invention the migration of the liquid may be controlled visually by observing the color of the treated material or the oozing of the liquid at another end of an interface this observation may be facilitated by adding coloring agents in the treatment liquid fig1 illustrates a particular embodiment of the method of the invention applied to the treatment of reinforced or pre stressed concretes the system allowing application of the method of the invention includes an injection part 1 comprising an admission tube 4 allowing a liquid to be injected into the compression chamber 5 said compression chamber 5 is essentially formed by the wall 6 of a cavity made drilled in a surface of said material to be treated 2 an outlet tube 8 allows discharge of the treatment liquid this liquid may be checked and then reinjected penetration of the liquid into the porous material is achieved by emitting a high power acoustic wave generated by means of a pulsating element 7 the depth at which the pulsating element 7 generates the acoustic wave may be adjusted by sliding a mobile part 3 relatively to the injection part 1 in particular it is also possible to obtain better cleaning of the porosities cracks and microcracks present in the porous medium allowing optimization of the penetration of the liquid into said medium in a particular embodiment of the invention fig2 the penetration within the porous material 2 of the liquid is improved by using an enclosure 15 in which vacuum may be generated by means 16 known to one skilled in the art said enclosure.