Strengthening and retrofitting of existing structures pdf

Retrofitting of existing structures with insufficient seismic resistance accounts for a major portion of the total cost of hazard mitigation. Research article materials and jacketing technique. Seismic assessment and retrofitting of existing buildings. In particular it must be considered the shrinkage of these two concretes. Twelve rehabilitation projects involving reinforced concrete buildings are presented in chapter 5. The weakening retrofit, which is an opposite strategy. Pdf retrofitting and strengthening of existing building foundation. Retrofitting is the modification of existing structures to make them more resistant. 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. 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. 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.

Health monitoring of structures use of sensors building instrumentation. Structural rehabilitation, retrofitting and strengthening of reinforced concrete structures international journal of. It has matured in the recent years to a highly reliable technology. Strengthening and retrofitting of existing structures request pdf. Widening and strengthening of existing foundations may be carried out by constructing a concrete jacket to the existing footings. In the united states, the federal emergency management. General a higher degree of damage in a building is expected during an earthquake if the seismic resistance of the building is inadequate. Pdf large numbers of existing buildings are made of concrete. The need of retrofitting of existing bridges has a risen preliminary because of age of the bridge, adjacent construction, traffic load. High tensile strength, lightweight and corrosion resistance characteristics of frp make it ideal for retrofitting applications.

Seismic retrofit with the addition of new shear walls to an existing frame design of new rc shear walls on the perimeter of a seismically deficient fivestorey building of example 1 is illustrated as a retrofit option. 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. Assessment and retrofitting of existing structures eurocodes. But, the expertise needed is not available in the basic level. The overturning effects and base shear are concentrated at the stiffer in fill locations. It aims to strengthen a structure to satisfy the requirements of the current codes for seismic design. 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. 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. The methods range from local strengthening and or upgrading of existing elements to changes of the lateral force resisting system in structures. It is necessary to take a decision whether to demolish a distressed structure or. Strengthening of existing foundations, floors, and walls to. It addresses in detail specific techniques for the.

Mlmce 1 civil engineering retrofitting of existing rcc buildings by method of jacketing chapter 2 strengthening of rcc structures 2. 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. Strengthening and retrofitting of existing structures. Validation through peeling of cover on 20 percent of columns and 10 percent of beams per floor. 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. Retrofitting techniques for existing damaged buildings. Retrofitting and rehabilitation of existing structures o2i. Strengthening existing reinforced concrete beams for flexure.

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. In repairing deteriorated concrete bridges the preliminary objective is to restore structure to its original shape. Such retrofits for rc buildings include steel braces, posttensioned cables, infill walls, shear walls, masonry infills, and base isolators. New and innovative techniques have been developed in the repairs of concrete structures. Repair and strengthening of reinforced concrete structures. Conclusion seismic retrofitting techniques for concrete structures. A new procedure to retrofit existing structures subjected to seismic excitation is proposed. Rehabilitation and retrofitting of structures notes rrs pdf. In order to reduce time and cost, shotcrete or precast panels can be used. 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. In this chapter, the author presents the basic principles and behavioral aspects of reinforced concrete rc strengthening with textilereinforced mortar trm. Necessity of strengthening reinforced concrete slabs for taking in consideration the necessity of strengthening rc elements we must analyse the situations that arise in practice where existing concrete structures or some of their components may, for a variety of reasons, be found to be inadequate and in need of repair and or strengthening. 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.

Seismic isolation is proven to be a very effective method for protecting buildings and other structures against seismic hazards. Define the fixed percentage method of evaluating the strength of existing. It has been noticed that some of them proved to be inadequate to resist lateral. 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. Strengthening and retrofitting of existing structures building pathology and rehabilitation. Reference rehabilitation and retrofitting of s tructures rrs notes pdf rrs pdf notes rrs pdf rrs notes. Reference rehabilitation and retrofitting of structures rrs notes pdf rrs pdf notes rrs pdf rrs notes.

The primary concern of a structural engineer is to successfully restore the structures as quickly as possible. 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. Generally the objectives of strengthening the structure are as below. Retrofitting of existing rcc buildings by method of jacketing mlmce 1 civil engineering. Strengthening and retrofitting of existing structures civil. Reinforcement or upgrading of existing structures to become more resistant and resilient. However, this information is only of interest if it has significance in the strength, stiffness, or global behavior of the structure. After briefly introducing how seismic action is described for design purposes, methods for assessing the seismic vulnerability of existing buildings are presented. 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. Further, some strengthening techniques for existing structures with moderate seismic deficiencies in the lower seismic zones are not appropriate for use in. Strengthen the structure before damage occurs is one form of retrofit which may also involve upgrading.

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. There are various methods of repair and retrofitting for earthquake damaged masonry structures in different categories. Strengthening of structures strengthening methods retro. Addition of rc structural walls adding structural walls is one of the most common structurelevel retrofitting methods to. The nature of work done and interval of time at which it is done depends upon. Structural assessment and redesign of an existing structure due to a structural intervention.

Review of documents on seismic strengthening of existing. The focus of this manual is on retrofitting buildings that are subject to flooding. Case studies of rehabilitation of existing reinforced by. Outsourcing retrofitting and rehabilitation of existing structures can present numerous benefits.

The advantages and limitations of each procedure are discussed. Several of the structural retrofit and strengthening techniques available to restore or add capacity to a bridge through rehabilitation or. Or concepts including strengthening, repairing and increasing the seismic types of retrofitting there are two types of retrofitting used for repairing the structures. In design process we must take two important points in considerations. Sep 02, 2018 strengthening and retrofitting of existing structures. Pdf retrofitting of existing rcc buildings by method of jacketing. Seismic retrofitting techniques for concrete structures. Structural retrofit an overview sciencedirect topics. Retrofitting is technical interventions in structural system of a building that improve the resistance to earthquake by optimizing the strength, ductility and earthquake.

Jacketing is the most popularly used method for strengthening of building columns. The decision to strengthen it before an earthquake occurs depends on the buildings seismic resistance. Assessment and retrofitting of existing structures. 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. It addresses in detail specific techniques for the strengthening of traditional constructions, reinforced concrete buildings, bridges and their foundations. Various retrofitting techniques have been developed for existing urm buildings. They should be models in providing examples of quality education and the. 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. 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. The methods range from local strengthening andor upgrading of existing elements to changes of the lateral force resisting system in structures. Retrofitting is any change made to an existing structure to reduce or. The seismic retrofitting of reinforced concrete buildings not designed to withstand seismic action is considered. 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. 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.

An attractive solution is strengthening of the existing structures using frp materials. Pdf retrofitting of existing rcc buildings by method of. Strengthening and retrofitting of existing structures building pathology and rehabilitation costa, anibal, arede, antonio, varum, humberto on. Retrofitting of bridges concrete building engineering. Global retrofitting local retrofitting the retrofitting in which we use to repair only the structural elements is called local retrofitting. Repair and rehabilitation structural rehabilitation of. Repair, strengthening or rehabilitation after damage has already took place is often also called retrofit. 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.

Throughout this manual, the following icons are used, indicating. 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. Engineering principles and practices for retrofitting floodprone residential structures. The strengthening may be limited to connections between existing building elements or it may involve adding primary resisting elements such. Rehabilitation and retrofitting of structures notes rrs. 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.

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. The exact configuration of elements that have significant strength or stiffness must be determined, whether traditionally classified structural or nonstructural. Introduction to repair and strengthening of reinforced concrete structures 1. Retrofitting of bridges free download as powerpoint presentation. An important disadvantage of the method, however, is that it cannot be applied partially to structures, unlike most other seismic retrofitting methods. The retrofitting of existing buildings for seismic. This book presents the fundamentals of strengthening and retrofitting approaches, solutions and technologies for existing structures. Research article materials and jacketing technique for. Jacketing consists of added concrete with longitudinal and transverse reinforcement around the existing column. 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. Design assessment and retrofitting and retrofitting of rc. Retrofitting reduces the vulnerability of damage of an existing structure during a future earthquake.