Looking at the problems from last week: re-bar bending, re-bar creeping upwards and taking the block below the cut upwards with it. Possible remedies. Heavier re-bar, placing block a little lower to allow for some upward creep, holding the re-bar down by using a pipe wrench on the re-bar near the block. This would necessitate a second person (Troy) to hold the pipe wrench while Ryan concentrates on tightening the clamp. After the wedge mouth closes, could the pipe wrench be removed as the maximum necessary force to close the cut would be over? If not, could the hole at the end of the pipe wrench be wired to the base of the re-bar and held in place.
Another consideration is cutting a little more at point where the two wedge planes meet in order to reduce the amount of force needed to close the gap.
Thinking out loud. An interesting engineering challenge.