What Is Honeycomb In Concrete | Cause of Honeycomb In Concrete| Cure of Honeycomb In Concrete | Types of Grouting

honeycomb concrete

What Is Honeycomb In Concrete?

This takes place when the mortar doesn’t fill the distance between the coarse aggregate particles. The presence of honeycomb indicates that the first stage of consolidation hasn’t yet been completed at these locations.

Where it shows on the surface, it necessary to chip out the area and make a repair. Such repairs must be kept to a minimum, mainly since they mar the appearance of the structure.

Honeycomb is caused by using faulty or improper vibrators or by poor vibration Processes. Unsystematic insertions at haphazard angles will cause an accumulation of mortar in the surface while the lower portion of the layer may be under vibrated.

 

HoneyComb

After removing the side phase of  shuttering ( HoneyComb Concrete )

Sometimes, there are other factors contributing to honeycomb, such as insufficient paste to fill the voids between the aggregate, improper ratio of sand to total aggregate, poor aggregate grading, improper ratio of sand to total aggregate, improper workability for the placing conditions or insufficient clearance between the reinforcing steel.

In setting steel spacing, both the designer and the builder should keep in mind that the concrete must be consoled.

Honeycomb is a void left in concrete due to the failure of the mortar to effectively fill the spaces among coarse aggregate particles. Rock pockets are generally severe conditions of honey-comb where an excessive volume of aggregate is found.

Also, read: Methods of Design | Difference Between Working Stress Method and Limit State Method

Cause of Honeycomb In Concrete

Primary Causes of Honeycomb

1. Design of Members

  • Highly Congested Reinforcement
  • Narrow Section
  • Internal Interference
  • Reinforcement Splices

2. Forms

  • Leaking at Joints
  • Severe Grout Loss

3. Construction conditions

  • Reinforcement Too Close to Forms
  • High-Temperature
  • Accessibility

4. Properties of fresh concrete

  • Insufficient Fines
  • Early Stiffening
  • Excessive Mixing
  • Aggregate That Is Too Large

5. Placement

  • Excessive Free-Fall
  • Excessive Travel in Forms
  • Lift That Is Too High
  • Improper Tremie or Drop Chute
  • Segregation

6. Consolidation

  • Vibrator Too Small
  • Frequency Too Low
  • Amplitude Too Small
  • Short Immersion Time
  • Excessive Spacing Between Insertion
  • Inadequate Penetration

Also, read: What Is Cement | Types of Cement

Cure for Honeycombs in Concrete

Corrosion is a process which continue through reinforcement rods even into good concrete. This results in losing grip between concrete and sticks, which is very dangerous to the safety and life of concrete structures. Concrete fall should be kept a minimum.

Honeycombs as a defect not only reduce the load-bearing capacity of concrete; however, water finds a simple method to reinforcement rods and rusting, and corrosion starts. Corrosion is a process that lasts through reinforcement rods even in good concrete, this result in dropping the grip between concrete and sticks that’s very dangerous to the safety and life of concrete structures

Strictly speaking, where honeycombs are detected in concrete, the affected area ought to be broken, and also the portion ought to be reconsecrated after applying grouting chemicals to the old surface.

Honeycombs as a defect not only reduce the load-bearing capacity, but water finds a simple method to reinforcement, corrosion, and rods rusting tarts.

Corrosion is a process which continue through reinforcement rods even into good concrete. This results in losing grip between concrete and sticks, which is very dangerous to the safety and life of concrete structures.

In the case of honeycombs on surface pressure grouting with cement-based chemicals that are non-shrinkable Could be adopted after taking the opinion of This designer and acting According to his advice.

Taping with a wooden hammer, the sides of shuttering from outside through concreting and moving will assist minimizing honeycombs to a great extent in the event of beams and columns.

At places of the junction of beams and columns concrete with strictly 20mm and down aggregates must be used with slightly more cement and water to avoid honeycombs.

Use of thinner needle says 25mm or less with vibrator at intricate places of concreting will also help in reducing honeycombs.

Also, read: Lab Test on Aggregates at Site

Types of Grouting 

5 Diffrent types of Grouting Method

  • Jet Grouting
  • Fracture Grouting
  • Permeation Grouting
  • Compaction Grouting
  • Vacuum Grouting

1. Jet Grouting

jet grouting

Jet Grouting 

Jet grouting uses a high-pressure ‘jet’ force apply of either grout, air, water, or a combination to erode soil whilst simultaneously injecting grout into the soil through a ‘jet monitor.’

The specially designed monitor and drill stem are rotated and raised at the same time to combine the grout with the original soil to form ‘silcrete.’

The end product is cemented round columns and is basically effective in any soil but not necessarily efficient in every soil.

Alos, read: What Is Workability of Concrete | Factors Affecting Workability | Test |Errors

2. Fracture Grouting

Fracture Grouting

Fracture Grouting

This method uses a low viscosity grout that splits through the ground by penetrates and hydraulic fracturing into the fractures. The in situ soils are soil and displaced immediately next to the fractures are densified, but to a lesser extent than compaction grouting.

This grouting can also be referred to as compensation grouting and is commonly used to relevel structures.

Also, read: What Is Raft Foundation | Types of Footing | Detail of Raft Footing

3. Permeation Grouting

Permeation grouting

Permeation grouting

Permeation grouting also called penetration grouting, is the most common and conventional grouting approach. It involves filling any joints, cracks, or void as in rock, soil, concrete, and other porous materials.

This method idea is to fill a void without displacing the formation or creating some change in quantity or configuration from the medium. It is done to strengthen the present formation, creating a water-impermeable barrier, or even both.

There are two forms of permeation injection grout systems: a circulating grout system and also a direct grout system.

Also, read: https: What is Plum Concrete | Application | Mix Design | Methodology

4. Compaction Grouting

Compaction Grouting

Compaction Grouting

Compaction Grouting involves an injection grouting of low mobility grout using drill casings that are drilled to pre-set depths. The grout, usually comprised of sand, cement, water, and fly ash, is placed from the bottom-up with pressure-based criteria.

After each consecutive stage, this drill casing is lifted upward until it is entirely taken out. Compaction Grouting is also commonly called as Low Mobility Grouting.

5. Vacuum Grouting

Vacuum Grouting

Vacuum Grouting

This types of grouting to a user in honeycomb time. Vacuum grout send  precise cement salary in concrete. Interestingly, although grout is typically propelled by pressure, if a void is placed under pressure, then the grout can be ‘sucked’ in this is known as vacuum grouting.


Faq

Honeycombing of concrete

Honeycombs are hollow spaces and cavities left in concrete mass on the surface or inside the mass where concrete could not reach. Improper vibration and workability of concrete are main causes of honeycombs in concrete.

How to Fix Honeycombing in Concrete?

  1. Isolate the affected area by removing layers of honeycombing until suitable concrete is exposed.
  2. Thoroughly clean the area to be repaired and remove all dirt and loose aggregate.
  3. Wet the cleaned area prior to applying non-shrink grout.
  4. Texture and colour should then be matched for aesthetic finish.

What Is Honeycombing in Concrete?

Honeycombing refers to voids in concrete caused by the mortar not filling the spaces between the coarse aggregate particles. It usually becomes apparent when the formwork is stripped, revealing a rough and ‘stony’ concrete surface with air voids between the coarse aggregate.

What Causes Honeycombing in Concrete?

Honeycombing is caused either by the compaction not having been adequate to cause the mortar to fill the voids between the coarse aggregate, or by holes and gaps in the formwork allowing some of the mortar to drain out of the concrete.

Concrete Honeycombing Repair

  1. Remove loose concrete or loosened aggregate by hammer or wire brush. Prevent the application of large forces such as electrical chippers to avoid sound concrete damage around the honeycomb area.
  2. Clean any dirt or loose material from the area.
  3. Wet the cleaned area before applying the repair material.
  4. Fill small voids and cracks using a mechanical injection pressure pump with a suitable material such as non-shrinkage epoxy grout.
  5. If the honeycomb covers a large area, you may need to create a patch hole to ensure proper bonding.

Is Honeycombing in Concrete Bad?

Small, shallow areas of honeycombing are probably mainly cosmetic. However, deeper areas will lead to a local reduction in the protection to the reinforcement from the concrete cover and hence possibly durability problems in the future.

How to Prevent Honeycombing in Concrete?

Avoid honeycombing by using appropriate concrete mixtures with sufficient workability, proper placement and consolidation techniques. Honeycomb, subsidence cracks, cold joints and excessive surface air voids are common surface blemishes associated with ineffective concrete consolidation.

How to Repair Honeycomb in Concrete?

  1. Remove loose concrete or loosened aggregate by hammer or wire brush
  2. Clean any dirt or loose material from the area.
  3. Wet the cleaned area before applying the repair material.
  4. Fill small voids and cracks using a mechanical injection pressure pump with a suitable material such as non-shrinkage epoxy grout.

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