On Sun, 20 Aug 2017 12:51:19 +0100, Andy Burns
wrote:

T i m wrote:

As has been mention ... there seems to be a distinct lack of rebar
visible on any of the broken edges. Nothing 'dangling' off it in any
case?

there seems to be an 'L' of rebar down the wall and under the
cantilevered deck, but it only just seems to reach the main beams, I'd
expect it to go a couple if feet into the main deck?

At least, and maybe one bar every 100mm or so (from what I've seen of
such projects).

I understand the difference made to the bending / tensile strength of
concrete by adding some steel reinforcement is enormous.

I saw a basic engineering science program on TV where they cast a
small concrete 'bridge' (to go across a couple of bricks) and when
someone stood on it it failed immediately. They cast another of the
exact same CSA and mix but with a bit a rebar up the middle and that
not only resisted being stood and jumped on and also didn't collapse
when also being hit with a club hammer (but it did fracture etc).

Concrete may be fine for anchoring fence posts but not good for making
them ... without reinforcement that is. ;-)

Cheers, T i m