Experimental Study on Precast Beam Column Connections Constructed Using RC Corbel and Steel Billet under Progressive Collapse Scenario

Progressive collapse denotes a failure of a major portion of a structure that has been initiated by failure of a relatively small part of the structure such as failure of any vertical load carrying element (typically columns). Failure of large part of any structure will results in to substantial loss of human lives and natural resources. Therefore, it is important to prevent progressive collapse which is also known as disproportionate collapse. Now a days, there is increasing trend towards construction of buildings using precast concrete. In precast concrete construction, all the components of structures are produced in controlled environment and they are being connected appropriately at site. Connections are the most critical elements of any precast structure, because in past major collapse of precast structure took place because of connection failure. In this study, behavior of four different reduced 1/3 rd scaled precast specimens having wet and dry connections is investigated under column removal scenario and their performance is compared with monolithic connection. Precast specimens considered for the study are constructed by adopting different detailing having column with RC corbel and column with steel billet for connection with precast beam. Performance of specimen is evaluated on the basis of ultimate load carrying capacity, maximum deflection and deflection measured along the span of the beam. From the results, better performance of precast connections is observed up to elastic phase but later on strength of dry precast connections degrades more as compared to monolithic connection. Wet precast connections exhibit superior performance as compared to monolithic connection, which advocates replacement of monolithic connection with appropriate connection detailing. From the results, is also observed that precast connections constructed using RC corbel performs better as compared to those constructed using steel billet.