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.
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.