When Bridges Collapse.

[ImLostAgain]

I've just watched this on BBC2. I found it very interesting and I'm not an engineer, but they said that steel cables were encased in concrete to stop them rusting. It obviously didn't work as the concrete developed minute cracks and water got in. That got me thinking, surely concrete is made wet when poured, so wouldn't that exacerbate the problem?

[Cloverjo]

Well, I don’t know. I’m not an engineer either, but we’ve just had massive leaks in our house because the concrete floors corroded the pipes.

[Spicerack]

Cables on bridges move, flex. Can't imagine they'd be coated in concrete. Embedded in it, yes.
I didn't see the programme. I'll have a look on the I-player.

[ImLostAgain]

Sorry to hear that Cloverjo.
Spicerack, The way I read it they had the steel struts were covered in some sort of protective covering first but with concrete inserted inside this covering. Even if that is incorrect the safety feature (at this time) was to then cover the cables in a concrete sleeve which would make them safer than any other steel cabled structure.

[Spicerack]

Watched it. I do like listening to Italians talk although I don't understand it.
They haven't, officially, announced a cause yet.
I was surprised they could make an hour long programme about shoddy Italian construction without mentioning the Mafia.

[Peter Pedant]

Prof sooti had grouped all the wires together and I wondered if that meant one breaks - they all break....(yes)
but honestly arent they paid to know that sort of thing

the concrete wasnt all encasing
and so rain leaked in

and concrete sets by a chemical reaction so that water in itself is not sort of squeezed out - concrete will set under water !

the brighton pavilion is a iron frame covered in concrete and that is eroding - the rust swells the iron and that shatters the structure

and there is an iron framed church in Liverpool with the same problems - - ploo sa change and all that

[douglas9401]

Rust never sleeps as a great man once said.

[Caran]

Recorded it but humax box refused to play it! It is infuriating this has happened twice tonight,

[ummmm]

Just watch it on iplayer!

[djtdjt]

I thought at the end they may have shown what is going to replace it.