Which factor should be monitored to avoid defects during the curing period?

Monitoring bleed and evaporation rates during the curing period is crucial for preventing defects in concrete. Bleeding refers to the process where excess water rises to the surface of freshly placed concrete, which can lead to a weaker surface layer if not managed correctly. High evaporation rates can lead to surface drying, which increases the risk of plastic shrinkage cracking.

When the evaporation rate is high, especially in warm and windy conditions, it can cause the surface of the concrete to dry out too quickly. This rapid drying can hinder proper curing and lead to weakened concrete structures due to inadequate hydration. By keeping an eye on these two factors—bleed and evaporation rates—inspectors can take proactive steps, such as applying curing compounds, using wet burlap, or protecting the surface with wet coverings, all aimed at maintaining moisture in the concrete during this critical phase.

Understanding these rates allows for better control of the curing environment, which is essential for achieving the desired strength and durability of the concrete.