Rebar in column - what length is adequate?

[angelboy]

I'm building a 'gazebo' with two 440mm brick columns at the front and the same at the back but they'll be tied with a single skin wall between them and then a fireplace in the middle of the wall.

I had planned to fill the columns with concrete and put a couple of L-shaped rebar lengths in the foundation pad to tie the poured concrete to the pad.

My question is, do I need to go all the way to the top of the column (2.1m-ish) with the rebar or can I used cut down lengths, say 150mm bent section with a 500mm (or whatever) vertical section?

 

[^woody^]

Do either, as they won't be doing much.

 

[angelboy]

Should I not bother putting them in then? I thought it would help to tie in the columns to the foundation pads.