Anyone knowledgeable on concrete (Turkey)

[ditchman]

Been watching these blocks of flats fall and crumple ..in the earthquake in Turkey/syria.......also been very surprised at the colour and powderey nature of the collapsed structures.......

now ive done a fair bit of large scale demo'...and i know what good concrete looks like....and i know what cut back base concrete looks like.......

i rekon alot of those buildings have been built using PFA cut back concrete to save money (back pocket job).....PFA is fine in compression for bases ...but for above ground is fatal

anyone got an opinion ?.......

[marsh man]

No opinion on the state of the concrete , but seeing those blocks of houses falling down like a pack of cards looked a terrible situation to be in , freezing cold and after shocks going off virtually all the while , death toll is going to be in the low 1000s .

[Spr1985]

I have nowhere near enough knowledge to pass educated comment. 
 

from things I’ve heard and been told whilst working on building sites etc over the years shouldn’t concrete have certain timescales to cure adequately, slow enough to set/cure correctly but in a reasonable amount of time to be worked on/with. Could the heat in those countries lead to it setting to quickly from the outside and therefore not curing properly internally? 

[Stonepark]

12 minutes ago, Spr1985 said:

I have nowhere near enough knowledge to pass educated comment. 
 

from things I’ve heard and been told whilst working on building sites etc over the years shouldn’t concrete have certain timescales to cure adequately, slow enough to set/cure correctly but in a reasonable amount of time to be worked on/with. Could the heat in those countries lead to it setting to quickly from the outside and therefore not curing properly internally? 

They run minimum cement in the concrete, bit like making things in China, i.e. down to a budget.

 

Admittedly, we are no better... Pre 1900 solid bricks are the equivalent of today's engineering bricks, whilst our common brick is half the strength, due to saving money in materials (by having holes through them), or OSB for floors and sarking, instead of proper timber boards, using Spruce for framing instead of larch, pine or oak etc

[rbrowning2]

Heartbreaking to see the devastation and loss of life.

[ditchman]

i wonder if Russia will be sending help to his mate in Syria.............

i would imajine everyone is in shock...........mass destruction in seconds.........apparently the first quake went on for 90 secs........that is a long time with all that shaking....glad to see we are stepping up to the plate.........

[eggy74]

crumbled as if it was made of screed

[roger M1CDQ]

1 hour ago, Spr1985 said:

I have nowhere near enough knowledge to pass educated comment. 
 

from things I’ve heard and been told whilst working on building sites etc over the years shouldn’t concrete have certain timescales to cure adequately, slow enough to set/cure correctly but in a reasonable amount of time to be worked on/with. Could the heat in those countries lead to it setting to quickly from the outside and therefore not curing properly internally? 

most of the time  they do pouring concrete in building projects in the winter time when its cooler.   They do get a hell of a lot of quakes. Every time ive been  always had 3 to5 on the Richter scale. when i was scuba diving once. one hit a 5.4   epicentre was about 10 miles away. I did not hear it but i felt it. One of the strangest sensations i have ever had.
But yes their building reg do seem to differ  

[Minky]

Last nighr on raduo 4 news There was a rescuer who said that because of the dire state of the Turkish economy in recent years that the lack of clerk of works inspections and application of building regs a lot of shortcuts had been taken and stuff just thrown up which is why whole streets had collapsed.  It was all of the modern buildings that had incured  structural  failures. Down to government policy and lack of supervision.  Cowboy get quick builders.  The finger pointing has yet to come. He said that they knew the risks but didn't  uiĺd into the structures the design and anti shake ability because of the money it cast to do it. A bit like Grenfell towers.and lots of other tower blocks,  They knew the risks but built them anyway.  We haven't dealt with that problem and the occupants of those fire candles are living with the probable life threatening risks, the costs and the fact that their flats can't be sold because of the problems. Lots of enquiries but no action. 

Edited February 7, 2023 by Minky

[Dave-G]

Beats me why they build so many and so high in those geo fault zones. Its gotta be better to rebuild in less risky parts of Turkey even if that means losing good agricultural land.

[Centrepin]

Concrete is supplied to a price. All builders quibble over the price and the only way to make it cheaper is cut cement content at their request.

Concrete is cubed, ie: blocks made from each batch. This is sent for testing and destruction testing. 

A supplier can only be certified once his Concrete passes tests, he (they) can then sell Concrete to the building trade.

Once on site, absolutely every delivery is ruined and taken out of spefication by lazy workers. As soon as the concrete arrives on site, workers begin shouting "give it a drink driver"

5 litres per 1 cubic meter is the maxium allowed by law before the load is out of spec and therefore no longer guaranteed.

In an average 6m load the ground workers will want anything between 150 - 250 litres upward.

The more water the more it flows and less work is required to lay it. Certain firms are known to only kick Concrete into place, ie: push with the foot. Raking or shovelling unless closely monitored by the site manager never happens.

The driver is required to make water entries on the delivery ticket and mark it out of spec. However, due to pressure put on by the ground workers this doesn't always happen ad is therefore kept in spec on paper. Paper is what counts when it fails.

If the drivers marks out of spec and how much water he's added the ground workers loose the ticket.

I spent 10 years as training officer for a national Concrete company and always carefully explained to every driver, nothing on the ticket, nothing added. Instant dismissal for non compliance. When the SHTF it would be directly on him/her. I sacked many drivers for this.

My son now runs a concrete company and follows the same practice. However, it still goes on, water is always and I state this as true, always added.

At a guess I would say that 98% of all concrete supplied to building sites is out of spec before the delivery is complete. This is directly due to lazy workers and employers exploring the faster they can get it down, the more they can do.

[Mice!]

1 hour ago, Centrepin said:

Paper is what counts when it fails.

Good post,  and it's always the paper trail that matters.

When making plane parts we had to stamp the inspection sheets, we were told those sheets are kept for the lifetime of the plane, plus 30 years, so if something is wrong you say so.

[Mungler]

2 hours ago, Centrepin said:

Concrete is supplied to a price. All builders quibble over the price and the only way to make it cheaper is cut cement content at their request.

Concrete is cubed, ie: blocks made from each batch. This is sent for testing and destruction testing. 

A supplier can only be certified once his Concrete passes tests, he (they) can then sell Concrete to the building trade.

Once on site, absolutely every delivery is ruined and taken out of spefication by lazy workers. As soon as the concrete arrives on site, workers begin shouting "give it a drink driver"

5 litres per 1 cubic meter is the maxium allowed by law before the load is out of spec and therefore no longer guaranteed.

In an average 6m load the ground workers will want anything between 150 - 250 litres upward.

The more water the more it flows and less work is required to lay it. Certain firms are known to only kick Concrete into place, ie: push with the foot. Raking or shovelling unless closely monitored by the site manager never happens.

The driver is required to make water entries on the delivery ticket and mark it out of spec. However, due to pressure put on by the ground workers this doesn't always happen ad is therefore kept in spec on paper. Paper is what counts when it fails.

If the drivers marks out of spec and how much water he's added the ground workers loose the ticket.

I spent 10 years as training officer for a national Concrete company and always carefully explained to every driver, nothing on the ticket, nothing added. Instant dismissal for non compliance. When the SHTF it would be directly on him/her. I sacked many drivers for this.

My son now runs a concrete company and follows the same practice. However, it still goes on, water is always and I state this as true, always added.

At a guess I would say that 98% of all concrete supplied to building sites is out of spec before the delivery is complete. This is directly due to lazy workers and employers exploring the faster they can get it down, the more they can do.

 

Good post.

To add that when they had problems like this in China (packing rubbish into foundations to bulk them out), they just executed everyone involved.

 

 

[Penelope]

15 hours ago, ditchman said:

Been watching these blocks of flats fall and crumple ..in the earthquake in Turkey/syria.......also been very surprised at the colour and powderey nature of the collapsed structures.......

now ive done a fair bit of large scale demo'...and i know what good concrete looks like....and i know what cut back base concrete looks like.......

i rekon alot of those buildings have been built using PFA cut back concrete to save money (back pocket job).....PFA is fine in compression for bases ...but for above ground is fatal

anyone got an opinion ?.......

It was mentioned on the news this morning, that a lot of these building were thrown up quickly and cheaply to accommodate those escaping from Syria.

[Vince Green]

3 minutes ago, Penelope said:

It was mentioned on the news this morning, that a lot of these building were thrown up quickly and cheaply to accommodate those escaping from Syria.

It's the same the world over. Very few countries have proper building controls and regulations in place.

[oldypigeonpopper]

Hello, can we still say jerry built 🤔, was there not another earth quake in the same area years ago with many  1000s killed, ? I'm no expert but watching the building collapse the concrete seem to crumble rather than come down in sections, very sad for all those who have lost loved ones in their own homes

[ditchman]

40 minutes ago, oldypigeonpopper said:

Hello, can we still say jerry built 🤔, was there not another earth quake in the same area years ago with many  1000s killed, ? I'm no expert but watching the building collapse the concrete seem to crumble rather than come down in sections, very sad for all those who have lost loved ones in their own homes

i notice that so much of the concrete has debonded from what looks like smooth re-bar............

what a hell of a task going thro' the rubble searching for life...........how on earth do you do it in a safe way....i see so many countries have stepped up to the plate

[old man]

Know  nothing about concrete other than the Germans are masters at it?

The type of sand and chemistry could be worth looking at?

[Centrepin]

Debonded concrete is called spalling concrete. It's what happens when rusty rebar is placed inside of poor quality or if you read my earlier post on this, out of spec concrete. The rust expands and causes cracks to appear, the concrete then crumbles allowing more water to cause more rust and so on.

@ditchman

Not noticeable underground but you often see buildings with the ends of rebar visible.

Precast houses, wimpy no fines and houses built of concrete that is pumped or poured are particularly prone to it. What is particularly worrying is all schools, most hospitals and certain office blocks are made like this. Houses less so since this practice was discovered in the mid 60s.

[Fisheruk]

Undoubtedly poor construction, but we’re not much better in many respects. Grenfell- I watched the fire in real time and new that Building Regulations had been compromised. Subsequently hundreds of properties were found to have similar problems. Clerk of Works, we don’t have them now in this country and with private Building Regulation contractors- it’s not far away from he who pays the piper calls the tune!

[Agriv8]

If uk can’t get it right ( greenfell) with our building regs how can turkey with its debt trying ? 
 

in both cases on hindsight it’s going to cost loss of life.

Agriv8 

[Centrepin]

The UK only has it right on paper. In practice from senior management down to the lowest workers corners are cut in favour of speed and ultimately profit.

 

 

[Pushandpull]

If you want to see dodgy concrete, ditchman, check out your local hospital at Lynn - 2,400 props holding the ceilings up at the last count.

[ditchman]

2 minutes ago, Pushandpull said:

If you want to see dodgy concrete, ditchman, check out your local hospital at Lynn - 2,400 props holding the ceilings up at the last count.

you are right ...ive seen the props...............but also i might say that building was meant to be replaced when it reached 20 years old ...as it was built to a budget....that was 30 years ago.....................(beyond the 20 years)

the govt still has not agreed to fund the building of a replacement hostpital...

[Vince Green]

I remember many years ago sitting in apartment on the Costa del Sol watching a big hotel being built on the plot opposite.

That was a lesson in how not to build a multi storey concrete building.