No description available.

No description available.

An investigation has been carried out to reduce the deformation behavior of polyethylene (PE) woven geotextile fabric by making PE fabric-glass yarn composite structure using stitching and laminating. The results showed that reinforcement significantly reduced the creep and IED as long as the tensile stress is lower than the total load bearing capacity of the glass yarns in the composite structure. However, the strength of PE-glass composite fabric was solely dependent on the strength of the glass yarns. The strength from PE yarns only contributes when all glass yarns are broken. Cast result of concrete columns using the glass yarn reinforced PE fabric by stitching method suggested that the glass yarn must face outside of the fabric formwork to avoid damage of both fabric surface and column surface.

El presente trabajo se enfoca en diseñar un encofrado metálico tipo arco para desarrollar el soporte de las vigas estructurales, de misma forma geométrica del puente Chacanto. Para ello hemos utilizado los criterios de modulación de encofrados de la empresa: ULMA Encofrados Perú S.A, en conjunto con la elaboración de una memoria de cálculo para validar el diseño desarrollado. Como resultado principal de este diseño hemos obtenido que: aplicando un diseño de encofrado metálico tipo arco del Sistema MK (ULMA) se logró soportar tanto las cargas del montaje como las del vaciado de la viga, y siempre teniendo que las fuerzas actuantes no superaron las fuerzas admisibles del Sistema MK. La conclusión principal es que diseñando y aplicando encofrados metálicos industrializados podemos conocer las propiedades de los materiales empleados, y también, desarrollar un mejor análisis estructural a estos diseños. Está demostrado que en la parte de la ejecución de este tipo de puentes se obtiene mayores rendimientos de mano de obra, comparado con un encofrado tradicional de madera. This paper focuses on designing a metal formwork type arc to develop structural support beams, Chacanto same geometric shape of the bridge. So we've used the criteria modulation formwork Office: ULMA Formwork Perú S.A., together with the development of a calculation to validate the design developed. The main result of this design we have obtained that: applying a pattern of metal formwork arc type of MK System (ULMA) it was possible to support both loads assembly as emptying of the beam, and always having to forces acting not exceeded System MK permissible forces. The main conclusion is that designing and implementing industrial metal formwork can know the properties of the materials used, and also develop a better structural analysis to these designs. It is shown that in the part of the implementation of this type of bridges higher yields of labor is obtained, compared with a traditional wood framing.

No description available.

This research includes a preliminary study prior to the commencement of the Ph.D. work and three phases of design, construction and testing of three generations of moment-shaped beams. Each phase of the research brought a better understanding of curved beams which follow the shape of the moment diagram. The moment diagram in this study was for simply supported beams supporting a uniformly distributed load as would be the case in the majority of building designs. The original theory for this research can be described as follows: Moment-shaped beams are the natural outcome of a fundamental understanding of stress paths in a horizontal load bearing member. By following these stress paths we may provide materials where required to most efficiently carry the compression and tension stresses to the supports. Allowing stresses to follow their naturally desired paths reduces regions where stresses cross paths called disturbed regions. The outcome of the final phase of this research was the development of the third generation of curved beams with a camber. These beams, designated as Cambered Curve beams (CCBs), exhibited the same behaviour as the rectangular control beam design using CSA-A23.3 up to the serviceability failure of L/360 (12mm). The CCB moment-shaped beams require 20% less concrete and 40% less reinforcing steel (no shear stirrups) to carry the ultimate load which is only 12% less than that carried by the CSA-designed control beam. Due to a closed system of internal forces, the moment-shaped beams remain intact and are able to sustain self weight, even after total failure. A significant part of this research was to modify and verify a FORTRAN-based finite element analysis program: FINIT-Y. This program was reconstructed to analyse a full size beam, and enabled the researcher to model and correctly predict the maximum load, crack pattern and failure mode. This study found that moment-shaped beams with no shear reinforcement have the same stiffness and load carrying capacity as the CSA-designed rectangular control beam with shear reinforcement up to serviceability failure (L/360). The study also found that moment-shaped beams have significantly lower ductility at the ultimate load.

This research includes a preliminary study prior to the commencement of the Ph.D. work and three phases of design, construction and testing of three generations of moment-shaped beams. Each phase of the research brought a better understanding of curved beams which follow the shape of the moment diagram. The moment diagram in this study was for simply supported beams supporting a uniformly distributed load as would be the case in the majority of building designs. The original theory for this research can be described as follows: Moment-shaped beams are the natural outcome of a fundamental understanding of stress paths in a horizontal load bearing member. By following these stress paths we may provide materials where required to most efficiently carry the compression and tension stresses to the supports. Allowing stresses to follow their naturally desired paths reduces regions where stresses cross paths called disturbed regions. The outcome of the final phase of this research was the development of the third generation of curved beams with a camber. These beams, designated as Cambered Curve beams (CCBs), exhibited the same behaviour as the rectangular control beam design using CSA-A23.3 up to the serviceability failure of L/360 (12mm). The CCB moment-shaped beams require 20% less concrete and 40% less reinforcing steel (no shear stirrups) to carry the ultimate load which is only 12% less than that carried by the CSA-designed control beam. Due to a closed system of internal forces, the moment-shaped beams remain intact and are able to sustain self weight, even after total failure. A significant part of this research was to modify and verify a FORTRAN-based finite element analysis program: FINIT-Y. This program was reconstructed to analyse a full size beam, and enabled the researcher to model and correctly predict the maximum load, crack pattern and failure mode. This study found that moment-shaped beams with no shear reinforcement have the same stiffness and load carrying capacity as the CSA-designed rectangular control beam with shear reinforcement up to serviceability failure (L/360). The study also found that moment-shaped beams have significantly lower ductility at the ultimate load.

O elevado nível de conhecimento na fabricação de novos materiais e nas etapas da elaboração do projeto de estruturas não se repete quando são avaliadas as técnicas de execução de edificações. Por outro lado, a economia globalizada tornou indispensável a racionalização na construção civil e, no que refere ao item fôrmas, esta só é possível com o ação de um profissional especializado, ainda raro no mercado de trabalho da engenharia brasileira. Neste contexto, este trabalho apresenta procedimentos para se alcançar a redução no custo final da construção quando bem delineados os projetos arquitetônico e estrutural, com ênfase em aspectos construtivos. São também mostrados os benefícios da correta definição do \"Projeto de Fôrmas\", necessidade imperiosa no conjunto de elementos gráficos que constituem o projeto de um edifício. Os princípios e as técnicas para a análise e o projeto das fôrmas para estruturas de concreto são apresentadas de acordo com a nova versão da norma brasileira (Projeto de Estruturas de Madeira - 1997), fundamentada no método dos estados limites. Os ensaios experimentais realizados nas faces laterais das fôrmas dos pilares definem uma proposta de formulação para o cálculo da pressão lateral que o concreto exerce nessas faces (segundo a teoria de Mohr-Coulomb), necessário para o dimensionamento de peças integrantes das fôrmas. Por fim, são apresentadas as premissas para a elaboração projetual de um sistema de fôrmas para edifícios de múltiplos andares. / The high level of knowledge in the production of new materials and in the steps of structural design is not present on the construction techniques of multistorey buildings. On the other hand, to global economy it becomes indispensable to introduce rationalization concepts in civil construction, especially in formwork. This introduction is only possible with the action of an expert, who is still rare in Brazilian Civil Engineering. In this context, this work aims the presentation of procedures to reach a reduction on the final cost of multi-storey buildings, when architectural and structural design are well outlined, with emphasis to constructive details. Furthermore, the benefits of a proper definition of the \"Formwork Design\" are presented, due to its fundamental role in the graphical elements of a project. The principles of formwork design are presented according to new Brazilian Code (Design of Timber Structures -1997), based on limit states method. Tests on the lateral faces of column formwork originated a proposal to estimate lateral pressures applied by the concrete (according to Mohr-Coulomb Theory), which is necessary to detail formwork elements. Finally, the premises to design the formwork of a multistorey building are presented.

O elevado nível de conhecimento na fabricação de novos materiais e nas etapas da elaboração do projeto de estruturas não se repete quando são avaliadas as técnicas de execução de edificações. Por outro lado, a economia globalizada tornou indispensável a racionalização na construção civil e, no que refere ao item fôrmas, esta só é possível com o ação de um profissional especializado, ainda raro no mercado de trabalho da engenharia brasileira. Neste contexto, este trabalho apresenta procedimentos para se alcançar a redução no custo final da construção quando bem delineados os projetos arquitetônico e estrutural, com ênfase em aspectos construtivos. São também mostrados os benefícios da correta definição do \"Projeto de Fôrmas\", necessidade imperiosa no conjunto de elementos gráficos que constituem o projeto de um edifício. Os princípios e as técnicas para a análise e o projeto das fôrmas para estruturas de concreto são apresentadas de acordo com a nova versão da norma brasileira (Projeto de Estruturas de Madeira - 1997), fundamentada no método dos estados limites. Os ensaios experimentais realizados nas faces laterais das fôrmas dos pilares definem uma proposta de formulação para o cálculo da pressão lateral que o concreto exerce nessas faces (segundo a teoria de Mohr-Coulomb), necessário para o dimensionamento de peças integrantes das fôrmas. Por fim, são apresentadas as premissas para a elaboração projetual de um sistema de fôrmas para edifícios de múltiplos andares. / The high level of knowledge in the production of new materials and in the steps of structural design is not present on the construction techniques of multistorey buildings. On the other hand, to global economy it becomes indispensable to introduce rationalization concepts in civil construction, especially in formwork. This introduction is only possible with the action of an expert, who is still rare in Brazilian Civil Engineering. In this context, this work aims the presentation of procedures to reach a reduction on the final cost of multi-storey buildings, when architectural and structural design are well outlined, with emphasis to constructive details. Furthermore, the benefits of a proper definition of the \"Formwork Design\" are presented, due to its fundamental role in the graphical elements of a project. The principles of formwork design are presented according to new Brazilian Code (Design of Timber Structures -1997), based on limit states method. Tests on the lateral faces of column formwork originated a proposal to estimate lateral pressures applied by the concrete (according to Mohr-Coulomb Theory), which is necessary to detail formwork elements. Finally, the premises to design the formwork of a multistorey building are presented.

This work claims to study the technical feasibility of using ferrocement panels as permanent self-supported formworks for execution of bridges on local roads. It is justified by changes in the production structure of agriculture in general that resulted in changing the type of traffic, impacting the service life of special engineering structure and also the limited capacity of infrastructure investments and technical capacity of municipalities to whom these systems are jurisdictional . The study was done by the development of theoretical models of a size which can be positioned with simple equipment and check its structural plates. The methodological approach included bibliographic and document analysis research. The theoretical development studies considered the reference group recognized research, relevant technical standards and analytical models already consolidated. / O objetivo deste trabalho é estudar a viabilidade técnica do uso de placas de argamassa armada como formas permanentes e autoportantes para execução de pontes em vias secundárias e vicinais. Justifica-se pelas mudanças da estrutura produtiva da agropecuária em geral que resultaram na alteração do tipo de tráfego, com impacto na vida útil das obras de arte viárias e também na baixa capacidade de investimentos em infraestrutura e capacitação dos municípios a quem estes sistemas estão jurisdicionados. O estudo foi feito pelo desenvolvimento teórico de modelos de placas de dimensões tais que possam ser posicionadas com equipamentos simples e a sua verificação estrutural. A abordagem metodológica contemplou pesquisa bibliográfica e análise documental. O desenvolvimento teórico considerou estudos de referência de grupos de pesquisa reconhecidos, normas técnicas pertinentes e modelos analíticos já consolidados. / Mestre em Engenharia Civil