Tunnels in hard and jointed rock are normally excavated in an arch shape to enable the rock mass to support its weight. Since the beginning of the 1980's, fibre reinforced shotcrete (FRS) in combination with rock bolts have been the dominating support method for hard rock tunnels. This type of rock support is a complex composite structure in which the structural behaviour depends on interaction between shotcrete, rock and bolts. The design is commonly based on a rock mass classification system in combination with analytical solutions or finite element (FE) modelling. However, the in-situ variations of important properties of the shotcrete are normally neglected.The aim of this thesis was to increase the understanding regarding the environmental impact of different fibre types used as reinforcement in shotcrete. First, a brief introduction to rock support and the role of shotcrete is presented. Along with this the technical performance and a short review regarding the production process involved in producing steel, synthetic and basalt fibres. To understand the environmental impact with respect to the production of different fibre types, environmental product declaration (EPD) from various producers were studied. Here, the environmental performance was studied from cradle to gate for the different fibres. The goal of this thesis was to study the global warming potential of fibres during the production stages and EPDs were used to compare the environmental performance for different fibres of different types and materials. For each fibre type different producers are also compared.To study the environmental impact, a case study in which the shotcrete should fulfil a specified residual flexural strength, or a minimum energy absorption was used. Within this thesis, any potential effects of deterioration of fibres or the need of technical improvement during the technical lifespan was not included. Fibre dosages to fulfil the structural performance were selected based on the experimental testing from the literature. Finally, a detailed discussion regarding the optimum dosages of the different fibre types and their environmental impact is presented.

yes / This paper presents an analytical method for estimating the flexural strength of reinforced concrete beams strengthened with externally bonded fibre reinforced polymer (FRP) laminates. The method is developed from the strain compatibility and equilibrium of forces. Based on the size of external FRP laminates, several flexural failure modes may be identified, namely tensile rupture of FRP laminates and concrete crushing before or after yielding of internal steel reinforcement. Upper and lower limits to the size of FRP laminates used are suggested to maintain ductile behaviour of strengthened reinforced concrete sections. Comparisons between the flexural strength obtained from the current method and experiments show good agreement. Design equations for calculating the size of FRP laminates externally bonded to reinforced concrete sections to enhance their flexural strength are proposed.

The target of the ‘Green Overlays’ research was a cost effective, minimal disruption, sustainable and environmentally friendly alternative to the wholesale demolition, removal and complete reconstruction of the existing structural concrete pavement. The important problem of flexural resistance for strengthening concrete pavements with structural overlays has been scrutinised. A new mix design method for steel fibre reinforced, roller compacted, polymer modified, bonded concrete overlay has been proposed. The mixes developed were characterized of high flexural strength and high bond strength with the old concrete substrate. ‘Placeability’ and ‘compactability’ of the mix were two dominant issues during laboratory investigation. An innovative approach for establishing the relationship between Stress and Crack Face Opening Displacement for steel fibre reinforced concrete beams under flexure was developed. In addition, a new and simple method for calculating the interfacial Strain Energy Release Rate of both, a two-dimensional specimen and a three-dimensional model of the overlay pavement system were developed. This method can be readily and easily used by practicing engineers. Finally, a new test specimen and its loading configuration for measuring interfacial fracture toughness for concrete overlay pavements were established. The interfacial fracture toughness of a composite concrete beam, consisted of steel fibre-reinforced roller compacted polymer modified concrete bonded on conventional concrete and undergoing flexure, was assessed. In summary, this thesis presents four key findings: A new mix design method for steel fibre-reinforced roller compacted polymer modified concrete bonded on conventional concrete. A new method for establishing the fibre bridging law by an inverse analysis approach. A new, simplified method for calculating strain energy release rate at the interface of a composite beam. A new, innovative technique for calculating strain energy release rate at the interface of an overlaid pavement. The thesis contains a plethora of graphs, data-tables, examples and formulae, suitable for future researchers.

Calcium phosphate cements (CPCs) are used as bone void fillers and as complements to hardware in fracture fixation. The aim of this thesis was to investigate the possibilities and limitations of the CPCs’ mechanical properties, and find out if these ceramic bone cements can carry application-specific loads, alone or as part of a construct. Recently developed experimental brushite and apatite cements were found to have a significantly higher strength in compression, tension and flexion compared to the commercially available CPCs chronOS™ Inject and Norian® SRS®. By using a high-resolution measurement technique the elastic moduli of the CPCs were determined and found to be at least twice as high compared to earlier measurements, and closer to cortical bone than trabecular bone. Using the same method, Poisson's ratio for pure CPCs was determined for the first time. A non-destructive porosity measurement method for wet brushite cements was developed, and subsequently used to study the porosity increase during in vitro degradation. The compressive strength of the experimental brushite cement was still higher than that of trabecular bone after 25 weeks of degradation, showing that the cement can carry high loads over a time span sufficiently long for a fracture to heal. This thesis also presents the first ever fatigue results for acidic CPCs, and confirms the importance of testing the materials under cyclic loading as the cements may fail at stress levels much lower than the material’s quasi-static compressive strength. A decrease in fatigue life was found for brushite cements containing higher amounts of monetite. Increasing porosity and testing in a physiological buffer solution (PBS), rather than air, also decreased the fatigue life. However, the experimental brushite cement had a high probability of surviving loads found in the spine when tested in PBS, which has previously never been accomplished for acidic CPCs. In conclusion, available brushite cements may be able to carry the load alone in scenarios where the cortical shell is intact, the loading is mainly compressive, and the expected maximum stress is below 10 MPa. Under such circumstances this CPC may be the preferred choice over less biocompatible and non-degradable materials.

O presente estudo teve como objetivo avaliar as propriedades de dois compósitos convencionais [Charisma Diamond (CD) e Filtek Z250XT (FZ250XT)] e dois do tipo Bulk Fill [Aura Bulk Fill, (ABF) e Filtek Bulk Fill (FBF)] em função da profundidade de polimerização e modo de obtenção (O) dos espécimes submetidos ou não a tratamento térmico (TT, 170?C x 10 min)) e um protocolo de envelhecimento acelerado (C, 150000 ciclos, 14,7 N). Para a obtenção dos corpos de prova em forma de disco (10 mm diâmetro e 1 mm espessura) utilizou-se dois tipos de molde de poliéster (segmentado e não segmentado). Foram fotoativados (1000 mW/cm2 X 20 s) nas espessuras de 2 mm (convencionais) e 5 mm (Bulk Fill.). As propriedades avaliadas foram: Grau de conversão (GC), dureza (KHN) e resistência à flexão biaxial (RFB). A análise estatística do GC % para as resinas convencionais mostrou diferença no fator Condição (imediato 58,8 %, sem TT 24h 66,3 %, com TT 83,8 %), na interação Marca X Tratamento Térmico a CD com TT (88,1 %) > FZ250XT (79,6 %) mas nas outras condições foi semelhante. Quanto às resinas do tipo Bulk, a FBF (73,5 %) > ABF (71,8 %), o GC em função da profundidade diminuiu, os primeiros dois milímetros foram semelhantes 1 mm (77,0 %), 2 mm (77,4 %) > 3 mm ( 72,1 %) e 4 mm (70,8 %), semelhantes entre si, e o 5 mm obteve o menor GC (66,2 %). Comparado o 5 mm, a ABF (61,1 %) < FBF (71,4 %). No fator Condição o GC aumenta em 24 h (70,2 %) comparada com o imediato (61,7 %) e com o tratamento térmico aumenta ainda mais (86,2 %). Com o tratamento térmico, a FBF foi a que obteve o maior aumento (88,4 %), ABF (84,1 %), mas as duas sem tratamento térmico não apresentaram diferença significante ABF (69,9 %), FBF (70,5 %). Os valores de KHN tanto para as resinas convencionais como para as reinas do tipo Bulk Fill variaram em função da marca; resinas convencionais FZ250XT (64,8 KHN) > CD (50,8 KHN) e resinas do tipo Bulk Fill FBF (47,2 KHN) > ABF (33,1 KHN); em função da Forma de Obtenção, resinas convencionais Bloco-topo (61,7 KHN) < Fatia-topo (67,3 KHN), Bloco-base (54,0 KHN) > Fatia-base (48,2 KHN), e as resinas do tipo Bulk Fill Bloco-topo (44,5 KHN) < Fatia-topo (48,1 KHN), Bloco-base (38,0 KHN) > Fatia-base (29,9 KHN); e em função do Tratamento Térmico, resinas convencionais com TT (54,15 KHN) > sem TT (53,23 KHN) e resinas do tipo Bulk Fill com TT (44,4 KHN) > sem TT (35,9 KHN). Quanto à RFB, o fator Forma de Obtenção apresentou diferenças significativas para as quatro resinas; o Tratamento térmico aumentou à RFB nas 4 resinas estudadas, a porcentagem de aumento foi de 16,1 % para a resina CD, de 4,7 % para a FZ250XT, de 14,1 % para a ABF e de 28,3 % para a FBF. Com base nos resultados obtidos, pode-se concluir que: maior grau de conversão conduziu à maior resistência à flexão; O tratamento térmico conduziu a um aumento de todas as propriedades estudadas. A ciclagem mecânica, utilizada como protocolo de envelhecimento, permitiu a diferenciação dos materiais. / The aim of this study was to evaluate the properties of two conventional composites [Charisma Diamond (CD) e Filtek Z250XT (FZ250XT)] and two bulk fill composites Fill [Aura Bulk Fill, (ABF) e Filtek Bulk Fill (FBF)] regarding the depth of polymerization and the mode of acquisition (O) of the specimens which were submitted or not submitted to heat treatment (HT, 170 ?C x 10 min) and a protocol of accelerated aging (C, 150,000 cycles, 14.7 N). For the acquisition of the samples in disc format (10 mm in diameter and 1 mm in thickness) two different polyester molds were used (segmented and non-segmented). The samples were light cured in the thickness of 2 mm (conventional composites) and 5 mm (Bulk Fill composites). The properties evaluated were degree of conversion (DC %), hardness (KHN) and biaxial flexural strength (BFS). Statistical analyses of the DC % for the conventional composites showed differences for the factors Condition (immediate 58.8 % < without HT 24h 66.3 % < with HT 83.8 %), in the interaction Brand X Heat Treatment the group CD with HT (88.1 %) was higher than FZ250XT (79.6 %) but for all other conditions the results were similar. As for the Bulk Fill resins, the DC% for FBF (73.5 %) showed higher DC % when compared to ABF (71.8 %). The DC% in function of depth decreased: for the first two millimeters the results were similar: 1 mm (77.0 %) = 2 mm (77.4 %) > 3 mm (72.1 %) = 4 mm (70.8 %), and the 5 mm obtained the lowest DC % (66.2 %). Comparing the 5 mm level among brands, ABF (61.1 %) was lower than FBF (71.4 %). For the factor Condition the DC % increases in 24h (70.2 %) compared to immediate (61.7 %) and with the HT increases even more (86.2 %). With the HT FBF obtained the highest increase (88.4 %), ABF (84.1 %), but both without HT present no statistically significant difference: ABF (69.9 %), FBF (70.5 %). The KHN values for both the conventional composites and the bulk fill ones varied based on the brand; conventional composites: FZ250XT (64,8 KHN) > CD (50.8 KHN) and Bulk Fill resins: FBF (47,2 KHN) > ABF (33,1 KHN); for the mode of acquisition, conventional resins block-top (61.7 KHN) lower than slice-top (67.3KHN), block-base (54.0 KHN) higher than slice-base (48.2 KHN); the bulk fill resins presented the results block-top (44.5 KHN) lower than slice-top (48.1 KHN), block-base (38.0 KHN) higher than slice-base (29.9 KHN); and regarding the HT, conventional resins with HT (54.15 KHN) higher than no HT (53.23 KHN) and bulk fill resins with HT (44.4 KHN) higher than without HT (35.9 KHN). Regarding BFS the factor mean of acquisition presented statistically significant differences for the 4 composites; heat treatment increased the BFS for all resins tested. 16.1 % was the percentage of increase for the CD resin, 4.7 % for FZ250XT, 14.1 % for ABF and 28.3 % for FBF. Based on the results obtained it can be concluded that: the higher conversion rate led to higher flexural strength resistance; the heat treatment led to an increase of all properties evaluated. Mechanical cycling, used as aging protocol, permitted the differentiation of materials.

Restauração provisória é uma importante fase da reabilitação bucal com prótese parcial fixa, deve fornecer proteção pulpar e periodontal, apresentar integridade marginal e estética, ter durabilidade suficiente para resistir às forças mastigatórias. Pacientes com bruxismo ou aqueles cujo tratamento requer períodos longos de uso das restaurações provisórias necessitam de material com melhores propriedades mecânicas. Vários métodos têm sido empregados para reforçar próteses fixas provisórias, como fios metálicos, reforço metálico e incorporação de diferentes tipos de fibras, como carbono, polietileno e vidro, nas resinas para restaurações provisórias. O objetivo desse estudo foi avaliar alteração de cor e propriedades mecânicas de resistência flexural, módulo de elasticidade e carga de ruptura em resinas acrílicas com incorporação de fibras de vidro silanizadas. Para avaliação de cor foram confeccionados quarenta corpos-de-prova circulares (15 x 3mm) de cada marca comercial de resina acrílica quimicamente ativada, usada para confecção de restaurações provisórias, Dencor (Clássico Ltda., São Paulo-SP, Brasil), Duralay (Reliance, Worth-IL, EUA) e Trim Plus II (Bosworth Company, Skokie-IL, EUA), sendo vinte corpos-de-prova controles, e vinte experimentais, com adição de 10% em peso de fibras de vidro moídas (Reforplás S/A, São Paulo, SP, Brasil). Após a realização do acabamento superficial dos corpos-de-prova com lixas de carborundum e feltros era realizada a avaliação dos componentes de cor (L*, a*, b*) em espectrocolorímetro portátil (BYK-Gardner GmbH, Gerestried, Alemanha), com três mensurações em cada corpo-de-prova. Para os ensaios de resistência flexural, módulo de elasticidade e carga de ruptura foram confeccionados 40 corpos-de-prova retangulares (10mm de comprimento, 65mm de largura e 3mm de espessura) de cada marca de resina, sendo vinte do grupo controle e vinte do experimental (com fibras). Os corpos-de-prova foram testados em uma máquina de ensaios universal (Emic DL 2000®, Emic, São José dos Pinhais, PR, Brasil), usando três, com velocidade de 5mm/min. Os dados foram analisados estatisticamente, usando testes paramétricos e não paramétricos, de acordo com a distribuição da amostra. Todos os componentes de cor (L*, a* e b*) foram alterados após a incorporação de fibras de vidro, com exceção do componente b* da resina Duralay. Para o ensaio de resistência flexural, a análise de variância evidenciou significância estatística (p<0,01) apenas para o fator resinas (Duralay: 85,748 N/mm2 (± 8,04) ,Trim Plus: 86,860 N/mm2 (± 7,73) e Dencor: 97,400 N/mm2 (± 8,18)).Na avaliação do módulo de elasticidade, a análise de variância mostrou significância estatística (p<0,01) para o fator tratamentos, sem fibra: 2572,138 MPa (± 290,92) e com fibras: 3446,691 MPa (± 411,13), e para a interação, evidenciando que a incorporação de fibras aumentou o módulo de elasticidade das três resinas avaliadas.Na carga de ruptura, a análise de Variância evidenciou significância estatística (p<0,01) para os fatores tratamentos, sem fibras: 482,607 N (± 53,18322) e com fibras: 557,53 N (± 59,49652), resinas Duralay: 494,06 N (± 86,63), Trim Plus: 525,177 N (± 42,85) e Dencor: 540,971 N (± 58,40). Conclui-se que a incorporação de fibras provocou alterações nos componentes de cor e aumentou ambos, módulo de elasticidade e carga de ruptura, contudo não alterou a resistência flexural. / Provisional restoration is an important rehabilitation phase in fixed prosthodontic therapy, it should provide pulpal and periodontal protection, showing marginal integrity and esthetics, should also have enough durability in order to resist to the forces of mastication. Patients with bruxism or those, whose treatment require long-term use of provisional restorations, need material with better mechanical properties. Several methods have been applied to reinforce fixed partial dentures, as well as metal wires, metal reinforcement and the application of different types of fibers, such as carbon, polyethylene and glass in the resins for temporary restorations. The aim of this study was to evaluate the color change as well as the mechanical properties of flexural strength, elastic modulus and load rupture in acrylic resin with silanized glass fibers. In order to evaluate the color, it was fabricated forty circular specimens (15 x 3mm) of each commercial brand of the resins chemically activated, used to make provisional restorations, Dencor (Clássico Ltda., São Paulo-SP, Brasil), Duralay (Reliance, Worth-IL, EUA) e Trim Plus II (Bosworth Company, Skokie-IL, EUA). Twenty specimens were control and the other twenty were experimental with an addition of 10% in glass fiber weights (Reforplás S/A, São Paulo, SP, Brasil). After the superficial finishing of the specimens with silicon carbide paper and rag wheel, it was done an evaluation of the color parameters (L*, a*, b*) with a portable spectrocolorimeter (BYK-Gardner GmbH, Gerestried, Alemanha), in three measures in each specimens. For the flexural strength, elastic modulus and load rupture, forty rectangular specimens were fabricated (10mm in length, 65mm wide and 3mm of thickness) of each resin brand and twenty were experimental with fibers. The specimens were tested on an universal machine (Emic DL 2000®, Emic, São José dos Pinhais, PR, Brasil), using a 3- point bending testing device at a crosshead speed of 5 mm/mim. The data was statistically analyzed using parametric and non-parametric tests, according to the sample distribution. All the color parameter (L*, a* e b*) were altered after putting glass fibers, except the parameter b* from resin Duralay. For flexural resistance, the variance analyzes showed significance statistic (p<0,01) just for the resins ( Duralay: 85,748 N/mm2 (± 8,04) ,Trim Plus: 86,860 N/mm2 (± 7,73) and Dencor: 97,400 N/mm2 (± 8,18)). In the elastic modulus evaluation, the variance analyses showed significance statistic (p<0,01) for the treatment factors, without fibers (2572,138 MPa (± 290,92)) and with fibers (3446,691 (± 411,13)). Regarding the interaction, it showed that the incorporation of the fibers increased the elastic modulus in the three resins analyzed. Regarding the load rupture, the variance analyzed showed significance statistic of (p<0,01) for the treatment factors with fibers: 482,607 N (± 53,18322) and without fibers: 557,53 N (± 59,49652), resins (Duralay: 494,06 N (± 86,63), Trim Plus:525,177 N(± 42,85) e Dencor: 540,971 N (± 58,40)). The results of this study indicated that the incorporation of the fibers caused alterations in the color components and increased both elastic modulus and load rupture; therefore, it didnt increase the flexural resistance.

Restauração provisória é uma importante fase da reabilitação bucal com prótese parcial fixa, deve fornecer proteção pulpar e periodontal, apresentar integridade marginal e estética, ter durabilidade suficiente para resistir às forças mastigatórias. Pacientes com bruxismo ou aqueles cujo tratamento requer períodos longos de uso das restaurações provisórias necessitam de material com melhores propriedades mecânicas. Vários métodos têm sido empregados para reforçar próteses fixas provisórias, como fios metálicos, reforço metálico e incorporação de diferentes tipos de fibras, como carbono, polietileno e vidro, nas resinas para restaurações provisórias. O objetivo desse estudo foi avaliar alteração de cor e propriedades mecânicas de resistência flexural, módulo de elasticidade e carga de ruptura em resinas acrílicas com incorporação de fibras de vidro silanizadas. Para avaliação de cor foram confeccionados quarenta corpos-de-prova circulares (15 x 3mm) de cada marca comercial de resina acrílica quimicamente ativada, usada para confecção de restaurações provisórias, Dencor (Clássico Ltda., São Paulo-SP, Brasil), Duralay (Reliance, Worth-IL, EUA) e Trim Plus II (Bosworth Company, Skokie-IL, EUA), sendo vinte corpos-de-prova controles, e vinte experimentais, com adição de 10% em peso de fibras de vidro moídas (Reforplás S/A, São Paulo, SP, Brasil). Após a realização do acabamento superficial dos corpos-de-prova com lixas de carborundum e feltros era realizada a avaliação dos componentes de cor (L*, a*, b*) em espectrocolorímetro portátil (BYK-Gardner GmbH, Gerestried, Alemanha), com três mensurações em cada corpo-de-prova. Para os ensaios de resistência flexural, módulo de elasticidade e carga de ruptura foram confeccionados 40 corpos-de-prova retangulares (10mm de comprimento, 65mm de largura e 3mm de espessura) de cada marca de resina, sendo vinte do grupo controle e vinte do experimental (com fibras). Os corpos-de-prova foram testados em uma máquina de ensaios universal (Emic DL 2000®, Emic, São José dos Pinhais, PR, Brasil), usando três, com velocidade de 5mm/min. Os dados foram analisados estatisticamente, usando testes paramétricos e não paramétricos, de acordo com a distribuição da amostra. Todos os componentes de cor (L*, a* e b*) foram alterados após a incorporação de fibras de vidro, com exceção do componente b* da resina Duralay. Para o ensaio de resistência flexural, a análise de variância evidenciou significância estatística (p<0,01) apenas para o fator resinas (Duralay: 85,748 N/mm2 (± 8,04) ,Trim Plus: 86,860 N/mm2 (± 7,73) e Dencor: 97,400 N/mm2 (± 8,18)).Na avaliação do módulo de elasticidade, a análise de variância mostrou significância estatística (p<0,01) para o fator tratamentos, sem fibra: 2572,138 MPa (± 290,92) e com fibras: 3446,691 MPa (± 411,13), e para a interação, evidenciando que a incorporação de fibras aumentou o módulo de elasticidade das três resinas avaliadas.Na carga de ruptura, a análise de Variância evidenciou significância estatística (p<0,01) para os fatores tratamentos, sem fibras: 482,607 N (± 53,18322) e com fibras: 557,53 N (± 59,49652), resinas Duralay: 494,06 N (± 86,63), Trim Plus: 525,177 N (± 42,85) e Dencor: 540,971 N (± 58,40). Conclui-se que a incorporação de fibras provocou alterações nos componentes de cor e aumentou ambos, módulo de elasticidade e carga de ruptura, contudo não alterou a resistência flexural. / Provisional restoration is an important rehabilitation phase in fixed prosthodontic therapy, it should provide pulpal and periodontal protection, showing marginal integrity and esthetics, should also have enough durability in order to resist to the forces of mastication. Patients with bruxism or those, whose treatment require long-term use of provisional restorations, need material with better mechanical properties. Several methods have been applied to reinforce fixed partial dentures, as well as metal wires, metal reinforcement and the application of different types of fibers, such as carbon, polyethylene and glass in the resins for temporary restorations. The aim of this study was to evaluate the color change as well as the mechanical properties of flexural strength, elastic modulus and load rupture in acrylic resin with silanized glass fibers. In order to evaluate the color, it was fabricated forty circular specimens (15 x 3mm) of each commercial brand of the resins chemically activated, used to make provisional restorations, Dencor (Clássico Ltda., São Paulo-SP, Brasil), Duralay (Reliance, Worth-IL, EUA) e Trim Plus II (Bosworth Company, Skokie-IL, EUA). Twenty specimens were control and the other twenty were experimental with an addition of 10% in glass fiber weights (Reforplás S/A, São Paulo, SP, Brasil). After the superficial finishing of the specimens with silicon carbide paper and rag wheel, it was done an evaluation of the color parameters (L*, a*, b*) with a portable spectrocolorimeter (BYK-Gardner GmbH, Gerestried, Alemanha), in three measures in each specimens. For the flexural strength, elastic modulus and load rupture, forty rectangular specimens were fabricated (10mm in length, 65mm wide and 3mm of thickness) of each resin brand and twenty were experimental with fibers. The specimens were tested on an universal machine (Emic DL 2000®, Emic, São José dos Pinhais, PR, Brasil), using a 3- point bending testing device at a crosshead speed of 5 mm/mim. The data was statistically analyzed using parametric and non-parametric tests, according to the sample distribution. All the color parameter (L*, a* e b*) were altered after putting glass fibers, except the parameter b* from resin Duralay. For flexural resistance, the variance analyzes showed significance statistic (p<0,01) just for the resins ( Duralay: 85,748 N/mm2 (± 8,04) ,Trim Plus: 86,860 N/mm2 (± 7,73) and Dencor: 97,400 N/mm2 (± 8,18)). In the elastic modulus evaluation, the variance analyses showed significance statistic (p<0,01) for the treatment factors, without fibers (2572,138 MPa (± 290,92)) and with fibers (3446,691 (± 411,13)). Regarding the interaction, it showed that the incorporation of the fibers increased the elastic modulus in the three resins analyzed. Regarding the load rupture, the variance analyzed showed significance statistic of (p<0,01) for the treatment factors with fibers: 482,607 N (± 53,18322) and without fibers: 557,53 N (± 59,49652), resins (Duralay: 494,06 N (± 86,63), Trim Plus:525,177 N(± 42,85) e Dencor: 540,971 N (± 58,40)). The results of this study indicated that the incorporation of the fibers caused alterations in the color components and increased both elastic modulus and load rupture; therefore, it didnt increase the flexural resistance.

A reciclagem de pavimentos com adição de cimento Portland é uma técnica que permite reutilizar estruturas degradadas de pavimentos flexíveis na conformação de uma nova camada estabilizada. Seu dimensionamento, no Brasil, tem sido abordado de forma empírica. Entretanto, os métodos racionais desenvolvidos para pavimentos semirrígidos estão baseados principalmente na previsão da vida de fadiga das camadas cimentadas, associada ao nível de deformação atuante na sua fibra inferior. Com o intuito de contribuir no desenvolvimento de um método de dimensionamento de pavimentos com camadas recicladas com adição de cimento, a pesquisa relatada nesta dissertação teve como objetivo principal o estudo laboratorial do comportamento a fadiga de misturas constituídas por fresado asfáltico (20%, 50% e 70%), brita graduada e cimento Portland (teores de 2% e 4%). O programa experimental foi baseado no protocolo para caraterização de materiais cimentados da Austroads (2008; 2012), para ensaios estáticos e de fadiga, além de recomendações para caracterização flexural da JCI (1984), procurando-se avaliar a sua aplicabilidade. Os ensaios de fadiga foram realizados em vigotas com dimensões 10 cm x 10 cm x 40 cm, curadas por pelo menos 28 dias. O modo dos ensaios foi o de tensão controlada como função da resistência à tração na flexão, previamente determinada. O sistema de carregamento é conhecido como fadiga a 4 pontos. Foram obtidos modelos de fadiga em função da tensão de tração atuante, da deformação inicial e da energia dissipada inicial. Os resultados dos ensaios estáticos indicam a predominante influência do teor cimento na resistência a tração na flexão das misturas (valores entre 0,21 MPa e 1,53 MPa), enquanto a porcentagem de fresado tem efeito significativo na deformação de ruptura, tornando as misturas mais dúcteis, e no Módulo de Elasticidade Flexural (que variou entre 1483 MPa e 12800 MPa). No caso dos ensaios de fadiga, os Módulos de Resiliência Flexural iniciais (valores entre 2913 MPa e 7725 MPa) mostraram-se mais dependentes do teor de cimento e independentes do nível de tensão. Nos modelos de fadiga obtidos, os valores dos exponentes de dano por deformação variaram entre 7 e 15, sendo próximos aos relatados pela Austroads para materiais cimentados. Esses modelos foram empregados na modelagem de estruturas de pavimento com camadas de base reciclada, de espessura de 18 cm a 40 cm, visando quantificar o efeito do teor de cimento e da porcentagem de fresado na vida de fadiga, bem como das espessuras da camada reciclada e da nova camada asfáltica sobrejacente. Observou-se que espessuras de camada reciclada inferiores a 30 cm terão curta vida de fadiga. Por outro lado, também ficou evidenciado que a vida de fadiga dessa camada depende significativamente da espessura da nova camada asfáltica sobrejacente, recomendando-se espessuras de no mínimo 10 cm. Finalmente, destaca-se que o volume de dados gerado durante os ensaios de fadiga, e seu processamento por meio de algoritmos desenvolvidos na pesquisa, permitiram abordar conceitos de energia dissipada, como aproximação à definição de critérios de micro e macrofissuração, o que mostrou a utilidade deste tipo de abordagem para futuras pesquisas. / Full-depth reclamation with Portland cement (FDR-C), is a technique allowing the reuse of flexible pavements damaged structures, in order to build a new stabilized layer. In Brazil, pavement design with FDR-C has been determined by empirical approaches. However, mechanistic approach developed for semi-rigid pavements mainly use fatigue relationships based on deformations occurring at the bottom of the cemented layer. In order to develop a pavement design method with FDR-C materials, this research work aimed to study, in laboratory, the fatigue behavior of FDR-C mixtures, for three cement grades (2 %, 4 % e 6 %) and three RAP (Reclaimed Asphalt Pavement) percentages (20 %, 50 % e 70 %).The experimental program was based on the protocol for the characterization of cemented materials of the Austroads (2008; 2012), for static and dynamic tests, and on the recommendations for flexural characterization of concrete reinforced with steel fibers, of the JCI (1984), evaluating the availability of these procedures. Fatigue tests were executed using beams (10 cm x 10 cm x 40 cm), static compacted and with a minimum curing time of 28 days. Stress controlled mode was used, based on flexural strength, previously determined. Loading system was a four-point bending test. Were developed fatigue strain, stress and dissipated energy relationships. Static tests results show that cement is the principal influence on the flexural strength of the mixtures (0.21 MPa up to 1.53 MPa), while the RAP have a major effect in the increasing of the tensile strains making it more ductile (flexural elastic modulus were 1483 MPa up to 12800 MPa). In the case of fatigue tests, flexural modulus were more dependent on the degree of cementation (2913 MPa up to 7725 MPa), and not on the applied stress level. About the fatigue models of FDR-C mixtures, strain damage exponents (7 up to 15) were similar to those reported by Austroads. Laboratory models based on strain were used in modeling of pavement structures, with a FDR-C base layer. Results showed benefits of thickness in FDR-C mixtures and asphalt layers (18 cm up to 40 cm), in order to evaluate the effect of the cement and RAP content on fatigue life, and FDR-C new asphalt thickness as well. This model highlights that FDR-C with a thickness inferior than 30 cm will have a shorter fatigue life. On the other side, was showed that the fatigue life of this layer mainly depends on new hot mix asphalt thickness layer (thickness recommended up to 10 cm). Finally, the volume of data generated during the fatigue tests and his processing through algorithms developed in research allowed using dissipated energy criteria as an approximation of the definition of micro and macro-cracking limits which indicate the utility of this methodology for future research. / El reciclaje de pavimentos con adición de cemento Portland es una técnica que permite la reutilización de estructuras degradadas de pavimentos flexibles para la conformación de una nueva capa estabilizada. Su diseño, en Brasil, ha sido abordado de forma empírica. Sin embargo, métodos racionales desarrollados para pavimentos semirrígidos están basados en la vida de fatiga de las capas cementadas, asociada al estado de deformaciones actuante en su base. Con el objetivo de contribuir al desarrollo de un método de dimensionamiento de pavimentos con capas recicladas con adición de cemento, la investigación relatada en esta disertación tuvo como objetivo principal el estudio laboratorial del comportamiento de fatiga de mezclas constituidas por fresado asfáltico (20%, 50% y 70%), base granular y cemento Portland (2%, 4 % y 6 %). El programa experimental fue basado en protocolos de caracterización de materiales cementados de la Austroads (2008, 2012), para ensayos estáticos y de fatiga, además de recomendaciones para caracterización flexural de concreto reforzado con fibras de acero de la JCI (1984), procurando evaluar su aplicabilidad. Los ensayos de fatiga fueron realizados en vigotas con dimensiones de 10 cm x 10 x cm x 40 cm, moldadas estáticamente y curadas por lo menos 28 días. El modo de carga fue de esfuerzo controlado en función de la resistencia de tracción en la flexión, previamente determinada. El sistema de carga es conocido como fatiga 4 puntos. Los resultados de los ensayos estáticos mostraron una influencia predominante del contenido de cemento respecto a la resistencia flexural de las mezclas (valores entre 0,21 MPa y 1,53 MPa), mientras que el material fresado tiene un efecto significativo en la deformación de tracción al tonar más dúctiles las mezclas, afectando módulo de elasticidad flexural (valores entre 1483 MPa y 12800 MPa). En el caso de los ensayos de fatiga, los Módulos de Resiliencia Flexural iniciales (valores entre2913 MPa y 7725 MPa) mostraron ser más dependientes del grado de cementación e independientes del nivel de esfuerzo aplicado. Los valores de los exponentes de daño por deformación en los modelos de fatiga, que variaron entre 7 y 15, fueron próximos a los relatados por la Austroads. Estos modelos fueron usados en la modelación de estructuras de pavimento con capas de base reciclada, de espesor entre 18 cm y 40 cm, buscando cuantificar el efecto del contenido de cemento y de fresado en la vida de fatiga. Se observó que espesores de la capa reciclada inferiores a 30 cm tendrán corta vida de fatiga. Por otro lado, fue evidenciado que la vida de fatiga de esta capa depende significativamente del espesor del nuevo revestimiento asfáltico, recomendándose espesores superiores a 10 cm. Finamente, se destaca que el volumen de datos generados durante los ensayos de fatiga y su procesamiento por medio de algoritmos desarrollados en la investigación permitieron abordar conceptos de energía disipada, como aproximación a la definición de criterios de micro y macro fractura que mostraron la utilidad de este tipo de metodologías para estudios futuros.

Materiais odontológicos inovadores que apresentem propriedades antimicrobianas são altamente desejáveis na cavidade oral. O objetivo deste estudo foi avaliar a atividade antimicrobiana do vanadato de prata nanoestruturado (&beta;-AgVO3) incorporado em duas resinas acrílicas frente a Candida albicans, Streptococcus mutans, Staphylococcus aureus e Pseudomonas aeruginosa, além de examinar as propriedades mecânicas e o padrão de incorporação do nanomaterial nas resinas. O nanomaterial foi caracterizado por difração de raios X (DRX), espectroscopia no infravermelho por transformada de Fourier (FTIV), análise elementar por energia dispersiva (EDS) e microscopia eletrônica de varredura (MEV). As propriedades antimicrobianas das resinas acrílicas incorporadas com diferentes porcentagens de &beta;-AgVO3 foram investigadas pelo método de redução do XTT, unidades formadoras de colônias (UFC) e microscopia confocal à laser e o comportamento mecânico por meio de ensaios de dureza e rugosidade superficial, resistência à flexão, à compressão e ao impacto. O padrão de incorporação do &beta;-AgVO3 nas resinas foi analisado por microscopia eletrônica de varredura (MEV) e análise elementar por energia dispersiva (EDS). Os dados foram analisados por ANOVA, Tukey e pelo teste Generalized Linear Models (&alpha;=0,05). Para ambas as resinas, em relação ao grupo controle, a incorporação de 5% e 10% de &beta;-AgVO3 reduziram significantemente a atividade metabólica de C. albicans e P. aeruginosa (p<0,05), enquanto que para S. mutans houve redução significante apenas com a incorporação de 10% (p<0,05). Não houve diferença na atividade metabólica pelo método do XTT frente a S. aureus (p> 0,05). Para ambas as resinas, observou-se uma redução significativa no número de UFC/mL de C. albicans para o grupo incorporado com 10% de &beta;-AgVO3 e de S. mutans para os grupos com 2,5%, 5% e 10% do nanomaterial (p<0,05). Para S. aureus e P. aeruginosa, houve redução significante com a incorporação de 5% e 10% (p<0,05). A dureza superficial da resina termopolimerizável permaneceu inalterada pela incorporação do nanomaterial (p>0,05) e da autopolimerizável aumentou com 0,5% (p<0,05). Concentrações maiores que 1% promoveram redução na resistência flexural das resinas (p<0,05) enquanto que a rugosidade superficial permaneceu inalterada (p>0,05). A resistência à compressão da resina autopolimerizável permaneceu inalterada (p>0,05) e da termopolimerizável reduziu com a incorporação de 0,5% e 10% (p<0,05). As concentrações de 5% e 10% promoveram redução significante na resistência ao impacto das resinas, em relação ao controle (p<0,05). A caracterização das resinas quanto a dispersão da carga utilizada mostrou a presença de domínios de &beta;-AgVO3 ao longo da matriz polimérica seguindo um padrão circular. Conclui-se que o método proposto foi capaz de promover atividade antimicrobiana às resinas acrílicas frente aos micro-organismos avaliados, sendo a mesma dependente da concentração do nanomaterial. Porém, alterações na dispersão do &beta;-AgVO3 na matriz dos polímeros são necessárias para não sacrificar as propriedades mecânicas e para potencializar o efeito antimicrobiano / Innovative dental materials that have antimicrobial properties are highly desirable in the oral cavity. The aim of this study was to evaluate the antimicrobial activity of nanostructured silver vanadate (&beta;-AgVO3) incorporated into two acrylic resins against Candida albicans, Streptococcus mutans, Staphylococcus aureus and Pseudomonas aeruginosa, while examining the mechanical properties and the pattern of nanomaterial incorporation into resins. The nanomaterial was characterized by X-ray diffraction (XRD), infrared spectroscopy Fourier transform (FTIR), elemental analysis by energy dispersive (EDS) and scanning electron microscopy (SEM). The antimicrobial properties of acrylic resins incorporated with different percentages of &beta;-AgVO3 were investigated by the reduction of XTT method, colony forming units (CFU) and confocal laser microscopy and the mechanical behavior through hardness, surface roughness, flexural, compression and impact tests. The pattern of incorporation of &beta;-AgVO3 resins was analyzed by scanning electron microscopy (SEM) and elemental analysis by energy dispersive (EDS). Data were analyzed by ANOVA, Tukey test and the Generalized Linear Models (&alpha; = 0.05). For both resins, compared to the control group, the incorporation of 5% and 10% &beta;-AgVO3 caused a significantly reduced in the metabolic activity of C. albicans and P. aeruginosa (p <0.05), while for S. mutans significant reduction was observed only with the incorporation of 10% (p <0.05). There was no difference in metabolic activity by XTT method against S. aureus (p> 0.05). For both resins, there was a significant reduction in the number of CFU / mL for C. albicans incorporated group with 10% &beta;-AgVO3 and S. mutans in groups with 2.5%, 5% and 10% of nanomaterial (p <0.05). For P. aeruginosa and S. aureus, there was a significant decrease with the incorporation of 5% to 10% (p <0.05). The surface hardness of the heat-cured resin was unchanged by the incorporation of the nanomaterial (p <0.05) and increased self-cured with 0.5% (p <0.05). Concentrations above 1% promote the reduction in flexural strength of the resins (p <0.05) while the surface roughness remained unchanged (P> 0.05). The compressive strength of the self-cured resin remained unchanged (P> 0.05) and heat-cured reduced with the incorporation of 0.5% and 10% (p <0.05). Concentrations of 5% and 10% caused a significant reduction in impact strength of resins, compared to control (p <0.05). The characterization of the resins as the dispersion of the filler used showed the presence of &beta;-AgVO3 domains along the polymer matrix following a circular pattern. It was concluded that the proposed method was able to promote antimicrobial activity to acrylic resins against microorganisms evaluated, with the same concentration dependent of the nanomaterial. However, changes in the &beta;-AgVO3 dispersion in the polymer matrix are necessary to do not sacrifice the mechanical properties and to enhance the antimicrobial effect

共著者あり。共著者名: 亘理文夫，今井徹，山方秀一，小林雅博. 日本歯科理工学会, 豊泉裕，亘理文夫，今井徹，山方秀一，小林雅博 = TOYOIZUMI, Hiroshi ; WATARI, Fumio ; IMAI, Tohru ; YAMAGATA, Shuichi ; KOBAYASHI, Masahiro, 光重合法による曲げおよびねじり剛性を有する審美性矯正ワイヤーの試作 = Fabrication of Aesthetic Wires with Flexural and Torsional Stiffness by Photo Curing Method, 歯科材料・器械 = The Journal of the Japanese Society for Dental Materials and Devices, 18(6), 1999 NOV, pp.429-440 / Hokkaido University (北海道大学) / 博士 / 歯学