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Defining Surface Defects on
Concrete Horizontal Slabs, Surface
Treatments and the Remediation of
these Surface Defects
W.R...
Cementitious Technology
2
Lets start with the basics:
Definitions
Cement = Powder
Cement + Water = Paste
Paste + Sand = Mortar
Mortar + Stone = Concrete
A chemical reaction...
The chemical reaction starts a crystal-
type growth in the cement
6
BAD WATER
GOOD WATER
The Water to Cement Ratio Controls Strength.
As the W/C ratio increases, compressive
strength decreases, by as much as 50%...
Properties Effected by Water to
Cement Ratio & Curing
• Compressive Strength
• Tensile Strength
• Flexural Strength
• Abra...
Durable Concrete
• ACI 201.2R-08, “Guide to Durable Concrete”
– Outlines procedures to design and place durable
concrete.
Some Common Concrete Flatwork
Surface Issues
• Surface Scaling
• Popouts
• Dusting
• Delamination
Surface scaling
• ACI 201.1R, “Guide for Conducting a Visual
Inspection of Concrete in Service” defines
scaling as:
– loca...
Surface Scaling – Typical Causes
• Inadequate or no air entrainment. (Concrete with
proper entrained air will still scale ...
Surface Scaling – Application Hints
During Concrete Placement
• Ensure proper air-entrainment for
environment.
• Do not us...
Popouts
• ACI 201.1R, “Guide for Conducting a Visual
Inspection of Concrete in Service” defines
popouts as:
– The breaking...
22
23
24
Surface Popouts – Typical Causes
• Use of non durable aggregates.
• Improper curing.
• High degree of freezable water cont...
Surface Popouts – Application Hints
During Concrete Placement
• Ensure that the aggregate is suitable for the
environment....
Dusting
• ACI 201.1R, “Guide for Conducting a Visual
Inspection of Concrete in Service” defines
dusting as:
– The developm...
28
Dusting – Typically Causes
• Any finishing operation performed too early.
• Use of additional water on the surface.
• Inad...
Dusting – Application Hints During
Concrete Placement
• Allow concrete time to adequately bleed.
• Do not use additional w...
Delamination
• ACI 201.1R, “Guide for Conducting a Visual
Inspection of Concrete in Service” defines
delamination as:
– A ...
Delamination – Typical Causes
– Finishing the concrete too early prior bleeding or
when the concrete is still bleeding.
– ...
Delamination – Application Hints
During Concrete Placement
• Allow the concrete sufficient time to bleed.
• Be wary of con...
Preventive Chemical Treatments
• Curing Compounds
• Linseed Oil Treatments
• Curing and Sealing Compounds
• Penetrating Se...
Curing Per ACI 201.2R-6
• Will ensure strength development of paste at
surface.
• Will also decrease the porosity of concr...
Curing Compounds
• Applied after bleeding and final finishing.
• ASTM C 309 (ACI 308)
– Type I (Non-pigmented)
– Type II (...
If the cement does not get enough water, the
reaction stops and the concrete will not reach
its designed strength.
ACI 201...
42
Linseed Oil Treatments
• Linseed penetrating and anti-scaling
compound
– is a specification-grade formulation of boiled
li...
44
Curing & Sealing Compounds
• ASTM C 1315 – Acrylic / Styrene Acrylic
• Passive protective barrier
– Minimum 25% Solids Con...
46
47
48
49
Penetrating Sealers
• Governing Specification
– NCHRP 244
– ALBERTA Ministry of Transportation Specification
• Common Chem...
Penetrating Sealers
• Chemical protective barrier
– Water-based or solvent-based
– Typically is applied at 100 – 200 sq. f...
Penetrating Sealers
• High degree of protection from freezable
water and reduces salt content
• Reduces water intrusion up...
Silicates
Floor Hardener & Densifier
• Eliminates dusting in most cases.
• Penetrates and chemically reacts with the soft
...
Silicates
Floor Hardener & Densifier
• Sodium based
– Existing concrete, must be washed off.
• Lithium based
– Fresh concr...
UNTREATED
TREATED AND BURNISHED
And if all else fails...Restore
• Polymer Modified Cementitious Thin Overlay
Repair Mortars
• Self-leveling Cementitious T...
69
70
71
72
73
74
75
76
77
78
79
80
81
82
90
Self-Leveling Cementitious Toppings
• Characteristics of a standard self-leveling
underlayment, but are true wearing surfa...
Application of a SL Topping
100
Floor Polishing
• Restore: Scaling, Dusting & Delaminations
• Mechanically removes the deteriorated layer
of concrete.
• U...
113
Metal bond
Resin bond
114
115
116
117
118
119
120
121
122
Summarize
• Read and follow ACI 201.2R-08, “Guide to
Durable Concrete”
• Do not finish concrete too early, this may
cause
...
Summarize
• If you don’t
– Properly finish the concrete
• And
– Cure the concrete
• Or
– Seal the concrete in harsh enviro...
Thank You
Causes of Surface Defects on Horizontal Concrete Slabs; Preventative Surface Treatments and Remediation - AIA
Causes of Surface Defects on Horizontal Concrete Slabs; Preventative Surface Treatments and Remediation - AIA
Causes of Surface Defects on Horizontal Concrete Slabs; Preventative Surface Treatments and Remediation - AIA
Causes of Surface Defects on Horizontal Concrete Slabs; Preventative Surface Treatments and Remediation - AIA
Causes of Surface Defects on Horizontal Concrete Slabs; Preventative Surface Treatments and Remediation - AIA
Causes of Surface Defects on Horizontal Concrete Slabs; Preventative Surface Treatments and Remediation - AIA
Causes of Surface Defects on Horizontal Concrete Slabs; Preventative Surface Treatments and Remediation - AIA
Causes of Surface Defects on Horizontal Concrete Slabs; Preventative Surface Treatments and Remediation - AIA
Causes of Surface Defects on Horizontal Concrete Slabs; Preventative Surface Treatments and Remediation - AIA
Causes of Surface Defects on Horizontal Concrete Slabs; Preventative Surface Treatments and Remediation - AIA
Causes of Surface Defects on Horizontal Concrete Slabs; Preventative Surface Treatments and Remediation - AIA
Causes of Surface Defects on Horizontal Concrete Slabs; Preventative Surface Treatments and Remediation - AIA
Causes of Surface Defects on Horizontal Concrete Slabs; Preventative Surface Treatments and Remediation - AIA
Causes of Surface Defects on Horizontal Concrete Slabs; Preventative Surface Treatments and Remediation - AIA
Causes of Surface Defects on Horizontal Concrete Slabs; Preventative Surface Treatments and Remediation - AIA
Causes of Surface Defects on Horizontal Concrete Slabs; Preventative Surface Treatments and Remediation - AIA
Causes of Surface Defects on Horizontal Concrete Slabs; Preventative Surface Treatments and Remediation - AIA
Causes of Surface Defects on Horizontal Concrete Slabs; Preventative Surface Treatments and Remediation - AIA
Causes of Surface Defects on Horizontal Concrete Slabs; Preventative Surface Treatments and Remediation - AIA
Causes of Surface Defects on Horizontal Concrete Slabs; Preventative Surface Treatments and Remediation - AIA
Causes of Surface Defects on Horizontal Concrete Slabs; Preventative Surface Treatments and Remediation - AIA
Causes of Surface Defects on Horizontal Concrete Slabs; Preventative Surface Treatments and Remediation - AIA
Causes of Surface Defects on Horizontal Concrete Slabs; Preventative Surface Treatments and Remediation - AIA
Causes of Surface Defects on Horizontal Concrete Slabs; Preventative Surface Treatments and Remediation - AIA
Causes of Surface Defects on Horizontal Concrete Slabs; Preventative Surface Treatments and Remediation - AIA
Causes of Surface Defects on Horizontal Concrete Slabs; Preventative Surface Treatments and Remediation - AIA
Causes of Surface Defects on Horizontal Concrete Slabs; Preventative Surface Treatments and Remediation - AIA
Causes of Surface Defects on Horizontal Concrete Slabs; Preventative Surface Treatments and Remediation - AIA
Causes of Surface Defects on Horizontal Concrete Slabs; Preventative Surface Treatments and Remediation - AIA
Causes of Surface Defects on Horizontal Concrete Slabs; Preventative Surface Treatments and Remediation - AIA
Causes of Surface Defects on Horizontal Concrete Slabs; Preventative Surface Treatments and Remediation - AIA
Causes of Surface Defects on Horizontal Concrete Slabs; Preventative Surface Treatments and Remediation - AIA
Causes of Surface Defects on Horizontal Concrete Slabs; Preventative Surface Treatments and Remediation - AIA
Causes of Surface Defects on Horizontal Concrete Slabs; Preventative Surface Treatments and Remediation - AIA
Causes of Surface Defects on Horizontal Concrete Slabs; Preventative Surface Treatments and Remediation - AIA
Causes of Surface Defects on Horizontal Concrete Slabs; Preventative Surface Treatments and Remediation - AIA
Causes of Surface Defects on Horizontal Concrete Slabs; Preventative Surface Treatments and Remediation - AIA
Causes of Surface Defects on Horizontal Concrete Slabs; Preventative Surface Treatments and Remediation - AIA
Causes of Surface Defects on Horizontal Concrete Slabs; Preventative Surface Treatments and Remediation - AIA
Causes of Surface Defects on Horizontal Concrete Slabs; Preventative Surface Treatments and Remediation - AIA
Causes of Surface Defects on Horizontal Concrete Slabs; Preventative Surface Treatments and Remediation - AIA
Causes of Surface Defects on Horizontal Concrete Slabs; Preventative Surface Treatments and Remediation - AIA
Causes of Surface Defects on Horizontal Concrete Slabs; Preventative Surface Treatments and Remediation - AIA
Causes of Surface Defects on Horizontal Concrete Slabs; Preventative Surface Treatments and Remediation - AIA
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Causes of Surface Defects on Horizontal Concrete Slabs; Preventative Surface Treatments and Remediation - AIA

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The one (1) hour course will review the cause of surface defects in concrete horizontal slabs. The course will give the viewer the ability to recognize the different types and causes of surface defects in horizontal concrete slabs. Learn about surface treatments for preventative maintenance to avoid surface defects. And, if all else fails, learn about proper techniques and materials to repair surface defects in horizontal concrete slabs. This program is registered with the AIA/CES for continuing professional education. The course earns one learning unit (LU).

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Causes of Surface Defects on Horizontal Concrete Slabs; Preventative Surface Treatments and Remediation - AIA

  1. 1. Defining Surface Defects on Concrete Horizontal Slabs, Surface Treatments and the Remediation of these Surface Defects W.R. MEADOWS, INC.
  2. 2. Cementitious Technology 2
  3. 3. Lets start with the basics:
  4. 4. Definitions Cement = Powder Cement + Water = Paste Paste + Sand = Mortar Mortar + Stone = Concrete A chemical reaction takes places when the water is mixed with the cement
  5. 5. The chemical reaction starts a crystal- type growth in the cement
  6. 6. 6
  7. 7. BAD WATER GOOD WATER
  8. 8. The Water to Cement Ratio Controls Strength. As the W/C ratio increases, compressive strength decreases, by as much as 50%. Severe environments ACI 201.2R – 0.45 w/c 0 500 1000 1500 2000 2500 3000 3500 4000 4500 5000 Strength w/c 0.4 w/c 0.5 w/c 0.6
  9. 9. Properties Effected by Water to Cement Ratio & Curing • Compressive Strength • Tensile Strength • Flexural Strength • Abrasion Resistance • Freeze-Thaw Resistance • Scaling Resistance • Porosity • Cracking
  10. 10. Durable Concrete • ACI 201.2R-08, “Guide to Durable Concrete” – Outlines procedures to design and place durable concrete.
  11. 11. Some Common Concrete Flatwork Surface Issues • Surface Scaling • Popouts • Dusting • Delamination
  12. 12. Surface scaling • ACI 201.1R, “Guide for Conducting a Visual Inspection of Concrete in Service” defines scaling as: – local flaking or peeling away of the near-surface portion of hardened concrete or mortar. Which can vary from light to very severe with loss of coarse particles greater than 20 mm (7/8”).
  13. 13. Surface Scaling – Typical Causes • Inadequate or no air entrainment. (Concrete with proper entrained air will still scale for the following reasons) • Improper Curing • Deicing salts on newly placed concrete or excessive deicing salts on concrete with poor surface strengths. • Concrete finished while bleeding or over worked. • High degree of freezable water content (late season pours) 17
  14. 14. Surface Scaling – Application Hints During Concrete Placement • Ensure proper air-entrainment for environment. • Do not use de-icing salts on new concrete, or excess de-icing salts on old concrete. • Do not perform any finishing operations with water present on surface. • Cure the concrete. • Seal the concrete. 18
  15. 15. Popouts • ACI 201.1R, “Guide for Conducting a Visual Inspection of Concrete in Service” defines popouts as: – The breaking away of a small portions of a concrete surface due to localized internal pressure that leaves a shallow, typical conical, depression with a broken coarse aggregate at the bottom.
  16. 16. 22
  17. 17. 23
  18. 18. 24
  19. 19. Surface Popouts – Typical Causes • Use of non durable aggregates. • Improper curing. • High degree of freezable water content. • Popouts may occur without freezing and thawing – Again, caused by internal pressures, but not by freezing and thawing / deicing salts, but by some deleterious reaction between the aggregate and cement alkali. 25
  20. 20. Surface Popouts – Application Hints During Concrete Placement • Ensure that the aggregate is suitable for the environment. • Properly cure the concrete. • Seal the concrete. • Avoid sealing if reactive aggregate is known. 26
  21. 21. Dusting • ACI 201.1R, “Guide for Conducting a Visual Inspection of Concrete in Service” defines dusting as: – The development of a powdered material at the surface of hardened concrete.
  22. 22. 28
  23. 23. Dusting – Typically Causes • Any finishing operation performed too early. • Use of additional water on the surface. • Inadequate ventilation. • Insufficient curing. • Inadequate protection from freezing.
  24. 24. Dusting – Application Hints During Concrete Placement • Allow concrete time to adequately bleed. • Do not use additional water to finish surface. • Ensure proper ventilation of heaters. • Properly cure the concrete. • Do not apply when temperature is expected below freezing.
  25. 25. Delamination • ACI 201.1R, “Guide for Conducting a Visual Inspection of Concrete in Service” defines delamination as: – A separation along a plane parallel to a surface, as in the case of a concrete slab, a horizontal splitting, or separation with in the slab in a plane roughly parallel to, and generally near, the upper surface. [from the base slab by a thin layer of water or air].
  26. 26. Delamination – Typical Causes – Finishing the concrete too early prior bleeding or when the concrete is still bleeding. – Over working and/or densifying the surface during the finishing operation. – Cool sub-grade or concrete, retards or delays bleeding. – Air content is too high for application. – Rapid drying of surface which causes the concrete to appear ready for finishing.
  27. 27. Delamination – Application Hints During Concrete Placement • Allow the concrete sufficient time to bleed. • Be wary of concrete that appears ready for final finishing before expected. • Use accelerators in cold weather. • Do not use air-entrained concrete on hard troweled floors. • Protect from rapid drying.
  28. 28. Preventive Chemical Treatments • Curing Compounds • Linseed Oil Treatments • Curing and Sealing Compounds • Penetrating Sealers • Silicates (Floor Hardeners) 37
  29. 29. Curing Per ACI 201.2R-6 • Will ensure strength development of paste at surface. • Will also decrease the porosity of concrete, thereby lowering content of freezable water. • Help maintain a concrete RH below 85 percent • Adequate curing will ensure that proper minimum strength development of concrete is achieved. – 500 PSI single freeze episode – 3,600 PSI multiply freeze episodes
  30. 30. Curing Compounds • Applied after bleeding and final finishing. • ASTM C 309 (ACI 308) – Type I (Non-pigmented) – Type II (White pigmented) • Class A – No vehicle restriction • Class B – Resins • Application rate – 200 sq. ft. / gal. • Film Dries in as little 4 hours. 39
  31. 31. If the cement does not get enough water, the reaction stops and the concrete will not reach its designed strength. ACI 201.2R – Min. 3,600 PSI 0 500 1,000 1,500 2,000 2,500 3,000 3,500 4,000 Strength Designed Strength Strength w/o proper curing Rapid moisture loss
  32. 32. 42
  33. 33. Linseed Oil Treatments • Linseed penetrating and anti-scaling compound – is a specification-grade formulation of boiled linseed oil in mineral spirits specifically compounded to prevent the scaling of concrete. This type of penetrating compound is recommended by many state Departments of Transportation for prolonging the life cycle of concrete exposed to water, de-icing salts and other destructive materials. 43
  34. 34. 44
  35. 35. Curing & Sealing Compounds • ASTM C 1315 – Acrylic / Styrene Acrylic • Passive protective barrier – Minimum 25% Solids Content – Typically do not yellow – Reduces (per ACI 201.2R) the amount of freezable water in the matrix and the salt content. – Enhances appearance. – Can be used as a curing compound.
  36. 36. 46
  37. 37. 47
  38. 38. 48
  39. 39. 49
  40. 40. Penetrating Sealers • Governing Specification – NCHRP 244 – ALBERTA Ministry of Transportation Specification • Common Chemistries – Silane – Siloxane
  41. 41. Penetrating Sealers • Chemical protective barrier – Water-based or solvent-based – Typically is applied at 100 – 200 sq. ft./gal. – Penetrates in to concrete / long lasting • Up to 5mm (3/16”) – Allows moisture to evaporate while keeping moisture from / chlorides out.
  42. 42. Penetrating Sealers • High degree of protection from freezable water and reduces salt content • Reduces water intrusion up to 90% • Reduces chloride penetration up to 99% • Passes scaling resistance per ASTM C 672 on non-air entrained concrete • Little or no affect on surface appearance • Highly breathable
  43. 43. Silicates Floor Hardener & Densifier • Eliminates dusting in most cases. • Penetrates and chemically reacts with the soft weak layer of concrete (Dust) to form a hard & Dense, highly abrasion resistant surface. 53 Normal 3-6 mm
  44. 44. Silicates Floor Hardener & Densifier • Sodium based – Existing concrete, must be washed off. • Lithium based – Fresh concrete, may be left on. • Increases abrasion resistance by over 50 Percent. • Reduces staining. • Polishes, thereby increasing reflectivity. 54
  45. 45. UNTREATED
  46. 46. TREATED AND BURNISHED
  47. 47. And if all else fails...Restore • Polymer Modified Cementitious Thin Overlay Repair Mortars • Self-leveling Cementitious Toppings • Concrete Polishing
  48. 48. 69
  49. 49. 70
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  62. 62. 90
  63. 63. Self-Leveling Cementitious Toppings • Characteristics of a standard self-leveling underlayment, but are true wearing surfaces. • Specialized Cement Technology • Typically interior applications. • Highly architectural.
  64. 64. Application of a SL Topping
  65. 65. 100
  66. 66. Floor Polishing • Restore: Scaling, Dusting & Delaminations • Mechanically removes the deteriorated layer of concrete. • Used with Floor Hardeners, leaves a dense wear resistant surface. 112
  67. 67. 113 Metal bond Resin bond
  68. 68. 114
  69. 69. 115
  70. 70. 116
  71. 71. 117
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  75. 75. 121
  76. 76. 122
  77. 77. Summarize • Read and follow ACI 201.2R-08, “Guide to Durable Concrete” • Do not finish concrete too early, this may cause – Scaling, dusting, delamination, popouts • Properly curing concrete may eliminate – Scaling, dusting & popouts • Sealing the concrete may eliminate – Scaling, dusting & popouts 123
  78. 78. Summarize • If you don’t – Properly finish the concrete • And – Cure the concrete • Or – Seal the concrete in harsh environments • You will be repairing the concrete. 124
  79. 79. Thank You

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