REPAIR MANUAL

1. REPAIR MANUAL Dr. Mohammed Maslehuddin Research Institute King Fahd University of Petroleum and Minerals

2. Purpose of the Manual • Assist engineers in diagnosing concrete deterioration problems and planning repair and rehabilitation of deteriorating structures.

3. Contents of Repair Manual • Chapter 1: Guide to mechanisms of concrete deterioration • Chapter 2: Assessment of the extent of concrete deterioration • Chapter 3: Strategy for repair of deteriorated concrete structures • Chapter 4: Repair materials and their evaluation

4. Contents (contd.) • Chapter 5: Repair procedures • Chapter 6: Repair systems • Chapter 7: Long-term monitoring strategies

5. Chapter 1A guide to forms of concrete deterioration • Reinforcement corrosion • Carbonation • Sulfate attack • Salt weathering • Alkali-aggregate reactivity • Cracking of concrete • Acid attack • Damage due to fire • Attack due to micro-organisms

6. Chapter 2Assessment of Concrete Deterioration • Preparation (preparatory desk work) • Preliminary investigation (visual inspection and appraisal) • Detailed investigation (data collection, field measurements, condition survey, sample collection, testing of samples, analysis and evaluation) • Conclusion and recommendations

7. Chapter 2 (contd.)Preparation prior to inspection • Design information • Plans/drawings, as-built drawings, specifications and other related information • Location of the structure and topology and accessibility • Structural drawings for reinforcement details • Service history

8. Chapter 2 (contd.)Preliminary investigation • Structural condition, extent of cracking, damage • Safety of the structure • Need for commissioning a detailed inspection • Accessories needed for detailed inspection • Traffic control requirements • Any unusual problems facing the structure

9. Chapter 2 (contd.)Detailed investigation • Data collection • Field measurements and condition survey • Sample collection • Testing and field samples • Analysis and evaluation • Report • Conclusions • Recommendations

10. Chapter 2 (contd.)Commonly used test methods • Methods for estimating in-situ concrete strength • Methods for determining properties other than strength • Methods for the physical evaluation of structures

11. Chapter 3Strategy for repair of deteriorated concrete structures • Cause and extent of damage • Consequence of the damage • Time for intervention • Economics • Operational constraints

12. Chapter 3Repair options • No repair • Repair • Cosmetic • Partial • Total • Partial repair or total replacement

13. Factors influencing the selection of repair strategy (No repair) • Minimal damage • No chance of re-occurrence of damage due to overload etc. • Expected service life is more than the design life • Appearance is not a problem

14. Factors influencing the selection of repair strategy (Repair) • Cosmetic repair • Limited deterioration • Rate of deterioration is too low as in the no repair option • Improve the appearance

15. Factors influencing the selection of repair strategy (Repair) • Partial repair (patch repair) • Rectify apparent defects • Structural safety is not affected

16. Factors influencing the selection of repair strategy (Repair) • Total repair • Advanced deterioration • Structurally unsafe • Operational constraints for total replacement

17. Factors influencing the selection of repair strategy for corrosion (No repair) • Active corrosion but corrosion rate is low • Low chloride concentration • Structural integrity is not compromised

18. Factors influencing the selection of repair strategy for corrosion (Repair) • Cosmetic repair • Active corrosion but corrosion rate is low • Chloride concentration is high • No spalling, localized delamination • Structural integrity is not affected

19. Factors influencing the selection of repair strategy for corrosion (Repair) • Partial repair (patch repair) • Active corrosion • Localized delamination or spalling • Structural safety is not affected

20. Factors influencing the selection of repair strategy for corrosion (Repair) • Total repair • Active corrosion • Uniform spalling or delamination • Excessive loss of cross section of bars at many locations

21. Factors influencing the selection of repair strategy for corrosion (Partial or total replacement) • Repair is economically not feasible • No operational constraints • Structure is structurally unsound

22. Chapter 4Repair Materials and their Evaluation • Repair mortars • Cementitious repair mortars • Polymer modified cementitious mortars • Resin-based repair mortars • Sprayed concrete • Injection grout • Flowing micro concrete • Bond coat materials • Steel primers • Surface coatings

23. Chapter 4Repair Materials and their Evaluation • Test methods • Compliance criteria

24. Chapter 5Repair Procedures • Repair of cracked and deteriorated concrete • Shrinkage cracks • Settlement cracks • Thermal cracks • Dormant or dead cracks • Live cracks

25. Chapter 5Repair Procedures (contd.) • Vacuum impregnation • Resin injection • Repair of surface defects • Repair of inadequate cover • Repair of deteriorated and cracked concrete due to sulfate attack and salt scaling • Repair of cracks caused by alkali-silica reaction • Repair of deterioration due to exposure to chemicals • Repair of deterioration and cracking due to exposure to high temperature and fire • Repair of spalled concrete

26. Chapter 6Repair systems • Marine environments • System 7 or 1 • Below ground structures • System 1 or 6 • Sulfur fumes • System 6, 5 or 8 • Acid exposure • System 6, 5 or • Sweet or saline water • System 9 or 10 • Fire damage • System 7 or 8

27. Chapter 7Long-term Monitoring Strategies • Visual inspection • Debonding • Monitoring chloride and moisture content • Measurement of carbonation depth • Assessing reinforcement corrosion • Resistivity • Corrosion potentials • Corrosion rate