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yupi
21-03-2014, 12:41 PM
Dear all, A new guy here and we have a big freezer in Guangzou China. We found the floor crack and heave recently. the technician told me the the sub-floor heating system had been stopped for many years and this should be the reason. this system use glycol system and the pipes is 15mm. I use some threa guide to insert to the pipes but it can't go throught. Can anybody help me on this?

We drill a hole in the cracked floor and removed the surface contrete and the isolation layers. I did't find any ice in the isolation layers.

where is the ice?

Urgent.

Magoo
21-03-2014, 08:49 PM
Hello Yupi.
Welcome to the forum.
The ice will be in the subsoil below the construction floor.
No quick resolve to problem. Other than dig it all out and start again.

smpsmp45
22-03-2014, 04:22 AM
Can you post some photos?

yupi
24-03-2014, 04:13 AM
Hi all,
Here is the photo of heat isolation. here only show one layer.1138811389

The smal pipes inderted into the floor are the glycol pipes and now is bloecked by ice.

mbc
24-03-2014, 05:00 AM
you should have heating system in floor to stop icing up the subsoil below the construction floor.
it can be by electric heating glycol system or air system.
in large system normally we use air system (cat way- cat path )

CHARLIE-OSCAR
24-03-2014, 07:34 PM
http://books.google.co.uk/books?id=0oGm9IfWSlYC&pg=PA47&lpg=PA47&dq=freezer+floor+frost+heave&source=bl&ots=-mDbN84dMe&sig=UpGDaAhWrXuG0i7SybYGtWzGbIQ&hl=en&sa=X&ei=hwguU-_qIo6u7Ab24YGgBg&ved=0CDMQ6AEwAQ#v=onepage&q=freezer%20floor%20frost%20heave&f=false

A Link with some good information on Frost Heave and information on Design & Construction of concrete floors. I found this information very interesting so thought I would share.:cool: Hopefully it will be of interest to you?

mbc
26-03-2014, 06:00 AM
if you have acad I can send you more information .

yupi
31-03-2014, 03:36 AM
Hi,
Thanks for the information. we used glycol system for anti-icing. but this system stopped working for years. the result is ice build up now. the problem is even we remove the surface slab and the heat isolation layers. will the structural layer be damaged by the ice? the structural layers is 400mm with mesh in it. the dimension is 6m and 4.5m. the heave now up about 20cm.

Magoo
01-04-2014, 12:16 AM
If the internal wear slab has lifted 20cm, the construction floor will have moved similar or greater amount and most likely has cracked open as well.

yupi
03-04-2014, 08:50 AM
We contacted a Horizontal Directional Drilling Company and plan to insert some HEPE pipes under the floor and want to use forced ventilation system. the pipe will be under the construction layer about 1.3 meter because of the big ground beam. will these pipes work to meld the ice?

yupi
03-04-2014, 08:52 AM
It that mean we need to rebuild the construction layer?

Magoo
03-04-2014, 10:14 PM
The only sure way is to remove wear slab and insulation and inspect and repair construction slab. Vent tubes are OK if ambient winter temps are well above freezing otherwise air will need to be heated.

mbc
04-04-2014, 06:25 PM
air temps is not important in the winter.
main thing between up floor and ground we have air and construction goods should be completely dry and it is very important.

Magoo
05-04-2014, 04:01 AM
mbc.
I totally disagree, the original poster has an ice heave problem already which would suggest that the sub soil below the construction slab is moist. Air ducts with sub zero air will only aggravate the problem.

mbc
05-04-2014, 06:14 PM
dear magoo
first apologize about my week English
I did not write my suggestion can solve his problem at the moment .
certainly it should be heated (from rooms side - wait until summer - electrical electrode low voltage( I live in very cold area some time we use this system to oped iced pipe and might it is illegal in some countries) -

spouse of gap between up floor and ground is stopping our room temps effect to moisture coming (rising)
form ground and the system we chose to do that , depends on where we want to use it?

is it large rooms(Cold stores ) - is it dry area or there is too much humidity - do we have a lot of rain ?.
for each condition we must choose right one

I thought in normal condition you asked for heated air between up floor and ground .
in dry and normal condition and large system we use air gape .
in high humidity and wet area we use electrical heating or glycol heating system.

hookster
05-04-2014, 08:27 PM
HEPE pipe has a very low thermal conductivity 0.37 KCal/Hr. So was wondering if going to the effort of horizontal drilling why not insert a new floor heater matrix? ie. insert a new pipe matrix, Carbon steel would be around 38.7 Kcal/hr and heat with waste refrigeration heat coupled with boost energy (especially for initial de-thaw)

You can read a paper published by FJB systems where they had some success in returning heaved floors to their normal state over time with reheating the substrate.
http://www.fjb.co.uk/wp-content/themes/fjb/publications/Frostheave%20Case%20Study.pdf

yupi
09-04-2014, 04:24 AM
HEPE pipe has a very low thermal conductivity 0.37 KCal/Hr. So was wondering if going to the effort of horizontal drilling why not insert a new floor heater matrix? ie. insert a new pipe matrix, Carbon steel would be around 38.7 Kcal/hr and heat with waste refrigeration heat coupled with boost energy (especially for initial de-thaw)

You can read a paper published by FJB systems where they had some success in returning heaved floors to their normal state over time with reheating the substrate.
http://www.fjb.co.uk/wp-content/themes/fjb/publications/Frostheave%20Case%20Study.pdf

Hi hookster,
Thanks for the information and I tried many times but it always says server error. Could you do me a favor and download the PDF file and email to me by 774530261@qq.com

Many thanks.

yupi
09-04-2014, 04:28 AM
mbc.
I totally disagree, the original poster has an ice heave problem already which would suggest that the sub soil below the construction slab is moist. Air ducts with sub zero air will only aggravate the problem.

Hi Magoo,
The facility is in Guangzhou China and it is quite hot and never get freezer even in winter. so is it possible to blow some hot air in the ducts to melt the ice?

hookster
09-04-2014, 06:55 AM
Hi mbc
Your annual temperature range in Guangzhou is 18 -33 DegC. The frozen substrate will naturally regenerate by conduction over time if you removed cooling input load from freezer. The addition of natural ducted air into your substrate will decrease time delay.

Judging from you ambient temperatures you should be able to prevent further ground freeze with forced ventilation and with time the heave will subside.

Trying to repair the crack in the freezer floor will be the fun bit as we have had limited success with patches and bonding between original floor and new patches at low setting temperatures.

Magoo
10-04-2014, 04:49 AM
Hi Yupi.
A few questions. Is the freezer floor level at or above ground level, example truck loading level.
What happened that the glycol sub level heating system failed, is that recoverable.
If construction floor is metres below ground level and then if you install air ducts, you have a risk of them filling with water/ condensate and blocking up, so will require headers at each end with fan pressurization for continuous air flow, possibly from plant room.
You will still need to identify if construction floor is cracked and vapour barrier is damaged.

One day I want to get to Guangzhou for the trade show.
magoo

yupi
13-04-2014, 01:10 PM
Hi Yupi.
A few questions. Is the freezer floor level at or above ground level, example truck loading level.
What happened that the glycol sub level heating system failed, is that recoverable.
If construction floor is metres below ground level and then if you install air ducts, you have a risk of them filling with water/ condensate and blocking up, so will require headers at each end with fan pressurization for continuous air flow, possibly from plant room.
You will still need to identify if construction floor is cracked and vapour barrier is damaged.

One day I want to get to Guangzhou for the trade show.
magoo

Magoo,
The freezer floor is about 1.3 meter above the ground floor for truck loading. The heating system was stopped for the pipe leakage. the construction floor is about 0.6m above the ground floor.

yupi
13-04-2014, 01:16 PM
Dear all,
We have contacted a Horizontal Directional Drilling company that can drill holes and insert pipes underneath our warehouse so we have a plan as below. Is there anybody can give his comment?

1. Drill holes and insert HDPE pipes in a space of 1.5 meters. These pipes will 110mm in diameter and with a thickness of 6mm.
2. The drilling will start from the side of the ambient warehouse and gradually go down to about 1.7 meters under the warehouse floor level to avoid the ground beam, then horizontally go to the freezer side and come out by the side of freezer.
3. Then the equipment will connect and hold the pipe and draw it back to the begin point. We will adjust the pipe to make the end of ambient warehouse lower than the other end.
4. The pipe will now be about 1 meter under the construction slab.
5. Because the outside ground floor in our DC is about 1.3 meter lower than the warehouse floor, and the pipe is 1.7 meter below the warehouse floor, both ends of the pips will be under the outside ground level. We plan to build two tunnels with drain system in case of raining.
6. In the tunnel of freezer side, we will connect two pipes as a group and connect to a fan/pump that can provide hot/warm air blow into, cooled air will come out from the end of the other side( this end will also install temperature sensor to monitor the status of the heating system.
7. We hope the pipes will transmit the heat to the ice and melt the it to a certain extent.
8. Because the construction slab is partly up about 20cm and we are not sure it was cracked or not, or we are not sure it will strong enough to support the rack and MHE if all the ice is melted and the sub-floor soil is muddy, we don’t want to melt all the ice, actually we want the ice help to support.
9. We will monitor the surface working slab heaving weekly and if we are lucky , the floor go down slowly and we will stop blow unheated air when the floor drop about 10cm.
10. The width of our freezer is about 25.5 meters and we plan to use 16 pcs of HDPE pipes.
11. The purpose of this plan is to melt some ice and lower the floor in some extent and prevent the frost heave going even worse.
12. The average temperature in Guangzhou is 22 ℃ and the lowest one is about 3 ℃ in winter.

Josip
13-04-2014, 09:52 PM
Hi, yupi :)


Dear all,
We have contacted a Horizontal Directional Drilling company that can drill holes and insert pipes underneath our warehouse so we have a plan as below. Is there anybody can give his comment?

1. Drill holes and insert HDPE pipes in a space of 1.5 meters. These pipes will 110mm in diameter and with a thickness of 6mm.
2. The drilling will start from the side of the ambient warehouse and gradually go down to about 1.7 meters under the warehouse floor level to avoid the ground beam, then horizontally go to the freezer side and come out by the side of freezer.
3. Then the equipment will connect and hold the pipe and draw it back to the begin point. We will adjust the pipe to make the end of ambient warehouse lower than the other end.
4. The pipe will now be about 1 meter under the construction slab.
5. Because the outside ground floor in our DC is about 1.3 meter lower than the warehouse floor, and the pipe is 1.7 meter below the warehouse floor, both ends of the pips will be under the outside ground level. We plan to build two tunnels with drain system in case of raining.
6. In the tunnel of freezer side, we will connect two pipes as a group and connect to a fan/pump that can provide hot/warm air blow into, cooled air will come out from the end of the other side( this end will also install temperature sensor to monitor the status of the heating system.
7. We hope the pipes will transmit the heat to the ice and melt the it to a certain extent.
8. Because the construction slab is partly up about 20cm and we are not sure it was cracked or not, or we are not sure it will strong enough to support the rack and MHE if all the ice is melted and the sub-floor soil is muddy, we don’t want to melt all the ice, actually we want the ice help to support.
9. We will monitor the surface working slab heaving weekly and if we are lucky , the floor go down slowly and we will stop blow unheated air when the floor drop about 10cm.
10. The width of our freezer is about 25.5 meters and we plan to use 16 pcs of HDPE pipes.
11. The purpose of this plan is to melt some ice and lower the floor in some extent and prevent the frost heave going even worse.
12. The average temperature in Guangzhou is 22 ℃ and the lowest one is about 3 ℃ in winter.

Maybe I'll sound rude, my opinion is; you are wasting money and time ... accidentally I've been there many years ago ... sometimes in the 1981-2 ... long time ago ... and I do not remember all details, but in short ...

In that time I was a young project site engineer leading a team of installation men to install refrigeration equipment for brand new cold store of 8 rooms (with controlled atmosphere, double temperature 0*C/-25*C for apples and pears and some frozen products) and 4 banana ripening rooms and one separate room to be used like charging freezing tunnel.

We did a job and all was good ... floor anti freezing system was with glycol, but installed by another company which installed floor insulation and slabs. Walls were sandwich polyurethane panels with additional metal sheets outside for protection from sun and rain. Whole carrying construction was of prestressed concrete beams on columns. All very modern and nice in that time.

Then after couple of years 2-3 they noticed that concrete floor in the freezing tunnel room suddenly start to rise in the middle of the room, they remain to use it until was not possible to brought the goods into the room with forklift .... so they stop to use it anymore - no more freezing, but meanwhile "mountain" remain to rise up almost to 0,5m ... then stopped.

Of course they called my company too to give them some explanation ... problem was with glycol system (pump was not working properly, glycol became "weak" and the first place to start to freeze was a freezing tunnel room, but due to piping mistake it was not possible to notice that (it was not a complete separate circuit, but in parallel with complete system) ... damage has been done and solution was to dig concrete slab and replace insulation and install electrical heat tracers ... of course when they open the floor there was not any ice within insulation layers what is normal - there was a vapor barrier and no water to freeze but soil was frozen down to 3,5 m (of course freezing process last for couple of years and build up a nice piece of ice.

Process is very simple ... it is going down until is coming to the solid rock without possibility to freeze, but then start to accumulate water from surroundings and growing up and rising all on its way .... showing us the power of trapped ice ...

My suggestion is to dig out all frozen soil refill with boulder and concrete aggregate and remake bottom slab, install vapor barrier, electrical heat tracers, insulation layers and then a top slab .... good civil company can do a good job ...

Actually we do not know all about your concrete construction and repairing can be very difficult, but I do believe there is some way to do it it on a proper way ...

drill a holes, insert a HDPE pipes, melting ice (point 9.) lowering the already broken-cracked floor and expect it will carry load is a dream .... it is much better to use a drilling company to make a hole in the middle of the room (place where your floor is up for 20cm) and take out a sample of frozen layer to see its thickness ...

I can be wrong (we are engineers here and we are talking about something without any drawings, cross section drawings ... you are from China I am from Croatia try to imagine what is lost in translation, etc) and sorry again, if I sound rude, but to solve some problem we have to investigate and found out how big problem we have then eliminate a cause (unfortunately, this can be quite expensive) otherwise after couple of months or years you would have the same problem again ....

Hope this is of some help to you to make a good decision.

Best regards, Josip :)

yupi
07-05-2014, 03:12 AM
Hi, yupi :)



Maybe I'll sound rude, my opinion is; you are wasting money and time ... accidentally I've been there many years ago ... sometimes in the 1981-2 ... long time ago ... and I do not remember all details, but in short ...

In that time I was a young project site engineer leading a team of installation men to install refrigeration equipment for brand new cold store of 8 rooms (with controlled atmosphere, double temperature 0*C/-25*C for apples and pears and some frozen products) and 4 banana ripening rooms and one separate room to be used like charging freezing tunnel.

We did a job and all was good ... floor anti freezing system was with glycol, but installed by another company which installed floor insulation and slabs. Walls were sandwich polyurethane panels with additional metal sheets outside for protection from sun and rain. Whole carrying construction was of prestressed concrete beams on columns. All very modern and nice in that time.

Then after couple of years 2-3 they noticed that concrete floor in the freezing tunnel room suddenly start to rise in the middle of the room, they remain to use it until was not possible to brought the goods into the room with forklift .... so they stop to use it anymore - no more freezing, but meanwhile "mountain" remain to rise up almost to 0,5m ... then stopped.

Of course they called my company too to give them some explanation ... problem was with glycol system (pump was not working properly, glycol became "weak" and the first place to start to freeze was a freezing tunnel room, but due to piping mistake it was not possible to notice that (it was not a complete separate circuit, but in parallel with complete system) ... damage has been done and solution was to dig concrete slab and replace insulation and install electrical heat tracers ... of course when they open the floor there was not any ice within insulation layers what is normal - there was a vapor barrier and no water to freeze but soil was frozen down to 3,5 m (of course freezing process last for couple of years and build up a nice piece of ice.

Process is very simple ... it is going down until is coming to the solid rock without possibility to freeze, but then start to accumulate water from surroundings and growing up and rising all on its way .... showing us the power of trapped ice ...

My suggestion is to dig out all frozen soil refill with boulder and concrete aggregate and remake bottom slab, install vapor barrier, electrical heat tracers, insulation layers and then a top slab .... good civil company can do a good job ...

Actually we do not know all about your concrete construction and repairing can be very difficult, but I do believe there is some way to do it it on a proper way ...

drill a holes, insert a HDPE pipes, melting ice (point 9.) lowering the already broken-cracked floor and expect it will carry load is a dream .... it is much better to use a drilling company to make a hole in the middle of the room (place where your floor is up for 20cm) and take out a sample of frozen layer to see its thickness ...

I can be wrong (we are engineers here and we are talking about something without any drawings, cross section drawings ... you are from China I am from Croatia try to imagine what is lost in translation, etc) and sorry again, if I sound rude, but to solve some problem we have to investigate and found out how big problem we have then eliminate a cause (unfortunately, this can be quite expensive) otherwise after couple of months or years you would have the same problem again ....

Hope this is of some help to you to make a good decision.

Best regards, Josip :)

Hi Josip,
Appreciated for the comment and my thought is get any comment.
Thanks indeed.

mjcornelissen
07-05-2014, 01:32 PM
Yupi,

I'm owner of a warehouse and we had the same problem in around 1980.

we digged up to 4 metres until we reached ground which wasn't freezed.

Afther this we made a isolation of 24 cm and then 15 cm concrete.
And what Josip said we put a decent ground warming unit on it. (using the warmth of our compressors to put underneath the concrete with pipes.

yupi
30-05-2014, 05:13 AM
Dear all,
we dig a tunnel under the freezer to check what happen and we did find ice block under the freezer. we plan to blow hot air into the tunnel to melt the ice.

Josip
30-05-2014, 08:07 AM
Hi, yupi :)


Dear all,
we dig a tunnel under the freezer to check what happen and we did find ice block under the freezer. we plan to blow hot air into the tunnel to melt the ice.

Thanks for update ... seems we were close to situation you found there ... and how to repair it ...

To build that ice block passed a very long time ... the same time you need to defrost it due to thermal conductivity of soil, and you cannot be sure if you melt it all ... it will be much better and faster to dig it out ... but final decision is your ....

I do hope you will come back with complete story about ... so we all can learn how to do or not similar repairing ...

Best regards, Josip :)

yupi
03-06-2014, 04:24 AM
Dear all,
Surely I will share our findings and solutions,successful or not.