A relatively new paradigm, performancebased design, has also had an impact on seismic retrofitting and rehabilitation. Kobatake, technical research institute, obayashi corporation, japan abstract new retrofitting techniques using carbon fibers are presented. One method employs permanufactured rigid frp strips approximately 4 in. Repair of earthquakedamaged rc columns with frp wraps. Retrofitting with frp materials is a technically sound and cost effective repair technology and is now extensively being used as a seismic retrofitting method all over the world.
Retrofit of rectangular bridge columns using cfrp wrapping. This paper describes and comments on some of the design approaches provided by the jbdpa guidelines for the strengthening of reinforced concrete rc columns. Research article materials and jacketing technique. Seismic analysis of a rc frame building with frp retrofitted. Only jackets fabricated using frp or steel material are considered because of their prevalence in practice. Pdf retrofitting is a process that is used to improve the strength, durability and performance of the structure. Finally, key issues on the seismic retrofitting of masonry walls for in. Frp in form of fibre, when continuously and rigidly connected to the beams and columns of the frame, are able to carry out to absorb the horizontal forces, increasing the capacity to absorb seismic forces. Thus, decision makers must approach using these materials with caution and must ensure that the design is performed with adequate knowledge and. Effect of external frp retrofitting on reinforced concrete. Seismic retrofitting is a process to modify or upgrade existing structures to make them resistant to earthquakes. Seismic retrofitting techniques for concrete structures focuses procedures to improve evaluation of seismic vulnerability of reinforced concrete buildings and provide innovative retrofitting techniques such as base isolation and mass reduction. The first seismic application of frp materials, thanks to their high strength, exhibited an effective performance for monotonic and seismic.
Many existing reinforced concrete structures were constructed with substandard characteristics. Outline of the japanese guidelines for seismic retrofitting of rc buildings using frp materials open pdf. The traditional method of repairing or strengthening reinforced concrete columns by means of concrete or steel jacketing involves difficult implementation procedures especially in building columns. Buildings free fulltext nonlinear modelling of curved. They provide many advantages over conventional mate. Many strengthening techniques have been introduced aimed at improving the structural performance of existing structures that, if properly designed and applied, provide an effective contribution. Retrofitting techniques for existing damaged buildings. Since the 1990s, composite materials applied by the wet layup method have become the main seismic reinforcement technology for civil engineering structures. While substandard structures are in need of retrofitting, particularly in seismic areas, problems such as high costs and disturbance to occupants are major obstacles. Overview of the japanese guidelines for seismic retrofitting. This study employs advanced composite materials such as highperformance fibre reinforced concrete hpfrc and glass fibre reinforced polymer gfrp in.
Despite the low probability of occurrence, risks related to natural disasters are considered to be unacceptable. Seismic retrofit with frp materials has gained notable acceptance from the civil engineering community in recent years. Polymers free fulltext seismic behavior of substandard. The research developed in this paper concerns seismic frp reinforcement.
Textile reinforced mortars trm versus fiber reinforced. For existing reinforced concrete columns, a cfrp winding technique is. Research article materials and jacketing technique for retrofitting of structures shri. A brief explanation of this retrofitting method as given in the recently published version of turkish seismic design code is also included as well. Wrapping the gfrp sheet or laminate tightly over a concrete cylinder in a two layers and apply the epoxy coat. Apr 26, 2012 the jbdpa guidelines mainly focus on seismic retrofitting of structural elements, which implies the strengthening for shear of deficient structural elements. The focus of this paper is mainly on the retrofitting of bridge superstructures and substructures including decks, girders, frames, and columns. A reliable numerical evaluation of the nonlinear behaviour of historical masonry structures, before and after a seismic retrofitting, is a fundamental issue in the design of the structural retrofitting. Department of civil engineering and environmental engineering, stanford university, california, usa. Frp composites are widely recognized for their potential use in seismic retrofitting applications. Retrofitting using frp laminates make a mixture of epoxy resin and hardener in the ratio of 100.
The research in this report concentrates on retrofitting deficient rc columns by jacketing columns to improve their seismic performance and prevent the possible collapse of a structure. In the research reported in this paper, the feasibility of using glass fiber composite laminates gfcl locally available in the egyptian market in retrofitting flexural reinforced concrete elements is studied. The results of this active research have led to significant developments in seismic retrofitting and rehabilitation procedures. Seismic retrofitting by frp of a school building damaged by emiliaromagna earthquake article pdf available in key engineering materials 624.
Seismic retrofit or rehabilitation strategies have been developed in the past few decades following the introduction of new seismic provisions and the availability of advanced materials e. Jun 11, 20 sikawrap seismic strengthening systems help ensure buildings, bridges, towers and other structures can withstand much higher earthquake loadings, and meet new zealands new earthquake regulations too. Life cycle assessment of sustainable infrastructure materials. Aug, 2001 some key behaviour and design aspects for shear. Fiber reinforced polymers for structural retrofitting.
Also, changes in service conditions, often made arbitrarily, may lead to substantial changes in the structural behaviour resulting in a degradation of the. The jbdpa guidelines mainly focus on seismic retrofitting of structural elements, which implies the strengthening for shear of deficient structural elements. Frp composite wraps for seismic repair to assess the effectiveness of this repair technique, damaged column specimens from another experimental. Advancements in retrofitting reinforced concrete structures.
Sikawrap seismic strengthening systems help ensure buildings, bridges, towers and other structures can withstand much higher earthquake loadings, and. Pdf fiber reinforced polymers for structural retrofitting. In september 1999, the japan building disaster prevention association jbdpa published the seismic retrofitting design and construction guidelines for existing reinforced concrete rc and steelencased reinforced concrete src buildings with frp materials. Now apply the epoxy mixture on concrete cylinder with the help of brush to paste the glass fiber reinforced polymer gfrp. Seismic retrofitting definition it is the modification of existing structures to make them more resistant to seismic activity, ground motion, or soil failure due to earthquakes. Increasing the strength of existing building using frp. Increasing the strength of existing building using frp materials in seismic zone vijay singh rawat department of civil engineering pacific university udaipur rajasthan. The concrete must start to crack up and dilate before the composite can take over. Two primary methods are used to attach frp composite materials to concrete structures and to masonry, timber, and even metallic structures for retrofitting purposes.
Seismic retrofit of framed buildings, fibrereinforcedpolymer structure, baseisolated structure, addeddamping structure, nonlinear dynamic analysis. This report presents the findings of an experimental study conducted on rectangular bridge columns retrofitted using frp. Seismic retrofit, strengthening and repair by quakewrap. The memberlevel retrofit approaches include the addition of concrete, steel, or fiber reinforced polymer frp jackets for use in confining rc columns and joints. The most of the structure throughout the world have seismic effect and are not capable of withstanding earthquake action according to the current code. Once the decision is made, seismic retrofitting can be performed through several methods with various objectives such as increasing the load, deformation. Seismic retrofitting definition, techniques using modern. It summarizes the scopes and uses of frp materials in seismic strengthening of rc structures and masonry retrofitting as well as the seismic retrofitting schemes for steel structures. Educational and research university, chennai, tamil nadu, india. The course drew on expertise both from outside turkey and from the large pool of local experts on this subject. Seismic retrofitting of corroded rc columns using advanced.
Consequently, new retrofitting methods for columns. Fiber reinforced polymers frp are investigated in this study in comparison with a new class of materials, textile reinforced mortars trm, for shear strengthening andor seismic retrofitting of concrete structures. Frp materials as a means of strengthening civil engineering structures. Sikawrap fibre reinforced polymer structural strengthening. This report presents the findings of an experimental study conducted on rectangular bridge columns retrofitted using frp composite materials. Low quality concrete, poor transverse reinforcement details and insufficient flexural strength are among the most common deficiencies.
Frp materials as a retrofitting technique for the structures not designed to resist seismic action. Appendix 11 section 11 japanese design and construction. Outline of the japanese guidelines for seismic retrofitting. Seismic retrofitting of concrete members with frp composites free download as powerpoint presentation. Column jacketing column retrofitting is often critical to the. The authors have spent 3 years researching the technology and the available guidelines. Retrofitting highrise structures using frp composite materials by david white f iberreinforced polymer frp composite materials have become a viable and accepted means of upgrading, strengthening, and rehabilitating structures over the past three decades. To achieve widerange use of these materials, however, there is need for further research into a number of issues related to mechanics, design, and durability of frp retrofitted concrete and steel systems. Epoxy epoxy is one of the most versatile materials used in structural repair and retrofitting and it is used as a sealant, adhesive or mortar.
In this paper we dealt with how the different frp materials could be used as a retrofitting material and be used based on cost effective 16. Seismic retrofitting techniques for concrete structures. Such problems can be reduced through proper design and anchorage of the external frp reinforcement. The retrofit techniques are also applicable for other natural hazards such as tropical cyclones, tornadoes, and severe winds from thunderstorms. Polymers frp as strengthening materials of concrete structures by t. Pdf seismic retrofitting by frp of a school building. Innovative textilebased composites for strengthening and. Innovative applications of textilebased composites in. Retrofitting of concrete structure with fiber reinforced polymer. Waghmare address for correspondence acharya shrimannarayan polytechnic,piprim, wardha maharashtra abstract seismic protection of buildings is a needbased concept aimed to improve the performance of any structure under future earthquakes. Fiber reinforced polymers for seismic retrofitting of structures. This study aims to develop retrofitting scheme for restoring the structural performance of corroded confined concrete hinge regions of rc columns.
Pioneered since the 1980s by quakewrap president, professor mo ehsani. Innovative materials for seismic and energy retrofitting of. We are a team of structural engineers and construction professionals focused on providing customized solutions for repair, retrofit and strengthening of structures using carbon fiber reinforced polymer frp products. Pioneered since the 1980s by quakewrap president, professor mo ehsani, frp is applied similar to wallpaper and becomes 23 times stronger than steel in 24 hours. Seismic retrofitting of concrete members with frp composites. Retrofitting of concrete, cfrp, gfrp, bfrp, seismic retrofitting, retrofitting of beam, column. Philosophy for strengthening seismic upgrade of structures located in seismic areas is generally aimed either at improving their seismic. Frp have attracted the attention of researchers and bridge owners as an alternative material for retrofitting reinforced concrete bridge elements. However, as of this day, there is no national guideline available which sets down recommendations for the design and detailing of frp for strengthening of civil engineering structures. New earthquake design codes, additional loads on buildings and bridges as well as insufficient reinforcement in earlier design has required seismic retrofit of many buildings and bridges. A common frp strengthening methods used for shear enhancement or inadequate length lap splice enhancement are passive methods. For seismic retrofitting, it is essential that the frp material is tight against the structure.
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