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Koichi Oba - One of the best experts on this subject based on the ideXlab platform.
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non destructive evaluation of heat welded seams of Roof Coverings
Building Research and Information, 1994Co-Authors: Koichi Oba, Folke BjorkAbstract:L'homographie des cordons de soudure par fusion sur produits en bitume elastomere peut etre etudiee par la methode de l'echo d'impulsion ulttrasonore. Un echo de resonance marque en provenance de la zone de soudure est indicateur de l'absence d'homogeneite du cordon. Le defaut peut alors etre calibre en differents types de structure, determines grâce aux differentes configurations d'echo. Des etudes complementaires sont necessaires pour optimiser les donnees obtenues.
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joint strength of single ply Roof Coverings adhered to sheet metal
Construction and Building Materials, 1994Co-Authors: Folke Bjork, Joseph Katowakabi, Koichi ObaAbstract:Abstract Heat-welded joints between organic Roof-covering materials and sheet metal were studied for three different products of single-ply Roof covering. Joints were formed at different temperatures of Roof covering and sheet metal. It was found that fairly strong seams could be formed when the welding temperature was high enough, although overheating was detrimental. Roof covering and sheet metal should both be heated.
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the relationship between welding temperature and t peel strength of heat welded seams in single ply Roof Coverings
Journal of Adhesion Science and Technology, 1993Co-Authors: Koichi Oba, Folke BjorkAbstract:The results of studying the parameters influencing the quality of watertight seams in single-ply Roof-Coverings for flat and low-sloped Roofs during heat-welding are summarized in this paper. Seam samples of four different single-ply Roof-covering products, i.e. atactic polypropylene (APP)-modified bitumen, styrene-butadiene-styrene copolymer (SBS)-modified bitumen, ethylene-copolymerized bitumen (ECB), and plasticized polyvinyl chloride (PVC), were prepared by welding at various hot-air temperatures and speeds. The seam strengths of the specimens cut off from the heat-welded samples were measured by the T-peel test. The results were supplemented by observation of fracture propagation during the test. The T-peel strength of heat-welded seams is correlated to the hot-air temperature and welding speed. For the bituminous products, there is a limitation to the hot-air temperature at which the seam will attain an acceptable T-peel strength. For the thermoplastic products, the welding speed is more significant...
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dynamic mechanical properties of single ply Roof Coverings for low slope Roofs and the influence of water
Polymer Testing, 1993Co-Authors: Koichi Oba, Folke BjorkAbstract:Abstract The results of five different commercial single-ply Roof-covering products for low-slope Roofs, i.e. atactic polypropylene (APP)-modified bitumen, styrene-butadiene-styrene copolymer (SBS)-modified bitumen, ethylene-copolymerized bitumen (ECB), plasticized PVC and ethylene-propylene-diene-methylene (EPDM)-rubber, studied by dynamic mechanical thermal analysis are summarized in this paper. Two samples of each product were tested, one which had only been conditioned at 20 °C, 50% relative humidity, and another which had been immersed in distilled water at 50 °C for 4000 h. The difference in the dynamic properties at the glass transition region of the two samples is discussed. The influence of water immersion on material properties such as T g and T onset was observed for the products of APP-modified bitumen, SBS-modified bitumen and plasticized PVC. The changes in these material properties may have significance for the durability of the products. Dynamic mechanical thermal analysis can be a useful tool for characterizing products used for single-ply Roof Coverings of low-slope Roofs. It may be useful in understanding how different types of products behave in application with different types of dynamic stresses.
Folke Bjork - One of the best experts on this subject based on the ideXlab platform.
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non destructive evaluation of heat welded seams of Roof Coverings
Building Research and Information, 1994Co-Authors: Koichi Oba, Folke BjorkAbstract:L'homographie des cordons de soudure par fusion sur produits en bitume elastomere peut etre etudiee par la methode de l'echo d'impulsion ulttrasonore. Un echo de resonance marque en provenance de la zone de soudure est indicateur de l'absence d'homogeneite du cordon. Le defaut peut alors etre calibre en differents types de structure, determines grâce aux differentes configurations d'echo. Des etudes complementaires sont necessaires pour optimiser les donnees obtenues.
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joint strength of single ply Roof Coverings adhered to sheet metal
Construction and Building Materials, 1994Co-Authors: Folke Bjork, Joseph Katowakabi, Koichi ObaAbstract:Abstract Heat-welded joints between organic Roof-covering materials and sheet metal were studied for three different products of single-ply Roof covering. Joints were formed at different temperatures of Roof covering and sheet metal. It was found that fairly strong seams could be formed when the welding temperature was high enough, although overheating was detrimental. Roof covering and sheet metal should both be heated.
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the relationship between welding temperature and t peel strength of heat welded seams in single ply Roof Coverings
Journal of Adhesion Science and Technology, 1993Co-Authors: Koichi Oba, Folke BjorkAbstract:The results of studying the parameters influencing the quality of watertight seams in single-ply Roof-Coverings for flat and low-sloped Roofs during heat-welding are summarized in this paper. Seam samples of four different single-ply Roof-covering products, i.e. atactic polypropylene (APP)-modified bitumen, styrene-butadiene-styrene copolymer (SBS)-modified bitumen, ethylene-copolymerized bitumen (ECB), and plasticized polyvinyl chloride (PVC), were prepared by welding at various hot-air temperatures and speeds. The seam strengths of the specimens cut off from the heat-welded samples were measured by the T-peel test. The results were supplemented by observation of fracture propagation during the test. The T-peel strength of heat-welded seams is correlated to the hot-air temperature and welding speed. For the bituminous products, there is a limitation to the hot-air temperature at which the seam will attain an acceptable T-peel strength. For the thermoplastic products, the welding speed is more significant...
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dynamic mechanical properties of single ply Roof Coverings for low slope Roofs and the influence of water
Polymer Testing, 1993Co-Authors: Koichi Oba, Folke BjorkAbstract:Abstract The results of five different commercial single-ply Roof-covering products for low-slope Roofs, i.e. atactic polypropylene (APP)-modified bitumen, styrene-butadiene-styrene copolymer (SBS)-modified bitumen, ethylene-copolymerized bitumen (ECB), plasticized PVC and ethylene-propylene-diene-methylene (EPDM)-rubber, studied by dynamic mechanical thermal analysis are summarized in this paper. Two samples of each product were tested, one which had only been conditioned at 20 °C, 50% relative humidity, and another which had been immersed in distilled water at 50 °C for 4000 h. The difference in the dynamic properties at the glass transition region of the two samples is discussed. The influence of water immersion on material properties such as T g and T onset was observed for the products of APP-modified bitumen, SBS-modified bitumen and plasticized PVC. The changes in these material properties may have significance for the durability of the products. Dynamic mechanical thermal analysis can be a useful tool for characterizing products used for single-ply Roof Coverings of low-slope Roofs. It may be useful in understanding how different types of products behave in application with different types of dynamic stresses.
Nil Türkeri - One of the best experts on this subject based on the ideXlab platform.
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Assessment of long term solar reflectance performance of Roof Coverings measured in laboratory and in field
Building and Environment, 2012Co-Authors: Sinem Kultur, Nil TürkeriAbstract:Abstract Heat island refers to the temperature increase in urban areas compared to rural settings, intensifying the cooling energy consumption of buildings. Roofs constitute a major part in urban areas, hence cool Roof Coverings contribute to mitigate heat island. Heat island is an important issue for cities located in western and southern parts of Turkey, however cool Roof Coverings are not a common application. This study presents the assessment of long term solar reflectance performance of commonly used Roof Coverings in Turkey. Assessment is based on the data obtained from laboratory measurements conducted on new and 1-year aged several test specimens and field monitoring of red clay tile and red shingle using pyranometers for duration of one year. Laboratory results revealed that standing-seam profiled metal Coverings and red colored mineral coated modified bituminous membrane required surface treatments to serve as cool Roof Coverings. Field results indicated that both the red clay tile and the red shingle showed a slight decrease in the solar reflectance due to weathering. Comparison of the new and 1-year aged solar reflectance values of red clay tile and red shingle measured both in laboratory and in field showed that there was no significant difference between the values.
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Solar Reflectance Performance of Roof Coverings in Istanbul; Turkey
Proceedings of the World Renewable Energy Congress – Sweden 8–13 May 2011 Linköping Sweden, 2011Co-Authors: Sinem Kultur, Nil TürkeriAbstract:Cooling energy load can be reduced by reflective Roofs. The reflective Roofs are recognized by Turkish architects, contractors and manufacturers, however, the solar reflectance performance of new and aged Roof Coverings produced in Turkey is still unknown. Purpose of this paper is to assess short-term and long-term solar reflectance performance of these Roof Coverings. In this context, solar reflectance measurements were conducted both in laboratory and in field. Firstly, solar reflectance performance of 13 unexposed test samples including clay, cement, bituminous and metal based was measured in laboratory. Then, 6 of these test samples were exposed to simulated solar radiation for a duration that is equivalent to 1-year exposure. The laboratory measurements indicated that white and shiny ceramic tile is the most reflective covering while black corrugated sheet is the most absorptive one. Secondly, two test specimens (red clay tile and bituminous shingle covered surfaces) with an automated weather observation system were set up in a field in order to measure the solar reflectance performance of the Roof surfaces. The initial results demonstrated that the clay tile-covered Roof surface had higher reflectance values. This paper will enable designers to choose the Roof covering appropriate for reflective Roofs that can be used to rehabilitate existing Roof Coverings or to design new Roofs.
Tatyane Nadja Martins De ,mendonça - One of the best experts on this subject based on the ideXlab platform.
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Telhado verde extensivo em pré-moldado de concreto EVA (Acetato Etil Vinila)
Universidade Federal da Paraíba, 2015Co-Authors: Tatyane Nadja Martins De ,mendonçaAbstract:As áreas verdes da cidade estão sendo ocupadas cada vez mais pelas edificações e impermeabilizações de pavimentos e isto implica em menor qualidade nos ambientes urbanos, uma vez que o efeito da vegetação nesses espaços vai muito além do paisagístico, sendo responsável pela purificação do ar, manutenção da umidade, equilíbrio térmico, entre outros benefícios. Diante da falta do espaço para o verde, e sabendo que os telhados constituem-se em uma porcentagem significativa das áreas impermeabilizadas, defende-se aqui a utilização dos telhados vegetados a fim de se aumentar o verde das cidades e aproveitar os seus benefícios. Uma tecnologia modular de telhado verde extensivo desenvolvida à base de um pré-moldado cimentício, que utiliza resíduo da indústria de calçado (EVA), foi investigada aqui desde sua concepção até a sua avaliação. Nos procedimentos metodológicos foram cumpridas as seguintes etapas: concepção do módulo (denominado bloco TEVA) e do molde para sua fabricação, moldagens experimentais com definição das proporções entre os materiais do compósito cimentício, simulações de sistemas de telhados verdes, instalação do sistema modular em escala real para acompanhamento do desenvolvimento vegetal, e em escala de protótipo para avaliação do comportamento térmico, comparado com quatro outros tipos de coberturas (laje exposta, telhado cerâmico, telhado de fibrocimento, telhado verde com blocos de concreto). Comparando os mesmos protótipos, também foi feita uma avaliação da água pluvial drenada pelos diferentes tipos de coberturas. Com base nos resultados pode-se concluir que o módulo idealizado para ora ser vegetado, ora ser utilizado como piso, tem geometria, resistência mecânica, leveza e permeabilidade à água satisfatórios para o tipo de telhado verde proposto. Os módulos também permitiram um bom desenvolvimento da vegetação. A avaliação térmica confirmou que o telhado verde modular com blocos TEVA promoveu um maior equilíbrio térmico e reduziu a temperatura do ar interno, quando comparado com os outros tipos de coberturas. Quanto à análise da água pluvial drenada por diferentes sistemas, o telhado verde modular com bloco TEVA também foi o que apresentou o melhor desempenho, diminuindo significativamente o volume da água escoada.Green areas of the city are occupied increasingly by buildings and waterpRoofing floors, and this implies lower quality in urban environments, since the effect of vegetation in these areas goes far beyond the landscape, it is responsible for purification air, moisture maintenance, thermal equilibrium, among other benefits. Given the lack of green space, and knowing that the Roofs are in a significant percentage of impermeable areas, it is defended here the use of vegetated Roofs, in order to increase the green of the cities and enjoy its benefits. An extensive green Roof modular technology developed on a pre-molded cement, which uses the residue of footwear (EVA) was investigated here, from its conception to its evaluation. In the methodological procedures the following milestones have been met: module design (called block TEVA) and from mold to manufacture, experimental moldings with definition of proportions among the cementitious composite materials, green Roof systems simulations, the modular system installation in real scale for plant development monitoring, and prototype scale to evaluate the thermal behavior and in four other types of coverage (exposed slab, ceramic Roof, fiber cement Roof, green Roof with concrete blocks). Comparing the same prototypes, was also made an assessment of rainwater drained by different types of Roof Coverings. Based on the results it can be concluded that the module designed to be sometimes vegetated, sometimes be used as floor, has geometry, mechanical strength, lightness and water permeability suitable for the type of green Roof proposed. The modules also allowed a good development of vegetation. A thermal evaluation confirmed that the green Roof with TEVA modular blocks provided a better thermal balance and reduced indoor air temperature when compared with other types of coverage. The analysis of rainwater drained by different systems, modular green Roof with TEVA block was also the one with the best performance, significantly reducing the volume of runoff
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Telhado verde extensivo em pré-moldado de concreto EVA (Acetato Etil Vinila)
'Portal de Periodicos UFPB', 2015Co-Authors: Tatyane Nadja Martins De ,mendonçaAbstract:Green areas of the city are occupied increasingly by buildings and waterpRoofing floors, and this implies lower quality in urban environments, since the effect of vegetation in these areas goes far beyond the landscape, it is responsible for purification air, moisture maintenance, thermal equilibrium, among other benefits. Given the lack of green space, and knowing that the Roofs are in a significant percentage of impermeable areas, it is defended here the use of vegetated Roofs, in order to increase the green of the cities and enjoy its benefits. An extensive green Roof modular technology developed on a pre-molded cement, which uses the residue of footwear (EVA) was investigated here, from its conception to its evaluation. In the methodological procedures the following milestones have been met: module design (called block TEVA) and from mold to manufacture, experimental moldings with definition of proportions among the cementitious composite materials, green Roof systems simulations, the modular system installation in real scale for plant development monitoring, and prototype scale to evaluate the thermal behavior and in four other types of coverage (exposed slab, ceramic Roof, fiber cement Roof, green Roof with concrete blocks). Comparing the same prototypes, was also made an assessment of rainwater drained by different types of Roof Coverings. Based on the results it can be concluded that the module designed to be sometimes vegetated, sometimes be used as floor, has geometry, mechanical strength, lightness and water permeability suitable for the type of green Roof proposed. The modules also allowed a good development of vegetation. A thermal evaluation confirmed that the green Roof with TEVA modular blocks provided a better thermal balance and reduced indoor air temperature when compared with other types of coverage. The analysis of rainwater drained by different systems, modular green Roof with TEVA block was also the one with the best performance, significantly reducing the volume of runoff.Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPESAs áreas verdes da cidade estão sendo ocupadas cada vez mais pelas edificações e impermeabilizações de pavimentos e isto implica em menor qualidade nos ambientes urbanos, uma vez que o efeito da vegetação nesses espaços vai muito além do paisagístico, sendo responsável pela purificação do ar, manutenção da umidade, equilíbrio térmico, entre outros benefícios. Diante da falta do espaço para o verde, e sabendo que os telhados constituem-se em uma porcentagem significativa das áreas impermeabilizadas, defende-se aqui a utilização dos telhados vegetados a fim de se aumentar o verde das cidades e aproveitar os seus benefícios. Uma tecnologia modular de telhado verde extensivo desenvolvida à base de um pré-moldado cimentício, que utiliza resíduo da indústria de calçado (EVA), foi investigada aqui desde sua concepção até a sua avaliação. Nos procedimentos metodológicos foram cumpridas as seguintes etapas: concepção do módulo (denominado bloco TEVA) e do molde para sua fabricação, moldagens experimentais com definição das proporções entre os materiais do compósito cimentício, simulações de sistemas de telhados verdes, instalação do sistema modular em escala real para acompanhamento do desenvolvimento vegetal, e em escala de protótipo para avaliação do comportamento térmico, comparado com quatro outros tipos de coberturas (laje exposta, telhado cerâmico, telhado de fibrocimento, telhado verde com blocos de concreto). Comparando os mesmos protótipos, também foi feita uma avaliação da água pluvial drenada pelos diferentes tipos de coberturas. Com base nos resultados pode-se concluir que o módulo idealizado para ora ser vegetado, ora ser utilizado como piso, tem geometria, resistência mecânica, leveza e permeabilidade à água satisfatórios para o tipo de telhado verde proposto. Os módulos também permitiram um bom desenvolvimento da vegetação. A avaliação térmica confirmou que o telhado verde modular com blocos TEVA promoveu um maior equilíbrio térmico e reduziu a temperatura do ar interno, quando comparado com os outros tipos de coberturas. Quanto à análise da água pluvial drenada por diferentes sistemas, o telhado verde modular com bloco TEVA também foi o que apresentou o melhor desempenho, diminuindo significativamente o volume da água escoada
Williams Chris - One of the best experts on this subject based on the ideXlab platform.
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Dutch Maritime Museum: Form-finding of an irregular faceted skeletal shell - Part a
Editorial Universitat Politècnica de València, 2010Co-Authors: Adriaenssens Sigrid, Ney Laurent, Bodarwe Eric, Williams ChrisAbstract:p. 1349-1355In the context of the search for an efficient structural shape to cover the Dutch Maritime Museum courtyard in Amsterdam, the authors briefly discuss the driving design factors that influenced the earliest glass Roof Coverings. The trends that have emerged during the late 20th and beginning 21st century in the design of skeletal steel glass shells are exposed. These design developments range from sculptural to geometrical and physical intentions (part a). The discussion of the competition design development of the Dutch Maritime Museum Shell Roof by Ney and Partners shows the quest for a structurally efficient catenary form based on a poetic geometrical idea. This paper presents a novel methodology that slightly adapts the catenary shape with the objective of achieving planarity in all the triangulated, quad angulated and pent angulated mesh facets. The challenge of facet planarity is gracefully solved and adds to the elegance, structural efficiency and economy of this design (part b).Adriaenssens, S.; Ney, L.; Bodarwe, E.; Williams, C. (2010). Dutch Maritime Museum: Form-finding of an irregular faceted skeletal shell - Part a. Editorial Universitat Politècnica de València. http://hdl.handle.net/10251/707
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Dutch Maritime Museum: Form-finding of an irregular faceted skeletal shell - Part b
Editorial Universitat Politècnica de València, 2010Co-Authors: Adriaenssens Sigrid, Ney Laurent, Bodarwe Eric, Williams ChrisAbstract:p. 1356-1366In the context of the search for an efficient structural shape to cover the Dutch Maritime Museum courtyard in Amsterdam, the authors briefly discuss the driving design factors that influenced the earliest glass Roof Coverings. The trends that have emerged during the late 20th and beginning 21st century in the design of skeletal steel glass shells are exposed. These design developments range from sculptural to geometrical and physical intentions (part a). The discussion of the competition design development of the Dutch Maritime Museum Shell Roof by Ney and Partners shows the quest for a structurally efficient catenary form based on a poetic geometrical idea. This paper presents a novel methodology that slightly adapts the catenary shape with the objective of achieving planarity in all the triangulated, quad angulated and pent angulated mesh facets. The challenge of facet planarity is gracefully solved and adds to the elegance, structural efficiency and economy of this design (part b).Adriaenssens, S.; Ney, L.; Bodarwe, E.; Williams, C. (2010). Dutch Maritime Museum: Form-finding of an irregular faceted skeletal shell - Part b. Editorial Universitat Politècnica de València. http://hdl.handle.net/10251/707
