Which statement is FALSE regarding shrinkage cracks?

Shrinkage cracks are primarily caused by the natural drying process of concrete as it cures, leading to volume reduction. Option C inaccurately describes a characteristic of shrinkage cracks; vertical shear typically relates to different failure mechanisms in structural elements rather than the volumetric changes associated with drying.

In contrast, the other statements correctly reflect the nature of shrinkage cracks. For example, shrinkage cracks typically do not extend into the footings because footing designs are meant to provide stability and support beneath the loads they carry. Additionally, it is common for shrinkage cracks to appear without corresponding cracks elsewhere in the structure, highlighting that these cracks can be isolated in specific areas. Lastly, shrinkage cracks are indeed frequent in poured concrete foundation walls, as these walls undergo significant drying and shrinkage after placement.

Understanding these aspects is important for accurately diagnosing and addressing potential structural issues in concrete constructions.