When you have a concrete structure that needs modification to prolong its lifespan, or a change of use needs to be accommodated, then strengthening is a possibility that should to be considered. Freyssinet are in a position to offer clients a wide range of options when it comes to strengthening. Some of the potential applications for the various strengthening techniques include: increasing the floor slab load that is allowed, strengthening of the bridge deck, adding strengthening to new openings, and strengthening columns. External post tensioning is appropriate when dealing with bridge decks in particular. Along with everything else Freyssinet have to offer is, a complete design and install post tensioning service for any of your existing structures. No matter how big the project may be Freyssinet can meet even the most demanding post tensioning applications. If the bridge structure is a large span box girder, Freyssinet can fit additional post tensioning inside the structure itself. External post tensioning can also be used to upgrade circular storage tanks, or to make them watertight. Tendons fitted to the outside of smaller span structures, are also something offered by Freyssinet.
In existing areas that have a high stress concentration or that may be subjected to bursting forces, pre-stress may need to be introduced. Freyssinet can meet these needs with their own Freyssibar pre-stressing system. This is a comprehensive range of fully threaded, high strength bars that are complimented by extension, coupling and anchoring systems. If you have an over-stressed area of an existing structure, this solution can be an effective remedial action. Freyssibars can also be an excellent option, if you are looking to increase the load carrying capacity of your existing structure with high tensile bars. If under strength floor slabs or beams are the problem, you may want to consider plate bonding. This is a process where Freyssinet can take appropriately sized steel plates, then bolt them or bond them, with an epoxy adhesive to a structure’s tension zone. By applying this process to the specific area, the load carrying capacity can be increased as required, up to a certain degree.
Another alternative solution offered by Freyssinet is the use of a carbon fibre product called TFC. This reinforced polymer carbon fibre product is manufactured in house by Freyssinet, and can be an outstanding option in the right circumstances. TFC can be particularly useful if the area you need to reinforce has a complex profile, or if clearance height is an issue, such as in a multi-storey car park for example. Other advantages of TFC are that it adds no extra weight to the structure, it is suitable for use in a wide range of temperatures, and it is resistant to UV, fire and shocks.
The correct type of strengthening application is dictated by the structure, its use, its design, and the amount of desired load carrying increase to be achieved. All of these factors require careful consideration, which is why Freyssinet offer a complete design and build service for its clients. Their in-house teams can assist in deciding which is the most appropriate technical and economical solution for your strengthening requirements.