1 m1 miura mechanical characteristics of chemically deteriorated cement based composites...
TRANSCRIPT
1
M1 Miura
Mechanical characteristics of chemically deteriorated cement based composites化学的に劣化したセメント系複合材料の力学特
性
＜ 2009/1/21＞
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Today’s Contents
1. Background
2. Purpose
3. Experimental Overview
4. Experimental Result
5. Conclusion
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1, BACKGROUNDHeretofore,①Strength doesn’t change due to eluviation
②Reduction of strength occurs due to eluviation
Evaluation of eluviation was not conducted by the unified approach
Then,It is necessary to comprehend whether eluviation could affect mechanical characteristics or not.
Advance prediction of degradationif eluviation could reduce mechanical characteristics...
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2, PURPOSEPURPOSE-1
PURPOSE-2
Comprehend the relation between eluviation and mechanical characteristicsEvaluate the transformation of mechanical characteristics after decreasing Hydrate
Identify the tensile softening diagram of mortar and cement-paste
Evaluate tensile softening diagram in meso scale after the eluviation
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3, Experimental OVERVIEW
PROPERTYPROPERTY
･ CH (Calcium Hydrate)
･ CSH(CalciumSilicate
Hydrate)
Mechanics･ Bending strength
･ Tensile strength
･ Elastic modulus
･ Fracture Energy
ImmersioImmersionn
1 2BendinBending testg test
3AnalysiAnalysi
ss
4ChemicChemic
al al analysianalysi
ss
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ResultResult
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Experimental PARMETER
Duration ：0,5,10day,0.5,1,1.5,2month
Parameter-① Duration of immersionMake a difference of degree of eluviation
MORTAR or PASTE
Parameter-② Variation of specimenComprehend the effect of aggregate
(6 specimens in the same condition)
― Mechanical characteristics― Tensile Softening Diagram― Degradation phenomenon
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Experimental CONDITION
NaCL-solution
CL-
→10g/L
Volume ： 500mL
Solution
Specimen
MORTAR 0.6 ：1 ： 3
PASTE 0.6 ：1：－
W ：C： S
Size
70×30×5mm3
Environment20℃
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Bending test•3-point bending test
•Notch （ about1mm ）•Drying condition
SpecimenNotch
Test environment
Experimental CONDITION
50mm
5mm
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4, Experimental RESULT4-1 Mechanical characteristics
…for bending test
& analysis
…for analysis4-2 Tensile Softening Curve
4-3 The amount of Hydrate…for chemical analysis
4-4 Relation to the results of analysis
45days0days
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Mechanical characteristics4-1
0
1
2
3
4
5
σb
N/m
m（
2 ）
0day5day10day15day30day45dayaverage
0
2500
5000
7500
10000
12500
15000
17500
20000
EN/m
m（
2 ）0.0
0.5
1.0
1.5
2.0
2.5
3.0
f tN/m
m（
2 ）
0
3
6
9
12
15
0 10 20 30 40 50 60day
σb
N/m
m2
（）
0
5000
10000
15000
20000
25000
30000
35000
0 10 20 30 40 50 60
day
EN/m
m（
2 ）
0.0
1.0
2.0
3.0
4.0
5.0
6.0
0 10 20 30 40 50 60
day
ftN/m
m2
（）
Cement-paste -50% -25% -50% MORTAR -50% -20% -25%
σb E ft~45days~
Cement-paste
Mortar
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Tensile Softening Curve4-2
0.0
0.5
1.0
1.5
2.0
2.5
3.0
0.00 0.02 0.04 0.06 0.08 0.10crack width (mm)
ft (N/m
m2)
2系列30ave45ave
0day30day ave45day ave
0.00 0.02 0.04 0.06 0.08 0.10crack width (mm)
0ave30ave
2系列
0day30day ave45day ave
0.00 0.02 0.04 0.06 0.08 0.10crack width (mm)
0ave2系列
4ave
0day ave30day45day ave
0.0
1.0
2.0
3.0
4.0
5.0
6.0
0.00 0.02 0.04 0.06 0.08 0.10crack width (mm)
ft (N/m
m2)
0.00 0.02 0.04 0.06 0.08 0.10crack width (mm)
0.00 0.02 0.04 0.06 0.08 0.10crack width (mm)
Cement-paste linearly curve
Mortar nonlinearly curve
ft
-50%
Crack width
-20%ft
-25%
Crack width
+100%
~45days~
~45days~
Gf
+25%
Gf
-25%
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4-3The amount of Hydrate
Cement-paste
Mortar
0%
20%
40%
60%
80%
100%
0 10 20 30 40 50 60day
CSH (
%)
0%
5%
10%
15%
20%
25%
0 10 20 30 40 50 60day
CH (
%)
0day 5day10day 15day30day 45dayaverage
0%
2%
4%
6%
8%
10%
0 10 20 30 40 50 60day
CH
(%)
0%
20%
40%
60%
80%
100%
0 10 20 30 40 50 60day
CSH (
%)
CSH
-75%
CH
-60%
CSH
-25%
CH
-50%
~45days~
~45days~
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4-4Relation to the results of analysis
CH
CSH
ft : ◎
E : ○
Gf : △
~relationship~
CH
5 10 15 20
0.2
0.4
0.6
0.8
1
1.2
0CH減少量 (%)
5 10 15 20
0.2
0.4
0.6
0.8
1
1.2
0CH減少量 (%)
20 40 60 80 100
0.2
0.4
0.6
0.8
1
1.2
0CSH減少量 (%)
20 40 60 80 100
0.2
0.4
0.6
0.8
1
1.2
0CSH減少量 (%)
20 40 60 80 100
0.2
0.4
0.6
0.8
1
1.2
0CSH減少量 (%)
ft/ft
o
E/E
o
Gf/G
fo
ft/ft
o
E/E
o
Gf/G
fo
5 10 15 20
0.2
0.4
0.6
0.8
1
1.2
0CH減少量 (%)
― mortar- - - cement-paste
ft : ◎
E : ○
Gf : △
~relationship~
CSH
The amount of CH decreasing (%) The amount of CH decreasing (%) The amount of CH decreasing (%)
The amount of CSH decreasing (%) The amount of CSH decreasing (%) The amount of CSH decreasing (%)
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5, Conclusion
Conclusion-1 Eluviation’s effectIdentify tensile softening curve of cement-paste and mortar immersed NaCl solution.
Clarify that the eluviation could influence mechanical characteristics of cement-paste and mortar in meso-scale.
Conclusion-2 Hydrate’s existenceDecreasing CH and CSH tends to go down Tensile strength, Elastic modulus and Fracture energy. Especially, Tensile strength has a strong relationship. On the other hands, if almost all CSH decrease, Fracture energy increases more than healthy cement-paste.
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Thank you for
Your kind attention!!
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Mechanical characteristics付録 1
0
1
2
3
4
5
0 0.1 0.2 0.3 0.4 0.5 (mm)変位
(N
/mm
2)応
力
1系列30ave45ave
0日30日平均45日平均
0
1
2
3
4
5
0 0.1 0.2 0.3 0.4 0.5 (mm)変位
(N
/mm
2)応
力
0ave1系列
45ave
0日平均30日45日平均
0
1
2
3
4
5
0 0.1 0.2 0.3 0.4 0.5 (mm)変位
(N
/mm
2)応
力
0ave30ave
1系列1系列1系列2系列
0日平均30日平均45日
0
3
6
9
12
15
0 0.1 0.2 0.3 0.4 0.5 (mm)変位
N
/mm
2)応
力（
0
3
6
9
12
15
0 0.1 0.2 0.3 0.4 0.5 (mm)変位
N
/mm
2)応
力（
0
3
6
9
12
15
0 0.1 0.2 0.3 0.4 0.5 (mm)変位
N
/mm
2)応
力（
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Analysis Data
付録2
0
20
40
60
80
100
0 10 20 30 40 50 60
day
Gf
J/m
2（
）
0
10
20
30
40
50
60
0 10 20 30 40 50 60
day
Gf（
J/m
2）
0日 5日 10日 15日
30日 45日 平均
0.0
0.1
0.2
0.3
0.4
0.5
0 10 20 30 40 50 60
day
Vol
ume
of s
alt
kg/m
3（
）
0.0
0.1
0.2
0.3
0.4
0.5
0 10 20 30 40 50 60
day
Vol
ume
of s
alt
kg/m
3（
） 0日 30日45日 平均値