Laboratory Tests of Foam Concrete Slabs Reinforced with Composite Grid

Nowadays foam concrete is commonly used as replacement of compacted soil to fill excavations, underground channels. There are also attempts to structural use of this material; among the examples are precast walls and slab foundations. The high degree of thermal insulation makes foam concrete a perfect material for use in the passive houses design. Unfortunately, foam concrete cannot be reinforced as easily as traditional concrete. Because of low resistance to concentrated stresses it is difficult to ensure sufficient bond of reinforcement. The idea of solid foam concrete slab presented in the paper incorporates bi-directional composite reinforcing mesh placed in tensile zone of the slab where transverse fibers are ensuring anchorage for fibers in main direction. This method of reinforcement, apart from the increase of bearing capacity, should reduce the risk of uncontrolled failure due to cracking. The paper describes the results of preliminary laboratory tests of nine slabs made of foam concrete reinforced with meshes made of carbon fibers. The results obtained at the initial stage show great potential of this method of reinforcement. There was a significant increase in capacity and less brittle failure mode.