TY - JOUR
T1 - Investigation of the compressive behavior and failure modes of unconfined and FRP-confined concrete using digital image correlation
AU - Fallah Pour, Ali
AU - Nguyen, Giang D.
AU - Vincent, Thomas
AU - Ozbakkaloglu, Togay
PY - 2020/11/15
Y1 - 2020/11/15
N2 - This paper presents a detailed study on the development of axial, lateral and Von Mises strains measured by contact and non-contact methods under axial compression fiber reinforced polymer (FRP) confined and unconfined concrete specimens. The focus of the study was on the correlation between macro responses and localized deformations and the effects of FRP confinement on the localization of deformations. A total of 10 specimens were experimentally tested with a range of instrumentation to measure different types of strain. Digital image correlation (DIC) was used to obtain full-field strain evolution during compressive loading of concrete specimens confined with various fiber reinforced polymers. The effect of confinement material on the compressive behavior and strain distribution of FRP-confined concrete was investigated. The evolution of axial, lateral and Von Mises strains were recorded and examined during axial loading, including post-peak strain softening behavior. Data recorded by the typical contact method of linear variable displacement transformers (LVDTs) and strain gauges were used to validate the non-contact DIC method. The results obtained from DIC data in this study showed that expansion of shear zone for unconfined concrete is more localized than FRP-confined specimens. The results also show that specimens confined with CFRP induced homogenous compressive behavior, whereas GFRP and BFRP specimens with lower lateral stiffness displayed local strain concentration and less homogenous response. It was also observed that DIC provides a more accurate estimation of the ultimate condition compared to the contact methods due to the ability of DIC to capture the evolution of full-field strains.
AB - This paper presents a detailed study on the development of axial, lateral and Von Mises strains measured by contact and non-contact methods under axial compression fiber reinforced polymer (FRP) confined and unconfined concrete specimens. The focus of the study was on the correlation between macro responses and localized deformations and the effects of FRP confinement on the localization of deformations. A total of 10 specimens were experimentally tested with a range of instrumentation to measure different types of strain. Digital image correlation (DIC) was used to obtain full-field strain evolution during compressive loading of concrete specimens confined with various fiber reinforced polymers. The effect of confinement material on the compressive behavior and strain distribution of FRP-confined concrete was investigated. The evolution of axial, lateral and Von Mises strains were recorded and examined during axial loading, including post-peak strain softening behavior. Data recorded by the typical contact method of linear variable displacement transformers (LVDTs) and strain gauges were used to validate the non-contact DIC method. The results obtained from DIC data in this study showed that expansion of shear zone for unconfined concrete is more localized than FRP-confined specimens. The results also show that specimens confined with CFRP induced homogenous compressive behavior, whereas GFRP and BFRP specimens with lower lateral stiffness displayed local strain concentration and less homogenous response. It was also observed that DIC provides a more accurate estimation of the ultimate condition compared to the contact methods due to the ability of DIC to capture the evolution of full-field strains.
KW - Axial compression
KW - Confinement
KW - Digital image correlation (DIC)
KW - FRP-confined concrete
KW - Lateral and axial stress and strain
KW - Stress-strain relations
KW - Von Mises strain
UR - http://www.scopus.com/inward/record.url?scp=85088146896&partnerID=8YFLogxK
UR - http://purl.org/au-research/grants/ARC/FT140100408
U2 - 10.1016/j.compstruct.2020.112642
DO - 10.1016/j.compstruct.2020.112642
M3 - Article
AN - SCOPUS:85088146896
VL - 252
JO - COMPOSITE STRUCTURES
JF - COMPOSITE STRUCTURES
SN - 0263-8223
M1 - 112642
ER -