ISBN 978-9937-0-9019-3 Pushover Analysis of Beam Retrofitted Multi Storey RCC Building using CFRP Namaraj Kafle Department of Earthquake Engineering, Thapathali campus Kathmandu, Nepal [email protected]Abstract— In this study seismic response of two storey reinforced concrete building is analysed by pushover analysis. Building frame is structurally analysed by using software SAP 2000 (version 14). Nonlinear pushover analysis is perform to check the performance point. Effect of external wrapping of carbon fiber reinforcement polymer (CFRP) on fail beam investigate the improvement on performance of beam. CFRP is used as retrofitting technique. It has been concluded that after the use of CFRP for retrofitting of beam, the structure were found to be within the targeted performance level. Keywords— CFRP, Capacity Curve, Performance Point, Seismic retrofitting, Pushover analysis I. INTRODUCTION Natural disaster are originated from natural event, causes loss of life and property. The most common natural disasters are earthquake, flood, storm, tsunami etc. Nepal is the one of most seismic regions of the world. Seismic retrofitting is considered one of most effective technique for earthquake risk reduction [1]. Retrofit refers to strengthening of existing structure. The retrofit process is general term that may consist of variety of treatment, including preservation, rehabilitation, restoration and reconstruction. According to the United Nations, Nepal is the 11th- most earthquake prone country [2]. Therefore, earthquake vulnerability in Nepal is great concern. Generally, used retrofitting technique for reinforced concrete structure are base isolation, seismic damper, reinforced concrete jacketing, steel caging, fiber reinforcement polymer. For masonry structure are plaster stitching, cement grouting, shotcreting, splint and bandage. In the recent decades, the availability of fiber reinforcement polymer (FRP) with its favorable property such as ease of application, high stiffness, strength, light in weight, advanced fatigue and corrosion resistances, etc., providing significant functional and economic benefits, ranging from strength enhancement and weight reduction to durability features [3]. However, the FRP strengthening technique has a few drawbacks, which are mainly associated with the use of epoxy resins— namely, high cost, poor performance in high temperatures, inability to apply on wet surfaces, and incompatibility with substrate materials (concrete or masonry). In an attempt to alleviate the problems arising from the use of epoxies, researchers have suggested the replacement of organic (epoxy resins) with inorganic (mortar) matrix [4]. The efficiency of FRP retrofitting in strengthening/repairing of structural beam column joints has confirmed in many studies worldwide. Researchers have also investigated the related problems such as FRP-concrete interface interaction and creep behavior in FRP strengthened structural members [5]. However, very few studies have scrutinized the overall behavior of FRP rehabilitated RC structures. Seismic performance of a full-scale RC structure repaired with carbon FRP (CFRP) laminates and wraps. Their experimental results proved the existence of a large displacement capacity in the repaired structure without any reduction of strength after the application of FRP at the beam- column joints and walls. In addition, the energy dissipation remains almost identical to the original structure. On the contrary, a reduction in the deformability of shear walls observed during the experiments due to the presence of CFRP laminates over the entire height. In another experimental study, Di Ludovico et al. [6] Investigated seismic retrofitting of an under-designed, full-scale RC structure with FRP wrapping. In their study, a bi-directional test with peak ground acceleration (PGA) equal to 0.2g applied to the original structure prior to retrofitting under which the structure found inadequate. The structure was then retrofitted in order to withstand a 50% higher PGA of 0.3g. The successful outcome of the tests proved the effectiveness of FRP in improving the global performance of the structure in terms of ductility and energy dissipating capacity. Improving the seismic behavior of deficient RC structures with FRP composites has also confirmed by Garcia et al. [7] Who through experimental tests and numerical modelling found that FRP retrofit results in substantial improvement of seismic performance of damaged RC frames. Following the main trend of the argument, the current study conducted to investigate to the seismic behavior of FRP retrofitted RC buildings. To pursue this objective, FRP sheets applied at the beams and columns regions that are prone to the development of KEC Conference 2021, April 18, 2021 “3 rd International Conference On Engineering And Technology” Kantipur Engineering College, Dhapakhel, Lalitpur, Nepal KEC Conference 2021 198
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Abstract— In this study seismic response of two storey
reinforced concrete building is analysed by pushover analysis. Building frame is structurally analysed by using software SAP 2000 (version 14). Nonlinear pushover analysis is perform to check the performance point. Effect of external wrapping of carbon fiber reinforcement polymer (CFRP) on fail beam investigate the improvement on
performance of beam. CFRP is used as retrofitting technique. It has been concluded that after the use of CFRP for retrofitting of beam, the structure were found to be within the targeted performance level.
Keywords— CFRP, Capacity Curve, Performance Point, Seismic retrofitting, Pushover analysis
I. INTRODUCTION
Natural disaster are originated from natural event,
causes loss of life and property. The most common
natural disasters are earthquake, flood, storm, tsunami
etc. Nepal is the one of most seismic regions of the
world. Seismic retrofitting is considered one of most effective technique for earthquake risk reduction [1].
Retrofit refers to strengthening of existing structure.
The retrofit process is general term that may consist
of variety of treatment, including preservation,
rehabilitation, restoration and reconstruction.
According to the United Nations, Nepal is the 11th-
most earthquake prone country [2]. Therefore,
earthquake vulnerability in Nepal is great concern.
Generally, used retrofitting technique for reinforced
concrete structure are base isolation, seismic damper,
reinforced concrete jacketing, steel caging, fiber reinforcement polymer. For masonry structure are