, so we're using an ingenious piece of machinery called a shooter truck (see photo). Basically its a 9-yd dump truck with a shoot and 25-ft-long conveyor belt. You rev up the conveyor belt, open the shoot and gravel goes a flying. It can be swung from side to side and elevated for distance throwing. The operators say the can shoot it 50-60 ft, so we'll see because its at least 40 ft. across the diagonal dimension of the basement, and no way to approach it from the rear. Should be exciting, especially the part where I (as in me) hold 4x8 sheet of plywood on the outside of the basement to act as a backstop for the flying gravel. Actually, you make a stand for the plywood and place it at the target, then skidaddle away.
This morning, the crew raked out the gravel, compacted it, covered it all with 6 mil plastic, and laid in the rebar on a 2' spacing. At about 9 am the concrete arrived and they poured the garage slab, about 10 yards. Since it was in the low 30s this morning, Don had them add hot water at the batch plant (warms the cold gravel), as well as accelerator (a chemical used to hasten setting up of the concrete), and it was poured on the dry side. All of these little tricks are intended to make the concrete set up quicker in the cool weather, otherwise they'd be there at midnight finishing it off. Don worked the concrete over with a "mag float" (photo to right), which has a light weight magnesium handle that extends to 30 ft in length. Then the young guys got on their knees and worked it over with hand trowels, all 780 square feet. Everything turned out fine and the troweling was done around 4 pm, about 8 hours after the concrete was mixed. It looks pretty good and will be hard enough to walk on in the morning.
While all this was going on I put in the 3" ABS drain pipe, floor drains and sump basin in the basement. All of this will be covered by gravel, then the slab will be poured over the pipe and up to the floor drains and sump basin. The perimeter drain for the outside of the basement comes through a 6"PVC pipe we cast in the footer, then enters the sump basin. Inside water (on the floor) and outside water will flow in the basin and be pumped up and out of the house through a 1.5 " pipe.Tomorrow (Friday), they'll shoot gravel into the basement, so we're ready for inspection on Monday and the slab on Tuesday. There are sill a bunch of forms to be removed, but they'll do that in their spare time. So, we are almost done with the foundation. Framing should start in about a week, when all the concrete has cured for a 7 days (ca. 50% of full strength, which = 3000 psi).
