1. From… Maintenance Technical Advisory Guide (MTAG) Chapter 7 Isolated Partial Depth Concrete Repair

2. Partial-Depth Repairs 3-4.2

3. Learning Objectives 1.List benefits of partial-depth repairs 2.Describe the advantages and disadvantages of different available repair materials 3.Describe recommended construction procedures 4.List important quality control activities 5. Describe potential unexpected adjustments or construction quality problems 6. Identify troubleshooting solutions

4. Presentation Outline II ntroduction DD esign considerations CC onstruction QQ uality control TT roubleshooting

5. Removal and replacement of small, shallow areas of deteriorated PCC at spalled or distressed joints. Definition Introduction Distress limited to upper 1/3 of slab Existing load transfer devices are functional

6. Benefits Restores structural integrity Improves ride quality Extends the service life Restores a well-defined uniform joint sealant reservoir

7. Good Candidate Projects Spalling associated with joint inserts Spalling caused by intrusion of incompressibles Spalling associated with localized areas of scaling, weak concrete, clay balls, or high steel

8. Poor Candidate Projects Joint spalling associated with dowel bar misalignment or lockup Spalled cracks Spalling associated with durability problems or reactive aggregate

9. Good candidate?

14. Presentation Outline II ntroduction DD esign considerations CC onstruction QQ uality control TT roubleshooting

15. Design, Materials & Specifications From… Maintenance Technical Advisory Guide (MTAG) Module 7-1

16. Design Considerations Selecting repair boundaries Material selection Curing Opening to traffic

17. DULLSHARP Unsound-DelaminatedSolid Sounding the pavement: Hammer Steel rod Steel chain Selecting Repair Boundaries Detecting Deteriorated Concrete

18. Selecting Repair Boundaries Sounding

19. Selecting Repair Boundaries Repair Dimension Recommendations Minimum dimensions Length: 300 mm (12 in) Width: 100 mm (4 in) Depth: 50 mm (2 in) Extend repair 75 to 100 mm (3 to 4 in) beyond visible deterioration Combine close patches (<0.6 m [2 ft]) Repair entire joint if > 2 patches

20. Cementitious PCC-based Gypsum-based Magnesium phosphate High alumina Polymeric Epoxy Methyl methacrylate Polyester-styrene Polyurethane Bituminous Material Selection Repair Material Types

21. Enhances repair to pavement bond Sand-cement grouts used with PCC repair materials Epoxy bonding agents used with both PCC and proprietary materials Material Selection Bonding Agents

22. Material Selection Factors Allowable lane closure time Ambient temperature Cost Size of repair Estimated performance

23. Curing Cure to avoid shrinkage cracks Hot-weather curing—curing compound, moist burlap, or polyethylene Cold-weather curing—insulating blanket or tarp Follow recommendations for proprietary materials

24. Opening to Traffic Opening criteria Minimum strength (20.7 MPa [3,000 psi]) Minimum time Opening based on actual PCC strength is preferred

25. Typical Item Codes Item CodeDescription 120090Construction area signs 120100Traffic control system 128650Portable changeable message sign 150846Remove concrete pavement 150306Repair spalled concrete 156515Repair spalled and unsound surface area 401108Replace concrete pavement (rapid strength concrete 413101Repair corner breaks 413111Repair spalled joint 413114Replace joint seal (existing concrete pavement) 413115Seal joint (existing concrete pavement) 420201Grind existing concrete pavement 511040Concrete surface finish 511055Concrete surface texture 515028Repair spalled surface area http://i80.dot.ca.gov/hq/esc/oe/awards/#item_code

26. Construction and Inspection From… Maintenance Technical Advisory Guide (MTAG) Module 7-2

27. Presentation Outline II ntroduction MM aterial selection CC onstruction QQ uality control TT roubleshooting

28. Construction Steps 1.Marking repair boundaries 2.Concrete removal 3.Repair area cleaning 4.Joint preparation 5.Bonding agent application 6.Patch material placement 7.Curing 8.Joint sealing

29. Marking Repair Boundaries

30. Concrete Removal Saw-and-patch (recommended) Chip-and-patch Mill-and-patch Hydrodemolition

31. Concrete Removal Saw-and-Patch Method

32. Concrete Removal Chip-and-Patch Method

33. Concrete Removal Mill-and-Patch Method

35. Concrete Removal Hydrodemolition

36. Repair Area Cleaning Sandblasting

37. Repair Area Cleaning Air Blowing

38. Joint Preparation

39. Plan View Profile View Bond breaker Patch Pavement 75 mm (3 in) Scoring 25 mm (1 in) Joint Joint Preparation

40. Bonding Agent Application Patch area must be clean Application techniques Coat horizontal and vertical surfaces Apply uniformly

41. Bonding Agent Application

42. Patch Material Placement General Guidelines Batch small quantities Temperature recommendations Some epoxy materials placed in lifts Overfill patch area by ~3 mm (1/8 in) Consolidate material Screed and hand trowel

43. Patch Material Placement Grout Mixer

44. Patch Material Placement Adding Admixture

45. Patch Material Placement Mixing an Epoxy Patching Material

46. Patch Material Placement Consolidation

47. Patch Material Placement Finishing

48. Curing

49. Joint Sealing

50. Finished Patch

51. Construction Process

52. Presentation Outline II ntroduction MM aterial selection CC onstruction QQ uality control TT roubleshooting

53. Quality Control Verify repair boundaries Monitor to assure no damage to surrounding concrete Inspection of repair preparation material placement, and finishing Proper curing techniques

54. Quality Control Class Exercise Break into three groups Preliminary responsibilities Equipment inspection, weather requirements, and traffic control Construction inspection considerations Identify importance of each item Use Reference Manual and your experience

55. Project Checklist Preliminary Responsibilities Document Review Project Review Materials Checks Concrete patch material Other materials Joint Sealing General

56. Project Checklist Equipment Inspections Concrete Removal Equipment Patch Area Cleaning Equipment Mixing and Testing Equipment Placing and Finishing Equipment Other Equipment Others Weather Requirements Traffic Control

57. Project Checklist Project Inspection Responsibilities Patch Removal and Cleaning Patch Preparation Placing, Finishing, and Curing Patch Material Resealing Joints and Cracks Cleanup Responsibilities

58. Presentation Outline II ntroduction MM aterial selection CC onstruction QQ uality control TT roubleshooting

59. Troubleshooting Identify Problem Determine Cause Identify Solution Unexpected adjustments and construction quality problems Approach:

60. Deterioration beyond original boundaries Troubleshooting Unexpected Adjustments Solution? Problem

61. Deterioration deeper than upper 1/3 of the slab thickness Troubleshooting Unexpected Adjustments Solution? Problem

62. Troubleshooting What is wrong here?

63. Patch material flows into joint Troubleshooting Construction Quality Problems Potential causes? Problem

64. Cracking or debonding of patch material Troubleshooting Construction Quality Problems Potential causes? Problem

65. Troubleshooting Guide – Causes and Solutions More deterioration than expected Exposed steel Patch material in crack or joint Patch cracking

66. Presentation Outline  Introduction  Material selection  Construction  Quality control  Troubleshooting

67. Learning Objectives 1.List benefits of partial-depth repairs 2.Describe the advantages and disadvantages of different available repair materials 3.Describe recommended construction procedures 4.List important quality control activities 5. Describe potential unexpected adjustments or construction quality problems 6. Identify troubleshooting solutions