Diploma thesis deals with composite materiál and it is dedicated to steel fiber concreat. The thesis focuses on verification of mechanical parameters of the steel fiber concrete. Especially on the compressive (tensile) strength at first cracking and the compressive strength in cracked state. Testing was conducted on concrete different tensile with 30 kg on m3 steel fibers KrampeHarex DE 50/1,0 N. The thesis is divided into theoretical and experimental part.

Deterioration of concrete structures due to the corrosion of embedded steel is a well-known universal problem. Norway with its numerous bridges, ports, offshore and floating structures along its coastline, is also encountered with corrosion degradation. The harsh environment of the Norwegian Sea regarding its low temperature, wind, and waves, makes the design and construction of marine structures more demanding. In recent years, usage of sustainable composite materials in the field of structural engineering has been rising. The usage of natural fibre reinforced polymer materials in the form of reinforcement bars or macro fibres with a low density, high strength, and excellent corrosion resistance, gives us better choices for the design and construction of marine structures. Our knowledge about the fibre reinforced self-compacting concrete has increased as a result of introducing it as a building material some decades ago. However, more research is still needed when it comes to the application of new types of fibres. This thesis is a result of this need, whereby the author has done two series of experimental programmes regarding the subject. In the first series, the flow characteristics of fresh state, conventional and self-compacting macro basalt fibre concrete were studied. In the second series, mechanical properties of high performance and medium strength macro basalt fibre concrete including the post-cracking behaviour, compressive strength and electrical resistivity were in focus. The findings were presented in three appended papers and the extended summary composing this thesis. Additionally, the thesis presents an overview of the design procedure of floating concrete structures and the possibility of using macro basalt fibre concrete via a case study. The author’s literature review shows that basalt fibres have an adequate resistance against alkali environment of the concrete matrix and corrosive environment of seawater. / <p>QC 20160607</p>

The objective of this thesis is to create summary of emissivity of wet surfaces, emissivity of rime surfaces and emissivity of dry surfaces. The next objective is to create materials for termovision measurement and find the use for this materials for practice. Theoretical part of thesis deals with a theory of ways of heat transfer (radiation mainly), description of emisivity concept, description of emisivity finding ways and the show emissivity of mesuared materials from avaible sources for working hypothesis. Emissivity of dry, wet and rime samples were measured as the experimental part of thesis. Experimental part of thesis consist of experiment description, working hypothesis, measuring instruments and measuring area description, measuring proces description and presentation of measured results. Obtained dependences are benefits for termovision measurent, energy evaluation and the thermal state microclimate simulations.

Slurry infiltrated fiber concrete (SIFCON) was first produced in 1979 in the USA, by incorporating large amounts of steel fiber in molds to form very dense network of fibers. The network is then infiltrated by a fine liquid cement-based slurry or mortar. The steel fiber content can be as high as 30 % by volume. This percentage usually does not exceed 2 % in normal fiber reinforced concrete (FRC) for reasons related to mixing and workability. Due to its high fiber content, SIFCON demonstrates unique and superior mechanical properties in the areas of both strength and ductility. Most of previous research work on SIFCON has focused mainly on investigating the mechanical properties of this material. On the other hand, the studies carried out in the field of durability of SIFCON are quite limited. v Therefore, it seemed that it would be worth to study the various durability aspects of SIFCON. In view of the above, the objectives of this study are to investigate and provide information about durability of SIFCON, mainly permeability, resistance to chloride penetration, freezing and thawing and drying shrinkage. This information will help in providing the necessary database and knowledge about the ability of SIFCON to withstand the conditions for which it has been designed without deterioration, especially when it is intended to be used in aggressive environments The investigations included studying the effects of the following on durability of SIFCON: (i) matrix type (slurry or mortar), (ii) fiber contents (7%, 9.5%, and 12% by volume), and (iii) steel fiber geometry (hooked or crimped). The results obtained indicated that SIFCON, especially when prepared using mortar not slurry, has shown good durability characteristics in spite of its apparent high water absorption. The SIFCON made with the highest possible fiber volume fractions showed the best results. However, it was concluded that SIFCON needs to be protected with suitable low permeability overlays to ensure ideal improved performance by protecting the steel fibers exposed on the surfaces especially against chloride attack.

Submitted by SBI Biblioteca Digital (sbi.bibliotecadigital@puc-campinas.edu.br) on 2018-08-14T11:38:43Z No. of bitstreams: 1 Jo?o Victor Rodrigues Martins.pdf: 6347531 bytes, checksum: da963af88129f7568a2e10f7c530b612 (MD5) / Made available in DSpace on 2018-08-14T11:38:43Z (GMT). No. of bitstreams: 1 Jo?o Victor Rodrigues Martins.pdf: 6347531 bytes, checksum: da963af88129f7568a2e10f7c530b612 (MD5) Previous issue date: 2018-06-27 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior (CAPES) / Funda??o de Amparo ? Pesquisa do Estado de S?o Paulo (FAPESP) / The process of assembling the reinforcement and the density of the concrete in structural pieces demand time and displacement of labor. The use of reinforcement with fibers in partial replacement of the transverse reinforcement could reduce the time of manufacture and facilitate the densification of the parts. Given this scenario, this research aimed at the study of concrete reinforced with fibers and reinforced concrete beams, in order to verify their behavior. Traces of concrete reinforced with steel fibers and traces of concrete with alkali-resistant glass fibers were made. In addition, the asphaltic milling residue was used for partial replacement of the small and large aggregate in the percentage of 15%. The material characterization was performed according to ABNT standards. Tests were performed to evaluate the Compressive Strength, Indirect Traction, Elasticity Modulus, and Tenacity through the Barcelona and ASTM C-1399 Tests. The evaluation of the mechanical behavior was performed by means of four-point bending in reinforced concrete beams, aiming to show its behavior to the applicant efforts. The results show the positive effect of the fibers for concrete with residues in their composition, mainly with respect to the steel fibers. It was verified a greater performance of the fibers as the Residual Resistance of the concrete and its Tenacity. It was also apresentated the viability of the structural application of asphalt milling residue as partial replacement of natural aggregates. / O processo de montagem da armadura e do adensamento do concreto em pe?as estruturais demandam tempo e deslocamento de m?o de obra. O uso do refor?o com fibras em substitui??o parcial da armadura transversal poderia reduzir o tempo de fabrica??o e facilitar o adensamento das pe?as. Diante de tal cen?rio, esta pesquisa visou o estudo de concretos refor?ados com fibras e de vigas de concreto armado, a fim de verificar seu comportamento. Foram confeccionados tra?os de concretos refor?ados com fibras de a?o e tra?os de concretos com fibras de vidro ?lcali-resistentes. Ademais foi utilizado o res?duo de fresado asf?ltico para substitui??o parcial do agregado mi?do e gra?do na porcentagem de 15%. A caracteriza??o dos materiais foi realizada conforme as normas da ABNT. Foram realizados ensaios para an?lise da Resist?ncia a Compress?o, da Tra??o Indireta, do Modulo de Elasticidade, da Tenacidade por meio dos Ensaios Barcelona e ASTM C-1399. A avalia??o do comportamento mec?nico foi realizada por meio de flex?o em quatro pontos em vigas de concreto armado, visando mostrar o seu comportamento aos esfor?os solicitantes. Os resultados revelam o efeito positivo das fibras para concretos com res?duos em sua composi??o, principalmente no que diz respeito as fibras de a?o. Foi verificada maior atua??o das fibras quanto a Resistencia Residual do concreto e a sua Tenacidade. Demonstrou-se tamb?m a viabilidade da aplica??o estrutural do res?duo de fresado asf?ltico como substitui??o parcial de agregados naturais.

Um Lebewesen oder Bauwerke vor Impakteinwirkungen zu schützen, können die unterschiedlichsten Herangehensweisen angewandt werden. Es kann beispielsweise Energie durch innere Reibung, plastische Verformung oder Abfederung absorbiert oder umgelenkt werden. Möglichkeiten der Umsetzung sind lose Schüttungen, die beispielsweise im Fall von Steinschlagschutzgalerien eingesetzt werden, oder geschichtete Aufbauten, wie sie zum Beispiel für Personenrüstungen zum Einsatz kommen. Letztere sind sowohl in der Natur als auch in der Technik oft zu finden und dienen als Grundlage für die nachfolgend entworfenen Schutzkonstruktionen, die sich aus mineralisch gebundenen Kompositen zusammensetzen. Sie sollen in der Lage sein, Stahlbetonkonstruktionen vor Impakteinwirkungen zu schützen. Zunächst wurden die Eigenschaften der verwendeten Materialien unter statischen und dynamischen Lasten untersucht. Anschließend wurden mehrlagige Dämpfungsschichtaufbauten auf Stahlbetonbauteile aufgebracht, um das Dämpfungsverhalten in größerem Maßstab in Fallturmversuchen zu charakterisieren.

The diploma thesis deals with self-healing of concrete composite. In the theoretical part, it represents the effect of polymer microfibers on reducing the development of cracks and on improving self-healing properties. It also describes the most commonly used types of bacteria used to enhance the self-healing process and their effect both alone and in interaction with fibers, calcium sources and absorbent additives. It also represents auxiliary additives in the form of superabsorbent polymers. In the practical part, it verifies the influence of the above elements and describes how much the self-healing of concrete has been enhanced by the use of combinations of fibers, absorbent polymers and a source of calcium in the form of calcium lactate. It also indicates whether the self-healing properties used were not improved at the expense of deteriorating the mechanical properties of the composite.