The joint stabilizer goes in a drilled 3-inch-diameter hole, centered on the problem joint or crack. The two halves are screwed apart with about 8000 pounds of force, locking the device in the hole and bridging the joint or crack. Dowels within the stabilizer transfer vertical loads from one half to the other. Springs maintain the clamping force as the joint or crack opens and closes, up to 1/8 inch.
Installed in 2005, these five stabilizers at the Pennsylvania factory were still working eight years later.