The causes and mechanisms of the plastic shrinkage are somehow similar to those of the drying shrinkage except that drying shrinkage means the shrinkage that happen in the hardened state of concrete (drying shrinkage is possible to happen in the early age state too).
Plastic shrinkage becomes more serious in hotter weather, less humid air and stronger wind.
Cracks due to plastic shrinkage are usually formed in the location of cement paste (not through the aggregate). The pattern of cracks is frequently in parallel direction to each other. Cracks length is usually about 0.1 to 1.0 meter and depth of the cracks is about 25 to 50 millimeter.