Shrinkage that occurs in freshly laid concrete and that shrinkage occurs if there are no aids to stop evaporation from freshly laid concrete. Plastic shrinkage occurs in the early stages almost within a first 10-12hours. Plastic shrinkage occurs in an early stages when concrete is in a plastic zone and this type of shrinkage mostly occurs on horizontal laid surfaces like beams, floors, pavements, slabs etc…
When water evaporates from the surface than due to rapid loss concrete volume reduces and cracks start developing. Due to strength of aggregates, concrete try to restrain the volume change and that creates tension in concrete, which becomes the source of cracking in concrete.
Air temperature is the most influencing factor, due to high wind rate, more temperature a difference occurs between temperature of concrete and wind, and to achieve equilibrium, water from concrete evaporates and cause plastic shrinkage in freshly laid concrete.
Concrete temperature also influences shrinkage in concrete. If concrete temperature is higher than surrounding, then concrete releases heat for the equilibrium and which carry water with itself and as a result, volume of concrete reduces.