Too cold for shotcrete?

Yes, HOA. they have not said anything but I think it looks terrible, so I will look into resealing at least the areas that got removed. OCD🤣

I would suggest waiting. Doing a partial seal on the road would probably look uglier and out of place than just letting it naturally fade and wear. Also, you’re going to be charged an arm and leg for a one-off job. Not sure how many asphalt driveways you’ve owned (from the looks of it, the houses have pavers) but chip & crack seal jobs are EXPENSIVE. As a small HOA, we all wait until the road gets sealed (every 2 years) and then the asphalt contractor will individually quote each home. It only costs slightly less because they are already here with the hot tar truck and the load is already paid for so it makes the jobs economical. If you try to get your driveway sealed as a one-off job, they charge a huge premium and you have to wait for them to have another job in the area so they can use a load they’ve already paid for. Asphalt work is weird that way because the contractor has to buy and entire load of hot tar whether he uses it or not and so their revenue model is to squeeze as many jobs as they can into one load to make the profit.

You can do cold tar sealing (the cheap stuff that is sold in the 10 gallon buckets at Home Depot) but that stuff is junk and will wash away in the next monsoon. And it’s not a whole lot cheaper.
 
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Good morning, so I woke up to water the shell and saw all this white on the shelf and what looks like crazing on the walls. Never saw this on an other pools. What is going on and do you think it’s an issue?
 

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Hard to tell for sure.

Maybe superficial and maybe structural.

You probably need a concrete expert to take a look and give you a professional opinion.

They might recommend a core drilled sample.

There are different compressive strength ratings at different times.

So, you might do a test at time X and then at time Y and time Z to get an idea about how the strength is developing.

You can wait 28 days to do the 28 day test as that is when the concrete should get most of the strength.
 


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The rate of gain of concrete compressive strength in higher during the first 28 days of casting and then it slows down.

From above table, we see that, concrete gains 16 percent strength in one day, 40 percent in 3 days, 65% in 7 days, 90% in 14 days and 99% strength in 28 days.

Thus, it is clear that concrete gains its strength rapidly in the initial days after casting, i.e. 90% in only 14 days.

When, its strength have reached 99% in 28 days, still concrete continues to gain strength after that period, but that rate of gain in compressive strength is very less compared to that in 28 days.


 
The concrete rated psi is based on the 28-day test as noted in the American Concrete Institute (ACI) standards.

Compressive strength can be tested at three, seven or 14 days and then again at 28 days to determine the psi.

The earlier tests are done to determine early strength gains.
 
Did you notice if they did a slump test when the concrete truck arrived?

Was this shotcrete (concrete truck supplies the premixed material to be shot) or gunite (dry concrete and water are mixed by the applicator on-site)?
 

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Highly unlikely that they did any sort of testing onsite.

My guess as well would be that they did not ... but, then again, a slump test probably isn't worth doing on pool concrete. If I recall correctly, you can only do a slump test on certain types of mixes and shotcrete probably doesn't qualify.
 
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Yes, HOA. they have not said anything but I think it looks terrible, so I will look into resealing at least the areas that got removed. OCD🤣
Waiting for the HOA to either say something or address it themselves might be best.
If you apply a fix acceptable to you, they may not like it - and will bill you for a fix acceptable to them.

Most probably, a little rain and sun will make it all blend in in no time.
 
the sub showed up, said its normal shrinkage cracks as its so cold those have not dried yet. He said they can’t stick even a piece of wire in them. If they get bigger they use a slurry to fill them? Of course i am getting the I have been doing this for 30 years, blah, blah, blah.

It was Shotcrete, they told me the slump was 3 1/2”, was delivered by a truck. There was a 45 min delay from truck 1 to 2 and a 20 minute wait from 2-3 was 20 minute.
 
We cannot tell from a picture if the cracks are superficial or maybe a serious problem.

I would refer you to a concrete expert.

Maybe a local engineering firm that specializes in testing concrete.

A Google search should turn up several local firms that do that type of testing.

A test at 28 days is the most reliable.

However, a test at 7 or 14 days can usually give a good indication if the strength is developing as expected or if it is much lower than expected.

If the concrete is seriously defective, then early tests will probably show very low compressive strength test results.

For example, a 4,000 psi mix is expected to be at about 65% strength at 7 days, which is 2,600 psi.

"Though many pool builders feel a 2500 psi (17 MPa) 28-day compressive strength is adequate for pool construction, ASA’s position is that shotcrete must have a minimum 4000 psi (28 MPa) to allow proper encasement of reinforcement, low permeability, and long-term durability.

This is especially important in shotcreted pool shells that are expected to be watertight and provide decades of troublefree service.

This topic is covered in more detail in the “Overview of ASA Position Statements” article on p. 28 of this issue and online in Pool and Recreational Shotcrete Committee Position Statement #1 www.shotcrete.org/media/pdf/ASAPositionPaper_PoolRec_1.pdf)".

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The mix was 3000 PSI.
ASA’s position is that shotcrete must have a minimum 4000 psi (28 MPa) to allow proper encasement of reinforcement, low permeability, and long-term durability.

In my opinion, a 5,000 psi concrete would have been a better choice.

In any case, I would refer you to a local concrete engineer expert who can come out to inspect the work and decide if any core samples are appropriate.
 
Ask the builder for a concrete batch report, which details the batch details specified and delivered.

When a concrete supplier delivers concrete to a job, they are required to have a batch report and you can request this to verify exactly what was ordered and what was delivered.

The report should include the ingredients like water, cement, aggregate, admixtures etc. and the amounts of each as well as the specifications for things like slump, strength etc.
 
Well it’s done, I think it went okay, they instructed me to lightly water 3x per day for 5 days. Temps still ok, did not drop below 40 last night and the high today was 59.

View attachment 548416

To someone who is more familiar with the process: is it normal to shoot all the walls out to the rebar like that and then come back to continue buildout?

I feel like the times I have seen it done they bring the wall out to the full thickness on the first pass or very soon after the first pass.
 

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