Abhishek Jodawat et al. Int. Journal of Engineering Research and Application www.ijera.com ISSN : 2248-9622, Vol. 6, Issue 7, ( Part -1) July 2016, pp.01-05 www.ijera.com 1 | Page Retrofitting Of Reinforced Concrete Column by Steel Jacketing Abhishek Jodawat 1 , Arihant Parekh 1 , Bhushan Marathe 1 , Ketan Pawar 1 , Sunny Patwa 1 , Yash Sahu 1 , Indrajeet Jain 2 ( 1 .Stutents And 2 Asst. Professor, Department Of Civil Engineering, Sinhgad Institute Of Technology And Science, SPPU, Pune-41) ABSTRACT Reinforced concrete structures often require strengthening to increase their capacity to sustain additional loads, due to change in use that resulted in additional live loads, deterioration of the load carrying elements, design errors, construction problems during erection, aging of structure itself or upgrading to confirm to current code requirements. These situations may require additional concrete elements or the entire concrete structure to be strengthened, repaired or retrofitted. Common methods for strengthening columns include concrete jacketing, fiber reinforced polymer (FRP) jacketing and steel jacketing. All these methods have been shown to effectively increase the axial load capacity of columns. The experimental study was carried out on RC column on designed and detailed using IS 456:2000 provisions. The concrete mix design being performed after conducting numerous material test and cube test to validate expected strength as per specified grade of concrete. The trial testing conducted to estimate load at 1st crack and failure load for normal RC column with capturing displacement using dial gauges at regular load increment in UTM. The loading conditions are decided based on failure load to induce cracks in column under 85% loading of the failure one. In all fifteen specimen casted and tested with three samples for failure load estimation, three samples each for plate jacketing & angle battening system and three samples each for plate jacketing & angle battening with column preloaded to 85% of its failure load. The angle batten system proves to be better compared to full plate retrofitting in terms of load carrying capacity and enhancing confinement effect. Keywords: Axially loaded column, Retrofitting, steel jacketing, epoxy resign, Cracks I. INTRODUCTION Throughout the world many existing reinforced concrete structures, constructed prior to up to date earthquake resistant design procedures, suffer from the inability to supply adequate ductility during earthquakes. Particularly, brittle columns without adequate transverse reinforcement may cause a total collapse of this type of structure due to lack of sufficient deformation capacity. Retrofit of this type of column by means afforming an additional jacket layer may supply the required transverse reinforcement and enhance the seismic performance by providing additional ductility, and reducing the seismic force demand. The different types of retrofitting techniques used and applied depending on the suitability, applicability, the type of damage to be repair, type of resistance required, whether the damage is local or global and extent of strengthening possible from existing state of stress. The purpose of this paper is to conduct experimental study on Reinforced concrete column to evaluate performance of steel plate jacketing and angle batten systems in strengthening or increasing load carrying capacity of members. In this study the behavior of strengthened reinforced concrete columns by steel jacketing techniques is studied experimentally and the behavior of retrofitted column is compared with undamaged reinforced concrete column and also with preloaded column with 85% of failure load with retrofitting done to it. II. EXPERIMENTAL STUDY ON RC COLUMN STRENGTHENING 2.1 Introduction The material used in construction has to satisfy bear minimum strength and criteria as per the Indian Standard code of practice for Plain and Reinforced concrete design (IS 456:2000) Further the relevance of specific IS codes have been extracted wherever necessary for different materials and procedures to obtain material character and parameters required for mix design. The mix design being performed to achieve target strength of specific grade of concrete to be prepared using basic ingredient in specific proportion. The numerous tests were conducted for cement, fine aggregates, coarse aggregate and water to figure out material properties. The RC structures are subjected to deterioration and degradation due to aging, extreme loading, workability and climatic conditions. The strengthening may be necessary due to change in use that resulted in additional live loads (like change in use of the facility from residential to public or storage), deterioration of the load carrying elements, RESEARCH ARTICLE OPEN ACCESS