Bridges can suffer from scour when flow conditions change, or rivers go into flood. This scour can threaten the structural integrity of bridges if allowed to develop, which can lead to settlements and failure.
Fabric formed concrete mattress offers reliable and long term protection from scour
Fabric formed concrete mattress seals against the piers and abutments preventing flow from eroding material under the mattress. The slab consists of high-quality plain concrete, able to resist flows of over 12m/s with a design life of 50 years or greater.
The slab extends beyond the structure, outside the influence of both local and contraction scour. The edges are usually protected with riprap to prevent underscour occurring or embedded as appropriate.