We experimented today with a modified shotcrete system. Shotcrete is using high pressure air (about 100 psi) to shoot concrete onto a surface, usually pools or walls. We had some experienced help with Dave, who has worked with it before, and Derek our new intern who has seen it done before. With our limited knowledge we forged ahead.
We had 2 goals in experimenting with shotcrete. The first was to try and figure out a method we can shoot it on our exisitng steel sided building to create a 2 hour fire rating. The second project is a shower stall and using durarock and shotcrete instead of precast concrete panels.
The first batch was mixed using 23 lb. of type 1 portland cement, 8 lb. water, 1.25 oz of super plasitizer polycarboxylite, and enough foam to acheive a finished density of 75 pcf. We sprayed this on a poly tank and a plywood wall. We are using a drywall texture gun to shoot the concrete. This stuck better than we thought but we weren't done experimenting.
The second batch we used 20 lb. of concrete and no plastizier. This didn't mix up as well and when shot had chunks of cement in it. We added sand but that didn't solve the problem. We will be doing more testing later this week.
