1994 Fiscal Year Final Research Report Summary
Size Effect in Concrete Structures Reinforced with New Materials
| Project/Area Number |
05650433
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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 | Nagoya University |
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Principal Investigator |
NIWA Junichiro Nagoya University, School of Engineering, Associate Professor, 工学部, 助教授 (60164638)
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| Project Period (FY) |
1993 – 1994
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| Keywords | New Materials / Size Effect / Fracture Mechanics / Shear Strength / Flexual Strength / Fictitious Crack Model / Lattice Model / Fracture Energy |
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| Research Abstract |
The aim of this research is to make a model for the resisting mechanism of concrete structure reinforced with fiber reinforced plastics, such as CFRP,AFRP and GFRP.
Using the fictitious crack model in which a newly developed rod element is incorporated, finite element analysis has been carried out. According to the analysis, it is predicted that the shear strength of concrete beams reinforced with FRP rods will be reduced with the decrease in the stiffness of longitudinal reinforcements. In addition, the shear strength of concrete beams reinforced with FRP rods shows the significant size effect as well as concrete beams reinforced with steel bars. These results have been summarized and published in several journals.
In addition to the fracture mechanics approach, nonlinear lattice model, that is a kind of macroscopic mechanical model, has been newly developed. In this model, the shear resisting mechanism is considered as the summation of truss mechanism and arch mechanism. Using this model, the decrease in the shear strength due to the decrease in the stiffness of longitudinal reinforcements and also the significant size effect in the shear strength can be predicted reasonably. These observations have been published in several journals.
Finally, the size effect in the flexural strength of concrete beams has been examined. Considering the initial stress distribution due to the shrinkage and also the actual fracture parameters, such as fracture energy of concrete, the change of the flexural strength of concrete beams and the size effect can be predicted accurately by the fracture mechanics approach.
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