Which sound is characteristic of "sound" concrete?

"Sound" concrete is characterized by a "pinging" sound when struck. This distinct sound indicates that the concrete has good integrity and density, suggesting it is free from significant cracks or voids that could compromise its structural integrity. The pinging sound arises from the solid nature of the concrete, which effectively transmits sound waves.

In contrast, other sounds such as clacking, humming, or buzzing typically indicate problems with the concrete. Clacking might suggest loose aggregate or deteriorating material; humming could be a sign of air pockets or other inconsistencies; and buzzing might imply underlying issues such as cracking or delamination. Understanding the acoustic responses of concrete is crucial in evaluating its condition, and recognizing the pinging sound is an essential skill for ensuring bridge and structural safety during inspections.