Material to fill a 2-meter deep space under the new terrace

Good morning,

in spring, a new terrace will be built next to our house.
Under this terrace is currently a room with a 5K oil tank, which will soon be removed because we heat with gas.
I want to fill and compact this room (2m deep; 2.5m wide; 3.5m long) to later lay terrace slabs on gravel.

Now I am wondering about the suitable material to fill this space.
The terrace should not sink later on the compacted base. Obviously, the terrace slabs will get a separate gravel and chippings bed later.

- According to the internet, definitely a mineral material is recommended. Gravel would be the appropriate material here.
The angular stones interlock when compacted and thus become stable.

- An acquaintance recommended sand as material because no air pockets are possible here.

What would you recommend?

What would you recommend?

Our architect insisted back then that in all areas around the house where paving or a terrace was planned later, only compacted gravel should be used for backfilling. Everything else, in his words, would always lead to the ground settling further. And so we used tons of that stuff.

What are the space conditions on site? How does the material get to where you want it?

Ideally deliver one truckload of sand, install it in layers. Then the rest with gravel should be enough.

Ask the local supplier about prices. In some regions gravel is scarce, in others sand...

The house is detached and fenced. The supplier would probably dump the material in my yard, and then it goes further by wheelbarrow to the hole (distance approx. 70m). I'll definitely have to recruit a few friends for shoveling and transporting :-D

What is the advantage of mixing sand with gravel instead of just taking gravel (regardless of price and availability)?

Thx

35 tons per wheelbarrow? And loading the material by hand?

You won’t have any friends after that.

Think about alternatives.
And then we’ll talk about materials ;)

(This is more than a marathon just in terms of distance ... and with a wheelbarrow. At least get a mini mini excavator to load the wheelbarrow if nothing else works)

Mini excavators and dumpers - or directly a tracked dumper with a shovel. Shoveling by hand is already the ultimate punishment. I speak from experience(s).