The main cause of delamination and segregation of concrete

Concrete segregation mainly refers to a situation in which the cohesion of the components of the concrete mixture is insufficient and the coarse aggregate sinks. Usually in this situation, if a large amount of water is secreted from the concrete, it can basically be determined that the concrete has segregated.

After segregation, concrete shows obvious stratification, with aggregate at the bottom and moisture at the top. If you mix concrete at this time, you will find that it has lost its original viscosity and has poor cohesion.

Causes of concrete segregation

The causes of concrete segregation are:

1. Inappropriate raw material quality and mix ratio;

2. Incorrect operating methods (including mixing, transportation, Pouring, vibration, etc.).

Practical experience has proven that concrete segregation is mostly caused by improper operating methods.

The segregation of concrete affects the strength, durability and homogeneity of concrete. It also brings inconvenience to concrete pouring and vibrating. It is the main cause of honeycomb pitting on the concrete surface and the intrinsic cause of uneven shrinkage of concrete.

Delamination, segregation and bleeding are typical symptoms of poor concrete workability. Delamination is the result of concrete segregation, and bleeding is a manifestation of segregation.

Concrete segregation refers to the separation, unevenness and loss of continuity of components. This is caused by the different sizes and densities of the various solid particles that make up the mixture. Differences in the shape and method of operation of the components can cause them to separate. Produce different movements and produce different displacements. For example, vertical components such as columns and walls often sink coarse aggregate and the cement slurry floats up. The upper and lower strengths are different, causing the upper and lower strengths to be weaker. The location of construction joints and node bending moments form weak links in the structure, which will adversely affect the integrity of the structure.