It’s likely a building will undergo a number of changes in its lifetime. Commercial structures in particular are potentially subject to different loads, with the introduction of new, equipment, and new openings cut to take services. When this happens, the reinforced concrete structural elements are placed under new stress’s and therefore in need of strengthening to take the additional loadings This situation also happens when buildings change use and extra floors are added, and in fact can affect all sorts of building from healthcare to residential.
As a solution, rather than use steel reinforcement to strengthen columns, beams, slabs, and walls, specifiers, clients and contractors are turning to carbon fibre. Flexible and versatile with a superior strength-to-mass ratio than traditional reinforcing methods, carbon fibre allows for a significant increase in performance without adding additional significant dead load. This solution is less intrusive and quicker and easier to install compared to traditional methods.
Carbon fibre strengthening comes in many different forms, plates, rods, near surface mounted plates, fabrics and shear links and are fixed using a range of high performance structural adhesives. Its increasing popularity as a proven solution for not only for reinforced concrete but also steel, cast iron, wood and masonry structures due to its strength, lightweight, easy-handling ability, durability, superb adhesion and rapid installation where downtime of a building is in short supply.
The range of solutions and flexibility makes it ideal for all types of buildings and structures where there is an increase or change of loading and enhanced bending, shear or axial enhancement required. For external and internal use, its performance helps safeguard a building against issues such as long-term fatigue, blast loading and general stability.
Carbon fibre strengthening, as well as offering greater weight resistance than traditional refurbishment processes, is also kinder to the environment. It requires fewer materials and less energy, labour and machinery to install than steel reinforcement. The prospect of future corrosion and costly, time-consuming refurbishment is also eliminated with the use of carbon fibre strengthening. Without heavy plant-based processes required to install it, fabric-based solutions are safer for onsite teams to apply.
Sika provides fully comprehensive solutions with complete systems for all kinds of structural strengthening and improvement. These include:
- Most widely-recognised and established carbon fibre-reinforced polymer (CFRP) strengthening solution available worldwide
- Comprises Sika CarboDur® CFRP plates and rods, together with the structural epoxy resin based adhesives Sikadur®-30 and Sikadur®-30 LP
- Highly durable, outstanding performance, curing times can be accelerated and down-time minimised, even at lower temperatures
SikaWrap® Fabric Strengthening:
- Flexible solution for a range of demands and projects
- Comprises SikaWrap® Fabrics, SikaWrap® FX fabric anchors, Sikadur®-330 epoxy-based four-in-one product (primer, filler, impregnating resin and adhesive)
- Applications including confinement, shear, seismic upgrading and weak substrate strengthening
- Unique L-shaped CFRP plates
- Shear capacity of concrete beams can be increased by the externally-applied Sika CarboShear L-shaped profiles
- Quick and easy installation; excellent anchorage; no drilling through top slab required
- Unique pre-stressed strengthening system
- Withstands loads more efficiently or with less total deflection
- CFRP plates and post-tensioning techniques form a unique active external strengthening solution
Flexible, cost and time-effective and a proven performer in helping strengthen weakening structures worldwide, carbon fibre is shaping-up as a long-standing alternative to steel-based structural refurbishment.
from The UK Construction Blog http://ukconstructionblog.co.uk/2017/06/12/carbon-fibre-offers-powerful-alternative-to-steel-in-structural-strengthening/