TY - JOUR
T1 - Analytical model to predict axial stress-strain behavior of heat-damaged unreinforced concrete columns wrapped by FRP jacket
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 first author also acknowledges the support provided by FCT PhD individual fellowship 2019 with the reference of “SFRH/BD/148002/2019”.
PY - 2023/8/15
Y1 - 2023/8/15
N2 - Although there are several confinement models to obtain analytically the axial stress-strain response (fc-εc) of concrete columns wrapped with fiber-reinforced-polymer (FRP) jacket at ambient conditions, a reliable design-oriented model to determine the fc-εc of heat-damaged concrete columns post-confined with FRP is still lacking in the literature. This study aims to address this research gap, by proposing a formulation that predicts the favourable effects of FRP confinement on concrete elements previously exposed to high temperatures. This model proposes a closed-form formulation to derive a fc-εc expression, including a set of strength and strain sub-models to calculate the stress/strain information at transition and ultimate points defining the stress-strain response. To develop the model and calibrate its key components by data analysis of statistical treatment techniques, a large test database of FRP confined unheated/heat-damaged concrete of circular/square cross-section consisting of 1914 specimens was collected. The proposed design-oriented model is able to demonstrate the influence of pre-existing thermal damage on the axial fc-εc relationship, whose reliability is revealed comprehensively through predicting data from several experimental heat-damaged concrete specimens confined with FRP systems.
AB - Although there are several confinement models to obtain analytically the axial stress-strain response (fc-εc) of concrete columns wrapped with fiber-reinforced-polymer (FRP) jacket at ambient conditions, a reliable design-oriented model to determine the fc-εc of heat-damaged concrete columns post-confined with FRP is still lacking in the literature. This study aims to address this research gap, by proposing a formulation that predicts the favourable effects of FRP confinement on concrete elements previously exposed to high temperatures. This model proposes a closed-form formulation to derive a fc-εc expression, including a set of strength and strain sub-models to calculate the stress/strain information at transition and ultimate points defining the stress-strain response. To develop the model and calibrate its key components by data analysis of statistical treatment techniques, a large test database of FRP confined unheated/heat-damaged concrete of circular/square cross-section consisting of 1914 specimens was collected. The proposed design-oriented model is able to demonstrate the influence of pre-existing thermal damage on the axial fc-εc relationship, whose reliability is revealed comprehensively through predicting data from several experimental heat-damaged concrete specimens confined with FRP systems.
KW - Axial behavior
KW - FRP confinement
KW - Heat-damaged concrete
KW - Stress-strain model
UR - http://www.scopus.com/inward/record.url?scp=85159363203&partnerID=8YFLogxK
U2 - 10.1016/j.engstruct.2023.116244
DO - 10.1016/j.engstruct.2023.116244
M3 - Article
AN - SCOPUS:85159363203
SN - 0141-0296
VL - 289
SP - 1
EP - 22
JO - Engineering Structures
JF - Engineering Structures
M1 - 116244
ER -