Ever notice your concrete appearing course and rocky, kind of looking like this ?This is a real issue that occurs in concrete. It is called honeycomb. Maybe you might just find a way to prevent this from occurring and how to treat or repair it if it has already occurred.
WHAT IS IT?
Honeycomb is a rough and stony surface that appears on concrete when there are air voids between the course and the aggregate. This happens when insufficient fine material gets into the concrete mixture due to poor mixing or incorrect aggregate grading. Normally, workers can identify this when the shuttering of concrete is removed or using techniques of ultrasonic testing.
CAUSES.
These hollow pockets known as honeycomb occur when the cavities and areas of the space are not all filled or reached by the poured concrete. Three common causes of honeycomb in concrete include:
Stiff concrete is used.
Improper vibration is used during the concrete process.
There is less cover for reinforcement bars.
While there are more reasons that this occurs, these three mentioned above are the most common reasons.
EFFECTS.
Honeycombing in concrete can lead to shrinkage cracks, reduced compressive strength, reduced durability and other issues that affect the performance of the concrete over time. It can also cause weakened load bearing capacity and negative impacts on waterproofing and corrosion protection systems.
HOW TO PREVENT IT IN CONCRETE.
To prevent honeycombing in concrete, several approaches can be taken. The first step is to ensure the appropriate mix design of the concrete. This means selecting a well-graded aggregate with a proper ratio of fine-to-coarse particles and controlling the water-cement ratio to achieve good workability and a high degree of compaction. Good consolidation is also necessary to reduce honeycombing; this can be done through vibrating or tamping during the pouring process.
In addition, curing the concrete properly is essential to decrease permeability and promote strength gain. It should be cured immediately after the initial set and maintained wet for at least seven days. This will help limit shrinkage cracks caused by moisture evaporation and enable better hydration of cement particles, filling any small air pockets that may form due to poor consolidation.
REMEDIES FOR TREATMENT AND REPAIR.
While there are at-home remedies one can use to repair and fix any honeycombing concrete issues, it is best to have a professional look over and assess the best course of action for fixing this problem. In many scenarios, to fix honeycomb, re-concrete might need to take place. This will hopefully help it from occurring in the future.
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