Existing reinforced concrete (RC) structure can be strengthened upon the addition
of externally bonded high-strength light-weight fibre-reinforced polymer (FRP)
composites. An abundance of research over the last two decades has established
the effectiveness of the externally bonded FRP via extensive experimental testing.
Perhaps the most commonly occurring failure mode though is premature
debonding of the FRP and debonding generally occurs at strains well below the
strain capacity of the FRP. Debonding failures are undesirable as they are
typically brittle and represent an under-utilisation of the FRP material. A
straightforward means to prevent or at least delay debonding is by the addition of
mechanical anchors, however, research to date on anchors is extremely limited. Of
the various anchor concepts examined to date by researchers, this dissertation will
focus on anchors made from FRP which are herein referred to as FRP anchors.
The details and results of a program of research on the performance of FRP
anchors in FRP-strengthened structures are presented in this dissertation. An
extensive review of exiting literature helps establish knowledge gaps which serve
to justify the need and the scope of the research reported herein. A novel bow-tie
FRP anchor concept is then proposed and tested in smaller-scale single-shear
FRP-to-concrete joint assemblages as well as larger-scale simply-supported FRP-strengthened
RC slabs. The anchors are shown to increase the strength and slip
capacity of the joints by up to 41 % and almost 600 %, respectively, in
comparison with unanchored control joints. The anchors are then shown to
increase the load and deflection capacity of slabs by 30 % and 110 %, respectively,
above an unanchored control slab. In addition to strength, it is the ability of FRP
anchors to introduce deformability into FRP-strengthened RC slabs which is
particularly beneficial in order to produce safer structures.
An analytical model is then developed which is based on a novel quad-linear
moment-curvature response which can capture the complete load-deflection
response of the FRP-strengthened slabs anchored with FRP anchors. The
analytical modeling approach enables closed-form equations to be derived which
can then be used by design engineers to relatively easily construct load-deflections
responses and accurately predict member responses. Following the
concluding comments for the project as a whole, future research topics of
relevance are identified. / published_or_final_version / Civil Engineering / Master / Master of Philosophy
| Identifer | oai:union.ndltd.org:HKU/oai:hub.hku.hk:10722/174538 |
| Date | January 2011 |
| Creators | Hu, Shenghua, 胡盛华 |
| Contributors | Au, FTK |
| Publisher | The University of Hong Kong (Pokfulam, Hong Kong) |
| Source Sets | Hong Kong University Theses |
| Language | English |
| Detected Language | English |
| Type | PG_Thesis |
| Source | http://hub.hku.hk/bib/B47849800 |
| Rights | The author retains all proprietary rights, (such as patent rights) and the right to use in future works., Creative Commons: Attribution 3.0 Hong Kong License |
| Relation | HKU Theses Online (HKUTO) |
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