Wednesday, August 06, 2008

MRR2: DEF the cause?

Halcrow's senior consultant (bridge engineering) Roger Buckby said the primary cause of the cracks was the delayed ettringite formation (DEF)




Collepardi said: in the absence of any of these elements (as shown in the diagram above), DEF-related deterioration cannot occur.

Below is the DEF crack pattern:








Below is the crack pattern on Pier 28:








How can this be due to DEF?

5 comments:

artchan said...

All this is due to the corrupt system of awarding contracts..not the carbon fibre straps, nor any other reasons.

moo_t said...

Kudos to Halcrow for giving Malaysia public the hint.

With google, you get tons of info on "delayed ettringite formation DEF", which DOES NOT limit to carbon fiber, but also concrete.

Maverick SM said...
This comment has been removed by the author.
Maverick SM said...

We are analyzing the failures of the RC structure and I'll leave out the political conspiracy theory.

I am keen on those who could share their knowledge in structural engineering analysis and probability analysis on the cause of failures and include the expert opinions on rectification.

The subject matter was discussed in 2004-2005 and DEF had been ruled out. What Halcrow is now saying is obsolete and the pictures should tell you a thousand facts why DEF induced failures was ruled out.

Kenny Ng said...

The crack lines doesn't look like DEF crack pattern, it's more like shrinkage.

Anyway, it's a design failure.