numerical analysis for the mechanism of deterioration of mortar by chemical attacks d2 yuji oiwa
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Numerical Analysis for the Mechanism of Deterioration of
Mortar by Chemical Attacks
D2 Yuji OIWA
![Page 2: Numerical Analysis for the Mechanism of Deterioration of Mortar by Chemical Attacks D2 Yuji OIWA](https://reader034.vdocument.in/reader034/viewer/2022051401/56649ebd5503460f94bc7608/html5/thumbnails/2.jpg)
Today’s Topics
• Background & purpose
• Last presentation
• Research results
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Background of my research
Recently, it seems that… ・ Decrease of natural aggregate resource ・ Increase of waste concrete in the future
New disposal system are developing.
Aggre
gate
resu
mpt
ion
Neutralize waste water
Functionality materialWaste concrete
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Purpose of my research
Aggre
gate
resu
mpt
ion
Neutralize waste water
Functionality materialWaste concrete
1.Clarify the mechanism of deterioration of mortar by chemical attacks2.Simulation of deterioration of mortar numerical analysis
My research associate red zone. In concrete teams,
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Purpose of my research
102 [m]
101 [m]
100 [m]
10-1 [m]
Structure
Member
Element (meso-scale)(Member=homogeneous)
(Element=homogeneous)
Verification
Constitutive model
10-2 [m]
Microscopic phenomena e.g. cracking and stress concentration can be simulated.
Because of the heterogeneity, environmental effects are easy to be introduced and combined with the mechanical action.
Chloride ion
Referenced Matsumoto paper
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0 0.02 0.04 0.06 0.08 0.10
1
2
3
4
Stress(MPa)
width(mm)
Last presentation
Our RBSM can not simulate all of 3 kind experiment (bending, compression, tension) quantitatively. Only Compression. But other 2 experiment cannot be.
Modification of constitutive law is necessary.
Constitutive law is re-evaluated.
0 0.1 0.20
100
200
ExperimentAnalysis
Laod(kg)
Displacement(mm)Bending Tension
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Last presentation
Parametric analysis
First, Tensile constitutive law is modified
Constitutive law is re-evaluated.
Kind ofanalysis
Affection of constitutive law
tension Compression Shear Variation
Tension ◎ △ △ △
Compression ○ ○ ◎ ◎
Flexure ◎ △ △ △
Tension
0 0.02 0.04 0.06 0.08 0.10
1
2
3
4
ExperimentModified model
Stress(MPa)
width(mm)Bending
0 0.1 0.20
100
200
ExperimentModified model
Laod(kg)
Displacement(mm)
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Last presentation
Other constitutive law is not determined.Because, there are multi-pairing of shear and variation.
Parametric analysisKind ofanalysis
Affection of constitutive law
tension Compression Shear Variation
Tension ◎ △ △ △
Compression ○ ○ ◎ ◎
Flexure ◎ △ △ △
Shear model changed
0 0.001 0.002 0.0030
10
20
30
40
50
0 0.001 0.002 0.0030
10
20
30
40
50
Variation put
Almost same
≒
Constitutive law is re-evaluated.
Stress(MPa)
Displacement(mm)
Stress(MPa)
Displacement(mm)
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Research results
Some problems are not solved yet.
1.Variation and shear spring model is not determined. There are multi-pairing of shear and variation.
2.My constitutive law are determined from other researchers. And three experiment data is not same mortar.
・ Experiment is necessary using same mortar in our laboratory.
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Research results
Current bending test system have some gaps ofDisplacement.
0 0.1 0.2 0.30
2
4
6
8
Displacement (mm)
fb (
MPa
)
AnalysisExperiment1Experiment2Experiment3Experiment4
Experiment Analysis
gapSteel plate
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Research resultsComparison of analysis data with good experimental data (Miura kun’s data)
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Research resultsComparison of analysis data with good experimental data (Miura kun’s data)
![Page 13: Numerical Analysis for the Mechanism of Deterioration of Mortar by Chemical Attacks D2 Yuji OIWA](https://reader034.vdocument.in/reader034/viewer/2022051401/56649ebd5503460f94bc7608/html5/thumbnails/13.jpg)
Environmental control room
Research results
Grade up universal testing machine in Q laboratory
Before After
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Research resultsFollowing box are made for setting displacement measurer.
DisplacementMeasurer
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Thank you for your kind attention !