Concrete Creep due to Increased Load on a 12 year old floor 1

[ajk1]

If an increased load is applied to a concrete floor slab after the floor has been in use for 12 years or so, what is the creep factor that should be used to predict the additonal long term creep due to the additional load?

Can creep be essentailly ignored because the concrete is so old at the time of application of the additional load?

 

[JAE]

I think creep is timeless but I'm not certain.


(I don't think I've ever written a sentence like that)

 

[rapt]

ajk1,

There is a maturity effect that reduces the amount of creep as the time of loading is extended, but there will still be creep. According to the Australian code it would reduce by about 30-40% from loading at 7 days after about 1 year and then stay constant at that figure. But the reduction from 28 days to 1 year is only 10%.

So it depends on your starting point or starting assumption! If you are simply using code multipliers, you would not know!

Other than that JAE is correct.

If you look at your design codes creep data it should tell you.

 

[msquared48]

Creep, like the IRS, continues until the bulding fails or is torn down.

Mike McCann
MMC Engineering

http://mmcengineering.tripod.com

 

[ishvaaag]

Little, see one case by CEB FIP.

Later I will add zip with some Mathcad 2000 worksheets giving creep data.

 

[ishvaaag]

Creep evaluation by several technical opinions, as Mathcado 2000 Professional worksheets.