ADVANCED FIBRE reinforced concrete (FRC) technology has been used for the first time to speed up the construction of composite floors on site by eliminating mesh reinforcement, it was claimed this week.
The first pours of the FRC floors took place recently on a multistorey commercial steel framed development in Derby.
A steel Holorib profile from Richard Lees Steel Decking was positioned, and the special FRC mix pumped into place to create a 160mm thick composite slab with a two hour fire rating.
Concrete specialist Grace Construction Products developed the mix with Richard Lees and the Steel Construction Institute.
It uses 40mm long co-extruded polyethylene/ polypropylene fibres and a Grace superplastisiser and pumping aid. The material was supplied to the site ready mixed by Tarmac Central.
The product's developers said the fibres provide the required level of shrinkage crack control, transverse shear and fire resistance. They also eliminate the need to handle and fix an upper layer of steel mesh reinforcement. In practice this means significant programme savings and reduced need for craneage.
In all, 6,000m 2of the new style floors will be poured on the Derby project and, as the floor construction nears completion, no problems have been reported.