1. Use at least 3 - #5 rebars continuous with a 22” overlap at any splice joints. Use #3 rebars for cross ties every 24” O. C.
2. Yes you should use a keyway in the footing to prevent movement from soil and hydrostatic pressure against the wall and as added insurance in the event the rebars rust through at the joint.
3. You should have #5 vertical rebars (bent dowels) that are embedded in the footing and stick up at least 22” above the footing. Tie additional rebars to them as needed. Horizontal bars should also be used to create a vertical “mat”. Ties the bars at 12” O. C. each way max.
4. When ordering the concrete, tell the plant to send it at a 3”– 4” slump max. Be sure to use a mechanical vibrator when placing the concrete to minimize any air pockets or honeycomb. To be certain you are getting the quality of concrete you order, and to control the addition of water after it leaves the plant, you should hire a soil & materials engineering firm to send a technician to the job for each concrete pour. They will make test cylinders and verify the air entrainment and slump of the concrete as it is being placed. The slump test is used to control the amount of water that can be added. A 4” slump should be the maximum allowed. The more water the greater the slump. The test cylinders will be “broken” in a hydraulic press at 7 and 30 days to test the compressive strength of the concrete as it cures. It should reach the 3000 lbs. Strength within the 30 days.
[This message has been edited by GlennG (edited May 15, 2002).]