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Mahdi Nematzadeh

Mahdi Nematzadeh

Academic rank: Professor
ORCID: 0000-0002-8065-0542
Education: PhD.
ScopusId: 36198613700
HIndex:
Faculty: Faculty of Technology and Engineering
Address:
Phone: 011-35302903

Research

Title
Axial compressive performance of steel reinforced fibrous concrete composite stub columns: Experimental and theoretical study
Type
JournalPaper
Keywords
Axial compressive behavior Steel Reinforced Concrete (SRC) Steel fiber reinforced concrete Ultimate bearing capacity Confinement
Year
2021
Journal Structures
DOI
Researchers Armin Memarzadeh Ghaffari ، Mahdi Nematzadeh

Abstract

This study is aimed at addressing the experimental and theoretical investigation of the compressive behavior of steel reinforced concrete (SRC) composite columns containing steel fibers considering the stirrups’ confinement effects. Variables used to fabricate and evaluate the performance of the steel reinforced fibrous concrete (SRFC) columns include the steel profile shape (both H-shaped and C-shaped), volume fraction of steel fibers (0, 0.75, and 1.25%), and spacing of stirrups (40, 65, and 130mm). In total, 36 short column specimens were fabricated and such parameters as the axial bearing capacity, compressive stress–strain curves, ductility, peak strain and toughness were investigated through the axial compression test. According to the results, the axial bearing capacity of concrete-confined steel columns was affected by the steel shape inside; the axial bearing capacity of H-shaped cross-section columns was more - due to their more confinement - than that of C-shaped ones. Although adding, and increasing the percentage of, steel fibers increased the columns’ axial bearing capacity slightly (up to 6%), their ductility and energy absorption improved significantly. Increasing the spacing of stirrups from 40 to 130mm not only resulted in a 12% reduction in the axial bearing capacity, but also reduced the contribution of the composite action of both H- and C-shaped profiles by more than 70%. Finally, as predicting the SRC column strength is important, relationships presented by ACIITG, AS3600, CSA-A23, EN1994, JGJ138, and NZS3101 for the prediction of the axial bearing capacity were thoroughly studied and showed that all had ignored the confinement effects. Considering the latter, this study modified the relationships, corrected the predicted results and compared them with both the experimental results of this study as well as those of other researchers’ which showed a good correlation between the results.