Application of ultrasonic shear-wave tomography to identify horizontal crack or delamination in concrete pavement and bridge

•Delamination in concrete columns can be evaluated by the MIRA system.•The MIRA detects concrete cover depth over reinforcing steel in concrete piers.•The MIRA is able to estimate of slab thickness and delamination depth. As more concrete structures and pavements in the US are approaching or have already exceeded their design lives, the number of distresses and needed repairs have increased, along with the amount of funding needed. In this study, various concrete distresses in structures and pavements were evaluated with MIRA testing, which is based on the ultrasonic pulse-echo method. The distresses evaluated included horizontal cracking or delamination at the mid-depth of concrete pavement slabs, spalling and map cracking in concrete pavement slabs, mudballs in concrete runway, concrete cracks and delamination in bridge columns, and shallow concrete cover in bridge piers. MIRA was able to detect discontinuities in concrete, whether they are cracks, delamination at an interface of two concrete slabs, mudballs, or reinforcing steel.