Electrically conductive asphalt composites have immense potential for various multifunctional applications such as self-healing, self-sensing, snow and ice removal, and energy harvesting, and controlling asphalt conductivity is the first step to enable such applications. Previous investigators have used conductive fibers as major conductive additive for asphalt composites, and the sudden transition from the insulated phase to the conductive phase, known as the percolation threshold, is commonly observed. Since the percolation threshold hinders precise control of asphalt conductivity, it is imperative to mitigate the sudden transition in the electrical resistivity curve to enable practical applications of asphalt composites. Some recent publications showed the potential of graphite in mitigating the sudden transition. The study presented herein investigates possibility of precisely controlling the electrical conductivity of asphalt concrete only by adding filler size graphite powder. Nine different types of graphite having different particle shapes and sizes are selected to investigate their effect on conductivity control. The volume resistivity of the asphalt mastic specimens containing various concentrations of graphite is evaluated. In addition, scanning electron microscope analysis is conducted for the graphite particles to provide physical explanation for their different effects on imparting conductivity. The results show that the electrical resistivity of asphalt mastic is significantly varied with the types of graphite. The mastics containing natural flake graphite show gradual decrease in volume resistivity as the graphite content increases, and sufficiently low resistivity can be obtained in the specimens with natural flake graphite. On the other hand, amorphous graphite is not efficient in reducing volume resistivity. Graphite with high surface area presents difficulty in mixing. In the next stage of research, two best performing graphite out of the nine different types are selected to be added to asphalt concrete, and the effect of aggregates on electrical resistivity is examined. It is found that flake graphite 516 provides good electrical conductivity along with improved mechanical performance of asphalt concrete. Thus the study provides fundamental information on the selection of graphite type and amount to achieve proper electrical conductivity required for multifunctional applications.

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El Stone Mastic Asphalt, SMA, diseño de origen alemán desarrollado en los años 60 ha permitido dar solución a los problemas de tránsitos pesados y climas fríos, de las carreteras en Europa, EE.UU. y Canadá y recientemente en Brasil y Argentina. El concepto de diseño SMA se basa en una estructura granular donde predomina el contacto piedra-piedra el mismo que le provee de alta resistencia cortante, baja deformación permanente o “rutting” y considera un buen porcentaje de ligante que le confiere una excelente durabilidad.

abstract: This study investigates the mastic level structure of asphalt concrete containing RAP materials. Locally sourced RAP material was screened and sieved to separate the coated fines (passing #200) from the remaining sizes. These binder coated fines were mixed with virgin filler at proportions commensurate with 0%, 10%, 30%, 50% and 100% RAP dosage levels. Mastics were prepared with these blended fillers and a PG 64-22 binder at a filler content of 27% by volume. Rheological experiments were conducted on the resulting composites as well as the constituents, virgin binder, solvent extracted RAP binder. The results from the dynamic modulus experiments showed an expected increase in stiffness with increase in dosage levels. These results were used to model the hypothesized structure of the composite. The study presented discusses the different micromechanical models employed, their applicability and suitability to correctly predict the blended mastic composite. The percentage of blending between virgin and RAP binder estimated using Herve and Zaoui model decreased with increase in RAP content. / Dissertation/Thesis / Masters Thesis Civil and Environmental Engineering 2014

Os adesivos são produtos capazes de manter materiais unidos, mediante ligações entre as superfícies. Selantes são produtos capazes de manter preenchido um espaço entre duas superfícies, por meio de uma barreira que se configura como uma ponte entre as duas superfícies. O mastic é um produto obtido por uma mistura de substâncias tendo como principal polímero o butil, com consistência de uma massa não secativa que pode ser utilizada como selante. Os polisiloxanos, também conhecidos como silicones são os mais importantes polímeros sintéticos com estrutura inorgânica, e são matrizes dos adesivos selantes de silicone. Para comprovar como o comportamento das forças de adesão destes produtos acontece, foram utilizadas cinco técnicas diferenciadas. Estes produtos foram submetidos a duas condições distintas para verificar o comportamento da adesão, um em condições ambiente e outro sob influência de radiação ionizante. Os resultados obtidos demonstraram não só a diferença entre produtos (silicone e mastic), mas também que as forças de adesão têm comportamentos diferentes nas condições às quais foram submetidas às amostras. Com isto atingi-se o objetivo desse estudo que é apresentar a diferenciação entre o mastic e o silicone, muitas vezes considerados como um só produto denominado mastic. Desta forma comprova-se que: 1. o silicone pode ser considerado um adesivo selante em condições ambientes, 2. o mastic melhora consideravelmente sua adesão, quando submetido à radiação ionizante, e esta característica de adesão pode ser uma excelente alternativa para o mercado de adesivos. / Adhesives are products that can keep materials together by bonds between the surfaces. Sealants are products that can keep filled a space between two surfaces, through a barrier that is configured as a \"bridge\" between the two surfaces. The mastic is a product made of a mixture of substances with the primary butyl polymer, with the consistency of a mass not dried that can be used as a sealant. The polysiloxane, also known as silicone are the most important synthetic polymers with inorganic structure, and are matrices of silicone adhesive sealants. To demonstrate the behavior of the adhesive forces of these products under different conditions, we used five different techniques. These products were subjected to two different conditions to verify the behavior of adhesion, one at the environmental condition and another under the ionizing radiation. The results showed not only differences between products (silicone and mastic), but also that the adhesive forces have different behaviors under the conditions which the samples were subjected. With this was reached the goal of this study that aspired show the differences between the mastic and silicone, this last one is often considered - erroneously - the same as mastic. Thus it was proven that: 1. silicone can be regarded as an adhesive and a sealant at ambient conditions, 2. mastic improves substantially adhesion in an environment of ionizing radiation and this property can be an excellent alternative to the adhesive market.

Os adesivos são produtos capazes de manter materiais unidos, mediante ligações entre as superfícies. Selantes são produtos capazes de manter preenchido um espaço entre duas superfícies, por meio de uma barreira que se configura como uma ponte entre as duas superfícies. O mastic é um produto obtido por uma mistura de substâncias tendo como principal polímero o butil, com consistência de uma massa não secativa que pode ser utilizada como selante. Os polisiloxanos, também conhecidos como silicones são os mais importantes polímeros sintéticos com estrutura inorgânica, e são matrizes dos adesivos selantes de silicone. Para comprovar como o comportamento das forças de adesão destes produtos acontece, foram utilizadas cinco técnicas diferenciadas. Estes produtos foram submetidos a duas condições distintas para verificar o comportamento da adesão, um em condições ambiente e outro sob influência de radiação ionizante. Os resultados obtidos demonstraram não só a diferença entre produtos (silicone e mastic), mas também que as forças de adesão têm comportamentos diferentes nas condições às quais foram submetidas às amostras. Com isto atingi-se o objetivo desse estudo que é apresentar a diferenciação entre o mastic e o silicone, muitas vezes considerados como um só produto denominado mastic. Desta forma comprova-se que: 1. o silicone pode ser considerado um adesivo selante em condições ambientes, 2. o mastic melhora consideravelmente sua adesão, quando submetido à radiação ionizante, e esta característica de adesão pode ser uma excelente alternativa para o mercado de adesivos. / Adhesives are products that can keep materials together by bonds between the surfaces. Sealants are products that can keep filled a space between two surfaces, through a barrier that is configured as a \"bridge\" between the two surfaces. The mastic is a product made of a mixture of substances with the primary butyl polymer, with the consistency of a mass not dried that can be used as a sealant. The polysiloxane, also known as silicone are the most important synthetic polymers with inorganic structure, and are matrices of silicone adhesive sealants. To demonstrate the behavior of the adhesive forces of these products under different conditions, we used five different techniques. These products were subjected to two different conditions to verify the behavior of adhesion, one at the environmental condition and another under the ionizing radiation. The results showed not only differences between products (silicone and mastic), but also that the adhesive forces have different behaviors under the conditions which the samples were subjected. With this was reached the goal of this study that aspired show the differences between the mastic and silicone, this last one is often considered - erroneously - the same as mastic. Thus it was proven that: 1. silicone can be regarded as an adhesive and a sealant at ambient conditions, 2. mastic improves substantially adhesion in an environment of ionizing radiation and this property can be an excellent alternative to the adhesive market.

El texto completo de este trabajo no está disponible en el Repositorio Académico UPC por restricciones de la casa editorial donde ha sido publicado. / The use of foamed asphalt as a technique that incorporates recycled bases stabilized with RAP is known, because it achieves important structural contributions. However, the component of aggregates, belonging to the fine fraction (through the # 200 mesh) takes special importance. This article seeks to develop a comparative analysis between the stabilizations of recycled foamed asphalt bases and asphalt emulsion. The importance of this study lies in analyzing the structural contribution of the fines fraction when comparing both stabilizations. For the present investigation, 48 pits were examined, where the combined granulometry of the RAP plus the granular base was evaluated. Here it was possible to identify a minimal presence of fines even within the recommended spindle for foamed asphalt mixtures, evidencing a deficit in indirect traction strength (ITS). The results obtained show, that a dry stability of 484.7 kg is achieved, and a conserved strength of 45% in the foamed asphalt. While in the asphalt emulsion a dry stability of 1862.1 kg and a conserved resistance of 70% is achieved. This demonstrates the impact on the structural behavior that have the fines fraction in stabilizations with foamed asphalt.

Reducing the impact of modern industrial production on the environment and reducing the waste generated is undoubtedly one of the most discussed topics of the present time. In the production of fossil-fueled electricity, a large amount of fine-grained waste fly ash is generated. The possible use of ash as secondary raw materials in the construction and building materials industry is one of the many environmental challenges that the energy industry is concerned with. The aim of this diploma thesis was to verify possibilities of utilization of different kinds of power station fly ash as filler in asphalt mixtures for the production of oxidized asphalt insulation strips. The main emphasis was put on the clarification of the influence of the properties of the different types of fly ashes on the resulting rheological behavior of the mixture of asphalt binder and power fly ash, which is professionally called mastic. Mastic forms a technology-critical insulating layer in the asphalt insulation strip. The prediction of the rheological properties and therefore the workability of mastic appears to be an essential element in the management of production, especially under the conditions of the variability of input raw materials. In order to solve the assigned task it was necessary to perform detailed analyzes of fly ash properties, to select the corresponding quantification variable for assessment of the mastic processability and to find the signal fly ash properties, which appears to be a control parameter of workability. As a suitable method for assessing the processability of mastic, a shear viscosity measurement method was chosen. On the basis of the findings, it is possible to state that the use of fly ash from the production of oxidized asphalt bands is not recommended as the mastic prepared from these fly ashes are unprocessed at the assumed concentrations. The negative effect of fly ash after denitrification on the mastic processability has not been demonstrated.

Refractory mastics are used for making compact brickworks or for sealing up the joints. This thesis deals with lenghthening of best before date of Regnaterm mastic, modification of recipe and suggestion of suitable method for evaluating reologic characteristics.

Hot mix asphalt pavements require adequate compaction to achieve the required density to resist rutting. The amount of energy required to achieve the optimum degree of compaction depends on the type of gradation, bitumen content, filler type and shape, type of compaction equipment etc. In this study, the net energy required to reduce the specimen volume (size) after each gyration of the superpave gyratory compactor is used as the compaction energy index (CEI) to measure the compactability of the samples. Samples with different filler types and content are used for the analysis. Effect of fillers on the viscosity of the mastic has been studied previously. Viscosity of mastics in return affects the compactability of the mix in general. In this regard this paper tries to study the effect of fillers on the compaction of hot mix asphalt with the help of the superpave gyratory compactor. Moreover, resistance of the asphalt mix samples against rutting is evaluated using the simple performance test. In this test, the sample is subjected to a hydraulic loading while strain transducers attached to the sample measure the displacement. A computer program receives the displacement data at various frequencies and calculates the dynamic modulus and flow number which are used for the evaluation of the pavement performance.     :