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

Abstract

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. Structures Congress 2015 1101

An Experimental and Computational Study of Precast Concrete Moment Frames under a Column Removal Scenario

“…Kang and Tan (2015) performed testing of half-scale precast concrete frame assemblies with cast-in-place connections under simulated column removal, comparing the performance of specimens with different reinforcement details in the joints. These recent reduced-scale assembly tests (Nimse et al 2014(Nimse et al , 2015Kang and Tan 2015) considered rectangular beams with clear span to depth ratios of approximately nine, which is comparable to the clear span to depth ratio of beams in the cast-in-place concrete assemblies tested previously by Lew et al (2011). However, much deeper spandrel beams are common for exterior frames in precast concrete construction.…”

“…As summarized by Elliott and Jolly (2015), several experimental studies have investigated the effectiveness of tie forces in precast concrete floor slabs at redistributing loads through catenary action (e.g., Regan 1974, Schultz et al 1977, Engström 1990). Recently, Nimse et al (2014Nimse et al ( , 2015 tested one-third scale precast concrete frame assemblies under a column removal scenario, comparing the performance of monolithic connections, cast-in-place ("wet") connections, and field-bolted ("dry") connections. Kang and Tan (2015) performed testing of half-scale precast concrete frame assemblies with cast-in-place connections under simulated column removal, comparing the performance of specimens with different reinforcement details in the joints.…”

Experimental and numerical study of unbonded post‐tensioned precast concrete connections with controllable post‐decompression stiffness

“…[ 22,23 ] Besides, the damage of the precast connections, especially in corbels and loss of seating, may result in strength degradation and even collapse of whole systems following seismic events. [ 24,25 ] Therefore, in this study a steel corbel (SC) is introduced in the unbonded PTPC connection to provide sufficient shear capacity, which can also be used as a temporary support during assembly to improve construction efficiency. SCs have higher shear capacity than commonly used reinforced concrete corbels, reducing the likelihood of corbel damage, and their smaller dimensions compared to a concrete corbel allow them to be easily incorporated into the depth of the beam–column connection, allowing for increased architectural flexibility around the connection.…”

A Numerical Study of Precast Beam-Column Moment Connections Under Column Removal Scenario

“…Main et al [2] conducted a study on both full scale testing and detailed Finite element modelling of a precast concrete moment frame assembly of a 10-story prototype building where failure modes were recorded. Nimse et al [3] and [4] studied different reduced onethird scaled precast wet and dry connections due to column removal. Failure mode and pattern for the studied connections were monitored and their resistance due to column removal were reported.…”