REPAIR MANUALREPAIR MANUAL

Dr. Mohammed MaslehuddinDr. Mohammed MaslehuddinResearch InstituteResearch Institute

King Fahd University of Petroleum and King Fahd University of Petroleum and MineralsMinerals

Purpose of the ManualPurpose of the Manual

Assist engineers in diagnosing concrete Assist engineers in diagnosing concrete deterioration problems and planning repair deterioration problems and planning repair and rehabilitation of deteriorating and rehabilitation of deteriorating structures.structures.

Contents of Repair ManualContents of Repair Manual

Chapter 1: Guide to mechanisms of Chapter 1: Guide to mechanisms of concrete deteriorationconcrete deterioration

Chapter 2: Assessment of the extent of Chapter 2: Assessment of the extent of concrete deteriorationconcrete deterioration

Chapter 3: Strategy for repair of Chapter 3: Strategy for repair of deteriorated concrete deteriorated concrete structuresstructures

Chapter 4: Repair materials and their Chapter 4: Repair materials and their evaluationevaluation

Contents (contd.)Contents (contd.)

Chapter 5: Repair proceduresChapter 5: Repair procedures

Chapter 6: Repair systemsChapter 6: Repair systems

Chapter 7: Long-term monitoring Chapter 7: Long-term monitoring strategiesstrategies

Chapter 1Chapter 1A guide to forms of concrete deteriorationA guide to forms of concrete deterioration

Reinforcement corrosionReinforcement corrosionCarbonationCarbonationSulfate attackSulfate attackSalt weatheringSalt weatheringAlkali-aggregate reactivityAlkali-aggregate reactivityCracking of concreteCracking of concreteAcid attackAcid attackDamage due to fireDamage due to fireAttack due to micro-organismsAttack due to micro-organisms

Chapter 2Chapter 2Assessment of Concrete DeteriorationAssessment of Concrete Deterioration

Preparation (preparatory desk work)Preparation (preparatory desk work)

Preliminary investigation (visual inspection Preliminary investigation (visual inspection and appraisal)and appraisal)

Detailed investigation (data collection, field Detailed investigation (data collection, field measurements, condition survey, sample measurements, condition survey, sample collection, testing of samples, analysis and collection, testing of samples, analysis and evaluation)evaluation)

Conclusion and recommendationsConclusion and recommendations

Chapter 2 (contd.)Chapter 2 (contd.)Preparation prior to inspectionPreparation prior to inspection

Design informationDesign information– Plans/drawings, as-built drawings, Plans/drawings, as-built drawings,

specifications and other related informationspecifications and other related information– Location of the structure and topology and Location of the structure and topology and

accessibilityaccessibility– Structural drawings for reinforcement detailsStructural drawings for reinforcement details

Service historyService history

Chapter 2 (contd.)Chapter 2 (contd.)Preliminary investigationPreliminary investigation

Structural condition, extent of cracking, Structural condition, extent of cracking, damagedamageSafety of the structureSafety of the structureNeed for commissioning a detailed Need for commissioning a detailed inspectioninspectionAccessories needed for detailed Accessories needed for detailed inspectioninspectionTraffic control requirementsTraffic control requirementsAny unusual problems facing the structureAny unusual problems facing the structure

Chapter 2 (contd.)Chapter 2 (contd.)Detailed investigationDetailed investigation

Data collectionData collection

Field measurements and condition surveyField measurements and condition survey

Sample collectionSample collection

Testing and field samplesTesting and field samples

Analysis and evaluation Analysis and evaluation

ReportReport– Conclusions Conclusions – RecommendationsRecommendations

Chapter 2 (contd.)Chapter 2 (contd.)Commonly used test methodsCommonly used test methods

Methods for estimating in-situ concrete Methods for estimating in-situ concrete strengthstrength

Methods for determining properties other Methods for determining properties other than strengththan strength

Methods for the physical evaluation of Methods for the physical evaluation of structuresstructures

Chapter 3Chapter 3Strategy for repair of deteriorated concrete Strategy for repair of deteriorated concrete

structuresstructures

Cause and extent of damageCause and extent of damage

Consequence of the damageConsequence of the damage

Time for interventionTime for intervention

EconomicsEconomics

Operational constraintsOperational constraints

Chapter 3Chapter 3Repair optionsRepair options

No repairNo repair

RepairRepair– CosmeticCosmetic– PartialPartial– TotalTotal

Partial repair or total replacementPartial repair or total replacement

Factors influencing the selection of Factors influencing the selection of repair strategy (No repair)repair strategy (No repair)

Minimal damageMinimal damage

No chance of re-occurrence of damage No chance of re-occurrence of damage due to overload etc.due to overload etc.

Expected service life is more than the Expected service life is more than the design lifedesign life

Appearance is not a problemAppearance is not a problem

Factors influencing the selection of Factors influencing the selection of repair strategy (Repair)repair strategy (Repair)

Cosmetic repairCosmetic repair– Limited deteriorationLimited deterioration– Rate of deterioration is too low as in the no Rate of deterioration is too low as in the no

repair optionrepair option– Improve the appearanceImprove the appearance

Factors influencing the selection of Factors influencing the selection of repair strategy (Repair)repair strategy (Repair)

Partial repair (patch repair)Partial repair (patch repair)– Rectify apparent defectsRectify apparent defects– Structural safety is not affectedStructural safety is not affected

Factors influencing the selection of Factors influencing the selection of repair strategy (Repair)repair strategy (Repair)

Total repairTotal repair– Advanced deteriorationAdvanced deterioration– Structurally unsafeStructurally unsafe– Operational constraints for total replacementOperational constraints for total replacement

Factors influencing the selection of repair Factors influencing the selection of repair strategy for corrosion (No repair)strategy for corrosion (No repair)

Active corrosion but corrosion rate is lowActive corrosion but corrosion rate is low

Low chloride concentrationLow chloride concentration

Structural integrity is not compromisedStructural integrity is not compromised

Factors influencing the selection of repair Factors influencing the selection of repair strategy for corrosion (Repair)strategy for corrosion (Repair)

Cosmetic repairCosmetic repair– Active corrosion but corrosion rate is lowActive corrosion but corrosion rate is low– Chloride concentration is highChloride concentration is high– No spalling, localized delaminationNo spalling, localized delamination– Structural integrity is not affectedStructural integrity is not affected

Factors influencing the selection of repair Factors influencing the selection of repair strategy for corrosion (Repair)strategy for corrosion (Repair)

Partial repair (patch repair)Partial repair (patch repair)– Active corrosionActive corrosion– Localized delamination or spallingLocalized delamination or spalling– Structural safety is not affectedStructural safety is not affected

Factors influencing the selection of repair Factors influencing the selection of repair strategy for corrosion (Repair)strategy for corrosion (Repair)

Total repairTotal repair– Active corrosionActive corrosion– Uniform spalling or delaminationUniform spalling or delamination– Excessive loss of cross section of bars at Excessive loss of cross section of bars at

many locationsmany locations

Factors influencing the selection of repair Factors influencing the selection of repair strategy for corrosion (Partial or total strategy for corrosion (Partial or total

replacement)replacement)

Repair is economically not feasibleRepair is economically not feasible

No operational constraintsNo operational constraints

Structure is structurally unsoundStructure is structurally unsound

Chapter 4Chapter 4Repair Materials and their EvaluationRepair Materials and their EvaluationRepair mortarsRepair mortars– Cementitious repair mortarsCementitious repair mortars– Polymer modified cementitious mortarsPolymer modified cementitious mortars– Resin-based repair mortarsResin-based repair mortars– Sprayed concreteSprayed concrete– Injection groutInjection grout– Flowing micro concreteFlowing micro concrete

Bond coat materialsBond coat materialsSteel primersSteel primersSurface coatingsSurface coatings

Chapter 4Chapter 4Repair Materials and their EvaluationRepair Materials and their Evaluation

Test methodsTest methods

Compliance criteriaCompliance criteria

Chapter 5Chapter 5Repair ProceduresRepair Procedures

Repair of cracked and deteriorated Repair of cracked and deteriorated concreteconcrete– Shrinkage cracksShrinkage cracks– Settlement cracksSettlement cracks– Thermal cracksThermal cracks– Dormant or dead cracksDormant or dead cracks– Live cracksLive cracks

Chapter 5Chapter 5Repair Procedures (contd.)Repair Procedures (contd.)

– Vacuum impregnationVacuum impregnation– Resin injectionResin injection– Repair of surface defectsRepair of surface defects– Repair of inadequate coverRepair of inadequate cover– Repair of deteriorated and cracked concrete due to Repair of deteriorated and cracked concrete due to

sulfate attack and salt scalingsulfate attack and salt scaling– Repair of cracks caused by alkali-silica reactionRepair of cracks caused by alkali-silica reaction– Repair of deterioration due to exposure to chemicalsRepair of deterioration due to exposure to chemicals– Repair of deterioration and cracking due to exposure Repair of deterioration and cracking due to exposure

to high temperature and fireto high temperature and fire– Repair of spalled concreteRepair of spalled concrete

Chapter 6Chapter 6Repair systems Repair systems

Marine environmentsMarine environments– System 7 or 1System 7 or 1

Below ground structuresBelow ground structures– System 1 or 6System 1 or 6

Sulfur fumesSulfur fumes– System 6, 5 or 8System 6, 5 or 8

Acid exposureAcid exposure– System 6, 5 orSystem 6, 5 or

Sweet or saline waterSweet or saline water– System 9 or 10System 9 or 10

Fire damageFire damage– System 7 or 8System 7 or 8

Chapter 7Chapter 7Long-term Monitoring StrategiesLong-term Monitoring StrategiesVisual inspectionVisual inspection

DebondingDebonding

Monitoring chloride and moisture contentMonitoring chloride and moisture content

Measurement of carbonation depthMeasurement of carbonation depth

Assessing reinforcement corrosionAssessing reinforcement corrosion– ResistivityResistivity– Corrosion potentialsCorrosion potentials– Corrosion rateCorrosion rate