e das deformações permanentes e determinação das curvas de retenção de água dos materiais. Avalia-se a influência do teor de umidade e grau de compactação nos parâmetros de deformabilidade e resistência destes solos. Maior grau de compactação implica para estes materiais, crescimento dos parâmetros de resistência (c’ e f’), aumentando a resistência às tensões cisalhantes. O aumento do teor de umidade provoca a redução da sucção que, como conseqüência, provoca a diminuição das tensões efetivas e aumento das deformações resilientes e plásticas. Verifica-se que o solo de Silveira Martins é mais sensível à umidade se comparado ao solo de São Martinho da Serra, pois com apenas o acréscimo 2% de umidade em relação à ótima, o material sofre enormes deformações permanentes entrando em colapso. O material de São Martinho apresenta-se mais deformável e seu módulo resiliente decresce quando ocorre aumento no seu teor de umidade. Ao final, a análise mecanística apresentada permitiu avaliar algumas alternativas de uso destes materiais, seja como revestimento primário ou como camada estrutural de pavimentos, principalmente, com revestimentos delgados. Como era de se esperar, o grau de compactação exerceu grande influência no desempenho destes materiais em camadas de revestimento primário, explicitando a importância de compactá-los adequadamente. / This MSc thesis presents the results of a study of two saprolitic soils from volcanic rocks taken from sites near São Martinho da Serra and Silveira Martins towns (central area of RS State), for use as wearing course on unpaved roads of the region or as under layer of thinly surfaced road. The study uses knowledge from Pavement Mechanics with insights of Soil Mechanics concepts. The soils applied on wearing course are subjected to direct traffic action and their behavior will be influenced by Soil Mechanics principles. The experimental program included characterization tests, materials classification, ISC and compaction tests, X Rays difratogrammetry, direct shear tests on saturated and unsaturated conditions, repeated loading triaxial testing for resilient moduli determination, tests of permanent deformations and characteristic curves of the materials. The influence of the humidity and degree of compaction on the shear strength and deformability of the soils has been evaluated. In these materials a larger degree of compaction results in a growth of the shear strength parameters (c’and f’), increasing the resistance to shearing stress. The increase of the water content causes a reduction of the suction and, as consequence, a reduction of the effective stress and an increase of resilient and plastic deformations. It was verified that the Silveira Martins soil is more affected by water content variation than the São Martinho da Serra soil as an increase of only 2% of humidity above the optimum causes large deformations leading to collapse. The São Martinho da Serra soil is more deformable and its resilient modulus decreases when the water content is increased. The mechanistic analysis presented allowed the evaluation of some alternatives of use of these materials besides as structural layers of pavement with thin structural surfaces. As expected, the degree of compaction exerted great influence in the performance of these soils in wearing course, emphasizing the importance of adequate compaction.
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Proposta para simplificação de ensaios destrutivos e não-destrutivos para o monitoramento do ganho de resistência de pavimentos de concreto para fast-track / A proposal to simplify destructive and non-destructive testing aiming at monitoring strength gain in fast-track concrete pavementsAzevedo, Ângela Azevedo de January 2008 (has links)
A construção de pavimento de concreto de cimento Portland para liberação rápida, conhecido como fast-track, é uma boa solução principalmente para reparos em locais onde não se pode interromper o tráfego por um período muito grande, cujas técnicas são abrangentes, servindo para obras de construção, reconstrução ou para execução de camadas superpostas. Normalmente o ensaio utilizado para verificar a resistência do concreto para pavimentação é o de resistência à tração na flexão. Em função da grande variabilidade deste ensaio e da demora dos resultados, uma vez que o corpo-de-prova é normalmente ensaiado em laboratório na idade em que se deseja saber a resistência, engenheiros que executam ou fiscalizam obras de pavimento de concreto para fast-track demonstram certa insatisfação com relação a este procedimento. Alternativamente, uma opção promissora para este monitoramento é a utilização dos ensaios de maturidade e ultra-som, que avaliam indiretamente a resistência do concreto in situ. Para contribuir nesta área do conhecimento, realizaram-se ensaios de resistência à tração na flexão, resistência à compressão, maturidade e ultra-som (método direto e indireto), em concretos, argamassas e pastas com cimento Portland de alta resistência inicial (CPV-ARI), para avaliar a possibilidade de correlações entre os ensaios de resistência à tração na flexão e os de ultra-som e maturidade. Os fatores controláveis foram a relação água/cimento (0,25-0,35-0,45) e a idade (1-2-3-7-28 dias). A diferença dos resultados de energia aparente de ativação (maturidade) utilizando diferentes tipos de corpos-de-prova não foi significativa em relação ao corpo-de-prova recomendado pela ASTM C 1074. Encontrouse um coeficiente de correlação de 95,4% entre os resultados de resistência à tração na flexão dos ensaios e os previstos pelo ensaio de maturidade. Não se constatou diferença significativa entre os resultados de velocidade ultra-sônica para os diferentes métodos de ultra-som utilizados. Todos os métodos de ultra-som apresentaram bons coeficientes de correlação com a resistência à tração na flexão, sendo que para o método indireto com três pontos de recepção obteve-se um coeficiente de correlação de 80,8% para as idades de até 24 horas e de 76,4% considerando todas as idades ensaiadas. Portanto, tanto o ensaio de ultra-som como o de maturidade mostraram-se eficazes para estimar a resistência à tração em idades iniciais, o que pode facilitar o controle de concreto para fast-track em campo. / The construction of concrete pavement made of Portland cement for fast use, known as fasttrack, is a good solution, mainly for restoration in places where traffic cannot be disrupted for long. Fast-track concrete pavement techniques are broad, and can be used for construction, reconstruction, and resurfacing. For determining concrete strength in pavement, the flexural strength test is usually used. Since this test presents high variability and demands more time because the specimen is usually tested in laboratories at certain selected ages, engineers who carry out or monitor fast-track concrete pavement projects have shown some dissatisfaction with this procedure. Alternatively, a promising option to monitor this work is the use of maturity and ultra-sound tests, which evaluate concrete strength directly in situ. In order to contribute to this area of knowledge, I have carried out flexural strength, compressive strength, and maturity and ultra-sound (direct and indirect methods) tests in concrete, mortar, and Portland cement paste with high early strengths (CPV-ARI) to evaluate possible correlations among the flexural strength tests and the maturity and ultra-sound ones. The controllable factors were the water-cement ratio (0.25-0.35-0.45) and the age (1-2-3-7-28 days). The difference in the results of the apparent activation energy (maturity), using different types of specimens, was not meaningful if compared to the specimen recommended in ASTM C 1074. Among the results of the flexural strength tests and the ones obtained in the maturity test, the correlation coefficient has been found to be 95.4%. No meaningful difference was found among the results of ultra-sonic speed for the different ultra-sound methods. All ultra-sound methods have shown good correlation coefficients with flexural strength: for the indirect method with three reception points, the correlation coefficient has been found to be 80.8% at ages up to 24 hours, and 76.4% at all test ages. Therefore, both the ultra-sound and the maturity tests have proven to be efficient to estimate tensile strength at early ages; thus, help control fast-track concrete in the field.
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