Design of chemical storage building

[hoshang]

Hi all
I'm now working on a new project. I have to design a chemical storage building (slabs, beams and columns all reinforced concrete)for academic studies (college of science, chemical department). The storage may include H2SO4, cyanide, ...etc.
Please find the attached link:

https://www.screencast.com/t/A5q1zCTmj3aQ

I searched this site for this and I gathered valuable information (concrete cover, epoxy coated reinforcement, 40MPa concrete).
1- Are there other considerations regarding design of RC design of such structures?
2- If I use 50mm concrete cover for the slab, how should I know that this cover is sufficient for protecting the reinforcement from chemical attacks?
3- As for H2SO4 attacking alkaline concrete, what would be the precautions? is coating the concrete with epoxy sufficient?
4- Should I use greater reinforcing diameter than required by analysis to overcome abrasive action of chemical attacks?

 

[hoshang]

Are there any ideas?

 

[dhengr]

Hoshang:
You might want to come up with several different levels of protection within your overall bldg. One area with max. attention to bldg. structure protection, fume ventilation, people protection, etc.; areas with long term storage and potential leakage, larger quantity spillage, etc., while getting/transferring smaller chemical quantities for actual work and usage out in areas of the rest of the larger bldg. And then, the rest of the bldg. with a somewhat higher level of bldg. structure protection, based on smaller quantities involved in any mishaps. I would take these questions directly to concrete and reinforcing authorities like ACI, CRSI, etc., in America, and ask them if they have any info. on this topic. I would also go to chemical industry groups and associations and ask them what their recommendations are on these matters. I suspect that any concrete cracking might be particularly important in this protection process, thus PT concrete might be appropriate in some areas, to control cracking.

 

[cvg]

suggest you stick with ACI 350 (or equivalent international standards) which has suitable guidance for your design

 

[hokie66]

I can only remember designing one such building, and one criteria was no joints in the floor. So we used a bonded post-tensioned slab on ground. With proper detailing, I suggest that is the best solution. Then you need a coating, but I can't advise on that.

 

[hoshang]

Thanks

I suspect that any concrete cracking might be particularly important in this protection process, thus PT concrete might be appropriate in some areas, to control cracking.

What other options could be used other than PT concrete to control cracking?

 

[jayrod12]

Lots of reinforcing to keep the crack width to a minimum so that the coating can bridge the cracks successfully.

 

[hoshang]

Thanks
How should I decide on minimum cover for concrete elements for chemical attack?

 

[JAE]

I think the chemical-resistant coating is the way to go.

Now whether the owner maintains that coating is another thing.

Check out Eng-Tips Forum's Policies here:
faq731-376

 

[hokie66]

If you are not doing it with PT, use 0.6% Ag reinforcement, small bars, centrally placed in the 5 or 6" slab. Cracks form because of restraint, so make the base as frictionless as possible, without ribs or edge restraints. Then cure, cure, cure. And consult the chemical companies for the right coating and application directions.

 

[hoshang]

Thanks all

use 0.6% Ag reinforcement, small bars, centrally placed in the 5 or 6" slab. Cracks form because of restraint, so make the base as frictionless as possible, without ribs or edge restraints.

I think you are talking about slab on grade. What about columns, beams, roof slab? What precautions should be applied to avoid chemical attacks?

 

[hokie66]

Yes, my answer was focused on chemical spills in the storage area, from leaking drums, etc. You don't want those chemicals leaking through the floor into the ground below. As to the superstructure, I imagine that ventilation is the key. Leaks would be cleaned up soon, I hope. The base of the columns and walls should probably have the same coating as the floor. As to the overhead structure, good quality concrete construction should suffice, I would think. The chemical storage building I worked on had steel columns and roof, and was specified to have a high quality coating system.

 

[hoshang]

The base of the columns and walls should probably have the same coating as the floor

I'm planning to use tile (either porcelain or ceramic) for the floor, cement plastering for the walls and columns (or tile), and gypsum board ceiling under the roof. What do you prefer for protecting these elements from chemical attack?

 

[MJCronin]

Suggest that you repost on the "Chemical Plant Design and Operations" Forum ....

MJCronin
Sr. Process Engineer

 

[hoshang]

Suggest that you repost on the "Chemical Plant Design and Operations" Forum ....

I'm concerned with structural design of the reinforced concrete elements.

 

[MJCronin]

I am so sorry ... I mistakenly thought you were interested in a sulfuric acid resistant coating for your concrete. Process engineering people could certainly help you there .....My bad ....

MJCronin
Sr. Process Engineer

 

[hoshang]

I am so sorry ... I mistakenly thought you were interested in a sulfuric acid resistant coating for your concrete. Process engineering people could certainly help you there .....My bad ....

However, thank you for your suggestion. If I couldn't manage it with structural design, I may propose a coating.

 

[15121981]

Firstly Have u done the Risk assessment study as a part of design as many chemical cannot be kept together due to different mitigation requirement during failure.

Now there are various concept from design point of view.

1.Plan for Safety showers if chemical are hazardous and is available in liquid form.
2.Each storage room should have one emergency exit provided with panic bar.
3,Entry door shall be provided for entry in the room including Rolling shutter for personnel excess.
4 Plan your drain for chemical spillage if not planned for local spillage control.
5 Wall should be segregated with fire wall with other room
6 Temperature control need to check for particular chemical or gas
7 Access between the racking shall be finalized based on aisle width of required forklift.
8 Based on distance plan the no of emergency exit from the building with minimum 2 on opposite direction.
9 Sprinkler need to be plan in each room as minimum.but again based on type of chemical buz many chemical react with water so in that case foam deluge system need to design.
10. Flooring must be epoxy coated with screed is preferred to provide slope to spillage.
11. Pit shall be planned for each chemical group differently.

 

[15121981]

I searched this site for this and I gathered valuable information (concrete cover, epoxy coated reinforcement, 40MPa concrete).
1- Are there other considerations regarding design of RC design of such structures?
Warehouse design is fully safety nothing specific wrt to RCC design.
At least 100 mm high skirting from FFL need to be paint with Epoxy to protect in case of spillage to all elements including walls, column.
If top is covered with RCC slab & there are chances of fumes leakage then also need to be paint all where or Fire rated celing grid need to be provided.
2- If I use 50mm concrete cover for the slab, how should I know that this cover is sufficient for protecting the reinforcement from chemical attacks?
I feel it is safe.
3- As for H2SO4 attacking alkaline concrete, what would be the precautions? is coating the concrete with epoxy sufficient?
6 mm Epoxy coating is enough to that with 40 mm minimum screed, Regarding Epoxy coating for particular chemcial you can take the guidance from applicator like BASF.
4- Should I use greater reinforcing diameter than required by analysis to overcome abrasive action of chemical attacks?
Providing 75 mm cover to Grade slab is enough to resist the chemical attack .

 

[hoshang]

At least 100 mm high skirting from FFL need to be paint with Epoxy to protect in case of spillage to all elements including walls, column.
If top is covered with RCC slab & there are chances of fumes leakage then also need to be paint all where or Fire rated celing grid need to be provided.

6 mm Epoxy coating is enough to that with 40 mm minimum screed, Regarding Epoxy coating for particular chemcial you can take the guidance from applicator like BASF.

Providing 75 mm cover to Grade slab is enough to resist the chemical attack .

Thank you for these suggestions.
Have you worked on the design of such buildings? This is the first time for me. I think the slab on grade should be impermeable and thick enough not letting the spillage of chemicals reaching the subgrade underneath. How much thickness is enough for such a condition?
Also the subgrade underneath should not cause cracking on the SOG (due to swelling, heave, friction, etc). How this is prevented?
Regarding 50mm concrete cover, I'm not familiar with using such concrete cover for roof slab. Doesn't it cause cracking? How much concrete cover is applicable to avoid cracking?
Is 50mm concrete cover sufficient for RC columns and beams to avoid chemical attacks?