Creep Shrinkage in Draft AS3600 1

[degenn]

The creep shrinkage properties in the new draft of AS3600 have everything happening much faster. For example Figure 6.1.8.2(A) creep 50% complete in 200 days for a 200 thickness where Figure 3.1.7.2 in the draft has 50% complete in 60 days. Does anyone know of data to support this.

It makes a big difference to the effectiveness of pour strips.

 

[rapt]

Rumour has it that AS3600-2009 will indeed be released in 2009, hopefully by the end of November. Apparently the probl;ems from ABCB are editorial and will be finalised quickly. But it will still not be referenced in BCA until at least 2011!

 

[rowingengineer]

You weren't still there when they announced that today were you, must have given you the inside running before the rest of us.

By the sounds of things I think the committee has got the sh*ts with SAI-Global.

There was talk of emulating ACI and crating the code through CIA, Which I can see no reason for exploring.



Arguing with an engineer is like wrestling with a pig in mud. After a while you realize that them like it

 

[asixth]

I agree, and I like the set-up that ACI has with sub committees (eg Creep and Shrinkage sub-committee, Carbon Fibre sub-committee, detailing sub-committee, FE sub-committee just to name a few). I also enjoy the ACI publication "Concrete International", I find it very helpful with the bi-monthly CRSI "Detailing Corner" and the regular Q&A postings.

 

[rapt]

Rowingengineer/Asixth

I left at afternoon tea.

I had written a great response to this and it crashed in the sending, so I will give a summary of it as I am not writing it all again (not happy!!!)

Yes, they are unhappy but with Standards Australia, not SAIGlobal. This has been developing for several years because of the problems with getting this code out. And it has been caused by some groups in the industry (all related to one main group) blocking the code plus the Standards rules on committees and consensus. Standards stuffup with its finances and future codes has not helped (wonder where all of the money went, it was not all to the GFC from what I hear (ever heard of BONUSES!).

Standards Australia has suggested different ways of funding/developing future versions of AS3600. CIA, ACI and EC2 were 3. Another was Standards Australia with monetary support from industry (eg CIA so why not do it themselves as most of the current committee are CIA members and doing it for nothing, not even airline fares and accommodation are paid).

If it was done by CIA it would be the same as ACI doing it for USA!

Noone on the current committee wants to adopt ACI or EC2 as they would need to be modified significantly anyway, and because of the way AS3600 is written, it is based on a lot of testing and developemnt that has gone into both of those codes plus other work. In fact, AS3600 is probably the best of the 3 because of that. Unfortunately it is not as advanced as it could be because of the problems above which have delayed future development.

All 3 codes are developed by a main committee with a sub-committee structure under it. There is no real difference in the way they work except that the chair of the main ACI committee gets to pick his committee, as distinct from AS3600 where the chairman gets who he is given by Standards Australia! In both cases the chairman of each subcommittee can put anyone he wants on a subcommittee and any main committee member can also join. There are good and bad points to both methods. A combination would be best!

EC2 is actually a model code and each country using it rewrites it anyway!

ACI has lots of testing and development work behind it. It is amazing it is such a bad code (in my opinion) considering this! But anything developed by a committee will always have problems.

I do not see what Concrete International has to do with this discussion about codes. It is unrelated and has gone downhill a lot over the years. The ACI Journal has a lot better articles as far as I am concerned and are in many cases reporting the research the ACI code is based on.

CIA also puts out a technical magazine. Does this make it eligible to produce a code also!

 

[IDS]

No doubt the immediate frustrations with AS3600 are directed at Standards Australia, but it seems to me that the root cause of many of the current problems is the strange system where Standards Australia (through a large band of unpaid volunteers) does all the work and the public listed company SAI Global gets all the reward.

The current issue of Engineers Australia has a letter jointly signed by many current or past chairs of Standards Australia committees (including several current members of BD2), expressing concern about the funding situation at Standards Australia, and looking for a more active role from Engineers Australia.

The director of Engineers Australia (Martin Dwyer) responded positively to this suggestion, but the question remains of how any organisation, whether it be Engineers Australia, CIA, or someone else, will fund the preparation of new standards when they are legally obliged to hand over their work for zero recompense to an organisation that exists for the purpose of making profits for its shareholders.

Doug Jenkins
Interactive Design Services

http://newtonexcelbach.wordpress.com/

 

[rapt]

IDS,

As I understand it, Standards Australia came up with the brilliant idea to sell the rights to print and sell all Australian Standards documents to SAI Global for (I think) a period of 20 years.

So SAI Global has paid for these rights. Something in the order of $250,000,000 as I understand it. This was then invested (less some significant bonuses paid to those brilliant people who organised the financial windfall for Standards Australia!). Standards Australia were then supposed to use the proceeds of this "sale"/contract, plus the interest/dividends from investing it, to fund its operations for the term of the contract, 20 years.

It is apparently down to closer to $150,000,000 now and is not sufficient to fund continuing operations like writing new standards to control every aspect of our lives like they have over the last few years (to increase their market and make themselves more valuable) and to pay their bloated burocracy.

Whether or not the above had happened, everyone on committees has been doing it for free since 1932 or whenever Standards began to be developed in Australia, supposedly because of their altruistic nature. The only difference is that, Previously Standards Australia made the money from each sale of a printed document, whereas now it has been paid upfront for the sales for the next 20 years.

So it is not SAI Global's fault as such. Standards Australia got themselves into the mess all by themselves. It is their rights contract and management of the money from the sale of this rights contract that has caused the problem.

They should be thrown into jail with the USA merchant bankers. They have basically made the same mistakes and ripped off us, the end user/taxpayer.

The only solution would appear to be a government bailout or an industry by industry bailout by each industry funding its own standard development, the sales rights to which still belong to SAL Global for 20 years, because legally, Standards Australia is currently the only body allowed to produce Standards Documents and they must be sold through SAI Global because they have already paid for the right to sell them!

So presumeably, we as an industry have to fund the development of the next AS3600 (committee members have been doing it for years, now everyone has to) and then pay for a copy of the final document as well or SAI Global might sue and consequently shut down Standards Australia for breach of contract. And that might be the best solution in the end!

 

[degenn]

I think a new thread is needed as we've changed subject!

I think some of the ideas raised at recent AS3600 conferences for a blog or faq site is perhaps a step in the right direction to resolve the problems of getting a formal code out in a timely fashion. Any thoughts?

 

[rowingengineer]

New thread created for discussion of new topic

thread744-258821

Arguing with an engineer is like wrestling with a pig in mud. After a while you realize that them like it

 

[asixth]

degenn

I will post my excel macros for the creep co-efficients and shrinkage strains when the new code is released so we can discuss how the two models compare to each other.

 

[IDS]

This link might be of interest to those following the AS 3600 saga:

http://newtonexcelbach.wordpress.co...ete-moment-curvature-–-2-shrinkage-and-creep/

It includes Excel functions for shrinkage and creep to the draft AS 3600 and EC 2, and adjusted age to EC 2


Doug Jenkins
Interactive Design Services

http://newtonexcelbach.wordpress.com/

 

[asixth]

Cheers Doug

I have never seen that site before, it looks like it has some good stuff in it.

 

[degenn]

Thanks for the reply Doug.

Your spread sheet has EC2 at 50% complete at 120 days where the draft has 50% complete at 60 days for a 200 slab.

 

[IDS]

degenn - yes, I don't know the details of the research behind the numbers in the new code (or if the numbers will be the same in the final code when it is released), but the EC 2 numbers would be based on much older research, with older cements.

I also note that the creep at one day is much higher in EC 2 than in AS 3600. If anyone knows the detailed background to these changes I'd be interested to hear it.

Doug Jenkins
Interactive Design Services

http://newtonexcelbach.wordpress.com/