How long do high-rise concrete structures last?

[userabcd]

1 hour ago, treetops said:

20m x 5m x 1m deep = 100 tonnes of water.

The load and safety factor and distribution thereof in accordance with international structural design standards would be considered and applied by the structural engineer. The design would then be checked and verified by an independent structural engineer.

 

 

 

Edited September 17, 2021 by userabcd

[userabcd]

4 hours ago, Cake Monster said:

Yes they are, but the one thing they all have in common, is that they are not made from Man made Concrete.

Having seen some of the " Sludge " expelled from the Concrete Trucks here in Thailand, I would question the very structural makeup of much of the Concrete used in Construction.

Maybe its different on Large Condo projects Etc, but I have never even seen a slump test performed, and much of the Ready Mix stuff seems to be very high in Water content

The ready mix batching plants also do their own qc testing, slump and cylinders in accordance with concrete specifications and what the customer additionally needs.

 

A lot of the concrete around has the specified water cement ratios and whatever else is required and admixtures to make it seem high slump which is used in many pump mix or self compaction placement projects around.

Edited September 17, 2021 by userabcd

[treetops]

9 minutes ago, userabcd said:

The load and safety factor and distribution thereof in accordance with international structural design standards would be considered and applied by the structural engineer. The design would then be checked and verified by an independent structural engineer.

And the maintenance and ongoing inspections will be carried out by Somchai.

[userabcd]

3 minutes ago, treetops said:

And the maintenance and ongoing inspections will be carried out by Somchai.

Yes this is the problem, the ongoing regular inspection and maintenance by qualified personnel/institutions which is necessary and who pays for all the regular upkeep and when something serious needs attention it gets quite costly.

[HeijoshinCool]

5 hours ago, cucme said:

Fact is that concrete deteriorates after 50 - 55 years. Excess of water or not, starts weakening even in dry conditions.

.

 

Really?

 

I'm driving out west next week, was hoping to see the Hoover dam one more time, but guess I'd better take another route.....

 

 

[1FinickyOne]

and I tell you over and over and over again, my friend, they don't believe, we're on the eve of destruction... 

[ericbj]

Rebar is protected from corrosion by the alkalinity of cement in the concrete.  However, particularly in or near industrial areas, acid rain (all rain is mildly acidic due to CO2, but here we are talking more of things like sulphuric acid) causes the concrete to become slowly acidic.

When the acidity reaches the rebar - which depends partially upon how deep it is buried in the concrete, the rebar begins to corrode, and the expansion then causes spalling and accelerated corrosion.

High-rise buildings in London dating from early post-War years have had to be demolished because of this.

Chlorinated swimming-pool water is slightly acidic.

Use of a waterproofing additive combined with high cement:water ratio + vibration will reduce moisture penetration.  But not entirely prevent it.

Reinforced concrete is always subject to microscopic fissuration due to the thermal expansion of steel relative to the inert concrete.  This latter fact is why marine concrete such as the hydro-electric dam on la Rance in France uses relatively  little steel, embedded deeply within the concrete.

[geisha]

Owners often complain about the cost of maintenance. A safe building is one that’s checked and maintained regularly. My apartment block  in France was built in 1976 and looks like new. Ok, it costs, but is a solid investment. Prices never go down, only up, as theres more room compared to new build,  easy to sell.

[LarrySR]

The weight of the pool water will not be an issue in a properly engineered structure unless the pool has hidden leaks and the supporting floor/columns are weakened. 

The problem with the high rise pools is, the plumbing, walls and floor are hidden from view, usually only accessible from a dark, tight crawl space that may not be inspected by Somchai for decades. 

The intersection of a supporting column and slab floor could easily fail if the rebar has rusted.

 

As in the Florida condo collapse, it is speculated a column pushed thru the slab, (punching shear) instantly shifting the load on adjacent columns that also were weakened by rust, creating a chain reaction that caused the building to collapse in seconds.

 

Check the "Building Integrity" YouTube channel for an engineers viewpoint on the story of greed and incompetence, with a contractor cutting corners, developers bribing city officials, lazy inspectors & questionable maintenance resulting poorly constructing buildings sold to an unsuspecting public......in Florida.

 

 

Edited September 17, 2021 by LarrySR

[LarrySR]

The collapsed Florida condo, 12 stories, didn't look too bad to an untrained eye.

However, after the city and a structural engineer evaluated the concrete spalling, the winning repair bid was $15 million USD.

The 228 condo residences in the 12 story tower were facing a bill of $66,000 each to put the building back into a safe condition.

 

The corrupt practices in the original construction along with the delay in the repairs ended sadly with 97 dead and a total loss of the structure.

 

 

 

Edited September 17, 2021 by LarrySR

[cooked]

Anybody following Chinese news will know that many "investment projects" get demolished before they are even finished (that is after 10 - 15 years standing there unfinished), so don't get too gloomy. That's the way to get rich, take the money and run.

[mokwit]

17 hours ago, Pravda said:

Look at hotels like banyan tree and Crowne plaza built by japanese decades ago. Then turn around and have a look at any Thai condo 5 years or older. What do you see?

Early on the civil Engineers were Japanese,German etc  hired from overseas, then the Thai's figured they could do it themselves and dispense with expensive foreign trained engineers...................

 

16 hours ago, hotchilli said:

They're made from stone, not a loose mix concrete on a Thai budget.

Colosseum is Roman grade cement.

[mikebike]

15 hours ago, treetops said:

You wouldn't put an extra 100 tonne tub of concrete on top of your building but it's OK for water.

Apparently you have no concept of how structural engineering works.

 

Say the pool is on top of a 20 story building. 100 tonnes of water on the 20th floor.

 

Next door is a 30 story building. Average of 250 tonnes of concrete to form each of the 10 floors above the 20th... or 2.5 million tonnes of concrete safely supported above the 20th story pool on the building next door.

 

Structural engineering accounts for the weight.

 

It's pretty simple.

[Delight]

18 hours ago, Liverpool Lou said:

Well, you seem to be unhappy with water being in a condo building because of it's weight yet you're happy with the weight of the much heavier concrete being there.   What was your point about water being heavy?

 The weight of water represents load.

The strength of the concrete represents resistance to cracking

The resistance of the concrete has nothing to do with its weight.

 

A combination of building sway and load has the possibility to cause the concrete to crack.

This is typically an extreme case.

It has -however-happened

[transam]

18 hours ago, hotchilli said:

They're made from stone, not a loose mix concrete on a Thai budget.

I thought the Romans invented/discovered concrete....????

[LarrySR]

20 hours ago, Jenkins9039 said:

If one falls, the land price has likely risen, so you can just collectively sell your plot, and buy somewhere else (further out from the city), chances are the appreciation offsets any actual loss...

The co-owners need a 100% vote to abandon and demolish a condo or I suppose the building could be condemned by the BMA.

Sale of the land plot then distributed to the co-owners.

 

A few years ago, I recall hearing the prime land on Sukhumvit was around 450,000 per Sq Meter. 

The owners in a building such as Lake Green Condo on Sukhumvit Soi 8 (guessing the land is 800 SqM) would then divide 360,000Bt million.

If there are 100 units, that =3,600,000Bt. each. Currently listed on Hipflat for around 14,000,000Bt.

 

Is there any doubt we will be seeing lots of this over the next 20 or 30 years?

 

 

[LarrySR]

20 hours ago, cucme said:

Fact is that concrete deteriorates after 50 - 55 years. Excess of water or not, starts weakening even in dry conditions.

Concrete has a high PH that inhibits rust on the rebar but the PH lowers over time.

If water or chlorinated pool water is reaching the rebar, the building is a time bomb.

[zappalot]

In Thailand no effective checks are made, no one cares about cracks, or rebars surfacing. Yes, a yearly inspection is mandatory. But no one, not the district office, not the land department and not the responsible department from the BMA takes action, not on any issues found. Not even on the serious issues found in our building by the BMA inspectors (who are very competent though). Comment from BMA inspectors: "This building is a death trap". Yet none effective action taken to get a lazy management/committee/JPM to do their jobs...

 

So be careful to invest in Thailand....

[hotchilli]

33 minutes ago, transam said:

I thought the Romans invented/discovered concrete....????

They did, but Thailand discovered how to make it cheaper and go further.

[digger70]

19 hours ago, Liverpool Lou said:

How would it make a difference?  The pool's being there would, obviously, have been considered during the design of the building, wouldn't it?   It hadn't just been slipped in there hoping no one would notice.

Probable would've been on the Plan but that doesn't say they've Built the Building strong enough to carry that extra weight. Remember that this is Los not Land Of Strong Buildings.

[Liverpool Lou]

1 hour ago, digger70 said:

21 hours ago, Liverpool Lou said:

How would it make a difference?  The pool's being there would, obviously, have been considered during the design of the building, wouldn't it?   It hadn't just been slipped in there hoping no one would notice.

Probable would've been on the Plan but that doesn't say they've Built the Building strong enough to carry that extra weight. Remember that this is Los not Land Of Strong Buildings.

So how many condo buildings in Thailand, such as are being discussed here, have proven to not be strong enough to carry that extra weight?  Remember, you implied that is a real danger here in Thailand so I imagine you must have some examples in mind of buildings not being strong enough?

[Liverpool Lou]

2 hours ago, Delight said:

 The weight of water represents load.

The strength of the concrete represents resistance to cracking

The resistance of the concrete has nothing to do with its weight.

 

A combination of building sway and load has the possibility to cause the concrete to crack.

This is typically an extreme case.

It has -however-happened

The weight of my initial comment was tongue-in-cheek, as I have stated, but, as you want to carry on with serious allegations about this, and you say that it has happened here in Thailand, I imagine you also have an example of what is being discussed in this thread actually happening, yes?  

[LongTimeLurker]

22 hours ago, Almer said:

Ah, but Stonehenge isn't premixed and poured, Stonehenge was dragged, from where i know not i got bored listening to the teacher.

But remember, it was the Romans that invented concrete.

[LongTimeLurker]

22 hours ago, Cake Monster said:

Yes they are, but the one thing they all have in common, is that they are not made from Man made Concrete.

Having seen some of the " Sludge " expelled from the Concrete Trucks here in Thailand, I would question the very structural makeup of much of the Concrete used in Construction.

Maybe its different on Large Condo projects Etc, but I have never even seen a slump test performed, and much of the Ready Mix stuff seems to be very high in Water content

But remember, it was the Romans that invented concrete.

 

I've never had any problems with readymix concrete supplies here in Thailand, except when the client insisted on a spec where the concrete had to be delivered below 30C, but it was manageable even though we had some cement lumps.

 

I'd have liked to have seen the spec for the Phase II project, whether the client amended it to not get the problems or not as I always suspected it was a ruse to get some kickback for relaxing the spec.

 

 

[RafPinto]

Just check how high you are from the ground.

Last year, I was renting on the 14th floor.

This year, it feels like the 13th????

[digger70]

2 hours ago, Liverpool Lou said:

So how many condo buildings in Thailand, such as are being discussed here, have proven to not be strong enough to carry that extra weight?  Remember, you implied that is a real danger here in Thailand so I imagine you must have some examples in mind of buildings not being strong enough?

I never said that there is a real danger ,I know what I said .

don't twist my words .

[Liverpool Lou]

4 hours ago, digger70 said:

6 hours ago, Liverpool Lou said:

So how many condo buildings in Thailand, such as are being discussed here, have proven to not be strong enough to carry that extra weight?  Remember, you implied that is a real danger here in Thailand so I imagine you must have some examples in mind of buildings not being strong enough?

Expand  

I never said that there is a real danger ,I know what I said .

don't twist my words .

I'm not twisting your words; this is what you posted...

"Probable would've been on the Plan but that doesn't say they've Built the Building strong enough to carry that extra weight"

If that is not suggesting that there is a real danger that the building is not strong enough to support it's own weight or that it is something that is known to happen here, I'm not sure what is.

 

Perhaps you meant to post, "Probable would've been on the Plan but that doesn't say they've not Built the Building strong enough to carry that extra weight".

[rickudon]

11 hours ago, mikebike said:

Apparently you have no concept of how structural engineering works.

 

Say the pool is on top of a 20 story building. 100 tonnes of water on the 20th floor.

 

Next door is a 30 story building. Average of 250 tonnes of concrete to form each of the 10 floors above the 20th... or 2.5 million tonnes of concrete safely supported above the 20th story pool on the building next door.

 

Structural engineering accounts for the weight.

 

It's pretty simple.

Hmm, glad i do not employ you. 250 tons x 10 = 2,500 tons, not 2.5 million. You are using Thai maths!

[Delight]

9 hours ago, Liverpool Lou said:

The weight of my initial comment was tongue-in-cheek, as I have stated, but, as you want to carry on with serious allegations about this, and you say that it has happened here in Thailand, I imagine you also have an example of what is being discussed in this thread actually happening, yes?  

 Yes -for certain

 

I also know how they fixed it.

Drain the pool. It worked

Edited September 18, 2021 by Delight
added detail

[bangkokbonecollector]

Basically I would be worried about any condo or high rise building that was built between 1985 and 2000 when corruption was f'''ing rife. I mean this sort of thing can and does happen anywhere, check out Sampoong Department Store collapse, hundreds died.