I have a slightly unconventional solution underway that involves joining a wooden beam measuring 100x200 mm with a concrete beam of the same size. The wooden beam is five meters long and will be spliced together with a similar beam in concrete, end to end.

I know this sounds COMPLETELY insane, but it's too late to change it now.

Now to my question: how do I attach the reinforcing bars to the wooden beam in the absolute best way?

The concrete beam is cast in place, against the end of the wooden beam.
 
Weld on a sturdy French screw at the end and thread it in.
 
Isn't there a high risk that the weld will break when the wooden beam bends under load? A solution that does not involve welding would be better since iron becomes so brittle when heated.
 
Drill holes in the wooden beam and thread in the iron?
 
It is not possible to cast any form of post shoe into the concrete beam?
 
Matti_75's response about drilling holes and inserting the rebar seems sensible.
Could chemical anchors work in wood?
 
Drill a "lagomt" hole and knock in the rebar, so no goo is needed in the wood. In that direction, there won't be any direct loads, so they will stay secure in the beam.
 
True, but the joint between the wood and concrete beam must not slide apart in this case, as they could slip off the support.

Chemical anchors in stone material hold incredibly firmly, I’ve heard that a 10mm iron chemically anchored in concrete cannot be pulled out, the iron stretches until it snaps.

I don’t know how it works in wood, but it should be stronger than just driving the irons into tight holes?
 
Polyurethane glue works perfectly for gluing steel and wood.
 
Well, damn right, you are! So many knives that I've made.
 
Prefer using epoxy glue to fill the holes as regular polyurethane glue is not gap-filling from a load-bearing perspective and requires both high clamping pressure and tight joints to hold. Epoxy is significantly more forgiving.
 
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If you drill the holes slightly crooked, and in different directions, the wooden beam cannot slip out of the grip of the rebar.
 
A weld is normally stronger than the base material.
If you want extra toughness in the weld, it is advantageous to use MMA (Stick) instead of MAG (Mig).
 
Hmm..

I'm not exactly convinced that the reinforcing bars are suitable for this splicing. The bars are meant to handle tensile forces in the concrete and are not intended for the bending forces that may arise in this case. There will also be intense edge pressure in the wooden beam, which carries the risk of it being torn apart.

A better solution might be to manufacture a 500 mm long square steel tube of 100x200 mm and insert the beams from each side, then secure them with through-bolts.
 
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The weak point of the last council should be that the drill holes in the concrete can cause the concrete to crack around its holes.

This is quite a tricky problem...
 
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