You most probably heard of fiber-reinforced polymers (FRP) being used for bridge strengthening, building renovation, slab openings, etc.
FRP technology has been used in fields such as energy, sports and the marine industry. It is still being used, increasingly in fields such as aeronautics, the automobile industry and other related areas.
Since the mid-1980s, FRP technology has been used in civil engineering. It can be said, then, that it is a proven technology, because it’s been available and has been performing for 30 years in building works. It might even be said that, currently in Canada, it is a trend that many engineers, building owners, university professors and contractors promote.
This blog will focus on externally bonded structural strengthening solutions by using FRP products
. In Canada, widely used solutions include carbon fiber fabrics, such as MapeWrap
® products; glass fiber fabrics, such as MapeWrap G Uni-Ax
; epoxy resin saturants, such as MapeWrap 21
; and pultruded carbon fiber plates, such as Carboplate
® E 170
, bonded onto the substrate using a structural epoxy putty adhesive like MapeWrap 11
or MapeWrap 12
. You can discover other innovative structural strengthening systems in our international structural strengthening manual.
You can specify FRP strengthening for many reasons, the most common being the enhancement of a structure’s capacity following a change in function or an increase in load demand over the years…
FRP strengthening is also useful for seismic upgrading. I will mention a few of the many advantages:
Lightweight and resistant
While having high tensile strength and very high tensile modulus, FRP products are much lighter than steel and more resistant to chemical attacks without causing corrosion.
External strengthening of reinforced concrete
Steel is certainly a good option for external strengthening of reinforced concrete; therefore, if we can use steel within the concrete, why not use it externally? Well, steel can corrode and is not a subtle solution when used as external reinforcement. If architects and engineers had to unanimously agree on a preferred type of external reinforcement, I am convinced they would opt for FRP technology.
can be used for ﬂexural strengthening of columns, beams and slabs; for ﬂexural strengthening around slab openings; for shear strengthening of walls, beams and columns; and for the confinement of circular, square and rectangular columns.
Good blending properties
In addition to delivering high doses of kN, MPa and kN/m, externally bonded FRP strengthening systems can be completely “hidden” from the general public by using cementitious protection such as Mapelastic
®, or an acrylic coating such as Elastocolor
and Elastocolor Paint
Finally, I encourage you to become familiar , if you haven’t already done so, with the Canadian design codes CSA S806 and CSA S6 – Chapter 16. The American standard ACI 440.2R also provides an excellent reference.
A preliminary design tool based on the CSA S806-12 code is available at www.mapeifrp.com.
Thank you for your attention. Know that our experts will be happy to help you with your projects. And for further tips, check out my next blog on the field application of externally bonded FRP strengthening systems for reinforced concrete structures.