The objectives of this research were to evaluate the sensitivity of indirect tensile strength (ITS) test results to stabilizer type, stabilizer concentration, and curing time for multiple clayey soils with varying plasticity indices (PIs), identify cases in which an ITS of 30 psi can be obtained, and create a general linear model that predicts ITS. The scope of work included laboratory testing of three clayey soils sampled from Monticello, Utah; Bloomington, Indiana; and San Antonio, Texas. Each soil was tested using two stabilizers, cement or lime, at three concentrations, and two replicate samples were prepared for each combination. ITS testing was performed on two specimens of each combination at curing times of both 7 days and 28 days, for a total of 72 tests. The procedures outlined in this study include soil characterization, determination of moisture-density relationships, Eades and Grim testing, soil preparation, soil compaction, ITS testing, and statistical analysis. Regarding stabilizer type, treatment with cement consistently yielded higher ITS values than treatment with lime. Regarding stabilization concentration, ITS consistently increased with increasing concentrations of cement for all three soils; however, the effect of lime concentration depended on the PI of the soil, where increasing ITS values were only apparent with higher PI values. Regarding curing time, the ITS values corresponding to 28 days were generally higher than those corresponding to 7 days. Differences in ITS among the soils were largely attributable to differences in PI, which can influence pozzolanic reactivity. A cement or lime concentration that was equal to or 2% above the lime concentration indicated by the Eades and Grim test was typically required for a minimum 28-day ITS value of 30 psi to be attained. For the model developed to predict ITS, the significant predictor variables included PI, stabilizer type, actual stabilizer concentration, and curing time, as well as the two-way interactions between PI and stabilizer type, PI and actual stabilizer concentration, PI and curing time, and stabilizer type and actual stabilizer concentration. Overall, the model has an R2 value of 0.943 and an adjusted R2 value of 0.936. The model is best suited for soils having a fines content greater than 50%, a PI greater than 20, and a soluble sulfate concentration less than 3000 ppm.

An evaluation of aged hot-mix asphalt (HMA) pavements was accomplished to develop a method for improving the prediction of remaining fatigue life of aged HMA surfaces. This is important for both planning Department of Defense airfield maintenance funds and for predicting the performance of operating surfaces in the theater of operation. This study involved the evaluation of HMA at several military airfields. After field inspections and field testing, slab samples were carried to the U.S. Army Engineer Research and Development Center for laboratory testing. Laboratory testing included the determination of mixture and binder properties, indirect tensile strength tests on cored specimens, and beam fatigue tests. The results from this study were used to develop improved fatigue performance predictions for field-aged HMA pavements.

"Susceptibility of Hot Mix Asphalt (HMA) mixes to moisture induced damage is one of the main reasons for premature failures of asphalt pavements. Hence, the evaluation of mixes for the moisture susceptibility is an essential part of the mix design. The existing methods are found to be in-sufficient to characterize mixes in terms of their moisture damage potential, and many studies have been conducted to establish an improved methodology that can better address the issue. Most of these methods involve the determination of changes in mix properties due to moisture conditioning in the laboratory or to verify the mix performance in the field or the laboratory. In the field moisture susceptible mixes are also found to lose material to extents that are dependent upon the properties of the mix and materials. So far, there has been no comprehensive study to investigate the loss of materials due to moisture induced damage. The objective of this study was to identify and evaluate a conditioning and a test method that can be used on a regular basis to detect moisture susceptible mixes and to understand the combined problem of moisture induced material loss and change in strength/stiffness of the mix. The Moisture Induced Stress Tester (MIST), Ultrasonic Pulse Velocity (UPV), Dynamic Modulus in Indirect tensile mode, and Indirect Tensile Strength (ITS) tests were utilized in the study. The effluent from the MIST was checked for the gradation of dislodged aggregates and the Dissolved Organic Carbon (DOC) content. A system dynamics (SD) approach was also adopted to investigate the problem and establish a model to reproduce field observations. The results showed that the use of MIST in combination with UPV or ITS is able to identify moisture susceptible mixes, in particular for mixes with the potential of aggregate breakdown. The mixes with a higher loss of asphalt binder during conditioning exhibit higher tensile strengths, and those with a loss of finer materials, which is indicative of aggregate breakdown, show a lower tensile strength. For the mixes used in this study, the rate of change in indirect tensile strength during moisture conditioning was found to be strongly correlated to the pre-conditioning modulus of the mix. A step-by-step framework to characterize the moisture susceptible mixes was presented."

Soil-cement is an integral part of pavement design, especially in areas that are aggregate deprived, such as Mississippi. Current designs are reliant on the relationship of unconfined compressive strength (UCS) to other mechanical properties. The other properties discussed in this dissertation are Modulus of Elasticity (E), Indirect Tensile Strength (St), and Modulus of Rupture (MOR). This dissertation includes a comprehensive review of past design methods and mechanical property relationships. While some mechanical property relationships were shown to be well understood (i.e. St to UCS), others were not as accurate, especially for the later life mechanical properties (i.e. MOR to UCS and E to UCS). This dissertation investigates the Plastic Mold (PM) Compaction (PM) Device and its ability to measure mechanical property relationships (UCS, E, St) for soil-cement as well as different materials, such as lime stabilized subgrade and Cold in Place Recycling (CIR) stabilized with cement. These mechanical property relationships were compared to soil-cement beam specimens, which are capable of being tested for the four previously mentioned mechanical properties from an individual specimen. Finally to have a better understanding of the later life mechanical properties and their relationships, PM and beam specimens were exposed to elevated temperatures to forecast out how these properties interrelate over time. These mechanical property values and relationship were then compared to Mississippi field cores ranging from 10 to 54 years old. These protocols, beam and elevated curing, were able to replicate what was seen for pavement cores that were extracted after decades of service. Over 1300 specimens were testing showing how these mechanical properties interacted from early ages and throughout a pavement’s life.

<p>U disertaciji su prikazani rezultati sopstvenog eksperimentalnog istraživanja<br />izvr&scaron;enog na uzorcima pripremljenim sa različitim uče&scaron;ćem struganog asfalta (RAP)<br />i dodatnog - &quot;novog&quot; drobljenog kamenog agregata. Variranjem uče&scaron;ća struganog<br />asfalta i dodatnog drobljenog kamenog agregata i variranjem uče&scaron;ća oba veziva<br />omogućeno je praćenje uticaja sastava na mehaničke karakteristike me&scaron;avine.<br />Uticaj vrste i količine upotrebljenog veziva na mehaničke karakteristike nosećeg<br />sloja kolovoza sagledano je kroz variranje sadržaja cementa i bitumenske emulzije.<br />Predmet istraživanja je definisanje međusobne zavisnosti odnosno korelacije,<br />određenih mehaničkih karakteristika me&scaron;avine u funkciji vrste i količine<br />komponentnih materijala i veziva i ocena njihovih fundamentalnih mehaničkih<br />karakteristika.</p> / <p>In dissertation are resented results of own experimental research on<br />samples that have been prepared with different amount of reclaimed<br />asphalt (RAP) and the additional - &quot;new&quot; crushed stone aggregate. By<br />varying participation of reclaimed asphalt and additional crushed stone<br />and varying participation of both binders monitoring of the impact of the<br />composition on the mechanical properties of the mixture was enabled.<br />The influence of type and amount of binder on the mechanical properties<br />of the pavement base layer is seen through variation in the content of<br />cement and bitumen emulsion. The subject of the research is to define the<br />mutual dependence and correlation of certain mechanical characteristics<br />of the mixture as a function of the types and quantities of component<br />materials and binders and evaluation of their fundamental mechanical<br />properties.</p>

Esta pesquisa foi baseada em um projeto de Stone Matrix Asphalt - SMA na faixa 0/8S com asfalto CAP 20, feito para a execução de revestimento delgado em trecho experimental na Rodovia Presidente Dutra, ligando São Paulo ao Rio de Janeiro. A ocorrência de alguns defeitos neste trecho experimental motivou o estudo de misturas SMA 0/8S alternativas empregando dois asfaltos convencionais: CAP 20 e CAP 50/60, e dois modificados por polímeros: um com 3,0% de SBS e outro com 6,5% de SBS. Foram realizados ensaios laboratoriais para a verificação da dosagem das misturas asfálticas e determinação de propriedades mecânicas em laboratório por meio de ensaios de deformação permanente em trilha de roda, de resistência à tração por compressão diametral e de módulo de resiliência. Observou-se que o uso de asfalto modificado por polímero e do asfalto convencional CAP 50/60 acarreta uma redução significativa de afundamentos em trilha de roda. O módulo de resiliência a 25°C também apresenta redução de valor nas amostras com asfalto modificado por polímero e com CAP 50/60, em comparação com o convencional CAP 20. A resistência à tração sofre pouca variação quando se comparam os asfaltos empregados, considerando-se ensaios realizados na mesma temperatura. Foram feitos ensaios em campo para a avaliação funcional e de aderência no trecho experimental da Rodovia Presidente Dutra, tendo sido realizados monitoramentos logo após a execução do trecho e decorridos 2 anos e 7 meses de operação. Os resultados demonstraram que o revestimento do trecho experimental apresenta atualmente poucos defeitos de superfície, com fechamento da macrotextura nas trilhas de roda e pequena diminuição do conforto ao rolamento. / This research was based on a Stone Matrix Asphalt SMA in the band 0/8S design made with asphalt binder AC 20, used as a thin wearing course of a test section on the Presidente Dutra Highway, that connects São Paulo to Rio de Janeiro. The occurrence of some distresses in the test section motivated the study of alternative SMA 0/8S mixtures using two conventional asphalt binders: AC 20 and AC 50/60, and two modified by polymer: one with 3.0% of SBS and other with 6.5% of SBS. Laboratory tests were conducted to verify the mix design and to determine their mechanical behavior such as the resistance against rutting, the indirect tensile strength and the resilient modulus. It was observed that the use of SBS polymer modified binders and asphalt binder AC 50/60 causes a significant reduction of rutting. The resilient modulus at 25°C also presents a reduction in the samples with SBS polymer modified binders and AC 50/60 in comparison with AC 20. The indirect tensile strength suffers little variation across the different types of asphalt binders, tested at the same temperature. Field tests related to functional evaluation and skid-resistance of the test section were carried out. The test section was monitored immediately following the construction and after 2 years and 7 months of continuous use. The results showed that the wearing coarse presented a few distresses in the surface, in particular a reduction of the macrotexture at the wheel tracks and a slight worsening of the riding quality.

To develop a project sizing concrete pavement is necessary to know the mechanical properties and the different treatment processes of material to be used. This study aimed to analyze the mechanical properties such as flexural strenght, compressive strength, indirect tensile strength and static modulus of concrete paving. The three types of concrete were studied: An actual reference (typically used in paving, one with the addition of polypropylene fibers (common practice for floors), and a high strength concrete used to rapidly release the traffic. Different methods of curing were applied: chemical cure with and without the use of wet burlap bags (widely applied in pavements) and curing in a moist chamber (as recommended by standard). This evaluation of the mechanical properties for the concrete studied in different curing methods applied, showed that the microstructure of concrete is significantly interfering with the results, especially in cured concrete to track conditions (chemical cure without and with the placement of burlap sacks). Where factors such as the absorption and reabsorption of water evaporation to cement hydration, cracking the interface folder / aggregate, ambient conditions related to temperature and humidity, are interfering with the tensile strength in bending, compressive strength, indirect tensile strength and particularly in the static modulus and still, from the results obtained in this study and those reported by other authors who studied a high-strength concrete, it is possible to verify that there are particularities still unknown about the behavior of high strength concrete. / Para o desenvolvimento de um projeto de dimensionamento de pavimentos de concreto é necessário conhecer as propriedades mecânicas e os diferentes processos de tratamento do material a ser utilizado. Este trabalho teve por objetivo analisar as propriedades mecânicas, tais como, resistência à tração na flexão, resistência à compressão axial, resistência à tração por compressão diametral e módulo de elasticidade estático em concretos para pavimentação. Foram estudados os três tipos de concretos: um concreto referência, (tipicamente empregado em pavimentação, outro com a adição de fibras de polipropileno (prática comum em pavimentos) e um concreto de alta resistência, utilizado para rápida liberação ao tráfego. Diferentes métodos de cura foram aplicados: cura química com e sem a utilização de sacos de aniagem úmidos (largamente aplicados em pavimentos) e cura em câmara úmida (conforme preconizado por norma). A avalição das propriedades mecânicas para os concretos estudados, nos diferentes métodos de cura aplicados, mostrou que a microestrutura dos concretos, está interferindo de forma significativa nos resultados obtidos, principalmente nos concretos curados para condições de pista (cura química sem e com a colocação de sacos de aniagem), onde fatores como a absorção e reabsorção da água de evaporação para hidratação do cimento, a fissuração da interface pasta/agregado, as condições ambientes relacionadas à temperatura e umidade, estejam interferindo na resistência à tração na flexão, resistência à compressão axial, resistência à tração por compressão diametral e principalmente no módulo de elasticidade estático e ainda, a partir dos resultados obtidos na presente pesquisa e daqueles apresentados por outros autores que estudaram um concreto de alta resistência, é possível verificar que existem particularidades ainda desconhecidas sobre o comportamento do concreto de alta resistência.

Esta pesquisa foi baseada em um projeto de Stone Matrix Asphalt - SMA na faixa 0/8S com asfalto CAP 20, feito para a execução de revestimento delgado em trecho experimental na Rodovia Presidente Dutra, ligando São Paulo ao Rio de Janeiro. A ocorrência de alguns defeitos neste trecho experimental motivou o estudo de misturas SMA 0/8S alternativas empregando dois asfaltos convencionais: CAP 20 e CAP 50/60, e dois modificados por polímeros: um com 3,0% de SBS e outro com 6,5% de SBS. Foram realizados ensaios laboratoriais para a verificação da dosagem das misturas asfálticas e determinação de propriedades mecânicas em laboratório por meio de ensaios de deformação permanente em trilha de roda, de resistência à tração por compressão diametral e de módulo de resiliência. Observou-se que o uso de asfalto modificado por polímero e do asfalto convencional CAP 50/60 acarreta uma redução significativa de afundamentos em trilha de roda. O módulo de resiliência a 25°C também apresenta redução de valor nas amostras com asfalto modificado por polímero e com CAP 50/60, em comparação com o convencional CAP 20. A resistência à tração sofre pouca variação quando se comparam os asfaltos empregados, considerando-se ensaios realizados na mesma temperatura. Foram feitos ensaios em campo para a avaliação funcional e de aderência no trecho experimental da Rodovia Presidente Dutra, tendo sido realizados monitoramentos logo após a execução do trecho e decorridos 2 anos e 7 meses de operação. Os resultados demonstraram que o revestimento do trecho experimental apresenta atualmente poucos defeitos de superfície, com fechamento da macrotextura nas trilhas de roda e pequena diminuição do conforto ao rolamento. / This research was based on a Stone Matrix Asphalt SMA in the band 0/8S design made with asphalt binder AC 20, used as a thin wearing course of a test section on the Presidente Dutra Highway, that connects São Paulo to Rio de Janeiro. The occurrence of some distresses in the test section motivated the study of alternative SMA 0/8S mixtures using two conventional asphalt binders: AC 20 and AC 50/60, and two modified by polymer: one with 3.0% of SBS and other with 6.5% of SBS. Laboratory tests were conducted to verify the mix design and to determine their mechanical behavior such as the resistance against rutting, the indirect tensile strength and the resilient modulus. It was observed that the use of SBS polymer modified binders and asphalt binder AC 50/60 causes a significant reduction of rutting. The resilient modulus at 25°C also presents a reduction in the samples with SBS polymer modified binders and AC 50/60 in comparison with AC 20. The indirect tensile strength suffers little variation across the different types of asphalt binders, tested at the same temperature. Field tests related to functional evaluation and skid-resistance of the test section were carried out. The test section was monitored immediately following the construction and after 2 years and 7 months of continuous use. The results showed that the wearing coarse presented a few distresses in the surface, in particular a reduction of the macrotexture at the wheel tracks and a slight worsening of the riding quality.

In the theoretical part of the thesis are generally characterized hydraulically bound mixtures, their types, classification systems, manufacturing technology and the laying. There are also described experiences from abroad with the use secondary and recycled materials in hydraulically bound mixtures. The practical part deals with the experimental verification of the possibility of the use of secondary materials in hydraulically bound mixtures in construction of road infrastructure. In road laboratory Institute of road structures Brno university of technology was the five proposed mixtures, an assessment of their parameters with regard to the possibility of using these mixtures in the road sub-base layers. The work is also aimed at comparison of results elasticity modules reached laboratory testing and experimental measurements on road polygon.

This master's thesis deals with the design of two asphalt mixtures for a wearing course containing 35 % R-material. The asphalt mixtures use a soft bitumen modified with crumb rubber (CRMB) or the unmodified soft binder itself with a penetration grade of 70/100. The work verifies the effect of crumb rubber as a bitumen modifier on the properties of the asphalt mixture with reclaimed asphalt pavement (RAP). At the same time, the work deals with the possibility of using higher amounts of reclaimed asphalt pavement only in combination with a softer binder without the use of rejuvenating additives. The properties of asphalt binders and mixtures are verified using suitable functional tests. Furthermore, the proposed mixtures and their results are compared from various perspectives. At the same time, the thesis in the theoretical part deals with the dosing of a reclaimed asphalt pavement into the asphalt mixture and describes the handling and use of reclaimed asphalt pavement in the Czech Republic and abroad