[en] Since 1974 CEA and EDF have developed in France a large programme with the aim to work out a means of computation reliable enough for the knowledge of the behaviour of reinforced concrete walls under missile impacts. The shots were performed on reinforced concrete slabs, the thickness of which were chosen to represent in a realistic way the thickness of the wall of a reactor containment. The scales used in this modeling were mainly one-half and one-third. The following parameters were kept constant: the properties of the concrete and the geometric shape of the missile (flat nose). Also studied were the effects of variation of parameters like missile velocity (25-450 m/s), its mass (20-300 kg), ratio of the missile diameter to the thickness of the slab (0.24-2.9) and characteristics of the steel reinforcement. The results of these tests may be summarized in a homogeneous perforation formula in the case of a velocity lower than 200 m/sec: Vsub(c)²=1.7 sigmarhosup(1/3)(sigmae²/M)sup(4/3), where Vsub(c), is the minimum velocity for perforation, phi diameter of the missile, M its mass, sigma the ultimate compressive strength of the concrete, rho its density and e its thickness. (Auth.)