I only use 30 MPa strength concrete. This is known as High Strength Concrete.
This is handpacked and cut and roughly finished to receive the final plaster finish.
Curing begins after the exposed surfaces of the concrete have hardened sufficiently to resist marring. Curing ensures the continued hydration of the cement and the strength gain of the concrete. Concrete surfaces are cured by sprinkling with water fog, or by using moisture-retaining fabrics such as burlap or cotton mats. Other curing methods prevent evaporation of the water by sealing the surface to retain the moisture in the concrete. The concrete will continue curing for 30 days to full strength. It continues to harden and gain strength over many years.
Not all concrete is sealed...if not... it must be cured with the wet sacks etc.
The casting MUST be completed in one continuous operation.
It is known as a Monocoque design.
As soon as I figure out how to post pics...I will show construction methods.