|
|
Hokkaido University Collection of Scholarly and Academic Papers >
Theses >
博士 （工学） >
Characterizations of RC Beams Intervened by ICCP-SS System with Externally Bonded Carbon-FRCM Composites
|
Files in This Item:
|
|
|
Related Items in HUSCAP:
|
| Title: | Characterizations of RC Beams Intervened by ICCP-SS System with Externally Bonded Carbon-FRCM Composites |
| Other Titles: | 炭素 FRCM 複合材の外部接着により ICCP-SS 工法を施した RC はりの特性評価 |
| Authors: | 魏, 亮亮 Browse this author |
| Keywords: | FRCM | | ICCP | | beam | | static | | fatigue | | anodic polarization | | S-N |
| Issue Date: | 30-Jun-2020 |
| Publisher: | Hokkaido University |
| Abstract: | The development of alternative techniques for structural rehabilitation is of critical importance
to the safety and sustainability of concrete structures suffered from corrosion of steel. The structural
strengthening (SS) and impressed current cathodic protection (ICCP) are conventional methods to
improve the safety and sustainability of corroded concrete structures at different perspectives. The
SS can recover the load-carrying capacity of deteriorated concrete structures, while the ICCP can
retard the corrosion of steel in concrete. Currently, a new strategy to integrate ICCP with SS has
been proposed that is termed as ICCP-SS intervention system. Fabric reinforced cementitious matrix
(FRCM) composites have emerged as an alternative reinforcement material to fiber reinforced
polymer (FRP) composites for structural strengthening and rehabilitation. The carbon-FRCM
composite can be adopted as the dual-functional material in the ICCP-SS system in which carbon-
FRCM plays the role of reinforcement material in the SS system and of anode material in the ICCP
system. To this end, an experimental program was undertaken to propel the application and
optimization of the ICCP-SS intervention system.
This study aims to clarify the characterization of RC beams with externally bonded carbon-
FRCM under static and cyclic loading. Two carbon-FRCM composites were considered for this
research, one with multilayer carbon-FRCM (M/C-FRCM) intended for understanding the
effectiveness of carbon-FRCM in strengthening beams and one with anodically polarized carbon-
FRCM (AP/C-FRCM) for evaluating the mechanical degradation caused by anodic polarization in
the ICCP on the strengthening characterization of RC beams. From the material perspective, the
mechanical properties of both M/C-FRCM and AP/C-FRCM composites were also studied.
The first study investigates the static performance of RC beams with externally bonded M/CFRCM.
The static tensile tests of M/C-FRCM were conducted, followed by the four-point bending
tests of beams with externally bonded M/C-FRCM under static loading. Nine M/C-FRCM
specimens were prepared for tensile tests, and four beams were prepared for bending tests. The
prediction model of apparent strain of carbon fabric (CF) mesh in the M/C-FRCM was proposed
based on the global strain of carbon-FRCM in tension. The load-carrying capacity of beams with
externally bonded M/C-FRCM improved that was largely dependent on the amount of CF mesh. An
analytical study on the prediction formulas in flexure for RC beams with externally bonded carbon-
FRCM was performed by using the model of apparent strain of CF mesh. Prediction results agreed
well with the experimental results.
The second study explores the fatigue performance of RC beams with externally bonded M/CFRCM.
The cyclic tensile tests of M/C-FRCM were performed and followed by the four-point
bending tests of beams with externally bonded M/C-FRCM under cyclic loading. Nine M/C-FRCM
specimens were prepared for cyclic tensile tests, and twelve beams were prepared for cyclic bending
tests. The fatigue life model and the fatigue strength model of M/C-FRCM composites were
proposed. The fatigue life performance of carbon-FRCM was compared with steels and CFRP
composite materials. Besides, the fatigue stress limit of M/C-FRCM was recommended to be 35%
of the ultimate tensile strength. Carbon-FRCM composites significantly improved the fatigue
performance of RC beams comparing with un-strengthened beams. The S-N curve for beams with
externally bonded M/C-FRCM was proposed.
The third study examines the influence of anodic polarization on the static performance of RC
beams with externally bonded AP/C-FRCM. An accelerated electrochemical (AC-EC) test was
performed to introduce the anodic polarization to the carbon-FRCM making the AP/C-FRCM. Then,
the static tensile tests of AP/C-FRCM were conducted and followed by the four-point bending tests
of beams with externally bonded AP/C-FRCM under static loading. The tensile strength of carbon-
FRCM reduced after suffering from anodic polarization. Effectiveness of carbon-FRCM suffering
from anodic polarization in strengthening did not change before the yielding of steel and weaken
slightly as increasing the intensity of anodic polarization.
The last study detects the influence of anodic polarization on the fatigue performance of RC
beams with externally bonded AP/C-FRCM. The identical AP/C-FRCM composites were adopted
in this study. The cyclic tensile tests of AP/C-FRCM were performed and followed by the four-point
bending tests of beams with externally bonded AP/C-FRCM under cyclic loading. The combined
damage effect of the anodic polarization and cyclic loading caused an acceleration of reduction of
stiffness and decrease of fatigue life of carbon-FRCM. Based on the total experimental data, the SN
curve for beams with externally bonded fabric reinforcement by inorganic matrix was proposed.
Overall, the constitutive behavior of both M/C-FRCM and AP/C-FRCM were assessed by
static tensile tests, and the fatigue degradation characterizations of both carbon-FRCM were
evaluated through cyclic tensile tests. The fatigue life prediction models of M/C-FRCM and AP/CFRCM
were proposed based on the experimental data. The strengthening behaviors of RC beams
with externally bonded M/C-FRCM and AP/C-FRCM were investigated under static and cyclic
loading. The prediction formulas in flexure for RC beams with externally bonded carbon-FRCM
was proposed. Besides, the fatigue life of strengthened beams was predicted well based on the
proposed S-N curve. However, in future studies, the further optimization design of carbon-FRCM
is necessary to improve the mechanical behavior of itself and bond behavior with concrete substrate.
Moreover, the fatigue performance of the bond between carbon-FRCM and concrete needs to be
investigated to improve the fatigue life prediction of RC beams with externally bonded carbon-
FRCM composites. |
| Conffering University: | 北海道大学 |
| Degree Report Number: | 甲第14163号 |
| Degree Level: | 博士 |
| Degree Discipline: | 工学 |
| Examination Committee Members: | (主査) 准教授 松本 浩嗣, 教授 松本 高志, 教授 横田 弘, 教授 杉山 隆文, 教授 上田 多門 (深圳大学), 教授 Zhu Ji-Hua (深圳大学) |
| Degree Affiliation: | 工学院（北方圏環境政策工学専攻） |
| Type: | theses (doctoral) |
| URI: | http://hdl.handle.net/2115/78928 |
| Appears in Collections: | 課程博士 (Doctorate by way of Advanced Course) > 工学院(Graduate School of Engineering)
学位論文 (Theses) > 博士 （工学）
|
|
