Debonding of FRP EBR: from testing to design

Introduction Chapter 1 1 Chapter 1 Introduction 1.1 General Reinforced concrete (RC) is widely used as a conventional material for building in civil and industrial engineering construction since it was invented in 19 th century. Nowadays, the unsatisfactory behavior of existing structures is becoming one of the major problems faced by structural engineers. Reasons for inadequate behavior include previous errors in design, inferior materials, corrosion due to environmental attack, bad construction practices, damage due to exceptional loads. In addiction load that for what they were originally designed for. Depending from the circumstances, there are two possible solutions: demolish and rebuilt or strength the structure. There is a large variety of material and techniques that are available for repair of damaged concrete building and structures. However, the traditional strengthening and repair methods present a great number of practical problems. In addition, most traditional techniques are intrusive, time consuming and expensive. In recent years the development of synthetic and epoxy adhesives combined with the using of Fiber Reinforced Concrete (FRP) has led to a very effective technique for repairing or strengthening concrete structures. There has been an increase in the use of fiber reinforced polymer to repair and strengthen structural members such as slabs, beams and columns. FRP uses to increase flexural strength of slabs, flexural strength and shear strength of beams and shear strength and the confinement of columns. Another application is to enhance continuity between precast members at joint. The principal reasons are to use FRP: the structural members that need to be strengthened by FRP are subjected to more applied load, for example, increasing the vehicle loads on bridges, changing the use of buildings from residential to commercial and accidental events such as earthquakes. Therefore it is necessary to add the reinforcement to the weaker members. Moreover, the occurrence rate of earthquake has increase over the past years, structures and building suffer from lack of proper maintenance and also the effects of natural disasters. Hence, FRP sheets are used to