Concrete honeycomb is becoming a serious issue nowadays. The Concrete make to form various structural elements like Columns, Beams, Foundations, Slabs. Concrete pour in formwork, it starts to flow like water so cavities/voids form when concrete does not reach all places. It appears like honey bee nest. If it does not vibrate properly it leaves voids exposing the aggregate. Honeycomb reduce strength. And provide passage for water that corrodes the reinforcement. The solution here is to ensure that joints are well sealed and leak-free.

1. Cause of Concrete Honeycomb

• Insufficient compaction to concrete.
• Less cover to reinforcement bars.
• Concrete already set before placing.
• High concrete free fall while pouring
• More coarse aggregates than designed mix proportions and oversized aggregates.
• Improper placement of bars at column and beam junction.
• Addition of more water than designed at the site for achieving workability.
• Steel congestion not allowing concrete flow to all corners.

2. Repairing Concrete Honeycomb 

Durability and strength of concrete will improve without making damages to concrete structures using cempatch. It is suitable for wide range of industrial environments such as warehouses, loading bays, bridge deck, car parks and ramps.

3. How to repair concrete honeycomb

Honeycomb seen on concrete structure prepares by wire brush, hammering,etc., to produce a clean, aggregate exposed finish, free from contaminants. Any expose steel to completely uncover. Remove all rust scale or corrosion products. This makes using cempatch mix with cement to a required amount as per the size of honeycomb.

4. Application

Mix Cempatch to ordinary cement mortar as required depending upon the size of honeycomb to repair. Ensure a  good compaction of the pre-dampened substrate. Fill and level up to existing profile of the surrounding concrete using a float or trowel. Once Cempatch Repair Concrete has achieved final set use appropriate curing methods to ensure good bonding.

5. HEALTH AND SAFETY

This process may cause skin irritation. Wear required PPE such as helmets, safety shoes, Nose Mask, safety goggles, rubber hand gloves etc.

Preventing water entering into water-bonding structures. Water leaking is the main problem occurring in many concrete structures. Mainly concrete structures like basement car parking, lift rooms, Tunnels, water leaking is the main problem. These leakages can repair and prevent in the concrete structures at the time of construction using chemical Admixtures.

Preventing water

Water leakage is becoming a serious issue in Underground structures nowadays. It makes serious impacts in concrete structures like,

• Basement retaining walls
• Parking structures
• Concrete slabs
• Tunnels
• subway systems
• Construction Joints
• Foundations
• Water retaining structures
• Underground vault
• Swimming pools
• Sewage water treatment plants
• Channels Reservoirs
• Bridges
• Dams and
• Roads

Waterproofing carries out to prevent water entering into underground structures. We explain how to carry out this waterproofing process.

How to carry out waterproofing operation

After the construction of concrete structures & removal of shuttering, the concrete surface has to clean. And have an open capillary surface. Remove laitance, dirt, grease, etc, by means of high-pressure water jetting, wet sandblasting or wire brushing. Faulty concrete in forms of cracks, honeycomb, to be phase out and fill flush with mortar. The Surface to be carefully pre-water and concrete surface to be dry but not wet.

Application

Apply waterproofing chemicals like Crystalline waterproofing coating in one or two coats of masonry brush or appropriate power spray equipment. When two coats specify, apply the second coat while the first coat is still green. The specified amount of chemical admix like penetron, etc, it distributes in powder form through a sieve. And trowel into the freshly placed concrete.

ADVANTAGES

The Active chemicals react with moisture and by-products of cement hydration cause catalytic reaction that generates an insoluble, crystalline structure. Applying to the concrete surface, Crystalline waterproofing coating crystals fill pores and minor shrinkage cracks in concrete. And prevent water leakage at high pressure.