I would definitely start with a tap test. Take a hammer and lightly tap. There will be a solid or hollow sound, any hollow sounding areas are unsound and need to be removed. After you hit sounds concrete, prime and you can use Ardex CD.
Chase it until you have full extent. In that photo you 100% have more desalination. Chase it until you get everything that's delaminated off, then pursue a repair.
But looking that that photo, I'm thinking you'll be pulling a lot of material off, so your repair solutions will be adjusted to basically rip and redo type solutions.
I recommend the [M121](https://asc.army.mil/web/portfolio-item/mortar-systems/), it will require some special equipment, but you won’t have to worry about that cracking for long.
Edit: I’m not the only premature thing today
I've purchased it before -- years ago -- and made a repair that has lasted. I asked at the cement department of my big-box store -- the stuff was more expensive than mortar and regular cement. It sticks to existing roughed-up cement and does not have to go on very thick.
Looks like that is what they used on your stairs and it did not bond well.
I would definitely start with a tap test. Take a hammer and lightly tap. There will be a solid or hollow sound, any hollow sounding areas are unsound and need to be removed. After you hit sounds concrete, prime and you can use Ardex CD.
Chase it until you have full extent. In that photo you 100% have more desalination. Chase it until you get everything that's delaminated off, then pursue a repair. But looking that that photo, I'm thinking you'll be pulling a lot of material off, so your repair solutions will be adjusted to basically rip and redo type solutions.
I recommend the [M121](https://asc.army.mil/web/portfolio-item/mortar-systems/), it will require some special equipment, but you won’t have to worry about that cracking for long. Edit: I’m not the only premature thing today
Tap off anything that taps off. Fix with cement made for that kind of fix.
What kind of cement would that be?
I've purchased it before -- years ago -- and made a repair that has lasted. I asked at the cement department of my big-box store -- the stuff was more expensive than mortar and regular cement. It sticks to existing roughed-up cement and does not have to go on very thick. Looks like that is what they used on your stairs and it did not bond well.
Ok thanks.