The evaluation of mechanical and chemical properties of concrete by non-destructive evaluation requires the adaptation of the techniques and of theirs exploitations. Under the ACDC national project, we developed, a methodology for the characterization of structures in which the reality of the material and the environmental conditions are taken into account. Correlations laws from the laboratory between non-destructive measurements and characteristics of the concrete are readjusted by several procedures. We invert the non-destructive evaluation and exploit the complementarity of the four techniques implemented (ultrasonic , electromagnetic, resistive and capacitive) through a process of data fusion. We develop the steps of the pre auscultation and the auscultation and define an estimator with a quality intrinsic of data fusion. Inversion procedures were defined and tested on two industrial structures. They rely on the consistency of non destructive measures or on data obtained from destructive testing. We present methods and results, the selection criteria and the approach adopted for operation. Ours propositions are written in a recomandations book to guide the auscultation.< Leer menos