Shotcrete look ok?

[Melissainphx]

Nervous first time pool builder here! Shotcrete was done today - does everything look ok? I’m not really sure what issues I need to keep an eye out for.

(and yes, watering 3x daily for 7 days!)

 

[ajw22]

It looks OK. Not the best as they left the surface very rough. See the difference in the pics below from @setsailsoon build.

Get in the pool and check the depths are what you expect.

 

[Melissainphx]

Thanks, AJW. I was a little concerned with how rough it is….that job you posted looks beautiful.

 

[ajw22]

Go around and check that you do not see any exposed rebar.

 

[AQUA~HOLICS]

On jobs that I’m not present during application, I will drag a heavy crowbar across the finished product and listen for inconsistencies in the sound that will indicate hollow spots.
I like to see all edges (steps and seats) at a 45 so the plaster application will have more product on the corners.
As far as the finish, your plaster is going to bond so strong to the Shotcrete, I like seeing them rougher than smoother just for that reason.

 

[proavia]

and yes, watering 3x daily for 7 days!

Great - with our extreme heat for at least the next two weeks, consider watering 4-5 times daily.
Water is evaporating quite fast in our 100+ temps an low humidity.

 

[AQUA~HOLICS]

American Shotcrete Association recommends a minimum of 7 days of continuous (not just a few times a day) wet curing to help control shrinkage issues, increase strength and reduce permeability.

 

[proavia]

American Shotcrete Association recommends a minimum of 7 days of continuous (not just a few times a day) wet curing to help control shrinkage issues, increase strength and reduce permeability.

So as long as it's damp/wet?
And maybe extend out to 14 or more days?

I was amazed at how much water soaked in when I watered my shell 4x daily - and that was in October here in AZ.

 

[AQUA~HOLICS]

Surface Saturation Dry, is the term used to describe how to hydrate the shell for the first 7 days minimum to ensure that it will cure properly.
Proper hydration has a significant impact on the shell and is commonly misunderstood.

 

[setsailsoon]

Surface Saturation Dry, is the term used to describe how to hydrate the shell for the first 7 days minimum to ensure that it will cure properly.
Proper hydration has a significant impact on the shell and is commonly misunderstood.

Couldn't agree more with this. For industrial concrete foundations our experts always presented data that concrete kept wet/moist nearly always had 40% higher crush strength. There were many ways to do it. In S Louisiana we would soak burlap twice per day over the surface. They explained it to me as having something to do with water of hydration that's required deep inside the concrete ( a lot of our foundations were over 10' thick). Sometimes they'd recommend we set up sprayers and run them several times per day. I chose that option and laid out 1" pipe with a couple irrigation heads and connected it to my sprinklers. See photo below. I ran this for 30 days. Did the same thing for my house slab. It has zero surface cracks and seems to be holding up well. Cores tested at 4850+ psi for 3500 psi concrete.

Chris

 

[phonedave]

They explained it to me as having something to do with water of hydration that's required deep inside the concrete ( a lot of our foundations were over 10' thick). Sometimes they'd recommend we set up sprayers and run them several times per day.

Concrete does not dry, as in water evaporate from it. Concrete (cement to be accurate, which is a component of concrete) cures. Hydraulic cement cures or sets via a chemical reaction where the water hydrates the cement particles and causes them to harden. The water actually becomes part of the cured cement. That is why cement does not soften again when you put it in water after it cures. As an analogue, it is like the difference between drywall compound sold pre-mixed in a bucked and bags of hot mud. Drywall compound dries, if you come back with a wet sponge after it dries you can re-hydrate it and smooth it out. Hot mud cures. Once you mix it with water you have whatever the specified time (10 minute mud, 20 minute mud etc) until it cures. Once it does, no amount of water is going to soften it back up.

In the concrete lab in college (yeah, I took classes on reinforced concrete in college) the cylinder curing room was kept at something like 90% humidity. It was a big humid walk in with lots of shelves (and mold). When we made concrete samples for strength testing over time, we would mold them into cylinders and then store them in the curing room. No need to spray them, as the room was a giant rain forest.

 

[sktn77a]

Crappy finishing job on the shotcrete! But as long as that rough surface isn't all rebound you should be OK.

 

[setsailsoon]

As I looked closely at the photos in top of this thread I noticed something I didn't see before. Is that wood exposed below the shotcrete? Also looks like could have some big chunks that might have been rebound that wasn't swept out.

 

[Melissainphx]

As I looked closely at the photos in top of this thread I noticed something I didn't see before. Is that wood exposed below the shotcrete? Also looks like could have some big chunks that might have been rebound that wasn't swept out.

View attachment 588613

Are you talking about the spot in the right hand corner of your red square? Thankfully, no - not wood. Just some muddy water that collected in a crevice.