الفهرس 
Chapter 1: IntroductionOnly 14 pages are availabe for public view
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Abstract
A sandwich panel consists of two thin skin layers of relatively high strength and modulus of elasticity, separated by a thick layer of a low strength material as a core. The advantage of this type of building materials is mainly the light weight of the unit compared to its equivalent volume of the conventional concrete. Such panels could be used as roof elements or as wall bearing elements. This is mainly due to the two thin skin layers at the two faces, which can carry loads, resist impacts, and accommodate architectural acceptance, while in the same time the core material provides thermal and sound insulation. Moreover, the core material can provide shear transfer between the two thin skin layers if the units are to be used for structural or load bearing purposes. In this case, the core material should possess adequate strength to be able to transfer the shear force between the two layers. Ferrocement lightweight sandwich panel system was investigated in previous researches and has proven that it is one of the most suitable structural . The objective of the work presented in this research was to develop light weight composite slab subjected to punching load by using column slab connection at the center of the slab which comprises polystyrene block of thickness 80 mm reinforced with welded galvanized steel mesh or expanded steel mesh. The use of expanded metal mesh and welded steel mesh was proposed as a viable alternative to ordinary steel bars in reinforcing ferrocement plates, also it was proposed to use it with ordinary steel bars to enhance the mechanical behavior of the composite slab. To improve the properties of concrete used in this work, the effect of silica fume on the properties of fresh and hardened concrete was investigated. The aim of this investigation was to determine the optimum percentage of silica fume as a cement weight replacement, which gives the highest compressive and tensile strength. This research presents the behavior of ferrocement lightweight slabs under punching shear. The effects of various types of reinforcing materials were investigated. The shape and location for the critical punching shear perimeter are proposed. Also an empirical equation is reached to predict the punching shear strength of the light weight tested slabs. The main objective of this study is to produce elements acting as slab elements subjected to punching loads using the concept of ferrocement. These developed elements can replace the conventional reinforced concrete elements because they are more economical and lighter in weight. Also, the study aimed at decreasing the cost of production of the new elements by using cheap materials like light weight foams and thin steel meshes. Using such lightweight materials will contribute to decreasing the weight of the elements and consequently decreasing the overall dead load of the building. Moreover, the study aimed at improving some other characteristics like flexural strength, crack pattern, first crack load, crack width, and deflection. For light weight sandwich elements, light weight polystyrene of density 12Kg/m3 is used as a core material and welded wire meshes or expanded steel meshes are to be used as steel reinforcement at the two thin skin layers. Shear connectors will be provided through the core material connecting the two steel layers at the faces to control the shear transfer. The thickness of polystyrene is kept constant for all light weight ferrocement slabs. The parameters investigated in this study are: • Effect of the number of layers of steel reinforcement provided • Effect of the type of steel reinforcement used Twelve square composite light weight slabs were developed having the dimensions of 1200mm x 1200mm and overall thickness of 140mm were tested simply supported along all four sides under central column slab connection until failure.