Wash the walls with an acidic solution check on amazon to neutralize the salt completely and allow to dry for a few hours.
Moist basement concrete wall repair crumbling.
Apply small amounts of water over a short period until it has absorbed water deep into the wall.
The walls in my 63 yr old full walk out basement are crumbling in spots.
Now you should apply water to the wall where you will be applying the mortar.
If dry the moisture is originating elsewhere in the basement most likely from a basement shower easily remedied by installing a vent fan in the bathroom to direct steam outdoors.
Mist the wall with water and then apply a coat of thoroseal with a latex additive check on amazon.
The wall needs to be moist so that the old concrete won t leach moisture out of the mortar that you apply and cause the repair to fail.