According to ElertGadget, this can be a good way of making sure the concrete you are laying does not dry too quickly.
The website recommended that construction professionals use water to dampen the surface of the sub-base.
It then advised they use a wheelbarrow to pour the concrete onto the sub-base until it fills the corners of the form.
After it has been compacted and smoothed with a tamping beam, builders can then remove any excess concrete, fill in the low spots and use any necessary concrete finishing tools to complete the work.
This process could then be repeated on the other areas of the site that need to be done.
Heavy duty steel roadforms could be one possible option to use with concrete slabs, while PolyMeta Forms may also be a good product to consider.