Gerçek Boyutlu Cam Panel Cephe Sisteminin Uzun Dönem Taşıyıcılık Ve Sızdırmazlık Performansının Değerlendirilmesi

Abstract

Panel giydirme cephe sistemleri özellikle çok katlı binalarda hafifliği, uygulama kolaylığı ve uzun dönem performansı bakımından yaygın olarak kullanılan sistemlerdir. Giydirme cephe sistemi tasarımında bina ölçeği ve kat yüksekliği arttıkça bakım ve onarım maliyeti de orantılı olarak artmaktadır. Bir binanın olası bakım ve onarım maliyetlerini azaltmak ve bina kullanımı süresince iç ve dış konfor koşullarının sürdürülebilmesi, binanın yaşam dönemi boyunca problem olabilecek faktörlerin belirlenmesi, test edilmesi ve test sonuçlarına bağlı olarak sistem tasarımlarının gerçekleştirilmesi önemlidir. Çalışma kapsamında, çok katlı binalara uygulanan bir panel giydirme cephe sisteminin dış ortama açık deney düzeneği üzerinde uzun dönemde göstereceği taşıyıcılık ve sızdırmazlık performansının belirlenmesi amacına yönelik olarak gerçek zamanlı ve gerçek boyutlarda deneysel çalışmalar yürütülmüştür. Deneysel çalışmalar, çok katlı binalarda üst katlarda rüzgâr yüklerinin artması ve iklimsel koşullardaki değişime bağlı olarak cephe performansının değişiminin belirlenmesi ilkesine dayanmaktadır. Çalışma kapsamında birebir aynı detaya sahip iki ayrı panel sistem seçilerek test prosedürleri uygulanmıştır. Sistemlerden yalnızca birine yorma deneyi uygulanmış ve her iki sistemin bir yıllık deneysel çalışma sürecinde rüzgâr, hava, su ve sismik dayanım deneyleri beş farklı dönemde gerçekleştirilerek sistemlerin farklı dönemlerdeki performans değişimleri belirlenmiştir. Her deney sonrasında sayısal sonuçlar alınarak standartlarda yer alan sınır değerlerin aşılıp aşılmadığı kontrol edilmiş ve sistemlerin farklı performans parametreleri ortaya konmuştur. Tez altı Bölüm’den oluşmaktadır. Bölüm 1’de çalışmanın amacı, kapsamı, yöntemi ve çalışma süreci hakkında bilgiler verilmiştir. Giydirme cephelerin bütünü ele alınarak, cephelerin gelişimi ve cephe bileşenleri hakkında bilgiler Bölüm 2'de incelenmiştir. Daha sonra, taşıyıcılık ve sızdırmazlık ölçütlerine bağlı olarak performans gereksinimleri açıklanmış ve giydirme cephelerin gelişmiş bir türü olan panel sistemler hakkında bilgiler sunulmuştur. Bölüm 3 tez çalışmasının ana bölümü olup burada deneysel çalışmanın süreç şeması ile deneyler açıklanarak deneylerden elde edilen sayısal sonuçlara yer verilmiştir. Önceki bölümde elde edilen sayısal sonuçlar kullanılarak performans değerlendirmesi Bölüm 4'de yapılmıştır. Performans değerlendirmesi yapılırken günümüzde birçok problemin çözümünde yaygın olarak kullanılan çok ölçütlü karar verme yöntemlerinden AHP, COPRAS ve TOPSIS yöntemleri kullanılarak sistemlerin uzun dönemde gösterdiği performans değişimi ortaya konmuştur. Gerçekleştirilen çalışmanın topluca genel bir değerlendirmesi Bölüm 5’de, elde edilen sonuçlar ve gelecekte yapılabilecek olası çalışmalar için öneriler ise Bölüm 6’da verilmiştir.

Unitized curtain wall systems have been widely seen on high-rise buildings’ façades by bringing benefits with regard to ease of construction, lightness, etc. However, some design and application problems related to structural and infiltration performance of a façade system might arise during its lifetime, which is difficult for the building to compensate. Therefore, tests related to building façade system performance are of importance for assuring the comfort requirements and reducing the maintenance and repair costs as well as preventing the potential problems which may be faced during building’s lifetime. Full-scale preconstruction curtain wall mock-up testing is today normally considered a standard practice for buildings where the curtain wall is a custom application for high-rise buildings, and for buildings where a high confidence level is desired. Within the scope of this work, real time and full-scale performance tests in accordance with the load-bearing and impermeability criteria are performed on an outdoor test rig for a unitized glass curtain wall panel which is mostly applied on high-rise buildings. The study is based on the principle of the determination of performance change depending on wind pressure increase in upper stories of high-rise buildings and the variations of climatic conditions during the building’s lifetime. Full-scale mock-up testing of two identical unitized curtain wall panels was carried out. During the testing process, one specimen was subjected to a prescribed fatigue process before conducting the standard test procedures while only the standard test procedures were applied on the other identical specimen. In total, six test sequences were conducted on the reference Specimen P and fatigued Specimen FP. The categories of the tests for P are air infiltration, water penetration under static pressure, wind resistance, seismic resistance as the standard tests. Water penetration under dynamic pressure tests and fatigue procedure were the additional tests for FP along with the standard tests. After each test sequence, quantitative results were determined and checked whether the limit values of the related standards were exceeded. Various experimental behavioral parameters of the two panels are presented with graphics. This thesis consists of six Chapters: In Chapter 1, the aim, scope, method and motivation for this study are given. The existing curtain wall systems are classified and general information was given considering the systems and the components in Chapter 2. Afterwards, minimum performance requirements to compensate the load-bearing and impermeability criteria are explained. Additionally, information regarding the unitized panel systems in particular is presented. Chapter 3 is the main chapter of the thesis and comprises of the testing sequence, full-scale experimental study, and quantitative test results. In Chapter 4, a numerical performance evaluation study is performed by using the experimental data obtained from the experimental study. Widely used numerical methods such as AHP, COPRAS, and TOPSIS were selected for the performance evaluation of the standard and fatigue tested panels by taking into account of multi-criteria as load-bearing and impermeability. With the help of these evaluation methods, comparative lifetime performances of the tested panels were obtained and critical level of the tested panels denoting the loss of performance was found. A general summary and evaluation of the thesis is given in Chapter 5. Chapter 6 presents the results obtained from the experimental work and also includes the suggested potential future studies for fulfilling the topic covered in this thesis. The experimental study was carried out on a large test rig located at the Façade Testing Institute, at Çatalca. Air infiltration, static and dynamic penetration, resistance to wind load, seismic resistance and fatigue test procedures were conducted for the full scale façade specimens. The test specimens consist of two identically detailed unitized curtain wall systems with 2,40m width, 4,45m height dimensions, and are comprised of aluminum framing members and insulating glass units. In total, 10 tests were conducted for the standard and fatigue specimens at five phases during 15 months with different intervals between each testing sequence. After completing each testing phase, the test specimens were exposed under environmental effects till the next phase. Air infiltration tests have been conducted in accordance with TS EN 1253 standard where the air infiltration limit value is set as 1,5 "m" ^"3" "/" "m" ^"2" "h" . Static water penetration tests have been conducted in accordance with TS EN 12155 standard and impermeability of the specimens were observed during the tests where quantitative data were not possible to obtain due to the testing procedure. Wind resistance tests have been conducted in accordance with TS EN 12179 standard, the 15 mm deflection limit value given by the standard was taken into consideration. Seismic resistance tests have been conducted in accordance with AAMA 501.4 and AAMA 501.7 standards where a horizontal movement/displacement was applied on the lower beams placed on the specimens in the amount stated in the standard. Potential damages were conducted following these tests. Dynamic water penetration tests have been conducted in accordance with AAMA 501.1 standard. A ROTAX aircraft type engine was used as a wind generator simultaneously with high pressure water application on the specimen. The water penetration of the inner surface of the specimen was inspected during the tests. The fatigue procedure application has been performed in accordance with ETAG 17 standard. Suction was applied in accordance with the standard. At the end of the test, the specimen was scrutinied whether there is any deficiency or failure. Both specimens used in the experimental part of the study are identical and 5 performance tests were conducted on each one during a 450 day long test process. Generally accepted and prevalently used standard test procedures were applied on specimen P whereas two additional procedures were conducted on specimen FP to fatigue the façade system in order to obtain more realistic results regarding the long term performance of the unitized curtain wall panels. These tests were defined as dynamic impermeability test comprising water spray application with high wind pressure and ETAG 17 comprising gradual increase in air pressure and sudden application of suction loads. A multi-criteria performance evaluation was conducted with the obtained experimental data by considering the load-bearing and impermeability criteria. Multiple criteria evaluation methods, namely AHP, COPRAS and TOPSIS, were used within the framework of the performance evaluation and the results were compared. One single and several best options to present the purpose or purposes were chosen by the performance evaluation method related with the decision making. The definition of the multiple criteria decision is being carried out by determining the criteria related to the problem as well as determining the suitability of the alternatives in relation to the chosen criteria. The multiple criteria decision process can be defined generally as defining the problem, determination of the assessment criteria, preparation of the criterion layers and their standardisation, the definition of the criterion weights and the application of the decision analysis. Assessment criteria have to be determined after defining the problem during the decision analysis. The criteria which were defined with regard to the purposes of the decision problem have to be measurable by a number indicating the choices of the decision maker. A total of 10 criteria have been identified in the study. The alternative with the highest numerical value received higher points during the scoring of the alternatives in the assessment. Therefore, a high score value indicates a high numerical result meaning that the relevant alternative provides values, which are closer to the borderlines values. The condition of being close to borderline values, proves that the relevant alternative provides more critical results in comparison to other results. The “critical level” was defined within the performance evaluation process and it indicates the values (%) of the obtained performance indicators as a result of the assessment results. The performance indicator data obtained from the calculations of the AHP, COPRAS and TOPSIS methods, were utilized during the numerical assessment process. Here, the critical levels of the samples at the 0th, 90th, 270th, 390th and 450th days were calculated. As a result of the performance evaluations, it has been determined that it is not possible to ignore the climatic effects on the building structure in which the façade system is mounted. Acquirement of appropriate results in a unitized curtain wall panel system which has been tested with adherence to the prevalently used experimental procedure, or in other words, the results which are not exceeding the limit values given in the standards, do not mean that this wall system will not experience any damage throughout its lifetime. One important result obtained as a result of this present study is that a unitized curtain wall panel system, which has been tested without taking into consideration the unexpected conditions it may endure, may face a shorter life expectancy in case it is exposed to these untested conditions.