ACI PRC-440.2:2023

TABLE OF CONTENTS
CHAPTER 1—INTRODUCTION AND SCOPE, p. 3
1.1—Introduction, p. 3
1.2—Scope, p. 4
CHAPTER 2—NOTATION AND DEFINITIONS, p. 6
2.1—Notation, p. 6
2.2—Definitions, p. 9
CHAPTER 3—BACKGROUND INFORMATION, p. 11
3.1—Historical development, p. 11
3.2—Commercially available externally bonded FRP systems, p. 11
CHAPTER 4—CONSTITUENT MATERIALS AND PROPERTIES, p. 12
4.1—Constituent materials, p. 12
4.2—Physical properties, p. 13
4.3—Mechanical properties, p. 13
4.4—Time-dependent behavior, p. 14
4.5—Durability, p. 15
4.6—FRP systems qualification, p. 15
CHAPTER 5—SHIPPING, STORAGE, AND HANDLING, p. 15
5.1—Shipping, p. 15
5.2—Storage, p. 15
5.3—Handling, p. 16
CHAPTER 6—INSTALLATION, p. 16
6.1—Contractor competency, p. 16
6.2—Temperature, humidity, and moisture considerations, p. 16
6.3—Equipment, p. 17
6.4—Substrate repair and surface preparation, p. 17
6.5—Mixing of resins, p. 18
6.6—Application of FRP systems, p. 18
6.7—Alignment of FRP systems, p. 19
6.8—Multiple plies and lap splices, p. 19
6.9—Curing of resins, p. 19
6.10—Temporary protection, p. 19
CHAPTER 7—FIELD INSPECTION,TESTING, AND EVALUATION, p. 19
7.1—General, p. 19
7.2—Field inspection, p. 20
7.3—Material testing, p. 20
7.4—Evaluation and acceptance criteria, p. 21
7.5— Evaluation of coatings, p. 21
CHAPTER 8—MAINTENANCE AND REPAIR, p. 21
8.1—General, p. 21
8.2—Inspection and assessment, p. 21
8.3—Repair of strengthening system, p. 21
8.4—Repair of surface coating, p. 22
CHAPTER 9—GENERAL DESIGN CONSIDERATIONS, p. 22
9.1—Design philosophy, p. 22
9.2—Strengthening limits, p. 22
9.3—Selection of FRP systems, p. 23
9.4—Design material properties, p. 24
CHAPTER 10—FLEXURAL STRENGTHENING, p. 25
10.1—Nominal strength, p. 25
10.2—Reinforced concrete members, p. 26
10.3—Prestressed concrete members, p. 30
10.4—Moment redistribution, p. 33
CHAPTER 11—SHEAR STRENGTHENING, p. 33
11.1—General considerations, p. 33
11.2—Wrapping schemes, p. 33
11.3—Nominal shear strength, p. 34
11.4—FRP contribution to shear strength, p. 34
CHAPTER 12—STRENGTHENING OF MEMBERS SUBJECTED TO AXIAL FORCE OR COMBINED AXIAL AND BENDING FORCES, p. 36
12.1—Pure axial compression, p. 36
12.2—Combined axial compression and bending, p. 38
12.3—Ductility enhancement, p. 39
12.4—Pure axial tension, p. 39
CHAPTER 13—SEISMIC STRENGTHENING, p. 39
13.1—Background, p. 40
13.2—FRP properties for seismic design, p. 40
13.3—Confinement with FRP, p. 40
13.4—Flexural strengthening, p. 42
13.5—Shear strengthening, p. 43
13.6—Beam-column joints, p. 43
13.7—Strengthening reinforced concrete shear walls and wall piers, p. 44
CHAPTER 14—FIBER-REINFORCED POLYMER REINFORCEMENT DETAILS, p. 45
14.1—Bond, delamination, and anchorage, p. 45
14.2—Detailing of laps and splices, p. 48
14.3—Bond of near-surface-mounted (NSM) systems, p. 49
CHAPTER 15—DRAWINGS, SPECIFICATIONS, AND SUBMITTALS, p. 50
15.1—Engineering requirements, p. 50
15.2—Drawings and specifications, p. 50
15.3—Submittals, p. 50
CHAPTER 16—DESIGN EXAMPLES, p. 51
16.1—Calculation of FRP system tensile properties, p. 51
16.2—Comparison of FRP systems’ tensile properties, p. 51
16.3—Flexural strengthening of an interior reinforced concrete beam with FRP, p. 52
16.4—Flexural strengthening of an interior reinforced concrete beam with near-surface-mounted (NSM) FRP bars, p. 58
16.5—Flexural strengthening of an interior prestressed (bonded strands) concrete beam with FRP, p. 62
16.6—Shear strengthening of an interior T-beam, p. 68
16.7—Shear strengthening of an exterior column, p. 72
16.8—Strengthening of a noncircular concrete column for axial load increase, p. 72
16.9—Strengthening of a noncircular concrete column for increase in axial and bending forces, p. 75
16.10—Plastic hinge confinement for seismic strengthening, p. 80
16.11—Lap-splice clamping for seismic strengthening, p. 82
16.14—Flexural strengthening of continuous unbonded prestressed concrete slab with FRP laminates, p. 93
CHAPTER 17—REFERENCES, p. 97
Authored documents, p. 99
APPENDIX A—SUMMARY OF STANDARD TEST METHODS, p. 106
APPENDIX B—AREAS OF FUTURE RESEARCH, p. 107
APPENDIX C—METHODOLOGY FOR COMPUTATION OF SIMPLIFIED P-M INTERACTION DIAGRAM FOR NONCIRCULAR COLUMNS, p. 108

This document provides guidance for the selection, design, and installation of externally bonded and near-surfacemounted (NSM) FRP systems for strengthening concrete structures.