Comparison of Prefabricated Cage System with Existing Reinforcement Methods in Concrete Columns
Author: Matthew John Fisher
Publisher:
Published: 2006
Total Pages:
ISBN-13:
DOWNLOAD EBOOKAbstract: A reinforced concrete column is composed of two main load bearing mechanisms; concrete and a steel reinforcing cage. The concrete is the primary vertical load bearing mechanism with the steel cage providing some vertical load carrying capacity while serving mainly to confine the core concrete. The steel cage consists of two types of bars; longitudinal, which carry any compressive or tensile loads, and transverse, which hold the longitudinal bars in place and also provide confinement of the core concrete under axial load. The transverse bars are bent and tied to the longitudinal bars. A new type of steel cage has recently been proposed by Halil Sezen PhD and Mohammad Shamsai PhD, both of The Ohio State University. The new method is termed Prefabricated Cage System (PCS) reinforcement, and it consists of a cage constructed from a solid steel tube. A grid is cut into the tube through the use of a laser-cutter, resulting in a reinforcing cage that is very similar to a rebar cage. The main differences between the two are: 1) The PCS cage is a solid entity, while the rebar cage is held together through the use of ties. 2) The steel in the PCS cage is in rectangular form while the steel in the rebar cage typically consists of round bars. The machine fabrication of PCS provides a more accurately constructed column, compared to the manually constructed rebar cage, at the same or less cost than a rebar column due to the reduced on-site construction time required by PCS. The research project will focus on the performance of PCS in circular columns. In all, six samples will be constructed and tested, consisting of two rebar reinforced columns and four PCS reinforced columns. Each test column will be 18 in. in height with a 6 in. diameter. There will be two test groups, each group containing one rebar column and two PCS columns. The strength of the steel, which is represented by the yield stress of the steel multiplied by the cross-sectional area of the steel, will be the same in each test group to allow for accurate comparisons. The purpose of this research is to not only compare the performance of a PCS reinforced column to a rebar reinforced column, but also to compare PCS cages with differently sized grid openings. The objective is to investigate whether the PCS column has a higher maximum load and a larger displacement capacity, due to the increased confinement provided by the rectangular shape of the PCS cage over the round shape of the rebar cage.
