The need of retrofitting of existing bridges has a risen preliminary because of age of the bridge, adjacent construction, traffic load. It is necessary to take a decision whether to demolish a distressed structure or. Retrofitting is any change made to an existing structure to reduce or. Retrofitting techniques for existing damaged buildings. Jacketing consists of added concrete with longitudinal and transverse reinforcement around the existing column. Strengthening and retrofitting of existing structures anibal costa. Selection of right materials, techniques and procedures to be employed for the repair of a given structures have been a major challenges. Structural assessment and redesign of an existing structure due to a structural intervention. Strengthening and retrofitting of existing structures building pathology and rehabilitation.
Obviously, older existing structures located in a lower seismic zone have a higher probability of requiring little or no strengthening than do similar structures in a higher zone. It has been noticed that some of them proved to be inadequate to resist lateral. Further, some strengthening techniques for existing structures with moderate seismic deficiencies in the lower seismic zones are not appropriate for use in. Conclusion seismic retrofitting techniques for concrete structures. Seismic retrofitting of existing structures by cetin sahin a research project report submitted in partial fulfillment of the requirement for the degree of master of science in civil and environmental engineering project advisor. High tensile strength, lightweight and corrosion resistance characteristics of frp make it ideal for retrofitting applications. Since december 2000, that is since the program of the swiss government for earthquake mitigation took effect, the swiss government has been examining the seismic safety of existing structures in its area of responsibility. Seismic evaluation and strengthening of existing buildings.
The weakening retrofit, which is an opposite strategy. Strengthening of structures strengthening methods retro. Pdf retrofitting of existing rcc buildings by method of. In order to reduce time and cost, shotcrete or precast panels can be used. Jan 29, 20 retrofitting upgrading of certain building systems existing structures to make them more resistant to seismic activity earthquake resistance structures can be earthquake damaged earthquake vulnerable retrofitting proves to be a better economic consideration and immediate shelter to problems rather than replacement of building. There are various methods of repair and retrofitting for earthquake damaged masonry structures in different categories. Repair and rehabilitation structural rehabilitation of. Pdf retrofitting of existing rcc buildings by method of jacketing. Widening and strengthening of existing foundations may be carried out by constructing a concrete jacket to the existing footings. Retrofitting reduces the vulnerability of damage of an existing structure during a future earthquake. They should be models in providing examples of quality education and the.
Or concepts including strengthening, repairing and increasing the seismic types of retrofitting there are two types of retrofitting used for repairing the structures. Engineering principles and practices for retrofitting floodprone residential structures. Several of the structural retrofit and strengthening techniques available to restore or add capacity to a bridge through rehabilitation or. Reference rehabilitation and retrofitting of s tructures rrs notes pdf rrs pdf notes rrs pdf rrs notes. The methods range from local strengthening andor upgrading of existing elements to changes of the lateral force resisting system in structures. We follow the ascesei standard 4106, which is a valuable software tool for structural engineers to improve the seismic performance of existing buildings and offer some unique advantages to their clientele. The primary concern of a structural engineer is to successfully restore the structures as quickly as possible. Introduction to retrofitting retrofitting is any change made to an existing structure to reduce or eliminate the possibility of damage to that structure from flooding, erosion, high winds, earthquakes, or other hazards. Twelve rehabilitation projects involving reinforced concrete buildings are presented in chapter 5. The seismic retrofitting of reinforced concrete buildings not designed to withstand seismic action is considered. Seismic retrofitting techniques for concrete structures. The advantages and limitations of each procedure are discussed. Seismic isolation is proven to be a very effective method for protecting buildings and other structures against seismic hazards.
Strengthening and retrofitting of existing structures. In design process we must take two important points in considerations. The decision to strengthen it before an earthquake occurs depends on the buildings seismic resistance. In the united states, the federal emergency management. Performancebased design aims to utilize performance objectives to determine acceptable levels of damage for a given earthquake hazard for new buildings or upgrade of existing buildings. The retrofitting of existing buildings for seismic. Modern repairing and retrofitting methods for existing structures make use of composite materials, consisting of high strength textiles and a matrix, which can be either polymeric or inorganic. Retrofitting is technical interventions in structural system of a building that improve the resistance to earthquake by optimizing the strength, ductility and earthquake. Repair and strengthening of reinforced concrete structures. Rehabilitation and retrofitting of structures notes rrs. Repair, strengthening or rehabilitation after damage has already took place is often also called retrofit. Research article materials and jacketing technique.
Seismic assessment and retrofitting of existing buildings. Strengthening and retrofitting of existing structures request pdf. Structural retrofit an overview sciencedirect topics. Case studies of rehabilitation of existing reinforced by. The exact configuration of elements that have significant strength or stiffness must be determined, whether traditionally classified structural or nonstructural. Strengthening existing reinforced concrete beams for flexure.
Such retrofits for rc buildings include steel braces, posttensioned cables, infill walls, shear walls, masonry infills, and base isolators. But, the expertise needed is not available in the basic level. Strengthening of existing reinforced concrete walls becomes necessary either when they lose their strength and capacity to take up the stipulated loads or when you need to increase their load carrying capacity. The strengthening or retrofitting of existing concrete structures to resist higher design loads, correct strength loss due to deterioration, correct design or construction deficiencies, or increase ductility has traditionally been accomplished using conventional materials and construction techniques. Research article materials and jacketing technique for. Review of documents on seismic strengthening of existing buildings 1. Strengthening is an improvement over the original strength when the evaluation of the building indicates that the strength available before the damage was insufficient and restoration alone will not be adequate in future quakes.
It has matured in the recent years to a highly reliable technology. Strengthening of existing foundations, floors, and walls to. Design assessment and retrofitting and retrofitting of rc. Reinforcement or upgrading of existing structures to become more resistant and resilient. Seismic retrofitting is the modification of existing structures to make them more resistant to seismic activity, ground motion, or soil failure due to earthquakes. Throughout this manual, the following icons are used, indicating. Review of documents on seismic strengthening of existing. Health monitoring of structures use of sensors building instrumentation. It addresses in detail specific techniques for the. Evaluating the strength of the existing structure evaluating the need of the structure selecting and implementing the repair procedure c routine maintenance it is the service maintenance attended to the structure periodically. The most common form of seismic retrofit to lower buildings is adding strength to the existing structure to resist seismic forces.
From the two methods it is considered that strengthening by adding new reinforced concrete layer is much easier to be realized when the works are. Rehabilitation and retrofitting of structures notes rrs pdf. Addition of rc structural walls adding structural walls is one of the most common structurelevel retrofitting methods to. It is an improvement over the original strength when the evaluation of the building indicates that the strength available before the damage walls insufficient and restoration alone will not be adequate in future quakes. The methods range from local strengthening and or upgrading of existing elements to changes of the lateral force resisting system in structures. Reference rehabilitation and retrofitting of structures rrs notes pdf rrs pdf notes rrs pdf rrs notes. Introduction to repair and strengthening of reinforced concrete structures 1. Global retrofitting local retrofitting the retrofitting in which we use to repair only the structural elements is called local retrofitting.
Outsourcing retrofitting and rehabilitation of existing structures can present numerous benefits. With better understanding of seismic demand on structures and with our recent experiences with large earthquakes near urban centers, the need of seismic retrofitting is well acknowledged. New and innovative techniques have been developed in the repairs of concrete structures. In repairing deteriorated concrete bridges the preliminary objective is to restore structure to its original shape. Pakistani specialists indicated a need for advice and training on building structural retrofit and strengthening methods and in procedures to compare the costeffectiveness of alternative approaches. General a higher degree of damage in a building is expected during an earthquake if the seismic resistance of the building is inadequate. Retrofitting of existing rcc buildings by method of jacketing mlmce 1 civil engineering. Strengthening and retrofitting of existing structures civil. A new procedure to retrofit existing structures subjected to seismic excitation is proposed. Define the fixed percentage method of evaluating the strength of existing. It addresses in detail specific techniques for the strengthening of traditional constructions, reinforced concrete buildings, bridges and their foundations. Validation through peeling of cover on 20 percent of columns and 10 percent of beams per floor.
Retrofitting of bridges concrete building engineering. The focus of this manual is on retrofitting buildings that are subject to flooding. In particular it must be considered the shrinkage of these two concretes. Jacketing is the most popularly used method for strengthening of building columns. An attractive solution is strengthening of the existing structures using frp materials. Frp strengthening of concrete structures design constraints and practical effects on construction detailing rob irwin 1 and amar rahman 2 introduction for eight years new zealand has been to the forefront in the development and use of. The main features of this procedure are to reduce maximum acceleration and associated forces in buildings subjected to seismic excitation by reducing their strength weakening. The overturning effects and base shear are concentrated at the stiffer in fill locations. However, this information is only of interest if it has significance in the strength, stiffness, or global behavior of the structure. Pdf large numbers of existing buildings are made of concrete. The nature of work done and interval of time at which it is done depends upon. Strengthening and retrofitting of existing structures building pathology and rehabilitation costa, anibal, arede, antonio, varum, humberto on. Pdf retrofitting and strengthening of existing building foundation.
The strengthening may be limited to connections between existing building elements or it may involve adding primary resisting elements such. In india there are large numbers of old existing buildings which are deteriorated because of their use, their age and may be due to fully consumption of their design life. Generally the objectives of strengthening the structure are as below. Strengthen the structure before damage occurs is one form of retrofit which may also involve upgrading. In this chapter, the author presents the basic principles and behavioral aspects of reinforced concrete rc strengthening with textilereinforced mortar trm. Retrofitting and rehabilitation of existing structures o2i. Retrofitting of bridges free download as powerpoint presentation. The method of epoxybonding steel plates and fiberglass reinforced plastics to the tensile face of reinforced concrete beams has been studied extensively as a method to strengthen existing reinforced concrete structures. This book presents the fundamentals of strengthening and retrofitting approaches, solutions and technologies for existing structures.
Assessment and retrofitting of existing structures. After briefly introducing how seismic action is described for design purposes, methods for assessing the seismic vulnerability of existing buildings are presented. It aims to strengthen a structure to satisfy the requirements of the current codes for seismic design. Structural rehabilitation, retrofitting and strengthening of reinforced concrete structures international journal of. To increase the strength of building, by providing extra reinforcement or by increasing the number of. Seismic retrofitting is a suitable technology for protection of a variety of structures. Assessment and retrofitting of existing structures eurocodes. Application of repair methods is expected to restore the structures to its preearthquake condition where as application of retrofitting methods to damaged structures is expected to increase strength and ductility of the. An important disadvantage of the method, however, is that it cannot be applied partially to structures, unlike most other seismic retrofitting methods.
Retrofitting is the seismic strengthening of existing damaged or undamaged structures. Thus, it is of critical importance that the structures that need seismic retrofitting are identified correctly, and an optimal retrofitting is conducted in a cost effective fashion. Various retrofitting techniques have been developed for existing urm buildings. Retrofitting is the modification of existing structures to make them more resistant. Retrofitting of existing buildings september 2008 a preliminary evaluation of building is carried out which involves broad assessment of apparent physical condition, robustness, structural integrity and strength of structure, including simple calculations. Manual on retrofitting of existing vulnerable school buildingsassessment to retrofitting part i i preface schools are institutions providing an education as well as a common place for community gatherings and meetings.
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