In bridge inspection, what type of deterioration may not be visible but significantly affects structural integrity?

Delamination is a form of deterioration that occurs when layers of materials, such as concrete or composite materials, separate and lose their bond with one another. This separation can happen beneath the surface of the material, making it difficult to detect visually during a standard inspection. Although the outer layer may appear intact, the internal structure can be compromised, significantly affecting the bridge's overall structural integrity.

This type of deterioration is particularly concerning because it can lead to unexpected failures; the external parameters might not exhibit any obvious signs until the problem has progressed considerably. Identifying delamination often requires specialized techniques such as non-destructive testing methods, which can reveal the hidden issues that could impact the performance and safety of the bridge.

In contrast, other types of deterioration, such as surface cracking or discoloration, are usually more visible and can often be assessed easily through routine inspections. Corrosion might show external signs like rust or other surface damage but may still be detectable through visual inspection before it leads to significant structural issues.