dc.contributor.advisor |
Gamage JCPH |
|
dc.contributor.author |
Perera UND |
|
dc.date.accessioned |
2020 |
|
dc.date.available |
2020 |
|
dc.date.issued |
2020 |
|
dc.identifier.citation |
Perera, U.N.D. (2020). Study on the performance of CFRP strengthened corroded steel members [Master's theses, University of Moratuwa]. Institutional Repository University of Moratuwa. http://dl.lib.uom.lk/handle/123/21358 |
|
dc.identifier.uri |
http://dl.lib.uom.lk/handle/123/21358 |
|
dc.description.abstract |
Most of the metallic structures such as offshore platforms and railway bridges are now in the
need of retrofitting due to corrosion. One of the efficient ways of strengthening these structures
is by using (Carbon Fibre Reinforced Polymer) CFRP materials. Since the weakest link in this
system is the bond between the adherends, the effect of pre-corrosion level of the steel
elements on the bond characteristics and durability performance of the strengthened units
should be properly evaluated. Even though there are many research studies on bond durability
none of them has used corroded steel plates for bond strength evaluation and considered the
inherent surface characteristics of the corroded steel surfaces. Therefore, this study aimed at
investigating the bond performance of CFRP bonded corroded steel plates which are subjected
to different ageing conditions and surface roughness characteristics.
A total of one hundred and twenty-eight conditioned and non-conditioned double strap joint
specimens were tested. Both corroded and non-corroded steel plates and two different surface
preparation methods were used to witness the importance of the surface texture properties.
Scanning Electronic Microscopic (SEM) analysis was carried out to determine the surface
characteristic properties of the corroded/non-corroded steel plates. The short-term bond
performance was evaluated along with different bonding configurations. In the long-term
analysis, six different environmental exposures; seawater, wet/dry cycles, open tropical
environment, and distilled water at three different temperature levels, 25
o
C -30
C and
3
o
C were considered for conditioning. Residual bond strengths of the conditioned test
specimens were evaluated after 6- and 12-month exposure periods at ambient temperature. A
numerical model was developed to estimate the stress-strain variation of CFRP/steel
specimens along the bond line. Bond-slip curves were evaluated to estimate the interfacial
fracture energy of CFRP/steel composites. Moreover, experimental results were compared
with the analytical results obtained from Hart-Smith model and a theoretical relationship
between the failure modes was derived.
Test results indicated a major influence of surface roughness on the long-term performance of
CFRP/steel joints. CFRP strengthened corroded steel joints showed a residual bond capacity
of about 90% in seawater immersion and 111% in tropical environmental condition suggesting
its suitability to adopt CFRP technique in these exposures. After 12 months of exposure
duration, a similar bond degradation was observed of about 31% in distilled water immersed
specimens at ambient temperature and about 60% in dry/wet cyclic condition irrespective of
the pre-corrosion level. During an exposure period of 12 months, the rate of bond degradation
was found to be less than 20% for cold water immersed specimens with non-corroded steel
plates. The interfacial fracture energy of CFRP/steel composites exposed to hot humid
environments indicated a significant reduction of 78% compared to control test specimens. |
en_US |
dc.language.iso |
en |
en_US |
dc.subject |
CFRP/STEEL |
en_US |
dc.subject |
DOUBLE STRAP JOINTS |
en_US |
dc.subject |
CORRODED STEEL |
en_US |
dc.subject |
BOND PERFORMANCE |
en_US |
dc.subject |
ENVIRONMENTAL DURABILITY |
en_US |
dc.subject |
CIVIL ENGINEERING-Dissertation |
en_US |
dc.title |
Study on the performance of CFRP strengthened corroded steel members |
en_US |
dc.type |
Thesis-Full-text |
en_US |
dc.identifier.faculty |
Engineering |
en_US |
dc.identifier.degree |
Master of Philosophy |
en_US |
dc.identifier.department |
Department of Civil Engineering |
en_US |
dc.date.accept |
2020 |
|
dc.identifier.accno |
TH4869 |
en_US |