It is know to be concrete, gunite or shotcrete.
You drain the water then plaster the walls from inside
No, salt does not damage the plaster. Improper water balance will.
No Plaster of Paris is too soft and too porous to be useful in any thing to do with a swimming pool.
no
paper and plaster
Plaster
Frescos are painted directly onto damp plaster on walls.
Yes, plaster will dry out and crack.
It is what the plasterer holds their plaster on. A flat piece of metal with a handle centred underneath
No, plaster of Paris and white cement are not the same. Plaster of Paris is a porous material that will disintegrate outside in the rain. White cement is more durable and should last outside in the rain.
Frescos are painted directly onto wet plaster.
you apply it directly to the wound and plaster it