Segregation

Summary

Segregation - is the separation of the different types of particles in a fresh concrete mix due to a difference in their properties.

Technical Information

Segregation can result from concrete that is not proportioned properly or mixed adequately, or from the concrete being too workable in its plastic state. It occurs due to a difference in the size, density, shape of the concrete constituents. It can also be affected by external factors, such as too much vibration, improper transportation and placement or adverse weather conditions.

Aggregate segregation can be a problem in concrete. It occurs when the denser, coarser aggregates settle to the bottom of the mixture, leaving a paste of sand and cement on the surface. This can cause greater shrinkage and cracking on the surface due to the higher proportion of cement paste near the surface.

Bleeding is a form of segregation, though controlled bleeding is required for finishing purposes.