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Vibrations associated with lightweight floor systems, as a serviceability criterion, are not well addressed in current residential construction practice. Cold-formed steel floor systems are usually lighter and have less inherent damping. If designers are going to use the current span deflection criteria when designing residential floor systems, it is imperative to find the construction and design details that will limit these annoying vibrations in cold-formed steel floor systems. Presented in this seminar are the results from a recent laboratory study and field study on the vibration characteristics of cold-formed steel floors performed at the University of Waterloo. Several full-scale floor systems with varying construction and design details were constructed and tested, and several in situ floor systems were tested. The objectives of this research were: to evaluate the dynamic response of residential floor systems supported by cold-formed steel joists; to investigate the influence of span length, joist types, subfloor materials, toppings, ceilings, strongbacks, live loads and framing conditions on the vibration characteristics of cold-formed steel floor systems; to identify the critical construction details that will limit annoying floor vibrations; to compare the vibration characteristics of in situ floor systems and laboratory constructed floor systems; and to evaluate the vibration performance of laboratory and in situ floor systems based on current acceptability criteria.

Vibrations associated with lightweight floor systems, as a serviceability criterion, are not well addressed in current residential construction practice. Cold-formed steel floor systems are usually lighter and have less inherent damping. If designers are going to use the current span deflection criteria when designing residential floor systems, it is imperative to find the construction and design details that will limit these annoying vibrations in cold-formed steel floor systems. Presented in this seminar are the results from a recent laboratory study and field study on the vibration characteristics of cold-formed steel floors performed at the University of Waterloo. Several full-scale floor systems with varying construction and design details were constructed and tested, and several in situ floor systems were tested. The objectives of this research were: to evaluate the dynamic response of residential floor systems supported by cold-formed steel joists; to investigate the influence of span length, joist types, subfloor materials, toppings, ceilings, strongbacks, live loads and framing conditions on the vibration characteristics of cold-formed steel floor systems; to identify the critical construction details that will limit annoying floor vibrations; to compare the vibration characteristics of in situ floor systems and laboratory constructed floor systems; and to evaluate the vibration performance of laboratory and in situ floor systems based on current acceptability criteria.

Experimental and analytical research was conducted to address the vibration properties of Long Span Deck Floor Systems (LSDFS). The research comprised three stages. In the first part, experimental in-situ tests were conducted on thirteen bays of buildings under construction. The natural frequencies and acceleration responses were captured to observe the vibration behavior of the tested floors. In the second part, a laboratory footbridge was constructed to determine the fixity level attained at the supports when a LSDFS is supported by CMU walls. For this purpose, the footbridge was tested with three support conditions, and a number of experiments were carried out to determine the dynamic properties of the structure. Static tests using both point and distributed loadings were conducted to measure the deflections at the footbridge midspan. The static test results were compared to the theoretical deflections for a pinned-end beam and a fixed-end beam. Dynamic tests using experimental modal analysis techniques were conducted to determine the natural frequencies and mode shapes of the structure. The measured fundamental natural frequency of the footbridge was compared to the frequencies calculated for a simply supported beam and a beam with fixed ends, to determine the degree of fixity attained in the connection between the LSDFS and the supporting walls. In the last part of the research, three analytical procedures to predict modal characteristics of long span deck floor systems are studied. Floor frequencies are calculated using finite element analyses. Two design guides for floor vibration analysis were used to calculate natural frequencies and response accelerations. The predicted results obtained from the analytical methods are compared to the experimental results to determine their accuracy. Recommendations for the use of the analytical methods are provided. / Master of Science

Longitudinal slab splitting in composite hot rolled girders and joist girders was investigated. Two different type of framing configurations were studied with two tests conducted per configuration. The framing configurations were designated as either flush-framed or haunched, which describes the framing of the joists into the joist girders or H-shape. Each floor system consisted of at least one exterior or spandrel joist girder, one interior joist girder, and in three of the four tests, an exterior or spandrel H-shape. The nominal lengths of the girders were 30 ft 4 in. with a centerline spacing of 7 ft for the flush-framed tests and 6 ft 9 in. for the haunch tests. Varying amounts of transverse reinforcement were used in the slab over each girder. Shear connectors were all 0.75 in. diameter headed shear studs of varying lengths. The results of these tests were used to determine the minimum amount of transverse reinforcement required to prevent longitudinal splitting from controlling the strength of the section. A comparative analytical study was performed to generate a design procedure for determining the appropriate amount of transverse reinforcement. This consisted of adapting existing procedures in reinforced concrete for similar shear problems and generating alternative procedures based on existing research for composite construction. Results from these methods were then calibrated against experimental data obtained in this study. / Master of Science

Devido à climatização dos ambientes internos condicionar o bem estar e o conforto térmico das pessoas é que se fazem necessárias novas pesquisas que procurem potencializar as tecnologias existentes e reduzir tanto os custos de instalação quanto o consumo de energia. É sabido que os sistemas convencionais de calefação proporcionam um alto consumo de energia e uma emissão de níveis de ruído muitas vezes inaceitáveis, entretanto os sistemas radiantes ganham, a cada dia, uma maior abrangência como alternativa de climatização devido às suas vantagens comparativas com relação aos sistemas convencionais. O emprego de sistemas de calefação por piso radiante em muitos países é limitada pelo preço da instalação como consequência do elevado custo dos materiais como é o caso da fabricação das tubulações. Estas geralmente são fabricadas de polietileno ou de cobre, sendo este ultimo o que entrega um maior desempenho térmico e, por conseguinte um melhor fornecimento de energia, mas o elevado custo deste material restringe o seu uso principalmente ao setor residencial, podendo atingir um mercado maior que compreenda edifícios públicos, de escritório, escolas, hospitais, etc. Com isso, este trabalho procura reduzir a quantidade de materiais de tubulação necessários para garantir o desempenho do sistema e o conforto térmico de uma habitação aquecida com um sistema radiante. Para isto, foi desenvolvida a resolução numérica do modelo matemático da transferência de calor no interior do piso pelo método dos volumes finitos na formulação implícita e implementada em código computacional na linguagem Matlab. Para isto, foram considerados dois parâmetros fundamentais para garantir o conforto térmico da habitação que correspondem à temperatura da água e a distancia entre os tubos que compõem o sistema. A análise corresponde ao cálculo da temperatura superficial do piso para distintas temperaturas da água e distintas distâncias, obtendo resultados interessantes que permitem reduzir o custo da instalação em até um 40%. / Due to temperature control of interiors conditioning the well-being and the thermal comfort of people, it is necessary to make new researches aiming to improve the existing technologies and to reduce both installation costs and energy consumption. It is known that the use of traditional heating systems involves high energy consumption and, in some cases, unacceptable noise levels; while radiant systems are gaining a wider scope as a heating alternative due to its advantages compared to conventional systems. The use of radiant floor heating systems in Brazil is limited by installation cost due to the high price of required materials. This fact restricts the use of these systems primarily to the residential sector. However, it may be possible for this technology to reach a larger market, including public buildings, offices, schools and hospitals. Therefore, to optimize the most relevant design parameters relating to the thermal performance of the system and reduce both the amount of required materials and the system operating time, this paper elaborates on a method consisting of a high-resolution numerical mathematical model of the heat transfer within a floor using a finite control volume method with an implicit solution scheme. In this work, we consider how the properties of the materials, environmental thermal comfort factors and the performance of the system work together with the theoretical underpinnings of the heat transfer phenomenon to define the design parameters to optimize the materials and provide greater control over the energy consumption. This optimization is achieved without changing any environmental thermal comfort conditions or the well-being of the occupants. Finally, a numerical solution for the heat transfer within the floor is implemented using the computer code Matlab.

A lightweight carbon fiber reinforced polymer (CFRP) sandwich panel has been developed for floor use in commercial office building construction. CFRP laminate skins were combined with low-density rigid polyurethane foam to create a composite sandwich panel suitable for floor use. The CFRP sandwich panel was optimized to withstand code prescribed office-building live loads using a 3D finite element computer program called SolidWorks. The thickness of the polyurethane foam was optimized to meet both strength and serviceability requirements for gravity loading. Deflection ultimately was the controlling factor in the design, as the stresses in the composite materials remained relatively low. The CFRP sandwich panel was then subjected to combined gravity and lateral loading, which included seismic loads from a fictitious 5-story office building located in a region of high seismic risk. The results showed that CFRP sandwich panels are a viable option for use with floors, possessing sufficient strength and stiffness for meeting code prescribed design loads, while providing significant benefits over traditional construction materials.

Devido à climatização dos ambientes internos condicionar o bem estar e o conforto térmico das pessoas é que se fazem necessárias novas pesquisas que procurem potencializar as tecnologias existentes e reduzir tanto os custos de instalação quanto o consumo de energia. É sabido que os sistemas convencionais de calefação proporcionam um alto consumo de energia e uma emissão de níveis de ruído muitas vezes inaceitáveis, entretanto os sistemas radiantes ganham, a cada dia, uma maior abrangência como alternativa de climatização devido às suas vantagens comparativas com relação aos sistemas convencionais. O emprego de sistemas de calefação por piso radiante em muitos países é limitada pelo preço da instalação como consequência do elevado custo dos materiais como é o caso da fabricação das tubulações. Estas geralmente são fabricadas de polietileno ou de cobre, sendo este ultimo o que entrega um maior desempenho térmico e, por conseguinte um melhor fornecimento de energia, mas o elevado custo deste material restringe o seu uso principalmente ao setor residencial, podendo atingir um mercado maior que compreenda edifícios públicos, de escritório, escolas, hospitais, etc. Com isso, este trabalho procura reduzir a quantidade de materiais de tubulação necessários para garantir o desempenho do sistema e o conforto térmico de uma habitação aquecida com um sistema radiante. Para isto, foi desenvolvida a resolução numérica do modelo matemático da transferência de calor no interior do piso pelo método dos volumes finitos na formulação implícita e implementada em código computacional na linguagem Matlab. Para isto, foram considerados dois parâmetros fundamentais para garantir o conforto térmico da habitação que correspondem à temperatura da água e a distancia entre os tubos que compõem o sistema. A análise corresponde ao cálculo da temperatura superficial do piso para distintas temperaturas da água e distintas distâncias, obtendo resultados interessantes que permitem reduzir o custo da instalação em até um 40%. / Due to temperature control of interiors conditioning the well-being and the thermal comfort of people, it is necessary to make new researches aiming to improve the existing technologies and to reduce both installation costs and energy consumption. It is known that the use of traditional heating systems involves high energy consumption and, in some cases, unacceptable noise levels; while radiant systems are gaining a wider scope as a heating alternative due to its advantages compared to conventional systems. The use of radiant floor heating systems in Brazil is limited by installation cost due to the high price of required materials. This fact restricts the use of these systems primarily to the residential sector. However, it may be possible for this technology to reach a larger market, including public buildings, offices, schools and hospitals. Therefore, to optimize the most relevant design parameters relating to the thermal performance of the system and reduce both the amount of required materials and the system operating time, this paper elaborates on a method consisting of a high-resolution numerical mathematical model of the heat transfer within a floor using a finite control volume method with an implicit solution scheme. In this work, we consider how the properties of the materials, environmental thermal comfort factors and the performance of the system work together with the theoretical underpinnings of the heat transfer phenomenon to define the design parameters to optimize the materials and provide greater control over the energy consumption. This optimization is achieved without changing any environmental thermal comfort conditions or the well-being of the occupants. Finally, a numerical solution for the heat transfer within the floor is implemented using the computer code Matlab.

[pt] Este estudo tem por objetivo avaliar o comportamento estrutural de um sistema de vigamento de piso tipo stub-girder, modificado para melhor aproveitamento dos perfis em sua fabricação. O estudo é baseado em formulações não lineares a partir do método dos elementos finitos (MEF), com uso do software ANSYS. Através do software FTOOL foi criado um modelo simplificado para a análise estrutural e o cálculo das resistências nominais foi feito com base na norma canadense CAN-S16-10 da Canadian Standards Association. Além disso, foram avaliadas as cargas de máximas e de serviço do sistema, bem como os deslocamentos associados a estes carregamentos. Com base nos resultados obtidos, foram feitas recomendações de projeto do sistema e foram avaliadas as condições de economia de material e possibilidade de utilização na prática de construção de edificações de andares múltiplos. Com vistas à fase de construção, é feita a discussão sobre a possibilidade de obtenção de um método construtivo industrializado, já que o sistema de fabricação é caracterizado pela rapidez de produção e montagem, que são facilitadas pelo fato deste sistema permitir a reutilização de pequenos comprimentos de perfis que sobram no processo normal de fabricação. / [en] This study s purpose was to evaluate the structural behavior of a stub-girder floor-system, which was modified to better utilize the steel profiles in its manufacturing process. The study is based on nonlinear analysis through the use of the finit element method (FEM), employing the software ANSYS. For the structural analysis, a simplified model was created through the use of the software FTOOL and the nominal resistances was obtained based on the canadian CAN-S16-10 Standard, by the Canadian Standards Association. Furthermore, the working and tensile loads were evaluated, as were the displacements associated to them. Based on the results, designs recommendations were made and the conditions of economy of material, as well the possibility of the system s practical use in multi-storey buildings were discussed. With regards to the construction phase, a discussion was made on the possibility of obtaining an industrialized construction method, since the manufacturing process is characterized by the fast production and assembly, which are facilitade by the fact that this system allows the reuse of small lenghts of remaining profiles from the normal manufacturing process.

This thesis deals with the possibility of using secondary raw materials from the energy industry especially the solid residues of high temperature combustion of coal. These materials should be now seen as a material with wide usage especially in the construction industry. One possibility of their usage is a replacement of binding parts in floor systems. The aim is to find the optimal composition of the mixture, which fits all the technical requirements and at the same time reduces the cost of its production. An advanced methods of powder X-ray diffraction analysis, particle size laser diffraction analysis and X-ray fluorescence analysis were used to determine the raw materials. Based on these analysis the experiments were designed focusing on the mechanical properties, the observation of the evolution of hydration’s heat in prepared mixtures and their time of setting and hardening.