a.b.e.® durafibre CFP Structural Strengthening System

• Flexural strengthening of beams and slabs
• Shear strengthening (in combination with fabrics or anchors)
• Seismic upgrade of structures
• Compensation for reduced reinforcement or design changes
• Strengthening after fire or corrosion damage

The system functions by transferring stresses from the substrate into the carbon fibre reinforcement through a structural adhesive bond.

1.1 Competency
Design shall be carried out by a competent engineer in accordance with applicable standards, including (but not limited to):

• fib Bulletin 14 – Externally bonded reinforcement
• ACI 440.2R – Design of FRP strengthening systems
• EN 1992 and relevant annexes
• EN 1542 – Pull-off testing

Application must be carried out by trained and experienced contractors familiar with carbon fibre strengthening systems.

1.2 Engineering Design
• A qualified structural engineer design consideration shall include:
◦ Plate size, thickness, and layout
◦ Required strengthening capacity
◦ Load calculations and combinations
◦ Number of layers and anchorage length

1.3 Environmental Conditions
• Material temperature: 12–18°C
• Ambient temperature: 10–40°C
• Temperature must not fall below 5°C for 24 hrs after application
• Substrate must be at least 3°C above dew point
• Avoid condensation, wind pressure (tunnels/underground), and dust interference

1.4 Equipment & Tools
Typical equipment required:
• Mechanical grinders or grit blasting equipment
• Industrial vacuum cleaners
• Mixing tools (low-speed mixers <500 rpm)
• Application trowels and spatulas
• Rubber rollers for consolidation
• Plate cutting tools (diamond saw or equivalent)
• Cleaning solvents and lint-free cloths
• PPE (gloves, goggles, respirators)

2.1 Concrete Age & Condition
• Concrete must be minimum 28 days old
• Surface must be sound, dry, clean, and free of laitance, coatings, grease/oil, curing compounds, loose particles, and contamination

2.2 Profile & Flatness
• Concrete must be mechanically prepared by chipping/grinding to expose coarse aggregate
• Preferred method: light grit blasting to achieve a mechanical key
• Surface irregularities must not exceed:
◦ ≤1 mm height variation
◦ ≤10 mm over a 2 m span
◦ Treat irregularities by grinding, scarifying or blasting

2.3 Crack, Blowhole & Honeycomb Repair
• Defects must be repaired using a compatible structural repair material: epidermix 314®, durafibre CFP adhesive, or other a.b.e.®
repair mortars
• Repairs must be cured adequately before adhesive application, as well as the repair materials must be compatible with the adhesive and suitable for the structural situation
• Achieve minimum tensile adhesion strength of ≥1.5 MPa, and carry out testing prior to installation

2.4 Cleaning & Dust Removal
• After mechanical preparation, vacuum clean thoroughly.
• Surface must remain dust free prior to adhesive application

2.5 Limitations
The system shall not be applied under the following conditions unless specifically approved:
• Unsound or weak substrates
• Excessive moisture or standing water
• Temperatures outside specified limits
• Surfaces contaminated with oil, grease, or laitance
• Fire exposure without protective measures

All structural decisions remain the responsibility of the design engineer

durafibre® Carbon Fibre Plate (CFP) typical properties:

• High strength fibres in epoxy matrix
• Tensile strength (ASTM D 3039): High strength, >2500 MPa
• Elastic modulus: High stiffness range, 165 GPa
• Elongation at break: >1.8%
• Density: 1.5 g/cm³, lightweight
• Plate thickness: 1.2 and 1.4 mm
• Plate widths: 50 and 100 mm

3.1 Cutting
• Cut plates to required length using a diamond saw, disc cutter, or fine file saw
• Inspect plates for defects such as splits or fibre damage; discard damaged pieces
• Use proper PPE: goggles, dust mask, gloves

3.2 Cleaning of Plate Bonding Surface
• Clean the ground/matt side of the plate thoroughly using MEK or abe® thinners No. 3; allow ±10 minutes drying
• Plate must be clean, dust free and uncontaminated before adhesive application

durafibre® CFP adhesive two-component structural epoxy adhesive:
• High bond strength to prepared concrete
• Thixotropic consistency for overhead and vertical work
• Suitable for specified temperature range
• Compatible with durafibre® system components
• Density: 1.5 – 1.7 kg/L
• Application temperature: 10°C – 40°C
• Compressive Strength: 60 – 90 MPa
• Tensile Strength: 20 – 35 MPa
• Bond Strength to Concrete: >1.5 MPa
• Elastic Modulus: 8 – 12 GPa
• Glass Transition Temp (Tg): 45 – 60°C

4.1 Mixing Ratio
• Mix 1:1 by volume or mass (base : activator)

4.2 Mixing Method
• Mix manually with trowel/spatula or mechanically using a low speed mixer (<500 rpm) with helical paddle for ~3 minutes until a uniform
consistency is achieved
• Avoid high speed mixing—this entrains air and weakens the adhesive
• Observe pot life limits—do not use partially cured material

4.3 Pot Life
• 60–100 minutes at 25°C (500 ml mass)
• Mix only small batches (≤250 ml each compound) to prevent premature gelling

4.4 Important Notes
• Do not thin or add solvents
• Discard adhesive once viscosity increases (end of useful life)
• All tools must be clean prior to use

5.1 Priming
• No primer required

5.2 Adhesive Layer on Concrete
Apply adhesive in two stages:
• Wetting Layer: 1 mm layer to the prepared concrete surface
• Levelled Layer: create a full bedding ensuring continuous contact

5.3 Adhesive Layer on Plate
• Apply 2 mm to plate edges, tapering to 4 mm at centre line to form a domed profile, ensuring no dry spots

5.4 Overall Minimum Thickness
• Total adhesive thickness should be approximately 3–4 mm, depending on plate width and tolerance

6.1 Placement
• Position the adhesive coated plate onto the adhesive prepared substrate while both are still wet
• Press plate onto substrate manually to establish initial contact

6.2 Consolidation
• Use a rubber or wooden roller to apply pressure from centre outward:
o Expel voids
o Ensure uniform adhesive squeeze out

6.3 Removal of Excess Adhesive
• Remove extruded adhesive using a spatula or dry cloth before initial set
• Ensure continuous bond without voids

6.4 Multiple Layers
• When a second layer is required, grind/lightly abrade the cured surface in a cross hatch pattern and clean before re-application
• Care must be taken when lightly abrading the surface to NOT damage the carbon fibre plate

7.1 Initial Cure
• Avoid any disturbance for 3–4 hours post installation, depending on temperature

7.2 Practical Cure
• Approx. 12 hours at 25°C

7.3 Full Cure
• 7 days for full mechanical properties

7.4 Environmental Protection
• Protect from: Rain, Dust, Debris, High winds for at least 24 hours

Although carbon fibre itself is corrosion resistant, epoxy matrices require UV protection.

• a.b.e.® recommends the following based on service environment:

◦ duracote PB or Solidkote UVC for UV
◦ duraflex® for damp and sub-merged conditions
◦ abecote® SF 356 or abecote® SF 217 for chemical exposure
◦ Renderoc series for fire protection

• Apply coatings after minimum 24 hours curing

• Clean tools immediately with abe® super brush cleaner before adhesive cures
• Cured adhesive must be mechanically removed

• Uncured adhesive is toxic; avoid skin/eye contact. Wear appropriate PPE
• Avoid inhalation of dust when cutting plates
• Ensure good ventilation in confined spaces
• Follow relevant safety data sheets (MSDS)

• Store materials in dry, shaded conditions in original packaging
• Maintain temperature within specified storage limits
• Protect plates from mechanical damage and contamination
• Store adhesive in cool, dry conditions
• Adhesive shelf life: 24 months in original sealed packaging
• Carbon plates have unlimited shelf life when dry-stored

12.1 Pre-installation checks:
• Surface tensile adhesion strength ≥ 1.5 MPa (pull-off testing)
• Surface cleanliness and profile
• Environmental conditions

12.2 Post-installation checks:
• Plate alignment and full surface contact and no defects
• No voids or dry zones by tap testing
• Correct plate orientation (unidirectional fibre direction)
• Adhesion failure must not occur in adhesive interface

12.3 Records:
Record for each project:
• Substrate preparation details
• Batch numbers of materials
• Environmental conditions during installation
• Test results (pull-off, inspection)
• Installation dates and personnel