Strengthening of RC beams using bottom and side NSM reinforcement

The allowable strain in fibre reinforced polymers reinforcement is limited by design codes to avoid debonding. The near-surface mounted (NSM) reinforcement technique has been proven to produce better anchorage behaviour compared to externally bonded reinforcement solutions. However, NSM solutions do...

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Bibliographic Details
Published in:Composites. Part B, Engineering Vol. 149; pp. 82 - 91
Main Authors: Sabau, Cristian, Popescu, Cosmin, Sas, Gabriel, Schmidt, Jacob Wittrup, Blanksvärd, Thomas, Täljsten, Björn
Format: Journal Article
Language:English
Published: Elsevier Ltd 15.09.2018
Subjects:
CFRP
Concrete cover detachment
Crack spacing
Debonding
Konstruktionsteknik
Non-contact optical measurements
NSM
Strain analysis
Structural Engineering
Strain analysis
Debonding
Crack spacing
NSM
Concrete cover detachment
CFRP
Non-contact optical measurements
ISSN:1359-8368, 1879-1069, 1879-1069
Online Access:Get full text
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Summary:The allowable strain in fibre reinforced polymers reinforcement is limited by design codes to avoid debonding. The near-surface mounted (NSM) reinforcement technique has been proven to produce better anchorage behaviour compared to externally bonded reinforcement solutions. However, NSM solutions do not always eliminate debonding issues, with concrete cover detachment (CCD) typically occurring in RC beams strengthened for flexure. This experimental study investigated the efficiency of side mounted (S) compared to bottom mounted (B) NSM bars to prevent CCD. The experimental results were compared to models available in the literature that predict the observed failure modes and the crack spacing in the NSM anchorage zone. Compared to B-NSM, the S-NSM solution was successful in avoiding brittle CCD failure and showed increased rotational capacity and energy dissipation at failure. Existing CCD debonding models were found to be conservative.
ISSN:1359-8368
1879-1069
1879-1069
DOI:10.1016/j.compositesb.2018.05.011