Damage characterization of concrete panels due to impact loading by motionless X-ray laminography

Excerpt

Concrete structures are often subjected to extreme dynamic loading conditions due to direct impact. Typical examples of these loading conditions include transportation structures subjected to vehicle crash impact, marine and offshore structures exposed to ice impact, protective structures subjected to projectile or aircraft impact and structures sustaining shock and impact loads during explosions or earthquakes. The assessment and extent of damage to the structure associated with these transient dynamic loading conditions is of paramount importance. Often there are external visual signs of damage after dynamic loading events, however, the extent of damage inside the structure and the determination of its integrity remains obscure. Therefore, one needs to resort to non-destructive evaluation (NDE) techniques not only to detect damage but also to assess the severity of damage. Unfortunately, high-resolution NDE methods to characterize damage in structural materials have been less successful when applied to concrete, partly due to its inhomogeneous micro- and macrostructure associated with heterogeneities at various length scales that create interferences, such as scattering, attenuation, reflection and diffraction. …