Reinforcing concrete structures with composites is an innovative alternative to the traditional method of using external metal plates, which offers the following benefits:
- Increased strength of deteriorated, damaged, or design/execution-deficient structures to extend their service life.
- Adaptation of the structure to changes in operational conditions or increased load-bearing capacity.
- Increased resistance to shear forces or bending in beams.
- Reinforcement of structures in cases of operational load modifications, changes in the static system, inadequate reinforcement, or improper execution.
- Earthquake-resistant strengthening to align the structure with updated standards.
- Enhanced strength and rigidity of concrete structures.
- Anchoring of posts, columns, or foundations.
- Reinforcement of structures when creating spans or funnels.
The application of this technique requires precise methodology and consideration of appropriate weather conditions. These conditions include working against rain, direct sunlight, outdoor temperature, limited relative humidity, resin usage time, and more. Adhering to safety criteria and precautionary measures during surface preparation is essential.
The concrete surface must have sufficient surface bonding (greater than 1.5 MPa) and an appropriate substrate, as the bond between the composite and concrete is crucial for the efficiency and durability of the repair.
The following considerations are essential for preparing the concrete substrate:
- The surface should be adequately rough and satisfactory.
- The surface must be chemically and physically clean and dry.
- All surface soils, dust, grease, and oil must be removed.
- Any coatings should be removed.
- Any defects such as holes, voids, etc., should be repaired before applying the composite coating.
Key techniques for surface preparation include wet or dry sandblasting, high-pressure water washing, and mechanical or manual sanding.
At Farasath Zarfam, the selection of the product and technical solution is based on the specific requirements of different structures, as follows:
- Size requirements: Tensile strength failure in shear, composite modulus of elasticity, fatigue behavior, creep under vibration, impact, fire, or earthquake…
- Installation requirements: Thermal conditions during bonding, structure’s service life, geometry of the component, etc.
- Durability requirements related to environmental conditions: Temperature, humidity, UV exposure, etc.
- Supervisory requirements
- Maintenance and operational use of the structure
Composites are either resin-impregnated at the time of installation or pre-impregnated in the factory or on-site, with both methods being carried out at Farasath Zarfam.
Fabrics or tapes are bonded to the substrate using a resin-coated roller. The repair process is completed with a degassing operation to remove any air bubbles between the support and the composite and eliminate any excess adhesive.