Unified Strength Model for Square and Circular Concrete Columns Confined by External Jacket

Abstract

When the corner radius ratio ρ is defined as 2r∕b (corner radius divided by half breadth of column), circular and sharp cornered square columns are just two special cases when ρ=1 and 0, respectively. It is quite logical that a confined concrete strength model for columns with a corner radius should degenerate into a model for circular and sharp cornered square columns when ρ=1 and 0, respectively. However, this is not the case in any of the existing models, except for the early one by Mirmiran et al. in 1998. Extensive experimental testing on fiber-reinforced polymer (FRP)-confined concrete columns that have a continuous variation of ρ from 0 to 1 has been undertaken by the writers. Based on the experimental findings, a rational procedure is proposed for developing a unified strength model for FRP-confined concrete columns with an arbitrary corner radius. A comprehensive database has been established by collecting all of the available experimental results from the open literature for evaluation of the un...