Giydirme Cephe Sistemleri Ve Bunların Tasarım Ve Uygulamalarında Dikkat Edilmesi Gereken Hususlar

Abstract

Bu araştırmada giydirme cephe sistemleri ve bunların proje lendirme ve uygulama esasları üzerinde duruldu. Konuyu daha iyi inceleyebilmek için birinci bölümde giydir me cephenin tanımı, tarihçesi, dünyada ve ülkemizde gelişimi ve çeşit li uygulamalardan örnekler verildi. İkinci bölümde ise giydirme cephe uygulamalarında kullanı lan malzemeler tanıtıldı. Malzeme olarak cam, alüminyum, ankraj par çaları tanıtıldı ve bunların işleme seçenekleri incelendi. Üçüncü bölümde ise ülkemizde uygulanan giydirme cephe sistemleri incelendi, bunların birbirlerine göre kıyaslamaları yapıldı. Dördüncü bölümde ise giydirme cephe uygulamasında karşı laşılan problemler, bu problemlerin kaynakları ve bu problemlerin çözülmesi için izlenmesi gereken önlem ve uygulamalar ele alındı. Beşinci bölümde ise giydirme cephelerde projelendirme esasları incelendi. Giydirme cephede projelendirme aşamasında ele alınması gereken kriterler belirtildi ve ileride problem yaratmaması için bu aşamada kriterlerin ele alınması gerektiği belirtildi. Sonuç bölümünde ise ülkemizde hızla artan giydirme cephe uygulamalarının getirdiği cazibenin büyüklü küçüklü birçok kuruluşun kurulmasına neden olduğu ve bu kuruluşların, yetkililerin oluşturaca ğı heyetler tarafından denetlenmesi gereği üzerinde duruldu. Ek bölümünde ise ülkemizdeki uygulamalarla ilgili fotoğraf ve detaylar incelendi.

This section deals with the curtain wall systems, develop ment there of and some matters to be taken into account. Within the first section, the definition, discovery and deve lopment of curtain walls have been described. The curtain wall is a prefabrique facade element that does not have a support to the rein forcement structure of the building but supported by the structure. The curtain wall systems have been discovered in response to the developments occurred in construction field. The first application of the covered facade took place in the US during 1820s. In 1886, follo wing the discovery of aluminum, it became to be applied more frequ ently. It's application became more widespread during 1950s. The app lication of curtain wall systems in Turkey has been accelerated follo wing the promotions provided after 1980 during which promotion decisions were taken. On many buildings this technique has been app lied. Curtain walls are among the most demanded coverings with regard to their quick application, easy cleaning and lightweight. The examples of such buildings in Turkey may be given as Akmerkez, Maya Akar Center, Sabancı Center, Yapı Kredi Plaza. If we examine the curtain walls with respect to the materi als used, three basic material are worthy to consider. These are glass, aluminum and steel anchors. If the glass used in the curtain wall is examined as for physical, chemical and optical views, it will be found out that the curtain wall materials are generally proper ones to be used in panels, the glass used in the curtain wall might gain some use ful features after having undergone some second range processes. These processes are safety Control, Sun Control, Sound Control and Heat Control. The second basic material to consider in the curtain wall is aluminum. Aluminum is not found purely in the nature. It is offered for use after some processes. Since such processes required high technology, aluminum could not be efficiently used until 1886, IX whereafter, it's rate of utilization speeded up in the whole world and became a generally demanded material. This rate increased to an extend that 25% of the total aluminum has been used in construction industry. Another material used in curtain wall issteel anchors. These are the components fixing the facade to the building structure. There fore, their importance has increased. These materials should be in accordance with the standards in order to avoid any problems. It would be possible to give the names of three names with regard to the curtain wall. These are bar system, panel system and semi-panel system. In bar system, reinforcement profiles are set verti cally on the building. Whereafter, these are supported by horizontal profiles. The latest stage is attachment of the glass. This system is a cost effective one but it is weak to withstand the horizontal and verti cal loads and has a greater risk of failure. In panel systems, the facade covering is prefabricated in dimensions to be reinforced and installed at the construction site. It's performance against the vertical and horizontal loads are well but it's an expensive system. It is advantageous for the constructions to be finished within a very short time, as in that case, the facade is prepa red even including glass parts. In case of semi panel system, the verti cal reinforcement bars are removed, it's horizontally supported form is taken to the construction site where it is installed. It is the joining of two structures consisting of cost effectiveness of the bar system and applicability of the panel system. It is frequently used in the world. It is also applied in Turkey. It is possible to define curtain wall system under three hea dings. Reinforcement frame, Window parts and Parapet parts. The reinforcement system connects covered facade system to the structure via anchors and bears the load of the facade system. Expansion clea rances should be left during its installation. The window section is applied where transparency to. light is required. The illumination required for offices could be better obta ined by facade covering. In that part of the facade system, it would be better to use twin-glass with regard to heat and sound insulation and sun control glass with regard to adjust sunlight. Within the parapet section, opaque glass material is utili zed in order to enclose the front part of the parapet and keep the concrete in the background hidden. Details of the joints should be defined well in order to obtain well performance. This is choosing suitable joint system. There are three types of joint system used in facade covering. These are closed system, water discharging and venti lating system and pressure balanced system. In case of the closed system the basic principle is taking the water out of the building. The refore sealing porvided by the elastic paste and seals becomes an important point. An additional measure is taken in order to provide taking water out of the joint considering that there would be a water leakage from the outer surface of the joint in water removing and ven tilating systems. The water is removed before it has reached to the surface of the building. In case of pressure balanced system, the wind causing water leakage is counterbalanced. Some factors should be taken into account at the design sta ge and selected in accordance. These criteria are: Function, Stability Static, Exphansion, Heat isloation, Sound Insulation, Sunlight con trol, Fire Detection and Cleaning. Thefollowing paragrpah defines those factors: Functional stability: This includes protecting building from the outside environmental conditions, letting sufficinet light and air to enter into the building, provide esthetical harmony. Static: The wind load effecting the constructional design of aliminum must be included in the static estimations. Expansion: Proper expansion joints must be left in the curta in walls. Heat isolation: Heat isolation can never be omitted. Heat isolation might be obtained by applying material between curtain walls and building in case of opaque sections while it will be maintai- XI ned by double glass application in case of transparent sections. Sound Isolation: Sound isolation will be maintained by doub le glass application in the buildings where curtain wall has been appli ed. Sun light control: Sun ray filtering glass will be insalled to the buildings. Fire Detection: Measures to provide spreading of fire shall be taken by applying fire holding materials. Cleaning: Necessary measures will be taken in order to pro vide easy cleaning of the buildings. A new curtain wall understanding became widespread as it is accepted by the architects. This is what the curtain wall puts into scene. It's cleannens, esthetic beauty (especially glass curtain walls) is widely under use in Turkish architectural applications. But this quick improvement brought some problems. The materials to be used are usually selected arbitrarily without any study on the curtain walls, which prevents the maximum itilaziton of the same. Many hion and Breat buildings existing in our environment are built with such mista kes. Therefore it is necessary to approach large project under scienti fic view. This is only way to reduce the problems to a minimum num ber. In case of curtain walls, many materials having very different features must be provided so that they exhibit a harmonic structure. This can be achieved by careful selection of those materials and appl ying the same as well. In the systems under use in the US and Europe some damages have occured due to applications took place within the time. This resulted iiv problems that are hard to compensate also expensive. This caused legal disputes between companies. In order to prevent such problmes to be encountered in Turkey, the problems encountered in abroad must be examined and the problems in the app lications of our country must be eliminated. Technical Staff to apply those systems at the design phase and application phase bear the xu most of the responsibilities. Therefore,they must be trained and beco me expert in their subject. Further, many companies operating in this field have been founded. The qualification of those companies must be evaluated by a technical commission to be appointed by the Cham ber of Civil Engineers and Architects.