Mesoscale analysis for the bond behavior of concrete under active confinement using coupled RBSM and solid FEM

Digital Image Correlation (DIC) provides measurements without disturbing the specimen, which is a major advantage over contact methods. Additionally, DIC techniques provide full-field maps of response quantities like strains and displacements, unlike traditional methods that are limited to a local investigation. In this work, an experimental application of DIC is presented to investigate a problem of relevant interest in the civil engineering field, namely the interface behavior between externally bonded fabric reinforced cementitious mortar (FRCM) sheets and concrete substrate. This represents a widespread strengthening technique of existing reinforced concrete structures, but its effectiveness is strongly related to the bond behavior between composite fabric and underlying concrete. To investigate this phenomenon, a set of notched concrete beams are realized, reinforced with FRCM sheets on the bottom face, subsequently cured in different environmental conditions (humidity and temperature) and finally tested up to failure under three-point bending. Mechanical tests are carried out vis-à-vis DIC measurements using two distinct cameras simultaneously, one focused on the concrete front face and another focused on the FRCM-concrete interface. This experimental setup makes it possible to interpret the mechanical behavior and failure mode of the specimens not only from a traditional macroscopic viewpoint but also under a local perspective concerning the evolution of the strain distribution at the FRCM-concrete interface obtained by DIC in the pre- and postcracking phase.

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Innovative models for predicting post-fire bond behavior of steel rebar embedded in steel fiber reinforced rubberized concrete using soft computing methods

Structures ◽

10.1016/j.istruc.2021.02.015 ◽

2021 ◽

Vol 31 ◽

pp. 1141-1162

Author(s):

Mahdi Nematzadeh ◽

Amir Ali Shahmansouri ◽

Reza Zabihi

Keyword(s):

Soft Computing ◽

Steel Fiber ◽

Computing Methods ◽

Rubberized Concrete ◽

Fiber Reinforced ◽

Bond Behavior ◽

Steel Rebar ◽

Soft Computing Methods

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Effect of steel fibers and concrete cover on bond behavior between steel deformed bar and concrete under high temperature

Structures ◽

10.1016/j.istruc.2021.03.062 ◽

2021 ◽

Vol 32 ◽

pp. 1507-1521

Author(s):

Habib Akbarzadeh Bengar ◽

Fatemeh Ahmadi Zarrinkolaei

Keyword(s):

High Temperature ◽

Concrete Cover ◽

Steel Fibers ◽

Bond Behavior ◽

Deformed Bar

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Bond behavior of dual headed bars in concrete structures

Case Studies in Construction Materials ◽

10.1016/j.cscm.2021.e00553 ◽

2021 ◽

Vol 15 ◽

pp. e00553

Author(s):

Haitham H. Saeed ◽

Ayman A. Abdulhamed

Keyword(s):

Concrete Structures ◽

Bond Behavior

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Experimental and Numerical Investigation on the Steel Reinforced Grout (SRG) Composite-to-Concrete Bond

Journal of Composites Science ◽

10.3390/jcs4040182 ◽

2020 ◽

Vol 4 (4) ◽

pp. 182

Author(s):

Luciano Ombres ◽

Salvatore Verre

Keyword(s):

Bond Length ◽

Failure Modes ◽

Peak Load ◽

Element Model ◽

Test Results ◽

Shear Tests ◽

Bond Slip ◽

Bond Behavior ◽

Direct Shear Tests ◽

Inorganic Matrix

In the paper, the bond between a composite strengthening system consisting of steel textiles embedded into an inorganic matrix (steel reinforced grout, SRG) and the concrete substrate, is investigated. An experimental investigation was carried out on medium density SRG specimens; direct shear tests were conducted on 20 specimens to analyze the effect of the bond length, and the age of the composite strip on the SRG-to-concrete bond behavior. In particular, the tests were conducted considering five bond length (100, 200, 250, 330, and 450 mm), and the composite strip’s age 14th, 21st, and 28th day after the bonding. Test results in the form of peak load, failure modes and, bond-slip diagrams were presented and discussed. A finite element model developed through commercial software to replicate the behavior of SRG strips, is also proposed. The effectiveness of the proposed numerical model was validated by the comparison between its predictions and experimental results.

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