Pervious concrete pavement has the capacity to perform as two types of infrastructure: a pavement; and a stormwater management solution. It is a low impact development as it does not alter the natural hydrological cycle when implemented, unlike a conventional impermeable pavement. This research represents some of the initial investigations into pervious concrete pavement in Canada. The two research hypotheses of this research were the following: 1. Pervious concrete pavement can be successfully planned, designed, constructed and maintained in Canada for successful performance based on surface evaluations of permeability rate and surface condition. 2. Verification that the subsurface drainage capabilities of pervious concrete pavement are as described in literature and can be quantified using instrumentation. Through monitoring of the design, construction, performance and maintenance of five field sites across Canada and various laboratory pavement slabs, the behaviour of pervious concrete pavement in freeze-thaw conditions has been evaluated. This thesis presents the findings from the various phases of the life cycle of pervious concrete pavement: planning; design; construction; and maintenance. An interpretation of the performance of pervious concrete pavement both from the perspective of the surface and subsurface is included. The various field sites led to pervious concrete being used in areas exposed to static or parked traffic and areas with slow moving traffic. At the two sites that included static and slow moving traffic, the permeability performance was better in the areas of static traffic than those with moving traffic. Each of the field sites had a unique mix design and some had multiple variations of one basic mix design. The relationship between the void content and hardened density of the pervious concrete cores was linear with none of the cores being visually identified as outliers. Substantial deterioration in pavement structure performance was identified at one site. Other field sites showed changes in structural capacity over the monitoring timeline. However, no locations of substantial decreases in structural capacity were identified. The surface condition of the sites over the analysis period indicated that compaction to the surface during construction was helpful in constructing a quality pavement. The results of the project indicated that pervious concrete will crack when joints are not included and may also crack similarly to conventional impermeable concrete pavements if joints are spaced too widely or do not match joints of adjacent pavement. Washing the pervious concrete pavement surface with a large hose or garden hose was found to be the most effective in improving permeability across a site and also in increasing the permeability of the pervious concrete. The initial permeability of the pervious concrete pavement was found to influence future performance. Freeze-thaw cycling and moisture were found to alter the internal structure of pervious concrete. However, did not generally lead to surface distress development. The application of sand as a winter maintenance method decreased the permeability, as did the use of a salt solution. However, neither winter maintenance method led to the permeability rates of laboratory slabs dropping below an acceptable level. All three slabs loaded with a salt solution deteriorated to a point where the slabs had failed. The initial permeability of the field sites proved to be important and although some sites started with what appeared to be very high permeability rates, these sites were successful in the multiple year evaluation in maintaining adequate permeability rates. The types of surface distresses that developed in the cores and slabs in the laboratory were generally not substantially worse at the field sites, suggesting that pedestrian and vehicle traffic do not necessarily escalate distresses caused by the Canadian climate and corresponding winter activities. The subsurface drainage that was quantified by the instrumentation included in three field sites confirmed observations from the surface of the pavement and exceeded other expectations. Two field sites exhibited limited drainage capabilities on the surface of the pervious concrete pavement, one shortly after construction, and the other within a year following construction. The subsurface analysis quantified and confirmed that moisture was not able to drain completely vertically through the pavement structures at these two sites due to the limited access in the pervious concrete pavement surface. In comparison, the subsurface drainage at another site surpassed the assumed behaviour of pervious concrete pavement structures. The pavement structure in general at this site was highly permeable and this was identified as moisture was not observed to be collecting in the bottom of the storage base layer at any time or for any period of time. The successful overall drainage performance of this site demonstrates the ability to effectively use pervious concrete pavement in Canada.

Traditionally, destructive methods such as coring are used for the condition assessment of an existing concrete structure. Although these methods may yield valid data about the corresponding concrete section, they are quite expensive and time consuming. More important than these, destructive methods damage the structure being investigated and these points usually become focal points for further deterioration. For all these reasons, only a few samples can be collected from a structure and this results in a poor representation of the complete structure. The impact-echo technique is one of the most suitable non-destructive test methods that may be used on concrete for thickness determination or for investigation of possible delaminations in the internal parts of a concrete structure without damaging the surface. It has been observed that reliable results can be obtained quickly. Unlike pulse-echo tests which are commonly used on steel, testing a heterogeneous material like concrete requires the use of low frequency sound waves as in impact-echo, in order to mitigate the effects of paste-aggregate interfaces or small air voids. This method may be used to locate internal cracks or large air voids existing in concrete. It is known that impact-echo has been used successfully on structures with varying geometries and various purposes such as evaluation of concrete pavements, retaining walls and other reinforced concrete sections. Besides the investigation of the internal state, it may also be used when the other side of the section cannot be reached, as in the case of concrete pavements, in order to find the thickness of the section. This is especially important for quality control and for cost calculations. Research conducted in this thesis study was concentrated on the thickness determination of existing concrete pavement sections, produced in the laboratory with dimensions of 1500 x 2000 mm four and varying thicknesses, and the accuracy associated with these results. In order to correctly determine the sensitivity, several other parameters were investigated and optimum ranges were determined for these to be used while on a field test. Among these factors were the steel impactor size, accuracy related to the data acquisition, distance between the impact point and the transducer and the location of the test point. Finally, the accuracy of the impact-echo method for concrete pavement applications was studied. By observing the large number of data points collected, it was found out that an average error of 1.5% exists for a single impact-echo reading regardless of section thickness, but this value reduces to 0.6% when the average of all test results is used while determining pavement thickness. Results of this study show that the impact-echo technique is reliable and may be used with success for the thickness determination of concrete pavements and for locating internal voids.

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.

Pervious concrete pavement has the capacity to perform as two types of infrastructure: a pavement; and a stormwater management solution. It is a low impact development as it does not alter the natural hydrological cycle when implemented, unlike a conventional impermeable pavement. This research represents some of the initial investigations into pervious concrete pavement in Canada. The two research hypotheses of this research were the following: 1. Pervious concrete pavement can be successfully planned, designed, constructed and maintained in Canada for successful performance based on surface evaluations of permeability rate and surface condition. 2. Verification that the subsurface drainage capabilities of pervious concrete pavement are as described in literature and can be quantified using instrumentation. Through monitoring of the design, construction, performance and maintenance of five field sites across Canada and various laboratory pavement slabs, the behaviour of pervious concrete pavement in freeze-thaw conditions has been evaluated. This thesis presents the findings from the various phases of the life cycle of pervious concrete pavement: planning; design; construction; and maintenance. An interpretation of the performance of pervious concrete pavement both from the perspective of the surface and subsurface is included. The various field sites led to pervious concrete being used in areas exposed to static or parked traffic and areas with slow moving traffic. At the two sites that included static and slow moving traffic, the permeability performance was better in the areas of static traffic than those with moving traffic. Each of the field sites had a unique mix design and some had multiple variations of one basic mix design. The relationship between the void content and hardened density of the pervious concrete cores was linear with none of the cores being visually identified as outliers. Substantial deterioration in pavement structure performance was identified at one site. Other field sites showed changes in structural capacity over the monitoring timeline. However, no locations of substantial decreases in structural capacity were identified. The surface condition of the sites over the analysis period indicated that compaction to the surface during construction was helpful in constructing a quality pavement. The results of the project indicated that pervious concrete will crack when joints are not included and may also crack similarly to conventional impermeable concrete pavements if joints are spaced too widely or do not match joints of adjacent pavement. Washing the pervious concrete pavement surface with a large hose or garden hose was found to be the most effective in improving permeability across a site and also in increasing the permeability of the pervious concrete. The initial permeability of the pervious concrete pavement was found to influence future performance. Freeze-thaw cycling and moisture were found to alter the internal structure of pervious concrete. However, did not generally lead to surface distress development. The application of sand as a winter maintenance method decreased the permeability, as did the use of a salt solution. However, neither winter maintenance method led to the permeability rates of laboratory slabs dropping below an acceptable level. All three slabs loaded with a salt solution deteriorated to a point where the slabs had failed. The initial permeability of the field sites proved to be important and although some sites started with what appeared to be very high permeability rates, these sites were successful in the multiple year evaluation in maintaining adequate permeability rates. The types of surface distresses that developed in the cores and slabs in the laboratory were generally not substantially worse at the field sites, suggesting that pedestrian and vehicle traffic do not necessarily escalate distresses caused by the Canadian climate and corresponding winter activities. The subsurface drainage that was quantified by the instrumentation included in three field sites confirmed observations from the surface of the pavement and exceeded other expectations. Two field sites exhibited limited drainage capabilities on the surface of the pervious concrete pavement, one shortly after construction, and the other within a year following construction. The subsurface analysis quantified and confirmed that moisture was not able to drain completely vertically through the pavement structures at these two sites due to the limited access in the pervious concrete pavement surface. In comparison, the subsurface drainage at another site surpassed the assumed behaviour of pervious concrete pavement structures. The pavement structure in general at this site was highly permeable and this was identified as moisture was not observed to be collecting in the bottom of the storage base layer at any time or for any period of time. The successful overall drainage performance of this site demonstrates the ability to effectively use pervious concrete pavement in Canada.

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.

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.

Neste trabalho são estudados os principais parâmetros do projeto estrutural de pavimentos rodoviários e de pisos industriais de concreto. Faz-se um levantamento bibliográfico, apresentando as características estruturais de diversos tipos de pavimentos rígidos. São discutidas as ações diretas e as indiretas em pavimentos de concreto e analisadas as formas de consideração das forças aplicadas. São apresentados modelos para representação da fundação, do pavimento e dos materiais. É feito um resumo da teoria de Westergaard, para determinação de tensões devidas ao tráfego, e da teoria de Bradbury, para determinação de tensões devidas ao empenamento. O comportamento dos pavimentos rígidos sob diversas configurações de carregamento são analisadas com auxílio de software com base no método dos elementos finitos. Apresentam-se os métodos indicados pelo DNER para determinação da espessura de pavimentos de concreto simples. São discutidas equações para determinação da área de aço para combate à retração e desenvolvido um procedimento para dimensionamento da armadura de flexão, com base na revisão da NB-1. São analisados os mecanismos de formação de fissuras e a importância das juntas. São apresentadas equações para dimensionamento das barras de transferência e das barras de ligação e analisada a influência da eficiência da junta nos esforços das placas. São desenvolvidos exemplos numéricos sobre dimensionamento de pavimentos de concreto simples e de concreto armado, e sobre detalhamento das juntas / In this work are studied the main parameters of the structural project of concrete highway and industrial pavements. A bibliographical rising is made presenting the structural characteristics of several types of rigid pavements. Direct and indirect actions in the concrete pavements are discussed and the procedures of load consideration are analyzed. Models for represent the foundation, the pavement and the materials are showed. A summary of Westergaard’s theory for determination of stresses owed to the traffic and of Bradbury’s theory for determination of stresses owed to the curling is presented. The behavior of rigid pavements under several loading configurations is analyzed, with a software based on finite elements method. The thickness design methods for concrete pavement indicated by DNER are presented and discussed. The equation for determination of shrinkage reinforcement is showed and a procedure for design of positive steel is developed, based on the brazilian code. The cracking mechanism and the importance of joints are analyzed. Design equations for dowels and tie bars are studied. Numeric design examples are developed for plain concrete pavements, for reinforced concrete pavement, and for design of the joints

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.

Este trabalho descreve um estudo experimental dos efeitos da temperatura em um elemento de pavimento de concreto, construído em laboratório interno e instrumentado com sensores de deformação, deslocamento, força e temperatura. A estrutura foi construída em duas camadas (placa e base) assentadas sobrepostas, sem aderência, sobre um subleito artificial. Os efeitos térmicos foram gerados artificialmente seguindo padrões sazonais da natureza. Os carregamentos estáticos foram realizados por meio de uma máquina hidráulica referenciados a um eixo simples de roda simples. A estrutura foi dimensionada e construída em uma escala de tamanho reduzido, distorcida e montada sobre uma laje de reação. Sob a placa do pavimento foi construído um sistema térmico auto controlado para causar diferencial de temperatura entre o fundo e o topo da placa pela passagem de um fluido. No topo um sistema térmico com controle manual foi construído para gerar gradientes térmicos através da estrutura. Todas as ações foram registradas automaticamente por meio de um sistema de aquisição de dados. Os resultados combinam com os dados da literatura, com experimentos realizados em pistas experimentais e se correlacionam com simulações realizadas por meio de software específico. Isso implica que a metodologia usada é apropriada para ser utilizada em outras situações e experimentos. / This paper describes the experimental study of the effects of temperature on a element of concrete pavement, constructed an internal laboratory and instrumented with sensors of strain, displacement, force and temperature. The structure was built in two layers (slab and base) overlapping settled without grip on an artificial subgrade. The thermal effects were achieved artificially following nature seasonal patterns. The static loads were performed by means of a hydraulic machine referred to a simple wheel axle. The structure was sized and built on distorted small scale and assembled over a slab of reaction. Under the pavement a selfcontrolled heating system was built to cause a temperature gradients between the slab top and bottom from a passing fluid. On the top a manual heating system was built to generate thermal gradients across the structure. All the actions were recorded automatically through a data system. The results agree with the literature data, with experiments performed on experimental roads and correlate themselves with simulations performed by using specific software. This implies that the methodology used is appropriate for use in other situations and experiments.

Die Dimensionierung einer Betonfahrbahn zielt darauf ab, den Anteil der im Nutzungszeitraum versagenden Platten auf ein akzeptables Maß zu begrenzen. Der Anteil ausgefallener Platten entspricht der Versagenswahrscheinlichkeit der einzelnen Platte. Damit ergibt sich die Notwendigkeit, die Versagenswahrscheinlichkeit zu berechnen. Innerhalb der vorliegenden Arbeit werden grundlegende Methoden und Verfahrensweisen zur Lösung dieser Aufgabe entwickelt. Es wird gezeigt, wie die für die Quantifizierung der Versagenswahrscheinlichkeit entscheidenden Streuungen der Einflussgrößen mathematisch beschrieben und im Dimensionierungsverfahren berücksichtigt werden können. Dabei wird regelmäßig Bezug genommen auf das in Deutschland eingeführte Dimensionierungsmodell der RDO Beton [2]. Die Grundlage für die Berechnung der Versagenswahrscheinlichkeit liefern die Methoden der Statistik und Wahrscheinlichkeitsrechnung, sowie der Zuverlässigkeitstheorie. Es wird gezeigt, dass sowohl die mathematisch exakte Lösung, wie auch verschiedene Näherungsverfahren für die Problematik der Betonfahrbahnen anwendbar sind. Näher untersucht werden die Zuverlässigkeitstheorie 1. Ordnung (FORM) sowie die Monte-Carlo-Methode. Die jeweiligen Vor- und Nachteile werden analysiert. Es zeigt sich, dass für die Anwendung des FORM-Algorithmus das Berechnungsmodell der RDO Beton modifiziert werden muss. Der zeitliche Bezug der Berechnung kann über die Benutzung von Extremwertverteilungen, die Modellierung stochastischer Prozesse oder die Einführung einer Schadensakkumulationshypothese hergestellt werden. Besondere praktische Bedeutung hat die Berechnung der Versagenswahrscheinlichkeit für den Nutzungszeitraum mit zeitlich varianten Bedingungen. Für diesen Fall werden vier verschiedene Lösungsansätze aufgezeigt. Um die teilweise sehr hohen Rechenzeiten zu minimieren, werden Näherungslösungen entwickelt. Die praktische Eignung wird mit beispielhaften Berechnungen demonstriert. Es zeigt sich, dass die Berechnungsergebnisse stark davon abhängen, wie sich die Werte einzelner Parameter über den Nutzungszeitraum entwickeln. Die betreffenden zeitlichen Verlaufsfunktionen sind gegenwärtig nur unzureichend bekannt. Um eine hinreichend verlässliche Prognose zu berechnen, sind alle Berechnungsverfahren möglichst objektbezogen zu kalibrieren. / The dimensioning of a concrete pavements aims to limit the percentage of failing slabs to an acceptable level. The proportion of failed slabs corresponds to the probability of failure of each slab. This results in the need to calculate the probability of failure. Within the present work, basic methods and procedures for solving this problem are being developed. It is shown how the variations of parameters can be mathematically described and considered in the dimensioning process. Reference is frequently made to the model of RDO Beton [2]. The methods of statistics and probability theory, and reliability theory provide the basis for calculating the probability of failure. It is shown that both the mathematically exact solution and various approximation methods as well are applicable to the problem of concrete pavements. Be examined more closely the reliability theory 1st order (FORM) and Monte Carlo method. The respective advantages and disadvantages are analyzed. It turns out that the calculation model of the RDO concrete has to be modified for the use of FORM algorithm. The temporal relation of the calculation can be made on the use of extreme value distributions, modeling of a stochastic process or the introduction of a damage accumulation hypothesis. Particular practical significance has to calculate the probability of failure for the period of use with time-variant conditions. In this case, four different approaches are discussed. Approximate solutions to minimize the sometimes very high computation times has been developed. The practical suitability is demonstrated by exemplary calculations. It turns out that the calculation results depend strongly on how to develop the values of individual parameters over the period of use. These time course functions are insufficiently known at present. To calculate a sufficiently reliable forecast, all calculation methods are possible to calibrate object-related.