A very long story but I hope worth the read.
Some background first. I worked for a precast concrete company as a job in between high-school and college. The job sucked but it paid well. We made a lot of the massive storm culverts and tunnel pieces that are dropped in place during construction instead of being made where they are. To put this in perspective our largest casting form could handle pieces 40'x30'. Absolutely massive pieces.
After a few weeks of working for this company I was trained to run the industrial concrete mixer and did this every day. This mixer was 3 stories tall, mixed up to 4.5 cubic yards of concrete at a time, and was the most beat up machine in the entire plant, which was saying something. It ran 6 days a week, two shifts a day, and was never maintained because the company couldn't get techs to come out on Sunday, it's only day not running, and didn't want to lose a work shift to get it maintained. The only good thing about it was that all the materials were weighed and fed in automatically. All it took was a button to start the process.
The most common problem was the bottom release door not sealing correctly. It would be just barely cracked, allowing all the water to run out of it resulting in an unusable chunky mess that would need to be dumped in a scrap hole instead of being used. If this happened the mess needed to be dumped out of the mixer quickly before it could partially harden inside the mixer. This only happened once that I was there and it took an entire shift to chisel the stuff out. We put a mark into the sliding door to show where it should be vs where it would be when it didn't seal.
The process worked like this. A cage of rebar and anchor points was constructed on a base, around a core, and a form bolted around it. The QA guy signed off and the form was then filled with concrete and left to cure. The curing time largely depends on the ambient temperature, the hotter it is the faster it cures and vice versa. Once the peice has cured enough to be lifted the form is stripped and the piece lifted by crane off the core. Repeat until you have as many pieces ordered.
Another thing to note is hard hat colors. They were color coded according to your role. Blue are plant supervisors, green QA, red the foreman, etc. For the 'normal' workers there was a choice of two colors. Yellow for people who don't know what they are doing (typically new or dumb people) and grey for those that do. This was about 5 months into my
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Should you choose precast concrete or site cast concrete? This is a vital question for anyone planning a commercial, hospitality or healthcare construction or renovation project. The answer will depend on what your business requires. >>>
Located in MA, footings need to be 4' down.
Do precast concrete require footings or just put on a concrete pad poured over crushed stone?
https://www.tatrosconcrete.com/wp-content/uploads/2014/04/image-11-e1397008062497.jpeg
Looking for recommendations on island contractors/companies that specialize in manufacturing/install of precast insulated exposed concrete panel homes and or build such a home on site.
Thanks!
