To use anchoring adhesive or not? Securing rebar to footings on rock.

[Återfall]

I'm going to cast 14 footings on a rock, and on the rock, a "attefallsstuga" will stand.
I've drilled 3 holes per footing (the footings are 20x20cm). The drill holes are 20mm and I had planned to use 16mm rebar.

I'm wondering if it's advisable to use anchoring adhesive or not to secure the rebar? I read somewhere that it doesn't protect against rebar corrosion with too "tight" a drill hole and anchoring adhesive, and if so, do I need galvanized anchor rebar?

I had initially thought of using expansion mortar or something similar, but maybe I should have drilled larger holes then?
Alternatively, should I go down in size on the rebar, to 12mm??

HELP!!

//Anders

 

[vepsä]

When using chemical anchor mass, the rule of thumb is to drill a hole 2 mm larger than the diameter of the bolt. Rebar has ridges that add more, so a 20 mm hole is perfect for 16 mm rebar. It's better to use galvanized bars because when casting against rock, moisture can still find its way between the concrete and the anchor bar. You can buy them at places like Byggmax. Usage of anchor mass is about 1 tube per 2 piers, with one tube costing around 250 SEK.

 

[Rowah]

One option is to slit the rebar and then insert a small wedge into the slit. After that, just bring out the sledgehammer.

Principle according to this: https://www.marinvaror.se/produkt/bergskil-armeringsjarn-1-hal-2/

 

[RoBo]

Sluring

 

[Återfall]

Great! Thanks for the quick responses. I will probably go with vepsä's line with anchor compound and galvanized iron.

 

[vepsä]

It's probably the only right thing, it sits bomb-proof and never rusts.