1. Presented by: Peter Emmons,
Achieving Durability in Concrete Repairs
Presented by: Peter Emmons,

2. Learning Outcomes At the end of this webinar, you will be able to:
Recognize when a repair method needs to be defined on a concrete substrate
Describe proper repair methods
Describe types of repair materials available

3. Introduction
This webinar focuses on concrete conditions that require removing some or all of the concrete before standard surface preparation for coating application.

4. Method of Repair
When the selecting the method and equipment for repair you should consider:
The size of the area to be repaired
Is there cracking
Is there exposed reinforcing steel (rebar)
Location of the floor (indoor/outdoor)
The ambient conditions
The specified ICRI Concrete Surface Profile (CSP)
The coating or coating system that will be applied over the repair areas

5. Repair Conditions
Before a successful repair project can begin, several key issues need to be addressed:
Determine the cause of concrete deterioration or damage
Determine the most suitable repair method, equipment and materials
Determine if there is an industry standard to follow (SSPC, ICRI, ASTM, ACI)
Determine if the project should involve a structural engineer and/or architect

6. Method of Crack Repair
Cause of cracking must be determined before a crack repair method can be selected
Is there a likelihood of further movement?

7. Settlement Cracking
Cracks resulting from settlement of the structure with a low likelihood of further movement can be repaired by epoxy pressure injection

8. Dynamic Cracks Cracks that will continually move due to:
Thermal expansion
Thermal contraction
Absence of adequate expansion joints

9. Damage Due to Thermal Property Changes

10. Expansion Joint

11. Cracks Causing Water Intrusion
The sources of water intrusion vary
Water may be coming through
Cracks in the
Concrete structure
Between concrete and piping through the concrete structure
Through honeycombs in the concrete
Through control or expansion joints

12. Photo Courtesy of Tnemec
Water Intrusion
Photo Courtesy of Tnemec

13. Reinforcement Repair
The most frequent cause of damage to reinforcing steel is corrosion

14. Spalling
Spalling of reinforced concrete is commonly associated with corrosion of the rebar
The increase of volume due to the corrosion product causes the outer layers of the concrete to detach

15. Reinforcement Repair
Proper steps to prepare the reinforcement will help insure that the repair method is a long-term, rather than temporary, solution
Remove concrete surrounding steel
Clean the reinforced steel by wire brushing
Repair of reinforcement
Replace the reinforcement
Supplement the reinforcement
Coat the reinforcement

16. Deteriorated Concrete
A repair or rehabilitation project will usually involve removal of deteriorated, damaged or defective concrete

17. Methods to Remove Deteriorated Concrete
Classification of concrete removal methods are:
Blasting
Cutting
Impacting
Milling
Hydrodemolition
Prospecting
Abrading

18. Surface Preparation
One of the most important steps in the repair of a concrete floor is the preparation of the surface to be repaired

19. ICRI Guideline No
ICRI Guideline No , Selecting and Specifying Concrete Surface Preparation for Sealers, Coatings and Polymer Overlays provides designers, specifiers, contractors and manufacturers with the tools needed to select and specify the methods for preparing concrete surfaces prior to the application of sealer, coating and polymer overlay systems

20. ICRI Guideline 310.2

21. Photo Courtesy of Tnemec
ICRI Guideline 310.2
Photo Courtesy of Tnemec

22. Surface Preparation Methods
Chemical cleaning
Acid etching
Mechanical preparation
Abrasive preparation

23. Material Selection
Things to consider when selecting which repair material to use are:
Coefficient of thermal expansion
Shrinkage
Permeability
Modulus of elasticity
Chemical properties
Electrical properties
Color properties

24. Selecting the Repair Product
Repair systems include:
Cast-in-place concrete
Pre-placed aggregate concrete
Troweling and dry packing
Injection grouting
Cement grouting
Chemical grouting

25. Bonding Methods Repair materials may require a separate bonding agent
Application must be done with care in order to avoid premature cure creating a bond breaker with the new repair material
Cement based
Epoxy and latex based

26. Surface Treatments
The objective is to limit corrosion by establishing conditions that reduce the free water in the concrete while preventing further moisture or chloride intrusion

27. Surface Treatments Generically classified as: Sealers Coatings
Membranes
Overlays

28. Sealers Penetrating Surface
After application material penetrates within the substrate of the concrete
Surface
Thin film that lays on the surface of the concrete

29. Penetrating Sealers Such products include, but are not limited to:
Boiled linseed oil
Silanes
Siloxanes
Epoxies
Methacrylates

30. Surface Sealers Such products include, but are not limited to: Epoxies
Polyurethanes
Methyl methacrylates
Moisture-cured urethanes
Acrylics

31. Coatings
Materials with a DFT greater than 10 mils and less than 30 mils

32. Coatings Such products include, but are not limited to: Acrylics
Styrene-butadienes
Polyvinyl acetates
Chlorinated rubbers
Urethanes
Polyesters
Epoxies

33. Membranes
Materials with a DFT greater than 30 mils and less than 250 mils

34. Membranes Such products include, but are not limited to: Urethanes
Acrylics
Epoxies
Neoprenes
Cement
Polymer concrete
Methyl methacrylates
Asphaltic products

35. Overlays
Materials with a DFT greater than 250 mils

36. Overlays Such products include, but are not limited to:
Polymer concrete
Concrete
Epoxies
Methyl methacrylates
Polymer modified concrete

37. Summary
This webinar has outlined important components of repairing concrete, resources for concrete repair and examples of how to successfully repair concrete. Proper identification of the cause of damage to concrete as well as the selection of appropriate repair methods and materials is important not only to successful patching but also to successful surface preparation and coating application