Tuesday, July 27, 2010
Foundation pour phase II
We finished the formwork, reinforcing, steel, and rough plumbing for the kitchen/dining room this morning about ten. The inspector came by at eleven, approved our work, and we started the pour at twelve. The foundation was pretty straightforward: 14 yards of a 5 five-sack with 10% fly ash and 3/4" rock at a 3" slump for a low water cement ratio. We used a crew of five and had all of the mud in the hole by 1:15.
A low slump mix makes for stronger concrete, but you need the vibrator to get the mud to flow. Wood floats, not mags or steel trowels, are the appropriate tool to level the concrete with the top of the form boards and keep the cement from rising to the surface. The top of the stem wall wants to be coarse for a good bond with the rammed earth. After the concrete has begun to set up, you can use a hose to clean the conduits, steel, and form board.
We also poured about two yards into the bond beam on top of the rammed earth walls we built last week. Here's a tip: don't try to lift a 3" hose full of concrete to fill forms ten feet in the air.
The photos in this post show the foundation pour, with great work by Khyber on the concrete vibrator. We'll strip the forms tomorrow and prep the rammed earth wall panel forms for moving with the crane on Friday.