Development of a Fiber Reinforced Self-Compacting ... Compacting Heavyweight Concrete by Considering the Factory ... Conclusion Basic mix design ... Development of a Fiber Reinforced

Development of a Fiber Reinforced Self-Compacting Heavyweight Concrete by

Considering the Factory Conditions

Entwicklung eines faserbewehrten selbstverdichtenden Schwerbetons unter Berücksichtigung der Werksbedingungen

M. Sc. Klemens Laub

Dipl.-Ing. (FH) Markus Tenwinkel Dr.-Ing. Barbara Leydolph

Dr.-Ing. Ulrich Palzer

25. Conference: "Rheology of Building Materials", Regensburg 02.03.2016

Cooperation Project Kooperationsprojekt

25. Conference: "Rheology of Building Materials", Regensburg 1

Zentrales Innovationsprogramm Mittelstand – ZIM

Objective Target of the Project Zielstellung des Projektes

“Development of a low-shrinkage, deformation-resistant, high-performance material with optimized dynamic load capacity for high-stressed ballast components of vehicles in aggressive environments” „Entwicklung eines schwindarmen, verformungsstabilen Hochleistungswerkstoffs mit optimierter dynamischer Belastbarkeit für hochbeanspruchte Ballastierungskomponenten im Fahrzeugbau in aggressiver Umgebung“


Main Approach

Deformation-resistance and dynamic load capacity

Fibers

Low dynamic E-Modulus

High tensile strength

Aggressive environment

Coating

Frame conditions:

− Density: ≥ 4000 kg/m³

− Acceptable early strength

Homogenous structure, no blowholes


Factory Conditions


bench-scale

Factory Conditions

Available and no change

1) Cement

2) Water

3) Fly ash

4) Fine aggregate

5) Coarse aggregate

6) Superplasticizer

Additional

7) Powder

8) Admixture

9) Fibers


SCC Concept

Why SCC?

High surface quality − Less rework (bubbles/blowholes)

Complete filling of: − Complex formworks

− Reinforced formworks

Fibers are more effective: − Better activation in mortar matrix

− Orientation in flow direction

No vibration: − Less noise pollution

− Less man power needed

− Less physiological stress


SCC Concept


SCC typical vol.-%

Components factory

Density kg/m³

Composition

10.3 Cement 3005 Paste

ρ ≈ 1800

kg/m³

Mortar

ρ ≈ 3140 kg/m³

10.4 Fly ash 2400

18.4 Water + SP 1000

2.4 Air void 0

28.8 Fine aggregate

0/2 5100 Aggregate

ρ ≈ 5050

kg/m³ 28.9 Coarse

aggregate 4/16

5000 Aggregate ρ ≈ 5000

kg/m³

Δρ ≈ 1860 kg/m³

Challenge:

Difference in density

Segregation

Solution:

Increasing paste density

Procedures:

Okamura et al. [1]

DAfStb-Guideline [2] Iron oxide d50 ≈ 35µm ρ ≈ 5400 kg/m³

SCC Concept

Paste

• Saturation point (βP)

• Robustness (slope)

• Calculated density

Mortar

• Slump

• V-funnel for mortar

• Density

Concrete

• Slump-flow

• V-funnel for SCC

• Density


Design of Experiments

• Pretesting

• Mixture-Design

• 3 components

• 18 runs

Design of Experiments

• Pretesting

• Central-Composite-Design

• 3 factors

• 17 runs

Variation

• w/c

• Cement content

• Fibers

• Mixing process

Procedure

Components

• Cement [vol.-%]

• Fly Ash [vol.-%]

• Powder [vol.-%]

Factors

• βP correction k [-]

• Fine aggregate [vol.-%]

• Superplasticizer [sp/c %]

Mix Design – Paste

Methods − VW/VP at saturation point (βP)

− Slope as measure for robustness

− Calculated density with water at βP

Experimental design based on pretesting − FA improves robustness,

packing density, workability

− Disadvantage: FA reduces density


ΔH2O

ΔSFM (red)

ΔSFM (green)

260

280

300

320

340

360

380

150 170 190 210 230 250

Wat

er

[g]

Slump [mm]

βP

0,8

0,9

1,0

1,1

1,2

1,3

0 1 2 3 4 5

Vw

/VP [

-]

Rel. spread Γ [-]

Mix Design – Paste

Results


Solution βP [-] Slope [-] Calc. density [kg/m³]

with fly ash 0.933 0.077 2573

without fly ash 0.953 0.051 2733

Numeric optimization

Design-Expert® SoftwareComponent Coding: ActualDensity at ß [kg/m³]

Design Points2781

2442

X1 = A: Cement [vol.-%]X2 = B: Iron oxide [vol.-%]X3 = C: FA [vol.-%]

A: Cement [vol.-%]60

B: Iron oxide [vol.-%]

60

C: FA [vol.-%]

20

0 40

40

Density at ß [kg/m³]

2500

2600

2700

Design-Expert® SoftwareComponent Coding: ActualOriginal Scale (median estimates)Slope [-]

Design Points0.092

0.044




60

C: FA [vol.-%]

20

0 40

40

Slope [-]

0.050

0.050

0.060

0.070

0.080

Design-Expert® SoftwareComponent Coding: Actualß [-]

Design Points1.068

0.821




60

C: FA [vol.-%]

20

0 40

40

ß [-]

0.900

0.920

0.940

0.960

0.980

1.000

190

195

200

205

210

215

220

225

230

0 100 200 300 400 500 600

Slu

mp

[m

m]

Time [s]

Mix Design – Mortar

Pretesting

− Constant amount stabilizer Extended mixing time

− Efficiency SP and thixotropy

− Time-dependent slump 4 points Function

Which yield point or slump is required for sedimentation- stable SCC?



Estimated max. slump

of the SCC mortar


𝜏0 ≥ 𝐾 𝜌𝐺 − 𝜌𝐹𝑙 𝑑𝐺𝑔

Roussel et al. [8]

𝜏0 =225𝜌𝐹𝑙𝑔𝛺2

128𝜋2𝑅5

𝑅 = 0.708 𝜌𝐹𝑙𝑔𝛺2

𝜏0

5

Stability criterion Geometry K

Theoretical sphere 1

18

Jossic et al. [3] sphere (rough)

1

17.2

Ansley et al. [4] sphere 4

21𝜋

Bethmont et al. [5] sphere 1

18.4

Beris et al. [6] sphere 1

21

Vogel [7] sphere

2

3𝜋

aggregate ~0.3

Unit Ordinary Heavy

𝝆𝑮 kg/m³ 2600 – 2750 5000

𝝆𝑭𝒍 kg/m³ 2000 – 2400 3200 - 3900

𝝆𝑮 − 𝝆𝑭𝒍 kg/m³ 200 – 650 1100 - 1800

𝒅𝑮 mm 16 16



SCC mortar heavy SCC mortar 100

120

140

160

180

200

220

240

260

280

300

320

340

1400 1600 1800 2000 2200 2400 2600 2800 3000 3200 3400 3600 3800 4000 4200 4400 4600

Max

. slu

mp

wit

h d

G =

16

mm

[m

m]

Fresh mortar density ρFl [kg/m³]

Beris

Bethmont

theoretical

Jossic and Magnin

Ansley and Smith

Vogel (sphere)

Vogel (aggregate)

ρG = 2600 kg/m³

ρG = 5000 kg/m³


Results


Numeric optimization

Solution Slump [mm] V-funnel [s] Density [kg/m³]

with fly ash 295 6.3 3571

Design-Expert® SoftwareFactor Coding: ActualFresh mortar density [kg/m³]

Design Points3703

3452

X1 = A: Sand [vol.-%]X2 = C: k [-]

Actual FactorB: Superplastisizer [sp/c %] = 3.875

35 38 40 43 45

0.80

0.83

0.85

0.88

0.90Fresh mortar density [kg/m³]

A: Sand [vol.-%]

k [-]

3500 3550 3600 36503

Design-Expert® SoftwareFactor Coding: ActualSlump [mm]

Design Points326

273

X1 = A: Sand [vol.-%]X2 = C: k [-]


35 38 40 43 45

0.80

0.83

0.85

0.88

0.90Slump [mm]

A: Sand [vol.-%]

k [-]

280

290300

310

3

Design-Expert® SoftwareFactor Coding: ActualOriginal Scale (median estimates)V-funnel [s]

Design points above predicted valueDesign points below predicted value10.8

3.6

X1 = A: Sand [vol.-%]X2 = C: k [-]


0.80

0.83

0.85

0.88

0.90

35

38

40

43

454.0

6.0

8.0

10.0

12.0

V

-fu

nn

el

[s

]

A: Sand [vol.-%] k [-]

Mix Design – Concrete

Paste composition is known

Mortar composition is known

Last remaining unknown: proportion coarse aggregate

Controlled by paste proportion - rest follows automatically

1st basic SCC mix design

With constant paste and coarse aggregate proportions:

Variation mix process

Variation w/c-ratio

Adding steel fibers



Results: Workability


workability range

(w/c)eq = 0.53 c: 306 kg/m³ upm: normal

SF: 30 kg/m³

SF: 60 kg/m³

(w/c)eq = 0.48 c: 320 kg/m³

upm: high

0

5

10

15

20

25

30

60 64 68 72 76 80

V-f

unnel [s

]

Slump-flow [cm]

Overall

Slump-flow [cm]

V-funnel [s]

Density [kg/m³]

Compressive Strength

1d [MPa] 28d [MPa]

Min 64.5 9.3 3936 10.8 61.5

Max 72.0 19.0 4083 13.5 76.1


Results: Segregation


Conclusion

Basic mix design for further investigations with three additional components: Powder, stabilizer, fibers

Frame conditions

Density

Workability

Segregation

Surface

Strength

Standard SCC procedures for mix design development

Handy, additional tool: Design of Experiments


Sources

[1] Okamura, H.; Ozawa, K.: Mix Design for Self-Compacting-Concrete,

Concrete Library of JSCE 25, 1995

[2] Deutscher Ausschuss für Stahlbeton (DAfStb): Selbstverdichtender Beton (SVB- Richtlinie), Beuth Verlag GmbH, 2003

[3] Jossic, L.; Magnin, A.: Traînée et Stabilité d‘Objet en Fluide à Seuil, Les Cahiers de Rhéologie, 2001

[4] Ansley, R. W.; Smith, T. N.: Motion of Spherical Particles in a Bingham Plastic, A.I.Ch.E. Journal 13, 1967

[5] Bethmont, S.; Tailhan, J.; d‘ Aloia-Schwartzentruber, L.; Rossi, P.: Role of the Granular Lattice Solid Fraction in the Stability of Self-Compacting Concrete (SCC), 5th International RILEM Symposium on Self-Compacting Concrete, 2007

[6] Beris, A. N. et al.: Creeping Motion of a Sphere through a Bingham Plastic, Journals of Fluid Mechanics, No. 158, 1985

[7] Vogel, Ruprecht: Zur Tragfähigkeit von Fluiden, R. VOGEL – FORSCHUNG, Labor für Strömungs- und Schüttguttechnik, 2004

[8] Roussel, N.; Coussot, P.: „Fifty-Cent Rheometer“ for Yield Stress Measurements: From Slump to Spreading Flow, The Society of Rheology, Inc., 2005


Acknowledgment

Thank you for your attention!

25. Conference: "Rheology of Building Materials", Regensburg Contact: [email protected]

Documents

Development of a Fiber Reinforced Self-Compacting ... Compacting Heavyweight Concrete by Considering the Factory ... Conclusion Basic mix design ... Development of a Fiber Reinforced