Development of a Fiber Reinforced Self- Compacting Heavyweight Concrete by Considering the Factory Conditions

Transcription

1 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

2 Cooperation Project Kooperationsprojekt Zentrales Innovationsprogramm Mittelstand ZIM 25. Conference: "Rheology of Building Materials", Regensburg 1

3 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 25. Conference: "Rheology of Building Materials", Regensburg 2

4 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 25. Conference: "Rheology of Building Materials", Regensburg 3

5 Factory Conditions bench-scale 25. Conference: "Rheology of Building Materials", Regensburg 4

6 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 25. Conference: "Rheology of Building Materials", Regensburg 5

7 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 25. Conference: "Rheology of Building Materials", Regensburg 6

8 SCC Concept SCC typical vol.-% Components factory Density kg/m³ 10.3 Cement Fly ash Water + SP Air void 0 Paste ρ 1800 kg/m³ Composition Mortar ρ 3140 kg/m³ 28.8 Fine aggregate 0/ Aggregate Δρ 1860 kg/m³ 28.9 Coarse aggregate 4/ ρ 5050 kg/m³ Aggregate ρ 5000 kg/m³ Challenge: Difference in density Segregation Solution: Increasing paste density Iron oxide d 50 35µm ρ 5400 kg/m³ Procedures: Okamura et al. [1] DAfStb-Guideline [2] 25. Conference: "Rheology of Building Materials", Regensburg 7

9 SCC Concept Procedure Paste Saturation point (β P ) Robustness (slope) Calculated density Design of Experiments Pretesting Mixture-Design 3 components 18 runs Components Cement [vol.-%] Fly Ash [vol.-%] Powder [vol.-%] Mortar Slump V-funnel for mortar Density Design of Experiments Pretesting Central-Composite-Design 3 factors 17 runs Factors β P correction k [-] Fine aggregate [vol.-%] Superplasticizer [sp/c %] Concrete Slump-flow V-funnel for SCC Density Variation w/c Cement content Fibers Mixing process 25. Conference: "Rheology of Building Materials", Regensburg 8

10 Water [g] V w /V P [-] Mix Design Paste Methods V W /V P at saturation point (β P ) Slope as measure for robustness Calculated density with water at β P 1,3 1,2 1,1 1,0 0,9 0,8 β P Rel. spread Γ [-] Experimental design based on pretesting FA improves robustness, packing density, workability Disadvantage: FA reduces density ΔH 2 O ΔSFM (green) 280 ΔSFM (red) Slump [mm] 25. Conference: "Rheology of Building Materials", Regensburg 9

11 Mix Design Paste Results Design-Expert A: Cement [vol.-%] Software Component Coding: 60 Actual Original Scale (median estimates) Slope [-] Design Points X1 = A: Cement [vol.-%] X2 = B: Iron oxide [vol.-%] X3 = C: FA [vol.-%] Design-Expert A: Cement [vol.-%] Software Component 60 Coding: Actual Density at ß [kg/m³] Design Points X1 = A: Cement [vol.-%] X2 = B: Iron oxide [vol.-%] X3 = C: FA [vol.-%] A: Cement [vol.-%] B: Iron oxide [vol.-%] 40 ß [-] 20 C: FA [vol.-%] 60 B: Iron oxide [vol.-%] 40 Slope [-] 20 C: FA [vol.-%] 60 B: Iron oxide [vol.-%] 40 Density at ß [kg/m³] 20 C: FA [vol.-%] Numeric optimization Solution β P [-] Slope [-] Calc. density [kg/m³] with fly ash without fly ash Conference: "Rheology of Building Materials", Regensburg 10

12 Slump [mm] 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 sedimentationstable SCC? Time [s] 25. Conference: "Rheology of Building Materials", Regensburg 11

13 Mix Design Mortar Estimated max. slump of the SCC mortar τ 0 K ρ G ρ Fl d G g Stability criterion Geometry K Theoretical Jossic et al. [3] Ansley et al. [4] Bethmont et al. [5] Beris et al. [6] Vogel [7] sphere sphere (rough) sphere sphere sphere sphere π π aggregate ~0.3 Roussel et al. [8] τ 0 = 225ρ FlgΩ 2 128π 2 R 5 R = ρ Fl gω 2 τ 0 Unit Ordinary Heavy ρ G kg/m³ ρ Fl kg/m³ ρ G ρ Fl kg/m³ d G mm Conference: "Rheology of Building Materials", Regensburg 12

14 Max. slump with d G = 16 mm [mm] Mix Design Mortar ρ G = 2600 kg/m³ 300 ρ G = 5000 kg/m³ Beris Bethmont 180 theoretical 160 Jossic and Magnin Ansley and Smith 140 Vogel (sphere) Vogel (aggregate) 120 SCC mortar heavy SCC mortar Fresh mortar density ρ Fl [kg/m³] 25. Conference: "Rheology of Building Materials", Regensburg 13

15 k [ - ] V - f u n n e l [ s ] k [ - ] Mix Design Mortar Results Slump [mm] 3 Design-Expert Software Factor Coding: Actual Original Scale (median estimates) V-funnel [s] Design points above predicted value Design points below predicted 280 value X1 = A: Sand [vol.-%] X2 = C: k [-] Actual Factor B: Superplastisizer [sp/c %] = Design-Expert Software Factor Coding: Actual Fresh mortar density [kg/m³] Design Points X1 = A: Sand [vol.-%] X2 = C: k [-] Actual Factor B: Superplastisizer [sp/c %] = Fresh mortar density [kg/m³] k [-] A: Sand [vol.-%] A: Sand [vol.-%] A: Sand [vol.-%] Numeric optimization Solution Slump [mm] V-funnel [s] Density [kg/m³] with fly ash Conference: "Rheology of Building Materials", Regensburg 14

16 Mix Design Concrete Paste composition is known Mortar composition is known Last remaining unknown: proportion coarse aggregate Controlled by paste proportion - rest follows automatically 1 st basic SCC mix design With constant paste and coarse aggregate proportions: Variation mix process Variation w/c-ratio Adding steel fibers 25. Conference: "Rheology of Building Materials", Regensburg 15

17 V-funnel [s] Mix Design Concrete Results: Workability workability range SF: 60 kg/m³ (w/c) eq = 0.48 c: 320 kg/m³ 10 5 SF: 30 kg/m³ (w/c) eq = 0.53 c: 306 kg/m³ upm: normal upm: high Slump-flow [cm] Overall Slump-flow [cm] V-funnel [s] Density [kg/m³] Compressive Strength 1d [MPa] 28d [MPa] Min Max Conference: "Rheology of Building Materials", Regensburg 16

18 Mix Design Concrete Results: Segregation 25. Conference: "Rheology of Building Materials", Regensburg 17

19 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 25. Conference: "Rheology of Building Materials", Regensburg 18

20 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., Conference: "Rheology of Building Materials", Regensburg 19

21 Acknowledgment Thank you for your attention! 25. Conference: "Rheology of Building Materials", Regensburg Contact: