Concrete shed base, expansion joints and reinforce - Expansion and reinforcement

[Shedbase]

Newbee, DIY er,
Please advise on the following?
Plan to lay concrete shed base 7 x 5 metre for Steel shed which will be 6 x 4 metres.
Shed / concrete base for Residential only, Garden / hobbie shed.
The concrete base to be 100mm thick, (sub base / membrane) and is away from any structures, essentially at the end of the garden.
Due to the size of the concrete base.
Will I require expansion joints?
Will I require reinforcement bars or fibres, one or the other, or both...?
What will you recommend?
Thanks for for your feedback.

[Carberry]

For a slab that thick the joints should be every 3m.

Get the readymix in with fibres, costs bugger all to add them.

[lutonlagerlout]

7by 5 M is big
I would go for 150mm of concrete
I am sure there is a formula for this but cannot find it
LLL

[seanandruby]

........30 x the slab thickness, so 100 ml thick is every 3 metres to 3.6 metres. 150 thick every 4 to 4.5mertres. Although for asthetic reasons you can place them strategically, the above is just a guide. That's for non reinforced slabs.