title: Condition assessment of PC tendon duct filling by elastic wave velocity mapping.
abstract: Imaging techniques are high in demand for modern nondestructive evaluation of large-scale concrete structures. The travel-time tomography (TTT) technique, which is based on the principle of mapping the change of propagation velocity of transient elastic waves in a measured object, has found increasing application for assessing in situ concrete structures. The primary aim of this technique is to detect defects that exist in a structure. The TTT technique can offer an effective means for assessing tendon duct filling of prestressed concrete (PC) elements. This study is aimed at clarifying some of the issues pertaining to the reliability of the technique for this purpose, such as sensor arrangement, model, meshing, type of tendon sheath, thickness of sheath, and material type as well as the scale of inhomogeneity. The work involved 2D simulations of wave motions, signal processing to extract travel time of waves, and tomography reconstruction computation for velocity mapping of defect in tendon duct.
authors.affiliation: Department of Civil Engineering, University of Malaya, Kuala Lumpur, Malaysia.
authors.forename: Kit Fook
authors.initials: KF
authors.lastname: Liu
authors.affiliation: Department of Civil Engineering, University of Malaya, Kuala Lumpur, Malaysia.
authors.forename: Hwa Kian
authors.identifier: 0000-0002-4153-9155
authors.initials: HK
authors.lastname: Chai
authors.affiliation: Department of Civil Engineering, University of Malaya, Kuala Lumpur, Malaysia.
authors.forename: Nima
authors.initials: N
authors.lastname: Mehrabi
authors.affiliation: Department of Civil Engineering, Nihon University, Tokyo, Japan.
authors.forename: Kobayashi
authors.initials: K
authors.lastname: Yoshikazu
authors.affiliation: Graduate School of Engineering, Kyoto University, Kyoto, Japan.
authors.forename: Tomoki
authors.initials: T
authors.lastname: Shiotani
mesh_terms: D000465:Algorithms; D003252:Construction Materials / Q000032:analysis*; D054459:Elasticity Imaging Techniques / Q000379:methods*; D008422:Materials Testing / Q000379:methods*; D012542:Scattering, Radiation; D013016:Sound