Door threshold concrete

[CCoomber]

I’m looking to fill in the cavity for my door threshold. I’ve read that I should be using a lean 1:8 cement, aggregate mix for foundation level strength however there is no mention of sand. Some other sources quote a 1:1:2 mix for this purpose. Should there be sand in the first mix? Which would provide the correct strength?

I will be adding another layer on top which will be 1 cement : 4 ballast: 2 sand.

Thanks for replies in advance.

 

[ree]

OP,
Why not post a pic?

 

[CCoomber]

Here’s a picture.

 

[ree]

OP,
From what I can see in your pic - is the idea to remove the bricks & then fill the cavity with some kind of concrete mix? Or to bed the bricks in mortar & then "add a layer on top"?
Mortar mix is 3sand & 1cement. Concrete mix is 1cement - 2sand - 4aggregate.

 

[CCoomber]

OP,
From what I can see in your pic - is the idea to remove the bricks & then fill the cavity with some kind of concrete mix? Or to bed the bricks in mortar & then "add a layer on top"?
Mortar mix is 3sand & 1cement. Concrete mix is 1cement - 2sand - 4aggregate.

The idea is to fill the cavity going above the inner skin to be level with the floor and include some insulation in to prevent thermal bridging.