| Dry or peramnently wet |
Concrete inside buildings
with low air humidity |
| Wet, rarely dry |
Concrete surfaces subject to
long-term water contact |
| Moderate humidity |
Concrete inside buildings with
moderate or high air humidity |
| Cyclic wet and dry |
Concrete surfaces subject to
water contact, not within XC2 |
| Moderate humidity |
Concrete surfaces exposed to
airborne chloridesr |
| Wet, rarely dry |
Concrete exposed to industrial
waters containing chlorides |
| Cyclic wet and dry |
Parts of bridges exposed to
spray containing chlorides |
| Exposed to airborne salt |
Structures near to or on the
coast |
| Permanently submerged |
Parts of marine structures |
| Tidal, splash and spray zones |
Parts of marine structures |