1994 Fiscal Year Final Research Report Summary
BEHAVIOR OF CRACK IN CONCRETE REINFORCED BY GRID-TYPE CARBON FIBER NET
| Project/Area Number |
05650436
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
土木材料・力学一般
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| Research Institution | KYUSHU UNIVERSITY |
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Principal Investigator |
MAKIZUMI Tatsunori KYUSHU UNIV., FACULTY OF ENG.ASSOCIATE PROFESSOR, 工学部, 助教授 (20136534)
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| Co-Investigator(Kenkyū-buntansha) |
TSURUTA Hiroaki KYUSHU UNIV., FACULTY OF ENG.RESEARCH ASSOCIATE, 工学部, 助手 (90253484)
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| Project Period (FY) |
1993 – 1994
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| Keywords | Carbon fiber / Continuous fiber reinforcement / Crack / Control of cracking / Anchorage / Effect of grid |
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| Research Abstract |
(1) Method for tensile test to examine the properties of Carbon Fiber Net
To examine the bihavior of crack in concrete reinforced by Carbon Fiber Net, it is necessary to understand the characteristics of materials and anchorage mechanism of fiber reinforcement. So the methods of bending test using beams with notch at the center of specimen was examined to understand them. As the results, it was possible to understand the characteristics of the materials and the anchorage mechanism by using the testing method like the case of direct tensile tests.
(2) Study on distribution of strain of Carbon Fiber Net in concrete
Strain characteristics of Carbon Fiber Net was studied by the above method under tensile loads. At first, strain gauges were attached to the center of longitudinal fiber within some meshes. In order to measure the resistance force in the transverse fibers, the longitudinal fiber strain in each mesh was measured. While the load was increasing, the changes of fiber strain were meas
… More
ured.
As the results are as follows :
a) Resistance forces were transferred to next transverse fiber in order.
b) The existence of transverse fibers that aren't necessary for anchoring don't influence the behavior of strain.
c) If fiber reinforcements have the scattering of strains, they rupture with keeping the scattering.
(3) Expression of equation that shows the anchorage mechanism of Carbon Fiber Net
The properties of strains were tried to understand quantitatively by using elastic spring model that express the effect of the grid. In this paper, to express correctly the real properties with reference to elastic spring model that suggested in the study of the past, the resistance of transverse fiber was used to the model. And this study made the following condition "If the resistance exceeds the ultimate, a displacement of grid's intersection point grow". That condition made it possible to calculate the strain that reduced like a stair. In future, we will investigate the calculating crack width by using this theory. Less
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