Shotcrete question

[valen]

My pool is getting shotcreted tomorrow and they told me I need to water it down for a few days while it cures.
I was aware of this and thought it was standard.
However, when my neighbors pool was being built they didn't water it down after shooting it. It was a new build and house wasn't done yet so owner hadn't officially bought it yet from builder.
I asked him if the builder was going to water it down for him and he said the builder told him that they used a special mix that didn't need to be sprayed down after being applied.
I was wondering if any of you had heard about a 'special' mix of shotcrete that didn't need to be watered down for a few days.
Is this true or did they just tell my neighbor that because the pool builder didn't want to come out to spray down the pool themselves since there was no owner on site.

 

[Patrick_B]

I can't say it isn't true but I never heard of it, and it doesn't sound right to me. Some special sort of cement....? Not so sure about that.

 

[pooldv]

I haven't heard of that either. Might have been a cooler time of year and it wasn't as important. My gunite was shot in June I think and my PB was pretty indifferent to whether I should water it or not.

 

[Patrick_B]

Mine was done in winter, it was cold, and we still had to do it. Sorry, but it doesn't sound right to me.

 

[Concreteman]

My pool is getting shotcreted tomorrow and they told me I need to water it down for a few days while it cures.
I was aware of this and thought it was standard.
However, when my neighbors pool was being built they didn't water it down after shooting it. It was a new build and house wasn't done yet so owner hadn't officially bought it yet from builder.
I asked him if the builder was going to water it down for him and he said the builder told him that they used a special mix that didn't need to be sprayed down after being applied.
I was wondering if any of you had heard about a 'special' mix of shotcrete that didn't need to be watered down for a few days.
Is this true or did they just tell my neighbor that because the pool builder didn't want to come out to spray down the pool themselves since there was no owner on site.

Not true Shotcrete is concrete ACI recommends 7 days water cure -

 

[remotedoug]

Maybe it was a "special mix" of laziness and gullibility! Water, water, and water again. You only get one chance.

 

[Patrick_B]

Not true Shotcrete is concrete ACI recommends 7 days water cure -

Thank you for posting that. I only know about Pool Concrete from what I've learned here and my PB. He had me wetting mine done in the winter. He stressed it a lot too.

 

[DaninFLA]

concrete should always be watered down while its curing. the worst thing you can let curing concrete do is dry out. water water water! submerging curing concrete is best, but not practical typically...but lots of spraying will be fine as well. if you don't, the concrete will NOT cure to its full strength. that's why concrete cores are submerged in water and removed to test.

The contractor that said he used a special mix is a liar...unless he applied a chemical membrane to it after it was set, but that is highly unlikely.

- - - Updated - - -

Thank you for posting that. I only know about Pool Concrete from what I've learned here and my PB. He had me wetting mine done in the winter. He stressed it a lot too.

that's because he knows what he is doing! good advice.

 

[Azgirl71]

I agree it has to be wet down during curing. It is no different than when you poor a slab of concrete and have to water it.

 

[Patrick_B]

I knew it could cure underwater, but had no idea they submerged cores for testing. Again, a new thing learned here today.

 

[DaninFLA]

I knew it could cure underwater, but had no idea they submerged cores for testing. Again, a new thing learned here today.

they will do submerged as well as not submerged testing.

I might not be a pool expert, but I know about construction, etc. concrete has certain strengths at certain cure times. if you have 3,000 psi strength concrete, that's 3,000 psi at 30 days, however a lot of the strength is gained in the first 7-10 days, which is why its critical to keep the concrete from losing moisture during curing. water/moisture is needed for the concrete to properly cure, another benefit of heavy water use is that is helps remove the heat that results from the chemical reaction of curing. more heat, means more moisture loss which affects the strength of the concrete.

basically, its critical to keep the concrete wetted for the first week or so. after that the strength gains are slower and the curing process slows down.

 

[valen]

Thanks for all the reply's. i thought it sounded fishy. They just didn't want to water it.