Civil Engineering Reference
In-Depth Information
Thaumasite attack (TSA) - a form of sulfate attack
The industry became aware of this problem in 1998, when the foundations
to a number of bridges on the M5 were found to be suffering from serious
erosion and crumbling of the outer part of the concrete in the foundations
(
Figure 1.14).
The problem was diagnosed as being due to an unusual form
of sulfate attack, known as thaumasite attack.
For the problem to occur, a number of factors have to be present:
•
A source of sulfate
•
Water (usually plenty of moisture)
•
A source of limestone (as aggregate, or filler, or possibly as fill or even
carbonated groundwater)
•
Low temperatures (<15°C)
