Exterior Materials Research Articles

Studies on Durability of Photocatalytic Self-Cleaning Performance of Building Exterior Materials in Snowy Cold Region

Studies on Durability of Photocatalytic Self-Cleaning Performance of Building Exterior Materials in Snowy Cold Region

유럽 집합주택의 입면 디자인 요소에 관한 연구 - 1980년대 이후 사례를 중심으로 -

In the late twentieth century, the multistory housing has become the most preferred housing type. Moreover, in multistory housing design, not only interior design but also exterior design, uniqueness and characteristic have been added as significant factors in design to break simplicity and uniformity. The purpose of this study is to understand the tendency of the elevation design in Europe and to suggest the idea for elevation design for domestic. Also, each elements of elevation were analyzed through classification and schematization which categorized by its own characteristic. Design elements can be classified into three categories. They are corresponding with inner spaces, emphasizing visual expression of exterior material and texture, and presenting aesthetic factors of building shape. Those are named as the Spatial Externalization, the Visual Expression, and the Expression of Building Shape. In this frame nineteen elevations of sixteen different cases were analysed. As a result of case studies, it is clear that elevation designs were not standardized and each cases has its own characteristics. Also it showed how the each design elements can be coordinated as a total design and how they expressed identities of each housing. This study could contribute to motivate diversifying the design of multistory housing.

MANAGEMENT OF CONSERVATION METHODS FOR EXTERIOR MATERIALS IN HISTORICAL RC BUILDINGS

In conservation and renovation of exterior materials in historical buildings, it developed that guideline of process is necessary because management and judgment in a variety of process is asked, even if the policy of conservation was decided.This report shows management in construction stage of conservation methods for exterior materials in historical RC buildings, through the analysis of process in conservation and renovation, as case of main building of Yokohama Customhouse.

WIND-INDUCED INTERNAL PRESSURES IN LOW-RISE BUILDINGS WITH PARTITION WALLS

The properties of internal pressures induced by wind in buildings are very important for evaluating the wind loads of exterior materials and partition walls in those buildings. This paper describes the properties of internal pressure induced by wind in nominally sealed but leaky low-rise buildings with partition walls. The internal pressures induced by wind in the twin-room building models are numerically simulated by using the external pressures and leakage model of leakage paths of external walls and partition walls. Also, the internal pressures of twin-room building models are measured in a wind tunnel experiment with the models having apertures in their external walls and partition walls. It is shown that the maximum value and minimum value of the mean internal pressure coefficients induced by wind in the twin-room buildings depend on the ratio of leakage in the external walls and the partition walls.

Moisture response of building facades to wind-driven rain: Field measurements compared with numerical simulations

Wind-driven rain (WDR) is one of the most important boundary conditions governing the hygrothermal behaviour of building facades, which is usually numerically analysed with the so-called Heat-Air-Moisture (HAM) transfer models. In the traditional approach of HAM transfer models, WDR is implemented in a simplified manner: the total mass of all raindrops impinging on a certain surface area of a building facade during the time interval of the meteorological input data (typically 1 h) is spatially and temporally averaged and is supplied to the facade as an averaged moisture flux. However, real WDR is the sum of individual raindrops that impinge on the facade in a spatially and temporally discrete modus, and that do not only spread at impact, but may also splash or bounce off the facade. Therefore the reliability of this simplification can be questioned. To investigate its validity, a new experimental set-up was developed at a full-scale test building. It allows simultaneous and continuous measurements of the reference wind speed and direction, WDR intensity, outdoor air temperature and humidity, as well as the response of facade material samples to these environmental conditions. For this purpose, a measuring device was developed that monitors the weight change of the sample with a resolution of 5 mg. Temperatures at the interior and exterior material surfaces are also monitored. The whole measurement data set is used to check the validity of the traditional numerical approach. Large differences are found between the measurement and simulation results, which cannot solely be attributed to the uncertainty in the convective moisture transfer coefficient, but may be due to two additional reasons: the occurrence of splashing and bouncing at raindrop impact on the facade, which is not included in the model, and/or errors in surface moisture evaporation and absorption due to modelling the actual random and discrete raindrop impingement as a simplified averaged moisture flux.

鉄筋コンクリート造の歴史的建築物における外装材に関する保存手法―横浜税関本関を通して―

In conservation and renovation of historical buildings, it is hoped that exterior is conserved by original materials, not be easy restored by new materials, because exterior materials are important factors for historicality, landscape and authenticity.This report presents conservation methods through the case of main building of Yokohama Customhouse in order to support conservation and renovation of exterior materials in historical RC buildings in the early Showa period.

Acoustic feedback of control elements in cars

Due to the complexity of modern car's on‐board systems, car manufacturers tend to use menu based user interfaces. These interfaces offer a relatively low number of control elements for a large number of functions. Optimization of both haptical and acoustical feedback of the remaining control elements can improve both acceptance and security of operation. Since cars nowadays are no longer sold simply as technical but as lifestyle products it is crucial for the success that the potential customer perceives every single aspect of the car to be valuable. Obvious examples are exterior design and material quality. Since the user interface of the car can be judged even before a test drive the feeling of buttons and switches is a key aspect. This work presents the results of a jury test which is part of an ongoing research project focused on acoustical feedback. Subjects were asked to judge both recordings of real control elements as well as synthesized signals which were presented on purpose‐built hardware. Based on the subjective results the recorded signals were analyzed in order to identify spectral features which correlate with the subject's responses.

Human survivability in motor vehicle fires

AbstractAutomobile fires are consistently among the largest causes of fire death in the United States (about 500 annually) and the U.S. motor vehicle industry and others have spent a significant amount of money in recent years studying this problem. The authors of this review have analyzed the auto industry reports, the scientific literature, and statistical data, and conclude that measures should be taken to improve survivability in automobile fires. The U.S. Federal Motor Vehicle Safety Standard 302 (FMVSS 302) was introduced almost 40 years ago to measure the flammability of interior materials, but improvements in the crashworthiness of automobiles and their fuel tanks and the increased use of combustible materials have changed the motor vehicle fire scenario significantly. In particular, the primary threat has changed from ignition of a small quantity of combustible interior materials by a lit cigarette, in 1960, to ignition of a large quantity of combustible interior and exterior materials by an impact‐induced fire, at present. The authors therefore suggest that FMVSS 302 is no longer relevant to automobile fire safety and recommend improved standards based on objective criteria for fire safety performance (fireworthiness) at the system/vehicle level as is routinely done for crashworthiness. Copyright © 2008 John Wiley & Sons, Ltd.

風によって誘発された低層建築物の室内圧の性状

The properties of internal pressures induced by wind are very important for evaluating the wind loads of exterior materials and structural frames in buildings. This paper describes the properties of internal pressure in nominally sealed but leaky low-rise buildings induced by wind. The internal pressures in the low-rise building models with the apertures are measured in a wind tunnel experiment. The internal pressure fluctuations in the nominally sealed but leaky low-rise buildings have also been simulated using the leak-flow model and the fluctuating external pressures obtained from the wind tunnel experiment. The relationship between external pressures and internal pressures in the low-rise building models with the apertures are also shown by normalized power spectra, coherence and phase spectra.

Digital photogrammetry, GPR and computational analysis of structural damages in a mediaeval bridge

Traditional architectonic heritage elements are fragile and irreplaceable resources, signs of the ancient ways of life and the history of the modern societies, and essential valuable elements of the own landscape of a region. Accurate updated documentation might be the basis for any conservation or restoration intervention over architectonic heritage in order to ensure the conservation in its original appearance and in a collapse risk-free state, with the minimum intervention. This paper shows a multidisciplinary approach to heritage documentation involving close range photogrammetry and ground penetrating radar techniques, as well as the development of finite elements based structural models. Specifically this study is focused on the documentation of a mediaeval bridge concerning the geometric shape, the building material and the current damages and its causes. The usefulness of close range photogrammetry techniques in the accurate 3D modelling, cracks detection and mapping and exterior material characterization is analyzed. Further, a non-destructive test through GPR is employed for the interior material and zones description. For both techniques, the methodology followed for data collection and data processing aimed at minimisation of time consuming and optimisation of results is described in detail. Advantages and limitations of these techniques are displayed and the accuracy of the obtained results is also estimated. Resulting information related to the whole bridge geometry is taken as basis to develop a numerical analysis using the finite elements methods (FEM). Linear finite analysis provides useful information for diagnosis although non-linear methods should be used when the properties and geometry of the internal and external elements are well known. Photogrammetry provides the exact geometry needed to perform the FEM pre-process. Radar data provide approximate information about the different internal zones of the bridge. Finally, the FEM analysis leads to obtain a stress distribution compatible with the detected damages, allowing identifying its possible causes. Close range photogrammetry, ground penetrating radar techniques and the FEM analysis are proposed to perform a complete survey of the stability of the bridge and its accurate geometry.

光触媒外装材を用いた温熱環境実測とシミュレーション : 実証実験棟における日射遮蔽スクリーン併用散水システムの蒸発冷却効果の検討

光触媒外装材を用いた温熱環境実測とシミュレーション : 実証実験棟における日射遮蔽スクリーン併用散水システムの蒸発冷却効果の検討

外付け日射遮蔽スクリーンを併用した光触媒外装材散水実験棟の温熱環境実測に関する研究

This study is designed to quantitatively comprehend changes in thermal environment by shading solar radiation and spraying water on photocatalyst-coated exterior materials. It has been confirmed that air-conditioning load was about 64 percent smaller when a solar shading screen was set up outside the building and water was sprayed on the exterior materials than when neither water was sprayed nor a screen was built. It has also been found that room temperature was about two degrees centigrade lower when a solar shading screen was installed and water was sprayed on the exterior materials than when a screen was installed but water was not sprayed.

Method for designing low vibration omni-directional wheels

An omni-directional wheel for an omni-directional vehicle that exhibits constant ride height, low vibration, and reduced maximum ground contact pressure is disclosed. The invention consists of a wheel assembly rotatably connected to the omni-directional vehicle chassis. The wheel assembly comprises a hub on which free spinning rollers are rotatably mounted at an angle to the wheel axis. Constant ride height and low vibration operation are accomplished by configuring the rollers with an exterior profile, thickness, material properties and surface grooving to achieve constant deflection of the roller contact surface at all wheel rotation angles.

Comparison of CO2 Fixation in Wood Used for Residence HOuses in Japan and Korea

In this study, we have estimated the amount of carbon (C) fixation in wooden materials used for residence house units in Japan and Korea. This type of C fixation might be helpful to prevent the global wamting. In year 2000, the arnount of C fixation in the wooden materials was approximately 7.30/0 (150million C ton) of total forest C accumulation in Japan, whereas in Korea, it was 2.00/0 (4.3million C ton) of the total forest C accumulation. The reason is that structural types of the house units on wood utilization in Japan and Korea are clearly different. Japanese have used 900/0 of wooden materials for their residence houses but Korean house units have built mostly using non-wooden materials such as concrete, bricks, and stones. It has resulted that the number of total houses in Japan is 5 times higher than that in Korea, whereas the arnount of C fixed by the wood materials in Japanese house units is 35 times higher than in Korean's. Therefore, to improve C fixation, it might be necessary to increase wooden residence houses and use of the wooden interior or exterior materials in the residence houses, especially in Korea.

Distribution of archaea in a black smoker chimney structure.

Archaeal community structures in microhabitats in a deep-sea hydrothermal vent chimney structure were evaluated through the combined use of culture-independent molecular analyses and enrichment culture methods. A black smoker chimney was obtained from the PACMANUS site in the Manus Basin near Papua New Guinea, and subsamples were obtained from vertical and horizontal sections. The elemental composition of the chimney was analyzed in different subsamples by scanning electron microscopy and energy-dispersive X-ray spectroscopy, indicating that zinc and sulfur were major components while an increased amount of elemental oxygen in exterior materials represented the presence of oxidized materials on the outer surface of the chimney. Terminal restriction fragment length polymorphism analysis revealed that a shift in archaeal ribotype structure occurred in the chimney structure. Through sequencing of ribosomal DNA (rDNA) clones from archaeal rDNA clone libraries, it was demonstrated that the archaeal communities in the chimney structure consisted for the most part of hyperthermophilic members and extreme halophiles and that the distribution of such extremophiles in different microhabitats of the chimney varied. The results of the culture-dependent analysis supported in part the view that changes in archaeal community structures in these microhabitats are associated with the geochemical and physical dynamics in the black smoker chimney.

Steady water flow around parabolic cavities and through parabolic inclusions in unsaturated and saturated soils

In this paper, we undertake the study of two closely related groundwater flow problems, both two-dimensional, steady and Darcian, and moreover involving parabolic inclusions. First we consider unsaturated flow for which the conductivity depends exponentially on the pressure. Second, we consider saturated flow and an inclusion with a differing, constant, conductivity from the exterior material. We apply the method of separation of variables, conformal mappings, and the Schwarz reflection principle. The distributions of the Kirchhoff potential, specific discharge, and flow net are derived in an explicit analytic form. We show the focusing/diverting properties of a parabola with a more/less permeable interior than the ambient medium, the location of the hinge point and separatrice, and the Maxwell–Philip uniformity of the flow in the interior zone.

建築外装材における色彩の様相 : 都市景観における色彩の様相に関する研究 その2

In this study, the relation between building exterior materials and mode of appearance of color in townscape were discussed based on the study on mode of appearance of color in commercial and business district in Osaka. It is important for creating attractive and comfortable townscape to clarify the relation between building exterior materials and mode of appearance of color. Building exterior materials were classified into groups; tile, coating with spraying, stone, metal, paint, concrete, glass and the rest. The groups were analyzed based on the mode of appearance of color and the characteristic of building exterior materials were clarified in four townscaps of commercial and business districts.

Chapter 6—Daylighting

To talk of architecture is to talk of light, and above all of natural light. It is not just a physical means enabling us to see the exterior and interior material form of buildings; rather, it provides architecture with its main energy component, necessary for the existence of a rich, integrated duality of matter and energy which, beyond mere usefulness, generates an aesthetic sensation in the users. It is for this reason that great architecture has always been associated with natural lighting, generating it with and within itself. From the categorical eloquence of the single opening of the Pantheon to the magical complexity of the Germanic baroque, via the increasingly finely wrought Gothic cathedrals, natural light has been a deciding factor in the quality of space. In spite of this, the role played by light in architectural aesthetics is often ignored, great works being analysed with parameters that are concerned purely with style and geometric form. In the narrower sense of architectural quality, the aesthetic power of light is what differentiates architecture from mere construction when we visit a building. Such it has been described by the great commentators on architecture, from Vitruvius to Bruno Zeni, when they speak of light with the enthusiasm that art alone can arouse. Yet when we attempt to analyse the role of light in contemporary architecture, we find a huge vacuum. Todays representative buildings almost totally neglect the important part natural light could play in their interiors. Excessive use is made of artificial systems, and architecture is conceptualized as glass geometry, with paradoxical curtain walls that instead of communicating with the exterior, create impractical barriers. A point is thus reached where the interior environment, which is theoretically controlled, frequently becomes more inhospitable than the exterior. In such cases, architecture works worse than the climate. Today, it is essential for the architectural profession to recover the systematic use of natural light. To this end, designers should be made aware of how spaces work in conjunction with light, and the best way to do this is not by way of elegant or sophisticated technical solutions. It is sufficient to be acquainted with certain basic principles, which can be divided into two well-defined areas: the physics of light and the physiology of vision. These basic principles can lead to the practice of natural light in design with greater efficiency than would be the case with the technology of particular solutions and systems. The physics of light allows us to understand how this electromagnetic radiation behaves in architectural space. By knowing its basic laws and its interaction with the surfaces that reflect, absorb and transmit it, we can control the effect of light on buildings and its distribution in interiors. The physiology (and psychology) of vision facilitates understanding of human reactions in lit spaces. By knowing the basic principles of perception and comfort, as we design buildings we can control the relationship between light and the users of their exterior and interior environments, and in this way define the lighting aesthetically and functionally from the very start of the project. Finally, providing a building with natural light is more than just the solution of a problem of energy consumption; more, even, than an aesthetic resource easily incorporated into the architecture. Natural light in architecture must be part of a more general philosophy that reflects a more respectful, sensitive attitude in human beings towards the environment in which they live.

Accretion of the Moon from an Impact-Generated Disk

We present the first published numerical calculations of accretion of an impact-generated protolunar disk into a single large Moon. Our calculations are based on the model developed by R. M. Canup and L. W. Esposito (Icarus113, 331–352, 1995) to describe accretion in the Roche zones around the giant planets. Previous numerical simulations of a large impact event predict the formation of a disk of material centered near or within the Roche limit (∼2.9R⊕). A natural expectation based on our previous results and comparison with the satellite systems of the outer planets would be for multiple small moons to arise from such a protolunar disk. Multiple moonlets could accrete to form a single Moon if they evolved into crossing orbits due to tidal interaction with the Earth. This would occur if the innermost moonlet in the disk were also the most massive, so that it evolved outward at the relatively fastest rate and swept up all exterior material. Our calculations, which include both moonlet accretion and orbital evolution, demonstrate that forming massive moonlets in the inner disk near the Roche limit is extremely difficult. We conclude that an Earth system with multiple moons is the final result unless some particularly severe constraints on initial conditions in the disk are met. A disk with a lunar mass of material exterior toa∼ 3.5–4R⊕or an extremely steep radial surface density profile at the onset of collisional growth is required for a single, lunar-sized body to result from accretion of silicate density material in a protolunar disk. The former corresponds most closely to disks produced by impactors with nearly twice the mass of Mars and about twice the angular momentum of the current Earth/Moon system. Other processes, such as gravitational instability or primary accretion of an iron core in the inner disk, might be able to “seed” accretional growth and allow for the formation of a single Moon if disk temperature and compositional requirements are met. Our analysis demonstrates the need for more detailed, higher resolution impact simulations.

寒冷地の外断熱工法コンクリートの乾燥による壁体透湿性状

The aim of this investigation was to study the vapour permeability of the out- side insulation wall in cold district. First, we examined the vapour permeability of insulations, exterior materials and paints at low temperature. Second, we examine the vapour permeability of the outside insulation wall by drying the concrete wall under experimental conditions. From the result of this investigation, we understood the vapour permeability of the outside insulation wall. The drying of concrete is mainly dependent on the insulation resistance of vapour permeability and outside temperature. The amount of humidity in the exterior materials was mainly dependent on the resistance of vapour permeability of exterior materials and paints. It was considered that the damage of paints related to the condition of painting at the site.