Concrete Continuously Reinforced with Flat_ Slotted_ Galvanised Steel Strips. Experience of FLEXARM Reinforcements. French Road Network 1986-1989

The dream of concrete pavement constructors, to replace the conventional difficult-to-fix reinforce-ments, which require a considerable manual work-force, with a continuous bobbin-wound reinforce-ment, has today become a reality. The chosensolution was a weldable carbon steel, with an elas-ticlimitgreater than 700MPA, a rectangular cross-section 40 mm x 2 mm, slotted for a bettersteel!concrete adhesion and delivered in 300 me-tres reels.The first trials carried out in June 1986 on theshoulder of the A6 motorway (SAPRR), showedthat 0.67% of conventional HA steel was equi-valent to 0.3% of flat slotted steel. In 1987a 450metre section of reconstruction of the heavy goodslane of the A6 motorway was built using this 0.3%proportion of steel. This site confirmed the feasi-bility of completely mechanised steelfixing of thestrips and the behaviour of this zone was inall res-pects comparable to that of the whole of the siteconstructed using conventional CRC. In Novem-ber 1988, a first industrial site, 4.800 metres longand 8 m wide, was remetalled, again on the A6motorway and finally, in 1989, a site of 2x 14ki-lometres of new pavement on the A.71Orleans-Bourges motorway enabled this techniqueto be fully operational.