Analysis of the experimental flexural behaviour of a concrete beam grid reinforced with CFRP bars

Abstract In recent years the use of composite materials as reinforcement in concrete beams has increased whenever durability is the main controlling parameter. Many studies have been performed on the behaviour of concrete beams but few have analysed the structural behaviour of plane elements like slabs or grids. The paper analyses the experimental flexural behaviour of a concrete beam grid reinforced with CFRP bars. An one-third scale experimental model of a real concrete floor, was tested in bending. The experimental results show the flexural behaviour in terms of cracking phases and deflection until the failure. The experimental model was affected by the cracking of concrete even under low loads. The experimental model is analysed both by elastic theory of orthotropic plate and a FEM code. An approximate method of calculation, based on an orthotropic plate model, is developed that considers modified bending rigidities for orthogonal directions.