STRUCTURAL ELEMENT REINFORCEMENT
In modern construction, the use of carbon fibers as a new technology for concrete reinforcement is becoming increasingly common. Due to a number of advantages over traditional steel reinforcement, the concept of using carbon fiber strips for strengthening structural elements was developed.
Carbon fiber strips have eight times higher tensile strength than steel, are lighter, more elastic, more resistant to aggressive environmental influences, and their service life is unlimited, similar to concrete.
Carbon fiber strips are manufactured as:
- Strips, Laminates in which the fibers are bonded together with a suitable epoxy resin. These strips can only carry loads in the direction of their fiber alignment.
- Strips, Fabrics“, produced by weaving „yarns“ of carbon fibers. The fabrics can carry loads in multiple directions, depending on the weaving pattern.
Bonding of carbon fiber strips and fabrics to concrete structural elements is performed using appropriate epoxy adhesives. These adhesives are supplied by the manufacturer along with the strips and must be compatible with the specific type of strip used. Prior to bonding, proper surface preparation of the concrete substrate and moisture content verification are essential. Strengthening with strips is only possible for concrete structures that meet a certain level of adhesion between the concrete and the adhesive.
The structural elements suitable for reinforcement include the following:
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Strengthening of beams in spans and at supports
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Strengthening of slabs by bonding strips on the underside
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Strengthening of slabs by bonding strips above supports on the top side of the slab
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Wrapping – “confinement” of columns with square and circular cross-sections
