Older bridges and buildings with prestressed concrete beams may be less safe than civil engineers think they are, an ICE publication warned last week.
The latest issue of the ICE Structures and Buildings journal says that prestressed concrete beams – in which the steel reinforcement is tensioned during construction – became particularly popular for bridge construction in the 1950s and 1960s.
But a series of high-profile failures has made civil engineers wary of them.
Now new research from Australia has cast further doubt on modern methods of assessing older, prestressed structures.
Researchers Torrill Pape and Robert Melchers of Newcastle University in New South Wales tested bonded post-tensioned beams from a dismantled 1957 marine causeway in Tasmania. They had failed at between 45% and 89% of their assessed theoretical capacity.
“The test results showed that the predicted ultimate capacity of prestressed concrete beams based on current design theory, actual material properties and free of cracking and corrosion damage may overestimate the actual capacity of the beams,” said Pape.
- For more information, contact ICE Proceedings editor Simon Fullalove on +44 (0) 20 7665 2448 or email firstname.lastname@example.org.