Beton esaslı giydirme cephe sistemleri
Concrete curtain wall systems
Yazar: CANER GÖÇER
Danışman: DOÇ. DR. OKTAY CANSUN
İstanbul Teknik Üniversitesi / Fen Bilimleri Enstitüsü / Yapı Bilgisi Ana Bilim Dalı
Derece: Yüksek Lisans, 1997
Konu: Mimarlık = Architecture
Dizin: Bina bilgisi = Building information ; Giydirme cepheler = Curtain walls

Özet:
ÖZET Bu çalışmada, giydirme cephe türleri ile beton esaslı (ağır) giydirme cephe sistemlerinin, tasarım, üretim, depolama, taşıma, montaj evreleri ve performans özellikleri incelenmiştir. Çalışmanın birinci bölümünde, yapıda taşıyıcı olmayan dış duvarın tanımı, üstlendiği görevler ile dış duvara ait bileşenlerin endüstrileşmiş teknik ve malzemeler ile oluşturulmasının nedenleri kısaca açıklanmış, çalışmanın genel içeriği hakkında bilgi verilmiştir. ikinci bölümde, giydirme cephe tanımı yapılmış, giydirme cephe sistemlerinde kullanılan malzemeler ile malzeme özelliklerine ve cephe bileşenlerinin konstrüktif olarak biraraya getirilişine bağlı olarak giydirme cephe türleri incelenmiştir. Üçüncü bölümde, beton esaslı hazır cephe elemanlarının üretim, depolama, taşıma ve montaj evrelerinin getirdiği tasarım kısıtlamaları ile elemanların birbirlerine ve binanın strüktürel bileşenlerine göre konumlandırılmasındaki boyutsal uyum çalışmaları incelenmiştir. Dördüncü bölümde, beton esaslı giydirme cephe sistemlerinin performans kriterine bağlı olarak değerlendirilmesi yapılmıştır. Sonuç ve öneri bölümünde, beton esaslı (ağır) giydirme cephe sistemlerinin hafif giydirme cephe sistemlerine kıyasla teknik ve estetik yönden olumlu ve olumsuz yönleri incelenmiş, beton esaslı hazır elemanların kullanılacağı bir giydirme cephe sisteminin tasarımında dikkate alınması gereken öneriler özetlenmiştir. xıı

Abstract:
SUMMARY CONCRETE CURTAIN WALL SYSTEMS The subject of the thesis is "Concrete Curtain Wall Systems". In the first part of the thesis, which consists of four parts, definition and functions of exterior wall, traditional and precast components, and the subject of the thesis is defined. In the second part, the definition and development of curtain wall systems, the materials used in curtain wall construction are given and types of curtain wall systems are examined. Curtain wall systems are classified in two parts: 1. Light Curtain Walls, 2. Heavy Curtain Walls. If the weight of curtain wall elements is less than 100 kg/m2, this is called "Light Curtain Walls". If the weight of curtain wall elements is more than 100 kg / m2, this is called "Heavy Curtain walls". Generally in use of heavy ourtain walls, basic material is concrete. Concrete curtain wall elements have panel construction. In this part, precast concrete panels are examined related to: a. Width, b. Stratification in cross - section, c. Height, d. Location of building structure. In addition, the connection types and joint systems are examined in this part The connections must be considered a major design factor influencing safety, performance and economy. Many different connection details will result from the combination of multitude of sizes and shapes of precast concrete and the variety of possible panel support conditions. A systematic analysis of the forces and movements of the panels and the building structure types is required to design different types of connection details. In the third part, these phases which belong to precast concrete panels are examined. xiu1. Design, 2. Production, 3. Storage, 4. Transportation, 5. Assembly. In design phase, the design criterias of precast concrete curtain wall systems are mentioned. In addition, formulas which will eliminate problems caused by the dimensional errors in the integration of a precast concrete panel of a framework and which change according to the cross - sectional charasteristics of a panel are given. On the other hand, exceptable dimensional deviations are defined. The tolerances for precast concrete panels have the following significance : 1. Length or width dimensions and straigtness of the precast concrete wil affect the joint dimension, opening dimensions between panels, and perhaps the overall leght of the front. Tolerances must relate to unit size and increase as unit dimensions inerease. 2. Panels out -of- square can cause tapered joint and make adjustment of adjacent panels extremely difficult. 3. Thickness variation of the precast concrete unit becomes critical when interior surfaces are exposed to view. A non - uniform thickness of adjacent panels will cause oflsets of the front or the rear faces of the panels. If reasonable tolerances and adjustments have been designed into the construction details and complied with, the erector should be able to: 1. Avoid joint irreqularities such as tapered joints (panel edges not parallel), jogs at intersections, non-uniform joint widths. 2. Maintain proper opening dimensions. 3. Properly execute all fastening connections. 4. Align the vertical faces of the umts to avoid oflsets. 5. Prevent the accumulation of tolerances. In production phase, places of pruduction and types of molds which is used in production are mentioned. Besides, relation between panel from and mold is examined and properties of the material and technology are mentioned, In addition, the techniques in making up surface estetics are examined. The architect can make a significiant contribution to economic production by designing precast concrete panels with a knowledge of the "Master Mold" concept, mold types and by providing the precaster with sufficient lead time to make duplication of tooling unnecessary. The master mold concept is based on the fabrication of one master mold which allows a maximum number of reuses per project. It may also be possible to provide some variety of panel size by adjusting the mold during production. Precast concrete can be cast in almost any color, form, or texture, to meet esthetic and preactical requirements of modern architecture. Color and texture may be achieved at xivdifferent stages of production. These stages are described in the sequence of precast concrete operations: a. Before Cast: finish is established by mold surface (before concrete is cast). b. Treated After Cast: finish is accomplished after the concrete is cast but during precasting operations. c. Finish After Hardening: finish is accomplished any time after concrete has hardened. In storage phase, techniques of the storage and general considerations are given. Techniques of the storage are examined in two parts: 1. Horizontal Storage, 2. Vertical Storage. In transportation phase, transportation systems and dimensional restrictions of precast concrete panels are examined. Asembly phase are examined in three parts: 1. Lifting, 2. Placing, Adjusting, Supporting, 3. Connecting. In addition, the considerations in use of equipments and tools are mentioned. In the fourth part, performance criterias related to "Concrete Curtain Wall Systems" are examined under following subtitles: 1. Heat Insulation and Condensation, 2. Sun Control, 3. Precautions Against Fire, 4. Sound Inslulation, 5. Joints Between Panels, 6. Cleaning. Precast concrete sandwich wall panels are idealy suited for energy conservation. Precast concrete sandwich wall panels offer a weatherproof exterior, effective insulation and a finished interior surface in one unit. Also, the danger of toxic fumes caused by the burning of cellular plastics is practically eliminated with insulation encased in the panel. The interior wall energy requirements were satisfied by placing insulation between two concrete layers. Precast concrete walls can be very energy efficient. Recessed window walls, vertical fins, and various other sculptured shapes facilitate the design of many types of shading devices for window areas, including vertical and horizontal sunshades. Shading is a fundamental design strategy in the summer for preventing solar heat gain and diffusing bright sunlight. In the cooler months, when the sun's angle of incidence is low, the shading devices may be angled to let the sunshine in and help reduce heating loads. xvWith high fire endurance of concrete, precautions against fire must be taken in these critical points: a. Joints between the panels, b. Connections between the panels and building structure. Joints between wall panels should be detailed to prevent the passega of flames and hot gases. Concrete wall panels expand when heated, so the joints tend to close during fire exposure. Flexible, noncombustible materials such as ceramic fiber blankets provide thermal, flame, and smoke barriers. The amount of protection depends on the stress - strength ratio in the steel at the time of the fire and the intensity and duration of the fire. The tihckness of protection material required is greather as the strees level and fire severity increases. Weight is concrete's greatest asset when it is used as a sound insulator. Precast concrete walls usually do not need additional treatments in order to provide adequate sound insulation. If desired, greater sound insulation can be obtained by using resilient ly attached layer of gypsum board or other building materials. The joints between concrete panels or panels and other building materials must be considered the weakest link in the overall watertightness of the wall. The design and execution of these joints is therefore the utmost importance and must be accomplished in a rational, economical manner. A joint will provide a degree of watertightness consistent with its design and exposure. In addition the purpose, size and function of the building will also determine design requirements for the joint. Design criterias for joints include: a Structural requirements (a mount of movement to accommodate), b. Architectural apperance, c. Function of the building, d. Exposure (orientation and climatic conditions), e. Economics. Related to above criterias, joints between precast concrete wall units may be devided in two basic types: 1. Open joints, 2. Closed joints (one or two stage). A primary consideration in the architectural design of buildings should be weathering. Weathering affects all exposed surfaces and cannot be ignored. The action of weather may enhance or detract from the visual appearance of a building, or may have only little effect. The final measure of weathering effects is the degree to which it changes the original building appearance. Visual changes occur when dirt or air pollutants combine with wind and rain to interact with wall materials. The run-off water may become unevenly concentrated xvibecause of facade geometry and details. The manner in which water is shed depends primarily on the sectional profiles of the vertical and horizontal discontinuities designed into the wall. Through the years, designers acquired ways of handling traditional building materials in order to control the water flow down specific parts of a structure - copings, drip molds, gargoyles, window sills, and plinth details. However, many of these useful and relevant details have been discarded an superfluos decoration. For precast concrete walls, the awareness of weathering should be reflected in the design of wall elements and the integration of windows to control water migration and collect and remove water run - off. Staining that occurs through differential surface absorption and uneven concentrations of dirt due to water run - off are considered the most common weathering problems. Proper design and detailing for weathering of precast concrete units increase in importance whenever the atmosphere is dirty or polluted, and where one or more of the following characteristics are present: a. Sloping surfaces, b. Panel forms, c. Textured surfaces, d. Colored surfaces, Weathering problems are less serious in relatively clean environments or when the precast conrcrete walls have one our more of the following charastersticts: a. Properly designed slopes and flow patterns, b.Near - vertical or lightly sculptured surfaces, c. Polished surfaces, d. Gray or dark colors. As a conculusion, advantages and disadvantages of concrete curtain walls are given in proportion to light curtain walls, In addition, in desing of concrete curtain wall systems, some propositions are examined. xvn