Fabric Reinforced Cementitious Matrix (FRCM) composites utilize a mineral mortar matrix as a
substitute for epoxy resin that is used for Fibre Reinforced Polymer (FRP). This eliminates issues
associated with the low thermal compatibility of FRP with concrete, susceptibility to UV radiation,
and sensitivity to high temperatures in which organic polymers undergo vitrification. This study
discussed the effect of varying parameters like the number of Carbon-FRCM (C-FRCM) layers (1,
2 and 3 layers), different anchorage configurations (non-anchored, spike anchor, wrap anchor and
mechanical anchor), bond length (300 or 200 mm), and the fabric type (unidirectional and
bidirectional) on the direct shear behaviour of C-FRCM composites bonded to a concrete substrate,
especially the fibre-matrix bond which is the most common debonding interface of FRCM
composites. Calibrated models of the bond – slip behaviour are provided based on the fabric type
and number of fabric layers.
The results indicate that the anchor type and the overall composite thickness are the main factors
that control the failure mode of the composite. All properly anchored specimens using spike and
wrap anchors failed due to fabric rupture. Moreover, a considerable number of the non-anchored
specimens failed due to composite-substrate debonding, although premature fabric rupture was
frequently observed.
Furthermore, specimens with bidirectional fabric demonstrated shallower penetration of the strain
into the composite which may be due to the horizontal fabric strands providing some anchorage
for the longitudinal strands. They also exhibited slip initiation at a higher stress compared to
unidirectional specimens. In addition, slip initiation stress of unidirectional specimens decreased
with more fabric layers which may indicate that the additional layers have a lower bond efficiency.
For the same reason, specimens with three layers of fabric generally experienced deeper strain
penetration into the composite than one-layered or two-layered specimens regardless of the anchor
type. The results also indicate that the use of bidirectional fabric and anchorage systems decreases
the strain penetration into the composite and correspondingly, the effective length is shortened.
Surface strain measurements captured using digital image correlation generally did not match the internal fabric strain values obtained from strain gauges.
| Identifer | oai:union.ndltd.org:uottawa.ca/oai:ruor.uottawa.ca:10393/45061 |
| Date | 16 June 2023 |
| Creators | Zahmak, Abdulla |
| Contributors | Noël, Martin |
| Publisher | Université d'Ottawa / University of Ottawa |
| Source Sets | Université d’Ottawa |
| Language | English |
| Detected Language | English |
| Type | Thesis |
| Format | application/pdf |
| Rights | Attribution 4.0 International, http://creativecommons.org/licenses/by/4.0/ |
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