Minimum anchor edge distance of a pad poured into existing floor

What would be the minimum anchor to edge distance for this scenario?

• How are the new sections of concrete attached to the pre-existing concrete? Are there any steel reinforcements between the sections? - The pre-existing concrete is drilled and doweled with 12 (3 per side) #4 rebar to the new sections. The new concrete has 1 mat of 10 (5 per side) #5 Rebar at 3" off the bottom
• Before pouring the new concrete, were there any preparations to the pre-existing concrete to control the transition? For example, was any adhesive applied to the existing concrete to improve the bond to the new concrete or was there any soft material barrier placed to prevent the existing concrete from bonding to the new concrete? - No adhesive to improve bonding or expansion joint to prevent bonding was put in
• What is the depth and quality/strength of the pre-existing concrete around the newly poured concrete? - The depth of the pre-existing concrete is 6" with #3 Rebar @ 16" C/C E.W. The Contractor estimated 4,000psi concrete and noted the clay and gravel base of the concrete was good and hard.