What does plastic shrinkage cracking in concrete indicate?

Plastic shrinkage cracking in concrete is primarily associated with cracks that develop in fresh concrete due to rapid evaporation of moisture from the surface. This condition often occurs when the concrete is exposed to high temperatures, low humidity, or wind, all of which can increase the rate of moisture loss.

When the surface of the concrete begins to dry quickly while the inner mass is still in a plastic (unset) state, tensions can develop, leading to cracks. These cracks typically form within the first few hours after the concrete has been placed and before it has gained significant strength.

Understanding this phenomenon is crucial for field practices, as it emphasizes the importance of taking preventive measures, such as using curing compounds, applying wet coverings, or controlling environmental conditions during the finishing of concrete, to mitigate the risk of plastic shrinkage cracks.