| Exposure Environment |
Exposure Description |
Typical Element Location |
| Mild |
Structure and/or elements of a structure:
- Generally exposed to mild weather conditions, i.e. may be sheltered or in an environment that results in little or no exposure to severe weather conditions; and/or
- Not exposed to any aggressive agents, e.g. no exposure to road de-icing salts or greater than 8m* away from traffic spray, not exposed to or buried in aggressive soil agents, no exposure to contaminated water, etc.; and/or
- With no ventilation or condensation problems or where poor ventilation or the level of condensation are unlikely to increase the rate of deterioration.
|
- Elements protected from salt spray with cladding or by a protective enclosure.
- Deck soffit and piers of integral bridges where the obstacle crossed is not a road, i.e. elements are not subjected to spray from salted road.
- Tenanted arch bridges.
- Half-joints or hinge joints overlaid with functional expansion joints.
|
| Moderate |
Structure and/or elements of a structure exposed to:
- Moderate (normal) weather conditions, e.g. direct rain, moderate humidity or condensation, some freeze-thaw action etc.; and/or
- Moderate de-icing salt spray and airborne chlorides; e.g. within 3 to 8m of traffic spray on routes with de-icing salts; and/or
- Low to moderate river flow. But elements are not exposed to or buried in aggressive soils.
|
- Top of roadside bridge pier or abutment subject to light vehicle spray from salted road.
- Bridge deck soffit subject to light vehicle spray from salted road.
|
| Severe |
Structure and/or elements of a structure exposed to:
- Continuous or regular severe/extreme weather conditions, e.g. hot and cold extremes, high freeze-thaw action, severe humidity or condensation, etc.; and/or
- Severe de-icing salt spray, e.g. within 3m of traffic spray on routes with de-icing salts; and/or
- Run-off and/or ponding on routes with de-icing salts; and/or
- Aggressive soils, i.e. completely or partially buried in aggressive soils that are contaminated with acidic water or water containing sulphates; and/or
- Marine environment and/or abrasive action of seawater or completely immersed in sea water; and/or
- Corrosive fumes in industrial areas; and/or
- Medium to rapid river flow and flooding.
|
- Roadside bridge abutment, parapet upstand or deck edge beam subject to heavy vehicle spray from salted road.
- Section of bridge deck near a leaking expansion joint or gutter e.g. deck end or crosshead.
- Half-joints or hinge joints overlaid with non-functional expansion joints.
|
| Protected |
Protected' refers to a finish 'freezing' deterioration of the component/material type. |
|
* The 8m limit is based on DMRB BD 43/03.
Article ID: 209, Created: 4/15/2014 at 12:51 PM, Modified: 11/9/2016 at 2:59 PM