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Thesis Jj Gaitero

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PhD dissertation

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Thesis Jj Gaitero

  1. 1. Multi-scale study of the fibre-matrix interface and calcium leaching in high performance concrete Juan J. Gaitero 2008
  2. 2. I wanna be a researcher
  3. 3. What’s a PhD. Thesis? Doctoral thesis 2008 ?
  4. 4. A thesis is not studying…
  5. 5. … is learning
  6. 6. A thesis is not the solution…
  7. 7. the problem … is solving
  8. 8. A thesis is not the results… A thesis is not the results… 0 100 200 300 400 Thousands of Years Before Present CO 2 Source: Petit et al. 1999 to 3310m Temperature
  9. 9. … is the conclusions GLOBAL WARMING
  10. 10. What do I need ?
  11. 11. Knowledge
  12. 12. October 2002
  13. 13. October 2002
  14. 14. October 2002
  15. 15. Now Now Now Now Now
  16. 16. MACRO -scale >1mm 20 mm
  17. 17. Micro-scale 20  m
  18. 18. Nano - scale HD-CSH LD-CSH 5 nm
  19. 19. Nano - scale Calcium Hidrogen Silicon Oxygen
  20. 20. Porosity 0 1 2 3 4 5 6 7 8 9 10 (×1 0 -1 mm)
  21. 22. Problems: Fibre push-in test Calcium leaching (2004-2008) (2003)
  22. 24. 0 10 20 30 40 50 60 0 250 500 750 1000 1250 Displacement (nm) Load (mN) Loading Reloading
  23. 26. 0 20 40 60 0 200 400 600 800 1000 Displacement (nm) Load (mN) Total Disp. Penetration Sliding
  24. 27. 0 50 100 150 200 250 Sliding displacement (nm) Load (mN) 0 20 40 60 80 100 120 Model 1:  =33.1 MPa;  u =32.0 MPa; F d = 0.0 mN Model 2:  =35.8 MPa; F d =7.1 mN ; F r =3.5 mN Model 3:  =28.8 MPa;  S =35.0 MPa;  = 0.82 Experimental
  25. 32. Conclusions: Interesting technique Good models Experimental problems
  26. 33. Conclusions: Interesting technique Good models Experimental problems
  27. 34. Conclusions: Interesting technique Good models Experimental problems
  28. 35. Conclusions: Interesting technique Good models Experimental problems
  29. 36. Problems: Fibre push-in test Calcium leaching (2003) (2004-2008)
  30. 37. Intact Degraded Lixiviado de calcio
  31. 38. It is real
  32. 39. Silica nanoparticles: Purity Size Reactivity Availability pH
  33. 40. 10 Nanosilicas + 2 Cements X Several Formulations = > 1000 Specimens
  34. 41. Samples 1x1x6cm Cem I - 52.5R; w/c=0.4 6 wt.% of nanosilica 4 nanosilicas Dry Powder 95 ----------- ---- 1400 Nyasil 20 Colloid. Disp. 40 Na 2 O 9.5 20 Bindzil 40/170 Colloid. Disp. 20 NH 3 10 120 Aerodisp W7520 Colloid. Disp. 45 Na 2 O 10 30 Levasil 100/45% Presentation SiO2 content (wt.%) Estabilizing agent pH Particle size (nm) Comercial nanosilica
  35. 42. Day 0: Mixing & casting. Day 1: Demoulding Immersion in CaO solution. Tests Day 7: Control tests. Day 28: Reference tests Immersion in NH 4 NO 3 6M. Day 28+9, 28+21, 28+42, 28+63: Study.
  36. 43. Multi-scale approach
  37. 44. Complementary Available Useful Techniques
  38. 45. Macro-scale <ul><ul><ul><li>Mechanical tests </li></ul></ul></ul><ul><ul><ul><li>Calorimetry </li></ul></ul></ul><ul><ul><ul><li>SEM-EDS </li></ul></ul></ul><ul><ul><ul><li>Hg intrusion porosimetry </li></ul></ul></ul><ul><ul><ul><li>Nanoindentation </li></ul></ul></ul><ul><ul><ul><li>X-ray diffraction </li></ul></ul></ul><ul><ul><ul><li>X-ray fluorescence </li></ul></ul></ul><ul><ul><ul><li>29 Si MAS NMR </li></ul></ul></ul>Micro-scale Atomic-scale
  39. 47. Time Evolution Length Scale
  40. 48. Hydration Degradation Time Evolution Length Scale
  41. 49. Hydration Degradation Macro-scale Atomic-scale Macro-scale Time Evolution Length Scale
  42. 50. Hydration Degradation Macro-scale Atomic-scale Macro-scale Time Evolution Length Scale
  43. 51. Measured by Jeffrey J. Thomas, ACBM (USA) Reference Nanosilica 3 wt.% Nanosilica 6 wt.% Calorimetry
  44. 52. Reference Nanosilica 1 Day 7 Days 28 Days 25 52 67 39 70 85 Compressive Strength (MPa)
  45. 53. Reference Nanosilica 1 Day 7 Days 28 Days 25 52 67 39 70 85 Compressive Strength (MPa)
  46. 54. Pore Volume (ml/kg) 120 1 Day 28 Days 100 60 30 Reference Nanosilica
  47. 55. Peak Area (cts × º2q) 1 Day 7 Days 28 Days 6 9 13 11 17 20 Reference Nanosilica
  48. 56. 6 wt.% Nanoindentation Collaboration with Prof. Shah, ACBM (USA) 18 wt.% 6wt% Nanosilica Rel. Vol. E(GPa) Rel. Vol. E(GPa) Property 39 19 44 17 LD-CSH 50 27 37 24 HD-CSH
  49. 57. 6 wt.% Nanoindentation Collaboration with Prof. Shah, ACBM (USA) 18 wt.% 6wt% Nanosilica Rel. Vol. E(GPa) Rel. Vol. E(GPa) Property 39 19 44 17 LD-CSH 50 27 37 24 HD-CSH
  50. 58. 6 wt.% Nanoindentation Collaboration with Prof. Shah, ACBM (USA) 18 wt.% 6wt% Nanosilica Rel. Vol. E(GPa) Rel. Vol. E(GPa) Property 39 19 44 17 LD-CSH 50 27 37 24 HD-CSH
  51. 59. 29 Si MAS-NMR Calcium Hidrogen Silicon Oxygen
  52. 60. -120 -110 -100 -90 -80 -70 -130 Q 0 Q 1 Q 2 Q 3 O H S i O H H O H O O S i O H O H O O H S i O H O H S i O H H O H O O H S i O H O H O O S i O H O O H S i O H O H S i O H H O H O O H S i O H O H O O H S i O H O O S i O O S i S i O H H O O H S i H O H O H O O H O H H O -60 Q 4
  53. 61. 28 Days 1 Day Reference Nanosilica Q 0 Q 1 Q 2 Q 0 Q 1 Q 2 Q 4 -120 -100 -80 -60 -120 -100 -80 -60
  54. 62. 28 Days 1 Day Reference Nanosilica Q 0 Q 1 Q 2 Q 0 Q 1 Q 2 Q 4 -120 -100 -80 -60 -120 -100 -80 -60
  55. 63. 28 Days 1 Day Reference Nanosilica Q 0 Q 1 Q 2 Q 0 Q 1 Q 2 Q 4 -120 -100 -80 -60 -120 -100 -80 -60
  56. 64. 28 Days 1 Day Reference Nanosilica Q 0 Q 1 Q 2 Q 0 Q 1 Q 2 Q 4 -120 -100 -80 -60 -120 -100 -80 -60
  57. 65. Hydration Degradation Macro-scale Atomic-scale Macro-scale Time Evolution Length Scale
  58. 66. Hydration Degradation Macro-scale Atomic-scale Macro-scale Time Evolution Length Scale
  59. 67. Reference Nanosilica Compressive Strength (MPa) 85 67 74 0 Days 9 Days 21 Days 63 Days 16 24 10 21 7
  60. 68. Reference Nanosilica Compressive Strength (MPa) 85 67 74 0 Days 9 Days 21 Days 63 Days 16 24 10 21 7
  61. 69. Reference Nanosilica Compressive Strength (MPa) 85 67 74 0 Days 9 Days 21 Days 63 Days 16 24 10 21 7
  62. 70. Pore Volume (ml/kg) Reference Nanosilica 0 Days 9 Days 21 Days 63 Days 602 350 31 60 45 356 292 526
  63. 71. Pore Volume (ml/kg) Reference Nanosilica 0 Days 9 Days 21 Days 63 Days 602 350 31 60 45 356 292 526
  64. 72. Pore Volume (ml/kg) Reference Nanosilica 0 Days 9 Days 21 Days 63 Days 602 350 31 60 45 356 292 526
  65. 73. Strength vs. Porosity 0 0 0,2 0,4 0,6 0,8 Pore volume (ml/g) Reference Nanosilica 40 80 120 Strength (MPa)
  66. 74. 0 Days 9 Days 21 Days 63 Days C/S Reference Nanosilica 3.2 2.4 1.4 2.3 0.9 1.0 0.7 0.9
  67. 75. 0 Days 9 Days 21 Days 63 Days C/S Reference Nanosilica 3.2 2.4 1.4 2.3 0.9 1.0 0.7 0.9
  68. 76. 0 Days 9 Days 21 Days 63 Days C/S Reference Nanosilica 3.2 2.4 1.4 2.3 0.9 1.0 0.7 0.9
  69. 77. 0 Days 9 Days 21 Days 63 Days C/S Reference Nanosilica 3.2 2.4 1.4 2.3 0.9 1.0 0.7 0.9
  70. 78. 0 0,2 0,4 0,6 0,8 0 0,5 1 1,5 2 2,5 3 3,5 C/S Porosity (ml/g) Porosity vs. C/S Reference Nanosilica
  71. 79. Strength vs. C/S 0 25 50 75 100 0 0,5 1 1,5 2 2,5 3 3,5 C/S Strength (MPa) Reference Nanosilica
  72. 80. E (GPa) Reference Nanosilica Nanoindentation Measured by Wenzhong Zhu, ACM (UK) 7.1-24 4.6-14 42 26 20 0 3.6 2.3 42 27 19 0 HD-CSH LD-CSH Deg. Time (Days)
  73. 81. E (GPa) Reference Nanosilica Nanoindentation Measured by Wenzhong Zhu, ACM (UK) 7.1-24 4.6-14 42 26 20 0 3.6 2.3 42 27 19 0 HD-CSH LD-CSH Deg. Time (Days)
  74. 82. E (GPa) Reference Nanosilica Nanoindentation Measured by Wenzhong Zhu, ACM (UK) 7.1-24 4.6-14 42 26 20 0 3.6 2.3 42 27 19 0 HD-CSH LD-CSH Deg. Time (Days)
  75. 83. 0 0,5 1 0 2 4 6 8 10 Position (mm) Degraded Intermediate Undegraded 0 1 C/S 0,5 Reference Nanosilica
  76. 84. 29 Si MAS-NMR Q 0 Q 1 Q 2 Reference 0 Days -120 -100 -80 -60
  77. 85. 29 Si MAS-NMR Q 0 Q 1 Q 2 Q 3 Reference 9 Days -120 -100 -80 -60
  78. 86. 29 Si MAS-NMR Q 0 Q 1 Q 2 Q 3 Reference 21 Days -120 -100 -80 -60
  79. 87. Reference 29 Si MAS-NMR Q 1 Q 2 Q 3 42 Days -120 -100 -80 -60
  80. 88. Calcium Hidrogen Silicon Oxygen
  81. 92. 29 Si MAS-NMR Q 0 Q 1 Q 2 0 Days Nanosilica -120 -100 -80 -60
  82. 93. 29 Si MAS-NMR Q 0 Q 1 Q 2 9 Days Nanosilica -120 -100 -80 -60
  83. 94. 29 Si MAS-NMR Q 0 Q 1 Q 2 Q 3 21 Days Nanosilica -120 -100 -80 -60
  84. 95. 42 Days Nanosilica 29 Si MAS-NMR -120 -100 -80 -60 Q 0 Q 1 Q 2 Q 3
  85. 96. Conclusion
  86. 101. I wanna be a researcher
  87. 102. Conclusion Knwoledge
  88. 105. Future Work
  89. 107. Reduction of the calcium leaching rate of cement paste by addition of silica nanoparticles , Cem. Concr. Res., 38 (8-9) 1112-1118 (2008) AFM study of the early corrosion of a high strength steel in a diluted sodium chloride solution , Cor. Sci., 50 (7) 1820-1824 (2008) Silica nanoparticle addition to control the calcium-leaching in cement-based materials , Physica Status Solidi (a), 203 (6) 1313-1318 (2006) Atomic force microscopy and nanoindentation of cement pastes with nanotube dispersion , Phys. Status Solidi (A), 203 (6) 1076-1081 (2006) Multi-scale approach to the study of cement pastes: calcium leaching, a case of study , (Submitted)
  90. 108. Reduction of the calcium leaching rate of cement paste by addition of silica nanoparticles , Cem. Concr. Res., 38 (8-9) 1112-1118 (2008) AFM study of the early corrosion of a high strength steel in a diluted sodium chloride solution , Cor. Sci., 50 (7) 1820-1824 (2008) Silica nanoparticle addition to control the calcium-leaching in cement-based materials , Physica Status Solidi (a), 203 (6) 1313-1318 (2006) Atomic force microscopy and nanoindentation of cement pastes with nanotube dispersion , Phys. Status Solidi (A), 203 (6) 1076-1081 (2006) Multi-scale approach to the study of cement pastes: calcium leaching, a case of study , (Submitted) [email_address] www.nanoc.info www.labein.es

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