Recommendation of RILEM TC 269-IAM: damage assessment in consideration of repair/retrofit-recovery in concrete and masonry structures by means of innovative NDT Methods for damage assessment of concrete members utilizing active elastic wave measurements

This recommendation specifies a method for measuring active elastic waves and assessing damage to concrete members such as decks and girders. The method uses elastic waves propagating inside the concrete member. Elastic waves generated near a surface of the concrete member are detected by acoustic emission sensors installed on the opposite side of the member. Elastic waves propagating in concrete are attenuated or diffracted by damage such as cracks and voids, resulting in fewer AE sources than that of intact areas. Thus, it is possible to distinguish a damaged region from others with density of the observed AE source distribution