Reinforced AAC panels and structural behavior of buildings constructed with these panels

In recent years, high amount of research has been conducted on earthquakes and their destructive effects on buildings. Researches about improving the techniques to design earthquake resistant structures and laboratory experiments that have been done to enhance these techniques led to the developments of the construction sector. Autoclaved aerated concrete (AAC) has been increasingly chosen in construction due to its many advantages such as its low specific weight and adequate physical mechanical properties. Thus, construction sector in Turkey has started to use autoclaved aerated concrete more widely. In addition to the advantages mentioned above, this kind of concrete exhibits useful properties such as high heat, sound insulation and good mechanical properties against its low specific weight. Over the last few years, reinforced AAC panels has been developed in addition to the more traditional masonry AAC blocks. The need testing of this new construction system under lateral and horizontal loads in laboratory conditions is another result of this development in the construction sector. Due to the absence of usage of reinforced autoclaved aerated concrete as a structural member in current earthquake regulation, experimental laboratory researches had been done with the cooperation of Turkish Autoclaved Aerated Concrete Association (TGUB), Istanbul Technical University (ITU) and Middle East Technical University (METU). In this thesis, mechanical properties of autoclaved aerated concrete blocks and reinforced panels have been explained. At the Structural and Earthquake Engineering Laboratory of Istanbul Technical University and with the cooperation of Turkish Ytong Company and TGUB, material and member tests of AAC specimens witn and without reinforcement have been conducted. The experiments are classified in two groups; material and member tests. The compressive and flexural strengths and modulus of elasticity of autoclaved aerated concrete have been determined with material tests. Furthermore, the friction coefficent between reinforced panels and thin bed - mortar and compressive strength of AAC panels have been determined through element tests. During determination of compressive, flexural strength and modulus of elasticity of AAC blocks, AAC bloks that belogs two different compressive stregnth classes (G3 and G4) are tested. All blocks are gathered from YTONG production plant according to rules stated in European Standart of each tests. Also, AAC blocks are tested according to rules stated in European Standart of each tests. After material tests, the axial loads which are going to be applied on 1:1 scaled shear walls that are constructed with reinforced AAC panels are calculated with cooperation of Aachen University. Next, three different size of shear walls are constructed by using two, for or six reinforced AAC blocks. To get realistic results, AAC blocks fixed between reinforced concrete foundations and beams. Shear walls of different sizes constructed with reinforced AAC panels are tested under two different axial loads as well as the combined actions of axial and revised cyclic loads and their behavior was inspected under lateral loads. By using results of shear wall tests, a new strength reduction factor, overstrength factor and behavior factor for seismic design of structures that are constructed with reinforced AAC panels is proposed. Furthermore, by examining of behavior of reinforced AAC shear walls under combined actions of axial and reversed cyclic loads, a new drift limit for shear walls constructed with reinforced AAC panels is proposed. Additionally, test results after material tests and element tests are compared with the results of equations stated in new Turkish Seismic Design Code. For this comparision, equations that are going to be used to determine initial shear strength of reinforced AAC structural walls, vertical load bearing capacity of reinforced AAC structural walls and shear strength of reinforced AAC structural walls according to new Turkish Seismic Design Code are used. In addition to test results, proposed strength reduction and behavior factors and drift limits for shear walls constructed with reinforced AAC panels that have been explained in this thesis, three dimentional, 1:1 scale building that is constructed in Istanbul Technical University has tested under lateral loads during this project. Also, to examine the diaphragm behavior of slabs constructed with reinforced AAC panels, three dimentional, 1:1 scale slabs are tested under lateral loads in YTONG production plant. The determined test results contributed remarkably to the design rules to be included in the new Turkish Seismic Design Code.