Abrasion zone

An abrasion zone is the band of a marine structure that takes mechanical wear from moving water, sediment, ice, and contact with vessels and mooring gear. On a quay or wharf it is the tidal and splash band of the face, where waterborne sand, fenders, and mooring lines grind the surface and the concrete cover spalls fastest, so it is detailed with a sacrificial cover, harder facing, or stone protection. The term also names the wave-cut abrasion platform on a rocky shore, cut at the cliff base by wave-driven sediment. Both are wear by entrained particles, not chemical attack.