Strength Properties of Self-compacting Mortar Mixed With GGBFS
Rheology of Self-compacting concrete mortar phase
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Transcript of Rheology of Self-compacting concrete mortar phase
Luiz A Pereira de Oliveira, Miguel C. S. Nepomuceno and José C. M. Carvalho
C_MADE Centre of Materials and Building Technologies
University of Beira Interior, Covilhã, Portugal webpage: http://www.c-made.ubi.pt/
Twin International Conferences 2nd Civil Engineering & 5th Concrete Future
26-28 May 2013, Covilha, Portugal
5th International Conference on Concrete Future
26-28 May 2013, Covilhã, Portugal
1- Introduction SCC fresh properties required
Filling capacity Segregation resistance Passing ability
Slump-flow test (Yield stress)
L –box test
V-funnel test (Viscosity)
SCC = mortar + coarse aggregates (60%-70%) (30%-40%)
Mortar phase
Modelling the rheological
behaviour of SCC
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portland cement (CEM I 42.5R) specific gravity of 3.14 mineral additions: limestone powder specific gravity of 2.72, biomass ash specific gravity of 2.85, glass powder specific gravity of 2.53. modified polycarboxylic based superplasticizer density of 1.05 fine aggregate crushed granite specific gravity of 2.71
fineness modulus of 2.52.
Materials
2- Experimental Program
Mix proportions and powder materials
Ref. Mixtures CEM I 42,5R (C)
Biomass ash (BI)
Limestone powder
(FC)
Glass powder
(GL)
1 100C 1.00 --- --- ---
2 80C+20BI 0.80 0.20 --- ---
3 80C+20FC 0.80 --- 0.20 ---
4 60C+40FC 0.60 --- 0.40 ---
5 80C+20GL 0.80 --- --- 0.20
6 60C+40GL 0.60 --- --- 0.40
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5th International Conference on Concrete Future
26-28 May 2013, Covilhã, Portugal
Methods /Studies in concrete mortar
30
270 mm
60
240
mm
29
V-funnel test Spread test
Ø 70 mm
59
mm
Ø 100 mm
Dimensions of spread and v-funnel tests
1D
DmGm
2
0
t
10Rm
2- Experimental Program
Mortars were produced combining each mixture of powder materials with a constant Vp/Vs =0.70
On average, for each combination of powder materials, three mortars were produced, varying the Vw/Vp and Sp/p% until required fresh properties were obtained.
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5th International Conference on Concrete Future
26-28 May 2013, Covilhã, Portugal
The experimental procedure is shown schematically
Mortar fresh properties
0,00
0,20
0,40
0,60
0,80
1,00
1,20
1,40
1,60
1,80
2,00
0,00 1,00 2,00 3,00 4,00 5,00 6,00 7,00 8,00 9,00 10,00
Gm
Rm
Increase of Sp/p% with constant value of Vw/Vp
Increase of Vw/Vp
Increase of Sp/p%
Sp/p% = constant
Vw/Vp = constant
Target assumed in this
research work
Mortar fresh properties
0,00
0,20
0,40
0,60
0,80
1,00
1,20
1,40
1,60
1,80
2,00
0,00 1,00 2,00 3,00 4,00 5,00 6,00 7,00 8,00 9,00 10,00
Gm
Rm
Increase of Vw/Vp with constant value of Sp/p%
Increase of Vw/Vp
Increase of Sp/p%
Sp/p% = constant
Vw/Vp = constant
Target assumed in this
research work
Methods /Studies in concrete mortar
2- Experimental Program
• Gm between 5.4 and 6.2 (Dm between 253 and 268 mm) • Rm between 1.14 and 1.32 s-1
(t between 7.58 e 8.77 s)
Rm and Gm when Vw/Vp increases with Sp/p% constant Rm and Gm when Sp/p% increases with Vw/Vp constant
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5th International Conference on Concrete Future
26-28 May 2013, Covilhã, Portugal
Methods /Studies in concrete mortar
2- Experimental Program
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5th International Conference on Concrete Future
26-28 May 2013, Covilhã, Portugal
Results of fresh properties of mortars inside the admissible range for Gm and Rm
3- Experimental Results and Discussion
Mixtures Mortar proportions
(in weight) W/B ratio Vw/Vp Sp/P%
100C 1.00:1.23 0.278 0.90 1.70
80C+20BI 1.00:0.23:1.54 0.292 0.90 1.80
80C+20FC 1.00:0.22:1.54 0.262 0.80 1.45
60C+40FC 1.00:0.58:2.05 0.269 0.85 1.55
80C+20GL 1.00:0.24:1.54 0.305 0.92 1.60
60C+40GL 1.00:0.54:2.05 0.311 0.90 1.45
Vp/Vs = 0.70
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5th International Conference on Concrete Future
26-28 May 2013, Covilhã, Portugal
Torque versus velocity
3- Experimental Results and Discussion Concrete mortar rheological behaviour
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5th International Conference on Concrete Future
26-28 May 2013, Covilhã, Portugal
Breakdown detail of different mortars
3- Experimental Results and Discussion Concrete mortar rheological behaviour
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5th International Conference on Concrete Future
26-28 May 2013, Covilhã, Portugal
3- Experimental Results and Discussion
Yield stress Plastic viscosity Shear rate
Bingham model Herschel-Bulkley model
b model parameter indicating the degree of non Newtonian behaviour
b > 1 shear-thickening behaviour b < 1 shear-thinning behaviour
Modelling the concrete mortar rheological behaviour
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5th International Conference on Concrete Future
26-28 May 2013, Covilhã, Portugal
Mixtures Bingham Model R2 Herschel–Bulkley Model R2
100C T=-7.372 + 0.994 N 0,979 T=14.83 + 0.045N1.60 0,995
80C+20BI T=15.646+ 1,313N 0,929
80C+20FC T=-0.645 + 0.544N 0,910 T=3.42 + 0.273N1.13 0,994
60C+40FC T=-1.121 + 0.386N 0,993 T=0.80 + 0.205N1.12 0,995
80C+20GL T=-4.142 + 0.779N 0,986 T=6.72 + 0.140N1.33 0,994
60C+40GL T=0.310 + 0.061N 0,978 T=2.54 + 0.001N1.76 0,989
Models equations and correlations values R2
3- Experimental Results and Discussion Modelling the concrete mortar rheological behaviour
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Relative flow area as function of powder addition percentage
Relative flow velocity as function of powder addition percentage
3- Experimental Results and Discussion
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26-28 May 2013, Covilhã, Portugal
Relative yield stress as function of powder addition percentage
Relative plastic viscosity as function of powder addition percentage
3- Experimental Results and Discussion
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5th International Conference on Concrete Future
26-28 May 2013, Covilhã, Portugal
Relative flow area versus relative yield stress
Relative flow velocity versus relative plastic viscosity
3- Experimental Results and Discussion
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26-28 May 2013, Covilhã, Portugal
Conclusions
The influence of waste glass powder on rheological behaviour of self-compacting mortar phase was studied comparatively with the most common powder addition employed in SCC, the limestone powder.
The increase of glass powder reduces the hysteresis area denoting a reducing in the thixotropy of mixtures.
Indifferently of the powder type the relative flow area was affected by the percentage of powder addition in the mixtures.
The increase of powder addition was also responsible by the relative yield stress decreasing.
The relative flow velocity was reduced at high percentage of glass powder addition and this powder type was also responsible by the lowers relatives’ plastic viscosity.
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