Choice of materials etc. – repair outdoor stairs

[Ducks]

Hi!

I need some advice on how to proceed with this matter. It's about an outdoor staircase from 1960, covered with limestone. The staircase itself is concrete, then a layer of some form of cement (? ) 20-30 mm, in this cement the limestone tiles have been fixed. The staircase is heavily frost/salt-damaged. I am currently removing the loose parts. Some pictures:

http://www.imagehost.se/images/zqrxqcjt.jpg
http://www.imagehost.se/images/xit0omt6.jpg
http://www.imagehost.se/images/uaggqs6q.jpg

The idea is to repair the largest holes with concrete, i.e., where it is so damaged that the concrete structure is visible. Then, the old fixing material, the "mass" used to fix the tiles, is also damaged in some places. Is there some kind of "putty" that can be used here to create a smooth surface where the adhesive for the tiles will be applied?

Is this the right thought, or am I off track?

 

[Trixern]

Hello!

I need some advice on how to proceed with this case. It's about an outdoor staircase from 1960, clad with limestone. The staircase itself is concrete, then a layer of some type of cement mortar (?), 20-30 mm, in which the limestone tiles have been fixed. The staircase is heavily frost/salt-damaged. I'm in the process of removing what's loose. Some pictures:

[link]
[link]
[link]

The idea is to repair the largest holes with concrete, i.e., where it is so damaged that the concrete structure is visible. Then, the old fixing compound itself, the "mass" used to fix the tiles, is also damaged in some places. Is there some form of "spackle" that can be used here to get a smooth surface where the adhesive for the tiles will then be applied?

Is this the right approach or am I barking up the wrong tree?

Hi, I think I have the same problem. Did you solve it?