What is carbon fibre column wrapping?
CFRP strengthening uses high-strength carbon fibres embedded in epoxy resin. For columns, unidirectional carbon fabric is saturated with epoxy and wrapped around the member in the number of layers and fibre direction specified by the engineer (wet lay-up). For beams and slabs, pre-cured carbon laminates (plates) or fabric strips are bonded to the tension face.
The system only works if the concrete is sound and well prepared, column corners are rounded, the epoxy fully saturates the fabric and the bond to the concrete is verified. Design is carried out by the structural engineer, commonly following guidance such as ACI 440.2R.
Benefits
- Increases strength with minimal increase in size or weight
- Faster to install than concrete jacketing, with less disruption
- Corrosion-resistant strengthening material
- Suitable for columns, beams, slabs and walls
Common problems and applications
Problems it solves
- Columns needing higher axial capacity or confinement
- Beams and slabs with insufficient flexural or shear capacity
- Change of use or additional loads on an existing structure
- Members with reinforcement loss after repair
- Seismic upgrading of existing structures
Where it is used
- Columns in residential and commercial buildings
- Beams and slabs in parking structures and podiums
- Industrial floors and equipment supports
- Heritage and occupied buildings where jacketing is impractical
Our carbon fibre column wrapping process
Design review
We study the engineer's CFRP design: number of layers, fibre direction, overlaps and anchorage, and the specified system.
Concrete repair
Damaged concrete is repaired and cracks are injected so the substrate is sound. See structural concrete repair.
Surface preparation
The surface is ground to remove laitance; column corners are rounded to the specified radius; bug holes are filled with epoxy putty.
Primer and saturant
Epoxy primer is applied, followed by saturant on the surface.
Fabric or laminate installation
Fabric is saturated and wrapped with the specified overlaps, removing air with rollers; laminates are bonded with epoxy adhesive.
Testing and finish
Pull-off adhesion tests and sounding checks are carried out; a protective coating or plaster finish is applied.
Materials and systems used
- Unidirectional carbon fabric
- Wrapped around columns or bonded to beams in the specified direction.
- Pre-cured CFRP laminates
- Bonded to beams and slabs for flexural strengthening.
- Epoxy primers and saturants
- Bond the fabric to the concrete and form the composite.
- Epoxy putty
- Fills surface irregularities before wrapping.
- Protective top coats
- UV and fire protection where specified.
Products are selected from the approved specification. Coverage, thickness and curing follow the manufacturer's current data sheet.
Why professional CFRP installation matters
CFRP is a structural element, not a coating. If the concrete is weak, corners are sharp, the fabric is dry or air is trapped, the system can debond and fail to carry load. These defects are hidden once the finish is applied.
A professional installer follows the engineer's design exactly, prepares the surface correctly and tests the bond. Each stage is documented so the engineer can approve the work with confidence.
Why choose us
- Design-faithful installation
- Layers, directions and overlaps exactly as the engineer specifies.
- Proper surface preparation
- Grinding, corner rounding and repair before any carbon is applied.
- Bond testing
- Pull-off tests and sounding checks recorded for the engineer.
- Repair and strengthening together
- We repair the concrete and install CFRP in one programme.
Read more about our team and how we inspect and record work.
Frequently asked questions
How strong is carbon fibre compared with steel?
Carbon fibre has a very high tensile strength relative to its weight, which is why thin layers can significantly strengthen a member. The actual design strength is set by the engineer using the manufacturer's data and design factors.
Can CFRP be applied to a column that is already damaged?
The column must first be repaired so the concrete is sound. CFRP is then applied over the repaired surface.
Does CFRP need fire protection?
Epoxy-bonded systems can lose strength at high temperatures. Where the design relies on CFRP in fire, the engineer specifies protection, such as fire-rated coatings or plaster.
Is carbon fibre wrapping the same as column jacketing?
No. Jacketing adds concrete and steel around the column. CFRP adds a thin composite layer. See RCC column rehabilitation and jacketing.
