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Please use this identifier to cite or link to this item:
http://hdl.handle.net/2108/479
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| DC Field | Value | Language |
|---|
| contributor.advisor | Grimaldi, Antonio | - |
| contributor.author | Galli, Gianluca | - |
| date.accessioned | 2008-05-13T10:27:50Z | - |
| date.available | 2008-05-13T10:27:50Z | - |
| date.issued | 2008-05-13T10:27:50Z | - |
| identifier.uri | http://hdl.handle.net/2108/479 | - |
| description | 17. ciclo | en |
| description.abstract | The aim of the paper is the characterization of the mechanic properties and the constitutive
law, for the usual utilization in the design practice, of the composite Fiber reinforced
concrete material (FRC).
Nowadays in this field a great interest is represented for this material, both new structural
element construction and external application of a thin layer in old or damaged conventional
concrete elements. The addition of polymeric or steel fibers to a cementitious matrix increases
the tensile strength and provides a residual strength in tension: this condition particularly
proves, for usual content of fiber (1% - 2%), that the FRC material presents softening
branches and residual strength; on the contrary for larger content of fiber (almost 4%) the
global response of the FRC material is ductile and the dangerous phenomena of strain
localization generated near the cracks is more reduced. This condition produces the
possibility of optimal use of the new material in the structural design (also for strengthening
intervention) because it assures adequate ductility in order to dissipate the energy related
expecialy to seismic phenomena. It’s required a deep evaluation of the constitutive material
response; for the constitutive law identification the international and Italian guidelines
suggest a “prestactional” approach. In Italy the CNR DT204/2006 document proposes the
mechanical characterization with the direct traction test or the undirected 4 points flections
test. The equivalent constitutive response obtained with this method is also simplified.
In this paper the constitutive law of FRC and the influence of fibers content is evaluated with
experimental analysis for the three points flections - beams and for special traction
specimens in accordance with CNR DT 204/2006.
There are also proposed a numerical model and an analytical model that reproduce the
experimental tests; the analytical and numerical models are based on the study of a cracked
element and these models account for cracking, material non-linearity, tension-stiffening
effects and presence of slip at the interfaces (the last one assumption only for analytical
model). The numerical model allows catching bi - dimensional and three – dimensional
aspects. It’s shown a good agreement in the graphic results in the paper.
Finally, in order to define the optimum material for construction or strengthening
intervention in seismic area, the ductility of r.c. real beams in FRC or r.c. real beams
damaged for vertical and seismic actions (and then reinforced with FRC material with high
performance) is evaluated with analytical and numerical examples. | en |
| format.extent | 257049 bytes | - |
| format.mimetype | application/pdf | - |
| language.iso | it | en |
| subject | calcestruzzo fibro–rinforzato | en |
| subject | FRC | en |
| subject | duttilità | en |
| subject | softening | en |
| subject | resistenza residua | en |
| subject | fessurazione | en |
| subject | frattura | en |
| subject | legame costitutivo | en |
| subject | rinforzi strutturali | en |
| title | Modellazione analitico-numerica e comportamento sperimentale di elementi in calcestruzzo fibro-rinforzato | en |
| type | Doctoral thesis | en |
| degree.name | Dottorato in ingegneria delle strutture | en |
| degree.level | Dottorato | en |
| degree.discipline | Facoltà di ingegneria | en |
| degree.grantor | Università degli studi di Roma Tor Vergata | en |
| date.dateofdefense | A.A. 2006/2007 | en |
| Appears in Collections: | Tesi di dottorato in ingegneria
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| File |
Description |
Size | Format |
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| Titolo_indice.pdf | | 251Kb | Adobe PDF | View/Open |
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