When my wood-frame apartment was built 20 years ago, lightweight low-strength concrete about 2" thick was poured on the plywood subfloors in each suite as a fire barrier.
The concrete has now fragmented and fractured in many places and makes crunching noises as the pieces grind against each other when someone walks on the floors.
Would anyone know of a simple and permanent way to rebond or secure the fragments and fractures so that they become a solid slab?
Thanks in advance for your helpful replies.