To mark the contribution made by Soletanche Bachy France Design Office to the drafting of recommendations for the French Civil Engineering Association (AFGC – Association Française du Génie Civil) on the use of composite reinforcements, let’s take a closer look at these structural elements which are still rarely used in our sector…
They are non-metallic reinforcements used to replace steel reinforcements (rebars and stainless steel bars) in reinforced concrete structures. They are made up of very fine fibres (generally glass, aramid, carbon, or occasionally basalt) which give the reinforcement its strength and a matrix (epoxy, vinyl ester or polyester) which holds the fibres together and protects them.
The composite materials market emerged in North America from 1970, before spreading to Europe in the early 1980s. Until 2000, it was a niche market, since composite materials were still expensive. Many more applications have emerged over the past 20 years, driving down prices. Canada was a pioneer in the use of composite materials in construction and was quick to adopt a regulatory framework that is now among the most advanced.
Whereas in France, the absence of national guidelines and a lack of historical data concerning the durability of composite materials means that they are rarely if ever used for permanent structures
Thus, our Soletanche Bachy France teams mainly use composite reinforcements for temporary structures, such as reinforcement cages for retaining structures which need to be cut using tunnel-boring machines (e.g. Nice tram, Grand Paris stations).
The forthcoming version of Eurocode 2 providing a regulatory framework governing the use of composite reinforcements, and this new guide offering a comprehensive operational tool for engineers designing structures should develop the use of composites materials in our foundation works.
Eurocodes are the European standards for dimensioning and justification of building and civil engineering structures.