Does SLS concern itself with shrinkage? 1

[bojoka4052]

I have a model, where you feed it the following variables;

- Thickness of the plate (e.g. 300 mm)

- Relative humidity (e.g. 80%)

- Quality of the concrete (e.g. B30)

- Class of cement

- Whether it dries out on one side or both.

And the age of the concrete at loading (e.g. 28 days). How should changing the amount of days at the age of the concrete at loading change the shrinkage (specifically the ε.cs the total shrinkage strain) we get? And is this at all relevant to SLS?

 

[BAretired]

I doubt that it is relevant to the Space Launch System.

BA

 

[Retrograde]

https://www.eng-tips.com/viewthread.cfm?qid=444698

 

[Agent666]

BAretired, in most of the world (you know outside of America) SLS stands for the serviceability limit state.

https://engineervsheep.com

 

[hokie66]

Well, I am not in the US, and didn’t get the acronym.

 

[BAretired]

BAretired, in most of the world (you know outside of America) SLS stands for the serviceability limit state.

I hope you know what BS stands for inside of America. Sure, I've seen SLS before, but it didn't dawn on me at the time of reading. I get fed up with acronyms used because the writer is too damn lazy to type a few extra characters. Got it 666?

BA

 

[Settingsun]

Hokie, aren't you American?

Regarding the age at loading, it may be for creep. A lot of the inputs for creep and shrinkage are shared, while age at loading is only for creep.

Edit: should've clicked Retrograde's link before posting.

 

[IDS]

Yes the age at loading affects creep, not shrinkage, but both creep and shrinkage definitely affect both cracking and deflections, which are two of the main considerations for the Serviceability Limit State (otherwise very widely known as SLS).


Doug Jenkins
Interactive Design Services

http://newtonexcelbach.wordpress.com/

 

[Settingsun]

What term do Americans use instead of SLS?

 

[HTURKAK]

The following excepts from EN 1990:2002+A1:2005

Section 4 Basic variables
4.1.1 Classification of actions
(1)P Actions shall be classified by their variation in time as follows :
– permanent actions (G), e.g. self-weight of structures, fixed equipment and road surfacing,
and indirect actions caused by shrinkage and uneven settlements


6.4.3.1 General
-(6) Imposed deformations should be taken into account where relevant

Clause A1.4.3(6)

-(6) Long term deformations due to shrinkage, relaxation or creep should be considered
where relevant, and calculated by using the effects of the permanent actions and quasipermanent
values of the variable actions.


In general,shrinkage , temperature changes, settlements may be considered as accompanying action and the stresses due to shrinkage and temperature may be controlled with movement joints..

I hope this respond answers to your question..

P.S.

Ref. EN 1990 EC 1

1.5.2.14
serviceability limit states (SLS)
states that correspond to conditions beyond which specified service requirements for a structure or structural member are no longer met.

1.5.2.13
ultimate limit states ULS
states associated with collapse or with other similar forms of structural failure

3.3 Ultimate limit states
(1)P The limit states that concern :
– the safety of people, and/or
– the safety of the structure
shall be classified as ultimate limit states.
(2) In some circumstances, the limit states that concern the protection of the contents
should be classified as ultimate limit states.
NOTE The circumstances are those agreed for a particular project with the client and the relevant authority.
(3) States prior to structural collapse, which, for simplicity, are considered in place of
the collapse itself, may be treated as ultimate limit states

 

[ThomasH]

@bojoka4052

I don't know what model you refer to when you say you have a model. But in the Eurocode part 2 (EN 1992-1-1) there is a model where shrinkage is based on the ago of the concrete at the beginning of drying shrinkage, also refered to as end of curing.

Regarding SLS, I am not in the US but it has until now been my impression that SLS (Serviceability Limit State) and ULS (Ultimate Limit State) are common acronyms in the US. But I certainly won't tell the US guys what is common in the US, it is just my very subjective impression .

 

[hokie66]

It's not the part of the world that caused BAretired and myself not to understand the acronym. We are still in transition from WSD to USD.

 

[ThomasH]

@hokie66

And now you lost me , what is WSD and USD ? Perhaps that was on purpose but i doubt USD means US Dollars in this context . Acronyms can be both confusing and fun.

 

[hokie66]

The codified principles for reinforced concrete design in the US changed from Working Stress Design to Ultimate Strength Design with the American Concrete Institute Standard ACI 318-63, introduced in June 1963. Some of us old timers started with that Code, and with few exceptions, it still remains a brilliant piece of work. Limit States Design was introduced a number of years later in the US, and at different times in other countries.

 

[dik]

I have the same problem (one of many) going from USD to WSD as I do going from Imperial to Metric... I kinda think in USD and Imperial and have to visualise things in USD and Imperial to understand them.

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better?

-Dik