Development of a Tomography Technique for Assessment of the Material Condition of Concrete Using Optimized Elastic Wave Parameters

Abstract

Concrete is the most ubiquitous construction material. Apart from the fresh and early age properties of concrete material, its condition during the structure life span affects the overall structural performance. Therefore, development of techniques such as non-destructive testing which enable the investigation of the material condition, are in great demand. Tomography technique has become an increasingly popular non-destructive evaluation technique for civil engineers to assess the condition of concrete structures. In the present study, this technique is investigated by developing reconstruction procedures utilizing different parameters of elastic waves, namely the travel time, wave amplitude, wave frequency, and Q-value. In the development of algorithms, a ray tracing feature was adopted to take into account the actual non-linear propagation of elastic waves in concrete containing defects. Numerical simulation accompanied by experimental verifications of wave motion were conducted to obtain wave propagation profiles in concrete containing honeycomb as a defect and in assessing the tendon duct filling of pre-stressed concrete (PC) elements. The detection of defects by the developed tomography reconstruction procedures was evaluated and discussed.

Imaging of Increasing Damage in Steel Plates Using Lamb Waves and Ultrasound Computed Tomography

“…The assumption that ultrasound waves propagate along straight paths from the transmitters to the receivers gives good results (cf. [ 41 , 42 , 43 , 44 , 45 , 46 , 47 , 48 , 49 , 50 ]). However, the quality of the tomography can be improved by using the actual ray path.…”

Lamb-Wave-Based Tomographic Imaging Techniques for Hole-Edge Corrosion Monitoring in Plate Structures

“…In the beginning of the 20th century, Kaczmarz and Cimmino developed iterative algorithms for solving linear systems independently [ 33 ]. In 1970, Gordon, Bender, and Herman rediscovered Kaczmarz’s method by applying it in medical imaging [ 34 ], and they called the method Algebraic Reconstruction Technique (ART) [ 35 ]. When image reconstruction is needed with sparse data, the ART method based on the Kaczmarcz algorithm is a natural choice [ 33 , 36 ].…”

Non-Destructive Assessment of Masonry Pillars using Ultrasonic Tomography

“…In this study, through-transmission tomography was applied (cf. [29,32,33,34,27]). The tomographic procedure is based on elastic waves passing through the tested specimen, from the transmitter (T) to receivers (R) (Figure 1b).…”

“…A structural health monitoring system of composite plates with through-thickness holes was presented by Prasad et al [25]. Ultrasound tomography was also widely used for defect imaging in concrete structures (e.g., [26,27]). Martin et al [26] examined post-tensioned concrete beams.…”

“…They obtained volumetric internal images to detect defects within concrete. Chai et al [27] identified the tendon duct filling, as well as honeycomb defects, in concrete specimens. In the case of masonry structures, ultrasonic tomography was used to assess the general condition or to evaluate the effectiveness of the conducted repair.…”