What causes honeycombing in concrete?

In the context of concrete, honeycombing refers to voids or cavities that are left in the hardened concrete due to incomplete filling of the formwork or improper compaction of the concrete. Honeycombing in concrete can weaken the structural integrity of the concrete and make it more susceptible to water penetration, which can lead to corrosion of the reinforcement and other durability issues.

However, to prevent honeycombing there are many things you can do. In this blog, we will be looking into everything related to honeycombing, from its causes to its repair, and ways to fix it. Let’s look at the causes.

CAUSES of honeycomb in concrete

Honeycombing in concrete is generally caused by one or more of the following factors:

1. Improper compaction
This can result in trapped air voids, which can cause honeycombing. This is usually due to insufficient vibration during the placement and compaction of the concrete.

2. Improper mixture proportioning
Using the wrong mix proportions can also lead to honeycombing in concrete. For example, using too much water in the mix can make the concrete more fluid, which can lead to the segregation and settling of coarse aggregates.

3. Formwork issues
Poorly constructed formwork can also result in honeycombing. If the formwork is not properly sealed or does not fit tightly, the concrete can leak out, resulting in voids and irregularities in the finished product. To avoid this, shuttering is common. Shuttering in construction is a temporary structure used in construction to provide support to the concrete until it is set.

4. Improper curing
If the concrete is not cured properly, it can lead to the formation of cracks and voids, including honeycombing. Proper curing is essential to ensure that the concrete gains strength and durability.

5. Placement issues
Improper placement techniques, such as pouring concrete from too high of a distance or using improper equipment, can also cause honeycombing. It is important to identify and address the root causes of honeycomb in concrete to ensure that the finished product is structurally sound and durable.