Apparently they started early - about 7am or so? Until nearly midday to get everything done.
I've seen plenty of pics of other people's slab works, but never look at it up close. From what I can tell, they've laid a big plastic sheet over the gravel, then some spacers and a steel/iron frame. On top of this, a bunch of big polystyrene waffles, then spacers, then more reinforcement. The wood bracing is just held in place with star pickets and a few metal corner joins. Looks fairly simple, but there were many string lines for measurement - looks good to me! In the above picture, the step down bit to the left is for the garage (about 150mm lower than the ground floor slab).
This pic shows the portico area. The first floor balcony will roughly go over this bit.
This pic is from the rear of the block.
And the best news? Tradies said they'd be back early tomorrow morning while the slab is being poured in case any adjustments are required! I'm going to get up early and see if I can get there for half an hour before work. I threw in a few gold coins anyway, just for good luck - in case I don't get the chance tomorrow!
So stay tuned for tomorrow night's pictures - hopefully we'll have a whole lot of concrete, and a 20% invoice for the slab very soon after!!