The diploma thesis deals with the design of an asphalt mixture for an abrasive layer with a standard R-material content (20 %) without the use of other softening additives, while the properties of the aged asphalt binder in the mixture were compensated by dosing "softer binder 70/100". Asphalt mixtures type ACO 11+ are designed to meet the requirements ČSN 73 6121: 2019. The aim of the work is to verify the expected properties of the asphalt mixture performed functional and empirical tests according to the standards for asphalt mixtures of the ČSN EN 12697 series.

In the introduction of the Master’s thesis describes for obtaining and processing of reclaimed asphlalt. Major point of the thesis is design of asphalt mixtures with use of higher amount of RAP for asphalt binder course. Asphalt mixtures were designed with contents of 0%, 30%, 50% and 70% of RAP. On each asphalt mixtures were compared parameters set out by functional tests – resistence to permanent deformation and resistence to water.

Diploma paper is dealing with complex analysis of the information and material flows in concrete mixtures production focusing on proposals of logistic cost optimalization. The complex analysis is based on the time and direct observation in selected subject. One part of this work is dealing with optimalization of supply of production raw materials especially self supply of gravel aggregate into the each concrete mixing plant. Second part of this work is dealing with selected subject fleet optimalization. Optimalization possibilities were based on the results of the comprehensive analysis of the information and material flows.

Made available in DSpace on 2014-07-29T15:03:31Z (GMT). No. of bitstreams: 1 Dissertacao Michelly L Borges 2009.pdf: 835129 bytes, checksum: 13f31a796619274490f950cf6ef9d999 (MD5) Previous issue date: 2009-12-14 / Due to the small number of studies about the process of production of the concrete dosed in central, as regards the type of employed mixture, this inquiry looked to contribute to the assessment of quality of concrete produced in mixing plant and metering plant. The principal objective of the work was checking if the form of mixing of the concrete can affect your characteristics in hardened state (compressive strength), for that, there was compared the quality of the concrete produced in metering plant and mixed in truck mixer in relation to the mixing plant. As the sample was taken a work, where they had installed a metering plant and a mixing plant, which together produced 300.000 m³ of concrete with the same materials. Inside the proposed objective, also were quantified statistically the existent types of concrete in the same truck mixer, using as the parameter the compressive strength of concrete produced in the metering plant. In the end, it was possible to conclude that the mixing plant produce a concrete of better quality with a less standard deviation than the metering plant. Was also observed a significant variability inside the truck mixer, which made the division of the concrete possible in five group, with different resistances' / Em razão do pouco número de estudos relacionados ao processo de produção do concreto dosado em central, no que tange ao tipo de mistura empregada, esta pesquisa busca contribuir com a avaliação da qualidade de concretos produzidos em centrais misturadoras e centrais dosadoras. O objetivo principal do trabalho foi o de verificar se a forma de mistura do concreto pode afetar suas características no estado endurecido (resistência à compressão), para isso, foi comparada a qualidade do concreto produzido em central dosadora e misturado em caminhão betoneira em relação aos produzidos em central misturadora. Como amostra tomou-se uma obra, onde havia instalada uma central dosadora e uma central misturadora, que juntas produziram 300.000 m³ de concreto a partir dos mesmos materiais. Ainda dentro do objetivo proposto, foram também quantificados estatisticamente os tipos de concreto existentes em um mesmo caminhão betoneira, produzidos na central dosadora e tendo como parâmetro a resistência à compressão. Ao final, foi possível concluir que as centrais misturadoras produzem um concreto de melhor qualidade com um menor desvio padrão do que as dosadoras. Foi observada também uma variabilidade significativa dentro do caminhão betoneira, o que tornou possível a divisão do concreto em cinco grupos, com resistências distintas.

At the beginning of the Master’s thesis the asphalt mixture of the type asphalt concrete and its basic properties are described. The main point of this work is to compare the functional properties of asphalt mixtures with the addition of higher amount of RAP and various rejuvenators used in the experimental section. From individual samples of asphalt mixtures taken during the laying, the control tests were carried out and the process of permanent deformation with the wheel tracking test was monitored. After that, using functional tests the properties of asphalt mixtures with conventional modified and unmodified asphalt bitumen enriched with the addition of declaring similar properties were compared.

This thesis deals with the R-material use in asphalt mixtures. In the theoretical part, different kinds of flexible pavement recycling and ways of adding R-material into asphalt mixtures are discussed. The practical part deals with asphalt layers design and manufacture, specifically for binder course ACL 16+. R-material content in the blends is 0%, 20%, 25% and 30%. EVOTHERM MA3 rejuvenator is used as additive for softening of R-material. Various mixtures are compared based on tests - resistance to permanent deformation, resistance to the effects of water and low temperature properties.

This thesis deals with the modification of asphalt binder 50/70 with fast reacting SBS. This is a relatively new additive that should be able to improve the binder properties during mixing of the asphalt mix at the plant. In the theoretical part, the issue of asphalt-mixing plant and polymer modification additives is presented. Furthermore, the test methods used such as needle penetration, softening point, determination of the elastic recovery, DSR and MSCR are described. Several modified binder samples were developed for the tests, in which mixing temperature, mixing time and SBS content were combined. The results of each test were compared and evaluated at the end of the thesis.

Diploma thesis deals with topic of using aramid (Kevlar) fibres in road engineering in asphalt mixtures. Theoretical part of thesis is describing characteristics of aramid fibres and their technical usage. Thesis deals with research and application of aramid fibres abroad and also in Czech Republic. Practical part deals with influence of aramid fibres, namely FORTA FI fibres in mixture with modified binder for wearing course. An integral part of this thesis is a description of all methods that were used during the processing of the practical part. In the end of the thesis there are outcomes of tests and theoretical research.