BEHAVIOUR OF CONCRETE SLABS REINFORCED WITH FRP GRIDS UNDER SERVICE AND ULTIMATE LOADING

A test program was set up at the Magnel Laboratory to study the use of Fiber Reinforced Plastic (FRP) as reinforcement for concrete slabs. The structural behaviour of seven simply supported concrete slabs reinforced with FRP grids is compared to that of a steel reinforced reference slab, in terms of ultimate state (failure aspect, ultimate load and ultimate deflection), serviceability behaviour (cracking and deflections), ductility and deformability. Calculations were made to verify these different limit states. It appears that the bond behaviour of the used FRP grids - good bond characteristics along the bars or mechanical anchorage of the longitudinal bars by means of the transverse bars - influences the cracking and the cracking moment. It is also shown that the design of the slabs is primarily governed by serviceability criteria and that, at the same time, sufficient "deformability" at ultimate is provided.