Continous 16Hrs of Concrete Pour Flow.

I'm a machanical engineer so I'm not sure, but I would think a pour of that size should be done in sections.

Can anyone tell us what the cure time would be on a pour of that size? I've seen pours of that size, but the depth was about 1/5th of what you discribe.

You can't decide to stop during a pour. Instead, you can plan to make the pour smaller by adding construction joints. This essentially consists of a bulkhead, keyway, and waterstop. The structural engineer should be consulted to approve these extra construction joints beforehand.

If the tank foundation requires 16 hours to pour as monolithically, then 1/4 pie slice could be accomplished in 4 hours.

If this is an open field, get everyone off during a lightning event. This is a very serious safety hazard.

Are you talking about a Tank Foundation, which would fall under ACI 318, or part of the Tank, which might fall under ACI 350. Construction joints are a standard practice for concrete pours that must stop for various reasons. However, they should have been anticipated before hand by the engineer, and any change should be discussed with the engineer before the pour begins. Some construction joints are very simple and basically just a clean edge between the two pours, which must be wetted before second pour is against first pour, and dowels connecting the two pours (or a key). A water stop or seal is not usually required in a construction joint if it is just a slab on grade structural component, but so method of sealing the joint may be required if it is secondary containment. I have seen the decision to place construction joints made during a pour, but they are always planned for ahead of time as an alternative in case of problems during the pour.

Regarding lightning, work should always stop during lightning, and with concrete pours you should plan the pours around the possibility of such storms to avoid them.

I cannot give you direct information, but am aware of pours that were over 15m thick and much "longer" and "wider" than your tank. These were done as single pours with re-inforcement being progressively tied as the hole was filled.

I seem to remember a serious focus on "slow set" mixture and sequence of fill of the hole to maintain "wet" surface mixing.

There was also substantial plumbing installed inside the pour and water pumped through this to "cool" the concrete at the right rate to avoid cracking. These pipes were later pumped full of concrete slurry that was then allowed to set to complete a solid foundation.

Three suggested contacts for reliable information.

a) Someone in your home country involved in pouring foundations for power station generators.

b) Someone in your home country involved in pouring portions for concrete dams. (Usually done as staged and keyed pours)

c) Your local concrete supplier. (If they cannot tell you about the details of postponed pours and such, then maybe they cannot achieve the blend of concrete that you need for the quality of job you want done.) Or at least they can put you in contact with others that have also done large pours.

You can detect lightning strikes in advance fairly easily. I seriously doubt you can build a large enough Faraday cage to stop them however. Best off is to schedule the pour in more clement weather. 16 hours is not so tough. We made what we were told was the largest continuous pour (~6K yd³) in the U.S. for 2007 (not the largest ever by FAR!) of a chimney foundation slab 11 feet thick. It took about 30 hours to complete. The ready-mix had ice included as most of the water to slow setting and keep the temperature within specifications (<94°F). Liquid N₂ can also be entrained for a similar purpose. Your engineer(s) and concrete supplier should be involved in this discussion first.