12/11/2019
The pool uses a completely different and much less expensive way of placing concrete. Instead of building complete forms, like was done for the walls, a pool’s interior dimensions don’t have to be exact, so only the outer form is roughly constructed and the concrete is “shot” into place. This process is called shotcreting and we’ll get to see exactly how it works. There will be 32 yards of concrete shot today!
The day starts early, it’s 6:29, the eastern horizon is just getting light and you can still see the lights on the valley floor past the hogback.
It’s now 6:55, almost sunrise.
It’s now 7:00 and the sunrise color is being picked up by some mountain wave clouds to the west of us. That pipe in the foreground is what will carry the concrete from the pumper to the flex house in the pool.
It’s now 7:06 and the first bit of the sun is above the horizon.
This is the top of the temporary cover that was built over the pool. It’s too cold in December for the concrete to cure without protection. This was actually shot at 6:55, the same time as the top-right photo. The iPhone X camera does an amazing job in low light!
Here’s a look under the cover. Everything is ready to go - rebar, plumbing and skimmers are installed. The 2 x 4s that hold up the temporary cover will be picked up as the shotcrete sets and placed on plywood spreaders.
Another overview looking into the deep end. The round white disk is the fixture for a light
The large white pipe is outside of the pool shell and lets us monitor the ground water level. If we see any water in it, we’ve had a failure of the drain system.
Here’s what it takes to support the shotcreting operation. The Schwing Wp 1250X is a small concrete pump. The red trailer in front of the Hitachi excavator is a large air compressor and there is one concrete truck emptying into the pump with a second waiting.
The very start of the operation! You can see just how hard that gun kicks. The air compressor tripped off for a bit, and when that happens, all the concrete just pours onto the floor.
Just a few minutes in and you can see how the concrete builds up on the walls.