What type of failure occurs when a concrete structure breaks rapidly under stress?

The type of failure that occurs when a concrete structure breaks rapidly under stress is classified as brittle failure. In the context of materials science, brittle failure is characterized by a sudden fracture with little to no plastic deformation. This means that when the stress applied to the concrete exceeds its strength, it will break suddenly rather than deforming beforehand.

Concrete is a material that typically exhibits brittle behavior, especially under tensile stresses. When a concrete element is subjected to load, it can withstand significant stress up to a certain point, but once that maximum strength is exceeded, it can fail quickly without warning. This rapid failure can lead to significant structural concerns since it does not provide indicators (like deformation) warning of impending failure.

In contrast, ductile failure involves substantial deformation before fracture and allows for more warning prior to the structural failure. Plastic failure represents a type of deformation that occurs under stress, leading to shape changes without a complete rupture. Elastic failure refers to the behavior of materials under stress where they can return to their original shape after the load is removed, which is not applicable in this context of sudden breakage in concrete. Thus, brittle failure is the correct designation for rapid fracture of concrete under stress.