Concrete Creep Coefficient

[NTCONLINE]

What is the normal range for concrete creep coefficient (sometimes called creep factor) as defined in EC2 Clause 7.4.3?

 

[Trenno]

Not sure about EC2 but below are the AS3600 values.

The long term creep coefficient is just the basic coefficient multiplied by the final coefficient.

 

[vEngii007]

It depends on the class of concrete, moisture, dry concrete, age of concrete at the time of loading and type of cement used. Range between 1 and 4.3 if it is loaded after 28 days. I refer to the EC 2 Figure 3.1.

https://www.hindawi.com/journals/ace/2012/626592.fig.0012.jpg

 

[IDS]

The spreadsheet here:

https://newtonexcelbach.wordpress.com/2017/04/06/rc-design-functions-7-03/

has a function that will return creep and shrinkage coefficients to AS 3600 or EC2. There can be quite large differences between the two.

Doug Jenkins
Interactive Design Services

http://newtonexcelbach.wordpress.com/

 

[Trenno]

Interesting the difference between the creep values.

Is there a main reason why AS3600 can be almost double the value of EC2?

 

[NTCONLINE]

Trenno,
I guess it could mainly be due to the local aggregates ?

I had a look at the AS3600 page 40, there is a factor dependent on the hypothesis thickness,
which seems significant.

If I design a 1-m width of a floor slab, should I use the full perimeter of the slab ? or just should use the sides which expose to the atmosphere (i.g. only top and bottom for calculation of perimeter "u") ?