Expansion joint or not for 200m long concrete building, 3

[hoangvhuy]

Hi everyone,
i am designing structure for a hotel, 12 stories, 200m long. all is reinforce concrete
For normally, we need seperate 3 block by expansion joints, but it makes many difficult problem because architectural design is complicated, non-regular, if building have expansion joint, the joint will seperate the basement,lift core, swimming pool. And impact to facade of hotel.
So, Anybody have experience about same long project, what is best solution?
Can I use post poured strip to deal with that.
Thank for your sharings.

Above is layout of project

 

[dik]

With irregular shapes like that I suspect you should have half a dozen expansion joints.

-----*****-----
So strange to see the singularity approaching while the entire planet is rapidly turning into a hellscape. -John Coates

-Dik

 

[dik]

You might be looking at some or all of these, or an added couple...

-----*****-----
So strange to see the singularity approaching while the entire planet is rapidly turning into a hellscape. -John Coates

-Dik

 

[rapt]

And do not just think in terms of shrinkage for this.

Temperature lengthening/shortening over the seasons will probably be worse and cannot be relieved by temporary strips.

It will affect both slab restraint cracking and also column/support cracking.

 

[dik]

As rapt notes, the proposed joints represent abrupt changes in plan.

-----*****-----
So strange to see the singularity approaching while the entire planet is rapidly turning into a hellscape. -John Coates

-Dik

 

[hoangvhuy]

hi @dik,
Thank for your advice,
Intial design, i intend same as your intend,
But this project, at a location, function is not same. So if we put a joint is make sense for this story, but make un-sense for other story,
It's why, I need avoid expansion joint. because expansion joint will go through swimming pool, tank , lift core.

 

[hoangvhuy]

hi @rapt
i understand you worry, I concern as you.
But, can you measure the internal force lengthening/shortening by temperature, we can add rebar to cover it.
If you know please share, thank

 

[dik]

I'm thinking of proper expansion joints, not pour strips. In general, with abrupt changes in geometry or materials, an expansion joint is prescribed. Over time, with subtle changes in temperature, foundation shifting, wind loading, minor seismic loading, etc. if you do not make allowance for some movement, the building will do it for you. I 'glossed over it' but rapt pointed it out... joints needed, are not just for the initial concrete shrinkage. Pour strips can often accommodate that type of movement.

By putting in a proper joint, you determine where the adjustment will take place. Once enclosed and once normal concrete shrinkage has occurred, thermal issues will not be a problem unless you have a HVAC failure or something of that ilk. Anything that will cause stresses to your structure may cause distortion that may cause cracking. This often occurs where you have a transition in shape or a change in construction materials that may cause distress.

Several years back I did a report on a building that had developed cracking. The likely reason was that the building was constucted of concrete and the cladding was clay brick. Over time, the concrete 'shrunk' and the clay masonry 'expanded'... not a good combination.


There is a little more planning involved in the location of the expansion joints and this can be very tricky, but it should be done.


Four of the lower joints are essential. It is unlikely that you can add enough rebar to prevent cracking in these areas and without joints, the cracking will not occur in a straight line. If you have tiles, it will likely occur through them and not around them.

The joints have to be reflected in the exterior wall finishes, too. These cracks can determine where the joints will form in the exterior wall finishes, too. The joints can vary in location on the floor plan, but the joint in the building envelope generally has to be the same.

-----*****-----
So strange to see the singularity approaching while the entire planet is rapidly turning into a hellscape. -John Coates

-Dik

 

[dik]

Can anyone recommend a couple of texts or articles on the inclusion of expansion joints in structures, in particular including effects of changes in shape of the floor plans and materials of construcion? This may assist hoangvhuy.

I've posted a query in the Structural area, too. Thanks, Gentlemen (binary)

-----*****-----
So strange to see the singularity approaching while the entire planet is rapidly turning into a hellscape. -John Coates

-Dik

 

[dik]

@hoangvhuy: is your building slab normally reinforced concrete? or is it post-tensioned concrete?

-----*****-----
So strange to see the singularity approaching while the entire planet is rapidly turning into a hellscape. -John Coates

-Dik

 

[hoangvhuy]

@dik
This project has ordinary span slab, from 4m to 7m ( 13 feet to 23 feet span), so in vietnam, i use normally reinforce concrete and cast in site.

 

[dik]

That makes it a little easier in some regards. Is it a flat concrete plate like slab, or is it a flat slab with drop panels?

-----*****-----
So strange to see the singularity approaching while the entire planet is rapidly turning into a hellscape. -John Coates

-Dik

 

[dik]

There doesn't seem to be much activity, for this, in the Structural part of this site; maybe because of the season or may because no one has any good references. On quick glance, I was unable to find good references, but joints should occur where there is a significant change in the structure plans, where areas might be restrained and others not, and where there may be abrupt changes in the 'direction' of the structure.

The expansion joints have to be very detailed or if you are using a commercial type of joint, you have to be very careful to select a good one. I've done a lot of parkades and you have to be very careful about the commercial joints you select. Joints are critical and subject to a lot of wear and tear... in a building, not so much. In a parkade, good joints are often expensive and that's not where you want to save money.

The way I broke up the building areas is pretty much what I would do, if it were my project. I might add another couple of joints, depending on the finishes. I suspect others would be similar.

-----*****-----
So strange to see the singularity approaching while the entire planet is rapidly turning into a hellscape. -John Coates

-Dik

 

[JedClampett]

This is a publication from 1974. It's not great, it has conflicting direction, but it's free.

 

[hoangvhuy]

hi @dik
Total agree with you,
But,Because this project is difficult to put expansion joint make sense, one reason , this project is hotel so , aethetics is high requirement.
So, i itend avoid expansion joint and solve by post poured strip

 

[hoangvhuy]

hi @JedClampett
I red above document already,
But it's kind of "general", i calculated , delta T = 11 degree celcius
And, i can not find answer my question " how to avoid expasion joint for this project"
Below is chart,which is calculated by me,result is 240feet is maximum distance, to set expansion jont , do need calculate

 

[dik]

Because of the irregular shape of your building the above chart is meaningless, and should not be considered.

Your joints will be determined by the building irregularities. The location of the vertical joints on the building wall should remain the same floor to floor. The pattern of the joint on the floor itself may vary from floor to floor, but should reach the same location at the exterior wall.

If you have a carpetted floor, the joints may or may not be hidden. If you have a tile floor, then the joint should be located in the tile joint line.

-----*****-----
So strange to see the singularity approaching while the entire planet is rapidly turning into a hellscape. -John Coates

-Dik

 

[dik]

Because of the shape, you cannot avoid expansion joints in this project. The ones I indicated, are the bare minimum.

I don't know if the Vietnamese celebrate Christmas, but I do know they celebrate New Years (Tet)... all the best in the coming New Year and Season's greetings...

-----*****-----
So strange to see the singularity approaching while the entire planet is rapidly turning into a hellscape. -John Coates

-Dik

 

[hoangvhuy]

hi @dik
As I mention above, put the joint same location at many floors is impossible, because architecture and zone is complicated in this hotel. and impact too a lot to exterio/interior
So, it's why in want to avoid expansion joint.

 

[dik]

With that irregular floor plan, you cannot avoid joints. I suspect most members here will concur. It's a matter of looking at all floors to determine the best location for the joints, but they will likely be in areas as noted. It may be tricky, but if you don't locate them, the building will locate them for you... where ever they happen.

'Throwing in a bunch of steel' may help, but will likely not be effective. What is the outside cladding? and where are the joints in it?

-----*****-----
So strange to see the singularity approaching while the entire planet is rapidly turning into a hellscape. -John Coates

-Dik