Contents
Editorial
1 Introduction
1.1 The reason behind this boo
1.2 Strengthening with adhesively bonded reinforcement
2 DAfStb guideline
2.1 The reasons for drawing up a guideline
2.2 Preparatory work
2.3 Work on the guideline
2.4 The structure and content of the guideline
2.4.1 General
2.4.2 Design and detailing
2.4.3 Products and systems
2.4.4 Execution
2.4.5 Planning
2.5 Safety concept
2.6 Applications
2.6.1 Member to be strengthened
2.6.2 Strengthening systems
2.6.3 Ambient conditions
2.6.4 Fire protection
2.7 Relationship with other regulations
2.8 Documents and assistance for practical applications
3 Design of strengthening measures with externally bonded CFRP strips
3.1 Principles
3.2 Verification of flexural strength
3.3 Bond analysis
3.3.1 Principles
3.3.2 Simplified method
3.3.3 More accurate method
3.3.3.1 General
3.3.3.2 Determining the crack spacing
3.3.3.3 Accurate analysis of concrete element between cracks
3.3.3.4 Simplified analysis of element between cracks
3.3.4 End anchorage analysis
3.3.4.1 General
3.3.4.2 End anchorage analysis at flexural crack nearest
to point of contraflexure
3.3.4.3 Anchorage analysis at an arbitrary concrete element
between cracks
3.3.4.4 End anchorage analysis with shear wrapping
3.4 Shear force analyses
3.4.1 Shear strength
3.4.2 Shear strengthening
3.4.2.1 Full wrapping in steel
3.4.2.2 Full wrapping in fibre-reinforced material
3.4.2.3 U-wrapping
3.4.3 End strap to prevent concrete cover separation failure
3.5 Fatigue analysis
3.6 Analyses for the serviceability limit state
3.7 Detailing
3.7.1 Strip spacing
3.7.2 Provision of shear straps
3.7.3 Steel shear straps
4 Example 1: Strengthening a slab with externally bonded CFRP strips
4.1 System
4.1.1 General
4.1.2 Loading
4.1.3 Construction materials
4.1.3.1 Near-surface tensile strength
4.1.3.2 Concrete compressive strength
4.1.3.3 Type and quantity of existing reinforcement
4.1.3.4 Position of existing reinforcement
4.1.3.5 Strengthening system
4.2 Internal forces
4.3 Determining the prestrain
4.4 Simplified analysis
4.5 Accurate analysis
4.5.1 General
4.5.2 Verification of flexural strength
4.5.3 Determining the crack spacing
4.5.4 Accurate analysis of concrete element between cracks
4.5.4.1 Determining the strip forces
4.5.4.2 Determining the bond strength
4.5.5 End anchorage analysis
4.6 Analysis of shear capacity
4.7 Serviceability limit state
5 Design of strengthening with near-surface-mounted CFRP strips
5.1 Principles
5.2 Verification of flexural strength
5.3 Bond analysis
5.4 Shear Force Analyses
5.5 Fatigue analysis
5.6 Analyses for the serviceability limit state
5.7 Detailing
6 Example 2: Strengthening a beam with near-surface-mounted CFRP strips
6.1 System
6.1.1 General
6.1.2 Loading
6.1.3.1 Concrete compressive strength
6.1.3.2 Type and quantity of existing reinforcement
6.1.3.3 Position of existing reinforcement
6.1.3.4 Strengthening system
6.2 Internal forces
6.3 Determining the prestrain
6.4 Verification of flexural strength
6.5 Bond analysis
6.5.1 Analysis point
6.5.2 Acting strip force
6.5.3 Bond resistance
6.5.4 Bond analysis
6.6 Shear analyses
6.6.1 Shear capacity
6.6.2 Shear strengthening
6.6.3 Check for concrete cover separation failure
6.7 Analyses for the serviceability limit state
7 Design of column strengthening with CF sheets
7.1 Principles
7.2 Properties of CF sheets relevant to design
7.3 Load-carrying capacity of cross-section
7.4 Load-carrying capacity of member
7.5 Creep
7.7 Analysis at serviceability limit state
8 Example 3: Column strengthening
8.1 System
8.1.1 General
8.1.2 Loading
8.1.3 Construction materials
8.1.3.1 Concrete
8.1.3.2 Type and quantity of existing reinforcement
8.1.3.3 Strengthening system
8.2 Internal forces
8.3 Determining the cross-sectional values
8.4 Boundary conditions
8.5 Verification of column load-carrying capacity
8.5.1 Creep of confined concrete
8.5.2 Properties of the CF sheet
8.5.3 Distribution of transverse compression
8.5.4 Multi-axial stress state in concrete
8.5.5 Calculation of column load-carrying capacity
8.6 Serviceability limit state
9 Summary and outlook
References
Index
VIII