precast concrete walls in water tank

[cvlenv]

good day to all...

i am very appreciative of the commentaries, suggestions and additional insights by you over the concerns i previously have...

here's now : i am considering to apply precast concrete walls for our ongoing water tank project as we are on a tight schedule...can anyone give me some basic ideas, design parameters, applicable codes, methodology for the construction/fabrication of precast concrete wall units?...what are some critical areas to give full attention to?...the option to seek precast concrete supplier is second as we consider mobilization/hauling/trucking cost especially when the supplier is quite far from the project site...

thanks again and more power...

 

[engineertipsman]

will this be cladding, or the actual tank?

 

[bigmig]

1. basic idea: don't leak
2. design parameters: 62.4 pcf water density, considerations for ice loading, water level changing, external loads (soil, wind, snow)and concrete expansion with various temperatures on different surfaces, overflow valves, soil conditions below the tank
3. applicable codes: ACI Manual of Practice Part 4, Special Structures + applicable local codes
4. method of construction/fabrication for precast....? I'm not sure what you are asking. Contact your precast fabricator, visit his yard and get a rundown in precast education.

It would help if you provided some of your best guess answers to your questions, at which point everyone can add to that. I always encourage my peers along the lines of if they have a question, bring an answer. I think you will start to see that your questions get a lot more specific once you roll these things around in your mind and you get into the details.

I have already given you some advise in your other post regarding items needing the most attention based on some experience we had with a cast in place concrete tank.

 

[Gumpmaster]

Square tank or round?

I would recommend looking up a precast tank manufacturer like Natgun. I think they do precast tanks.

A specialized manufacturer like that will have a much better chance of getting a leak free tank than you coming up with details yourself.

Personally I wouldn't recommend it in a seismic area, but it should be passable in much of the country (USA at least). Also bear in mind that the longevity of a precast tank probably isn't as good as a cast in place tank.

 

[HeavyCivil]

I've worked with NATGUN in the past, and agree that if you want to go with precast someone else's tried and true system will definitely do better than something you devise. Especially considering that from your post you're pretty much starting at square one of tank design..

 

[hokie66]

Circular concrete tanks which consist of precast concrete panels which are then circumferentially post-tensioned are fairly common, but are not my favourite type of tank. If you must go this way, get someone involved who has done it successfully before.

 

[Zambo]

How big is this tank?

 

[cvlenv]

it is the actual wall, specifically partition walls between water tanks...

we're planning precast rc walls, details of which are the same with the cast-on-place concrete (vertical & horizontal rebars for each face with spacers...size @ 2.0m x 1.0m x 0.25m (lwt), concrete 3000psi@28days design, rebars @ grade40(or 40000psi yield)...rebars are protruded at points where the panels are connected by welding during installation

it is the design of the filler grout for the connection that i am concerned about...would the design mix of the filler grout be the same as that of the precast unit?

 

[msquared48]

I think that a non-shrink grout would be needed here. I would be very concerned with providing for expansion and contraction of the structure with associated water level and temperature changes.

You could be getting yourself into a real can of worms here if you have not done this sort of structure before. They are very specialized. You do not need to learn the ropes on a tight time schedule. Let someone else be the bad guy the first time around.

Does this tank have a structural lid?

Mike McCann
MMC Engineering
Motto: KISS
Motivation: Don't ask