The
sudden collapse of Ynys-Y-Gwas bridge in
1985 caused
concern over the durability of post-tensioned structures.
Demolition of other structures has proven these fears to
be real.
Unlike many types of construction, post-tensioned structures
show little or no signs of distress despite holding severe
defects. Because of this, inspection methods need to be
more vigorous.
As post-tensioned cables are buried within the concrete,
intrusive methods of inspection are necessary. If not
reinstated properly these locations can be a source of
further deterioration. Destructive methods could also
further weaken
an already
highly stressed structure.
| 
Prestress
determination