Water Retaining Tank Mat

[mzaitz]

All

We have an aeration basin that is approximately 128 ft by 130 ft in plan with a 61 ft by 40 ft corner cut out. The contractor has submitted an RFI to place this 2 ft thick mat in 1 day. It is approximately 1130 cy of concrete. The mat is reinforced with 2 layers of #6 at 6" o.c. Currently we show construction joints about 30 feet on center. I have seen larger pours than this for a mat but never for a water retaining structure. I am very concerned about the structure cracking (then leaking) due to shrinkage. Has anyone done a mat this size in one day for water retaining structures? Any advice on it?

Thanks,

Mike

 

[JedClampett]

Don't do it. What are you getting for this reduction in quality? Make them follow the specifications:
* Thirty feet between joints
* Pour slab in a checkerboard pattern
* Wait 14 days between adjacent pours.
I've done a lot of large basins. If it leaks, the contractor will never admit his changes created the leaks. You'll be answering questions for a long time after the contractor hits the golf course. The owner will hire some technical expert (maybe me) and I'll tell them the large pour caused the problem.