Did you know that Honeycombs in Concrete are quite common in concrete structures? If you don't care about how to avoid honeycomb in concrete and it converts info huge loss.
Here in The civil experiences article, we briefly explain how to avoid honeycomb in concrete & honeycombs in concrete and remedies with Type of Concrete honeycomb, effect, and many more important tips which you don't want to miss.
What is Honeycombing in Concrete
Honeycomb in concrete meaning: Honeycombing in concrete can be defined as a rough concrete surface area where cement paste doesn’t fill around aggregate or area concrete containing voids or concrete which have hollow cavities It's known as Honeycombing in Concrete (Honeycombs in Concrete).
In other words, concrete which not cover the reinforcement bar properly due to concrete has not reached enough
Honeycomb Structure in Concrete may be created by the insufficient amount of fine aggregate in the concrete mix also due to wrong aggregate grading or bad concrete mixing of ingredients or poor concrete vibrator used
Honeycomb detect on the surface if available as soon as we remove the shuttering but if honeycomb is present inside of concrete then it required advanced technic like ultrasonic testing
Types of Honeycombs in Concrete
Small size Honeycombs in Concrete
Medium size Honeycombs in Concrete
Large size Honeycombs in Concrete
Where do the Honeycombs form Concrete?
Cause of Honeycomb in Concrete
Honeycombing in concrete is caused due to many factors which are explained below in civil experience.
1. Improper Workability
Workability is a wider topic to explain in the honeycomb article so please read the already published article in deep if you want to understand in-depth about workability
2. Water Cement ratio
High W/c ratio
If the water is used to make concrete in excess amount then the water/cement ratio goes high which is the reason for segregation of concrete end of result honeycomb in concrete created low w/c ratio
If the water used in concrete is below the certain limit determined during the concrete mix design then concrete pore enough to reach every corner or badly cast in formwork end of result honeycomb created
Sometimes admixture is used to improve workability without the use of excess water
Also Read: Segregation of Concrete || Causes & Prevention of Segregation
3. Higher A/C ratio
It is also known as Improper mixing of concrete ingredients like low cement contain or high amount of aggregate which forms a poor concrete mix design which is not good for pouring and also not fully compacted so that it also is the honeycombing in concrete is caused due to this factor.
Create a perfect error less Concrete Mix Design Calculator
4. Improper Compaction of Concrete
If labour does not have technical skill knowledge about the use of vibrator during compaction then there is the possibility of failure of formwork by touch vibrator to formwork and also reinforcement so that cement slurry leak through from works and honeycombs comes
When we use an excess amount of vibrator during the casting of concrete then it leads honeycombs to produce in concrete also leads to segregation
5. Casting Concrete from a Height
When you cast building member concrete from a certain height then there is a high possibility of honeycombs in concrete due to segregation and lots of factors
I recommended you to bookmark this Honeycombs in Concrete Civil Experiences Blog to study every daysAakash Dudhat
Suggestion: Guideline for Construction Process of RCC Column
Effect of Honeycombs on Concrete
- Reduce load carrying capacity of concrete alternatively affect the strength of the structure
- Permeability of concrete increased if Honeycombs developed Concrete
- The concrete honeycombed surface may be cured by pressure grouting of cement slurry
- Water and air enter the structure which leads to rusting and corrosion of reinforcement bars
- Corrosion of reinforcement due to honeycombs reduce the structure of life/durability
How to Avoid Honeycomb in Concrete?
There are various technic to for how to avoid honeycombs in concrete because every engineer has a unique idea to overcome in How to Prevent Honeycombing in Concrete.
List of an idea to prevent honeycombs of concrete
- Be careful during the calculation of mix design proportion
- Provide proper minimum cover as per structure element refer to this link
- At the time of casting use a proper vibrator. Guide labour to use of vibrator so that chances of failure of formwork eliminated so cement slurry not leak from formwork or if leakage
- The casting of concrete must be cast from the desired height level means penetrated properly. This will help to reduce honeycomb concrete
- After casting of beam or columns the sides should be To slowly knocked immediately by using a wooden hammer from outside which greatly helps to reduce honeycombs
- Supervising by an expert is important before casting because if reinforcement placement is wrong like to close due to improper lapping or at the junction, it is also the top reason for honeycombs
- Concrete should be cohesive enough which help greatly to avoid honeycombs also in the durability of the structure
- The slump of concrete maintain properly which helps decrease the chances of honeycomb
- Be care full because contractors and supervisor generally try to hide their honeycombs problem by applying cement past on it which create serious issues
Remedies for Honeycombs in Concrete
How to Repair Honeycomb Concrete is the major goal of any contractor or supervisor
We can Cure Honeycombs or honeycomb in concrete repair structures in the following ways
- Strictly speaking, where honeycombs are found in concrete, the affected area should be demolished, and even the part should be reconstructed after applying grouting chemicals to the old surface
- Corrosion is a process that continues even in good concrete through reinforcement rods. This is the result of losing the grip between the concrete and the reinforcement, which is very dangerous to the safety and life of the concrete structures so casting is done in a better way if the honeycomb has seen then compacted properly or cast again
- Keep the height of casting should be minimum as possible
- Honeycombs as a defect not only reduce the load-bearing capacity of concrete but also reduce the durability of the structure so we can save the structure and improve durability by eliminating honeycomb
- The sides should be To slowly knocked immediately by using a wooden hammer from outside which greatly helps to reduce honeycombs
- Properly Grading the Size of aggregate also at places of the junction of beam-column use 20 mm aggregate and used slightly more cement water to avoid honeycombs
- Clean the area before applying repaired materials
- By filling cracks and voids using a mechanical injection of concrete honeycomb repair material with help of a pressure pump such as non-shrinkage epoxy grout
- Materials should match the characteristics of virgin concrete for repairing honeycomb on concrete
- You need to make a patching honeycomb concrete hole to make sure proper bonding If the honeycomb covers a large subject area
Concrete honeycomb in concrete repair method are full described above as all possible method
Also Read: Composition of Good Brick Earth | Function of brick Ingredients
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