TY - JOUR
T1 - Analysis-oriented model for partially FRP-and-steel-confined circular RC columns under compression
AU - Shayanfar, Javad
AU - Barros, Joaquim A.O.
AU - Rezazadeh, Mohammadali
N1 - Funding Information:
This study is a part of the project ‘‘Sticker –Innovative technique for the structural strengthening based on using CFRP laminates with multifunctional attributes and applied with advanced cement adhesives’’, with the reference POCI-01-0247-FEDER-039755. The firs author also acknowledges the support provided by FCT PhD individual fellowship 2019 with the reference of “SFRH/BD/148002/2019”.
PY - 2023/2/1
Y1 - 2023/2/1
N2 - Even though analysis-oriented models exist to simulate the axial and dilation behavior of reinforced concrete (RC) columns strengthened with fiber-reinforced-polymer (FRP) full confinement arrangements, a reliable model developed/calibrated for FRP partially imposed confinements is not yet available, identified as a research gap. Therefore, this paper is dedicated to the development of a new analysis-oriented model generalized for fully and partially confined RC columns under compression. In addition to vertical arching action phenomenon, the influence of the concrete expansion distribution along the column height on confining stress is considered in the establishment of the combined confinement from FRP strips and steel transverse reinforcements. A new unified dilation model is proposed, where the substantial effect of additional axial deformations induced by damage evolution in unwrapped zones is formulated by considering available experimental results. This model is coupled with an axial stress-strain formulation that includes a new failure surface function for simulating the dual confinement-induced enhancements, which are strongly dependent on the confinement stiffness. The developed model considers the influence of partially imposed confinement strategy on the axial and dilation behavior of RC columns, whose validation is demonstrated by simulating several experimental tests. Lastly, a parametric study is performed to evidence the dependence of FRP-steel confinement-induced enhancements on steel hoop and FRP spacing, and on the concrete compressive strength.
AB - Even though analysis-oriented models exist to simulate the axial and dilation behavior of reinforced concrete (RC) columns strengthened with fiber-reinforced-polymer (FRP) full confinement arrangements, a reliable model developed/calibrated for FRP partially imposed confinements is not yet available, identified as a research gap. Therefore, this paper is dedicated to the development of a new analysis-oriented model generalized for fully and partially confined RC columns under compression. In addition to vertical arching action phenomenon, the influence of the concrete expansion distribution along the column height on confining stress is considered in the establishment of the combined confinement from FRP strips and steel transverse reinforcements. A new unified dilation model is proposed, where the substantial effect of additional axial deformations induced by damage evolution in unwrapped zones is formulated by considering available experimental results. This model is coupled with an axial stress-strain formulation that includes a new failure surface function for simulating the dual confinement-induced enhancements, which are strongly dependent on the confinement stiffness. The developed model considers the influence of partially imposed confinement strategy on the axial and dilation behavior of RC columns, whose validation is demonstrated by simulating several experimental tests. Lastly, a parametric study is performed to evidence the dependence of FRP-steel confinement-induced enhancements on steel hoop and FRP spacing, and on the concrete compressive strength.
KW - Dilation model
KW - FRP confinement
KW - RC columns
KW - Steel confinement
KW - Stress-strain model
UR - http://www.scopus.com/inward/record.url?scp=85144051291&partnerID=8YFLogxK
U2 - 10.1016/j.engstruct.2022.115330
DO - 10.1016/j.engstruct.2022.115330
M3 - Article
AN - SCOPUS:85144051291
SN - 0141-0296
VL - 276
JO - Engineering Structures
JF - Engineering Structures
M1 - 115330
ER -