How much reinforcement for casting?

[magnusss]

I am going to cast a beam to place over the opening of an insert fireplace.
The beam's length will be 1m. Is it sufficient with two reinforcement bars at 10mm?

I will then build with lightweight concrete 1-1.5 meters on top (to enclose the fireplace).

Grateful for tips.

 

[jawen]

Place 4 pieces in the shape of a 4 on a die, that's usually done in "balkkonstruktioner".

Best regards, Jawen

 

[Fasting65]

Can this image help a little?

 

[magnusss]

Great!
Thanks for the help.
Just need to cast then.