Study the Behavior of Different Types of Precast Beam-Column Connection

Abstract

There is increasing trend towards construction of buildings using precast con- crete during recent past. The main concept of precast concrete construction is that all the components of structures are produced in controlled environment and it is being transported to the site. At site such individual components are connected by some means. This leads to major advantages like; reduced formwork and scafolding, speedy construction, less requirement of skill labor and better quality as compared to normal reinforced concrete construction. Because of such advantages the precast concrete construction is being adopted world-wide including India. In precast concrete construction, connections are considered as critical elements of the structure. It is also evident that major collapse of precast building was taken place because of connection failure. Therefore it is crucial to study the performance of connection between beam and column. Proper connections plays major role in stability of precast buildings under gravity as well as lateral loading. In this study, (G+5) Storey Precast concrete building having four bay in lon- gitudinal direction and three bay in transverse direction is considered. Analysis and design of the building is carried out by following guidelines provided by Precast Con- crete Institute design handbook [2] which is based on ACI 318 [21] and BS 8110: 1997[20]. Modeling is done using commercial software ETABS. Behaviour of three dry and three wet precast beam column connection is studied and its performance is compared with that of monolithic connection. Connections are considered at two different location i.e. exterior junction and interior junction. Specimen representing exterior junction having column and beam projecting from it in one direction while specimen representing interior junction having column and beam projecting from it in both direction. For precast connections, the column with concrete corbel and the column with steel billet is designed to take reactions generated at the end of the beams.The cleat angles are used to avoid the torsion as well as to increase moment carrying capacity in beam in case of dry connection and stifener is provided for additional rigidity. Dowel bars are used for beam to column connection for wet connection. The empty space is then filled up with the help of micro-concrete. Load is applied with the help of hydraulic jack at the free end of beam. The experimental results of the precast specimens have been compared with that of the monolithic connection. The performance of the precast connections is evaluated in terms of the load-displacement relationship, ultimate load carrying capacity and strain at critical Locations.