Repair mortar or repair concrete

[jokar]

Hello!
I am new to casting, etc., but I have a staircase with an accompanying retaining wall that needs renovation.
The staircase itself wears out a lot, so I hired professionals for that. In places where the concrete was damaged, the tiler repaired it with Redirep 25.

But the wall itself is not as exposed, and I plan to repair it somewhat myself.
It is built of concrete and blocks of natural stone.

I intend to only repair the joints "from above" to reduce the amount of water that creates (most) frost damage. The purpose is watertightness, not strength.

I understand that there is a big difference between regular coarse concrete for construction and concrete intended for repair. But I don't understand the difference between repair mortar (for example at Bauhaus from Combimix for 99kr/20kg) and repair concrete (for example Mapei Redirep 25 for 850kr/25kg).
In addition to this, there is concrete filler.
Very confusing 🤔

It should preferably last a long time, but not for load-bearing purposes.
Achieve the goal of limiting water intake.
I value cost-effectiveness a lot, no expensive brands just to get 20% better results, so to speak.

 

[Claes Sörmland]

If cost-effectiveness is key, mix your own cement mortar:

1 part construction cement
3 parts masonry sand (max 0-4 mm)

Mix well and the less fluid you make it, the denser and stronger the final product will be.

 

[jokar]

If cost-effectiveness is what you're after, then mix your own cement mortar:

1 volume part construction cement
3 volume parts mason sand (max 0-4 mm)

Mix well, and the less runny you make it, the denser and stronger the final product will be.

Thank you!
What is the equivalent product called that is pre-mixed?

 

[Plupp 405730]

Concrete repair mortars similar to Rep 25 and 45 cannot be mixed by yourself as they have additives and fiber reinforcements, and they are shrinkage-compensated, which is difficult to achieve on your own. Additionally, these mortars are texotropic, meaning they can be used for repairs upwards in ceilings, etc.

 

[Claes Sörmland]

Thank you!
What is the name of the equivalent product that is pre-mixed?

Cementbruk A?

https://www.bauhaus.se/cementbruk-f...CXNecuD9FZLvDToYzrGpq0Ngi5LqzN_xoCXScQAvD_BwE

 

[jokar]

Thank you for the response!
Still a bit unclear if there is a difference between reparationsbetong and lagningsbruk.

Another question: how do you achieve joints like these?
They are almost perfectly semicircular in profile.

 

[Plupp 405730]

Thanks for the answer!
Still a bit unclear if there is a difference between repair concrete and patching mortar.

Another question: how do you achieve joints like these?
They are almost perfect half-circles in profile.

There are different convex joint trowels, I'll include one from KGC, but there are cheaper brands too..

https://www.kgcverktyg.se/mur-puts-betongverktyg/mur-puts/slevar/fogslev-konvex-fog-10x170mm

It's perfectly fine to use cement mortar A for jointing in this case..

 

[cpalm]

Still a bit unclear if there is a difference between repair concrete and repair mortar.

A product with a name ending in -concrete is likely intended for casting. If it ends in -mortar, it's probably suitable for application with a trowel. Just as @Rejäl writes, these are products with different special additives according to the manufacturer's "secret" recipe, so they are not necessarily comparable, and you need to check what the manufacturer specifies for the properties of each product.