The output power of a rocket is different than a blow torch. The sound pressure alone is near or above atmospheric pressure. That concrete is being exposed to vacuum and more than 1atm pressure fairly rapidly. The heat on top of that and if the concrete has any moisture, the water inside is going to rapidly sublimate and condense several times a second. That is on top of the concrete being slammed into by an entire atmosphere of pressure in the meanwhile.

There is a reason that NASA dumps a few million liters of water under their rockets.