What is Spalling in Concrete?
Spalling is the process by which some parts of the concrete structure like, the beam, column or slab break down itself to expose the upper surface of the reinforcement. It may be 200 mm in diameter or more in some extends. Spalling may occur up to a depth of the layer reinforcement.
Here we will discuss spalling o concrete along with its cause and prevention. If you are constructing a concrete house, then you have to take care of preparing concrete in a proper way and we should also care about its placing and finishing.
Improper placing and finishing and mixing of concrete may cause various defects in concrete like bleeding, segregation, spalling etc.
Spaling is one of the dangerous defects in concrete due to improper activities on-site with concrete. These types of defects can be seen in bridges, buildings, RCC roads etc.
Spalling should be repaired soon to prevent steel rods inside the structure from corrosion. It decreases the load-bearing capacity of the structure and spoils the aesthetic appearance of the structure.
Causes of concrete spoiling
- Spalling may cause due to corrosion of reinforcement since it creates a larger volume than its original steel rod which exerts pressure on the outer surface of the concrete i.e clear cover. These activities break down the concrete parts.
- It may cause due to the less thickness of the clear cover to the structure.
- It may cause due to the poor quality of the cement in the concrete.
- Spalling may cause due to not proper mixing of different ingredients like cement, sand and aggregate.
- Spalling may occur due to over compressive and tensile load on the structure than the safe bearing load.
- Spalling may cause due to joint of the concrete with different grades of concrete.
- It may cause due to insufficient curing on the concrete structure.
Effects of Concrete spalling
- The spalling of concrete may cause injuries to the people.
- There may be corrosion of reinforcement to decrease the loading capacity of the concrete structure.
- It causes buckling of reinforcement due to the removal of the clear cover of concrete.
- It spoils the aesthetic appearance of the structure.
- It decreases the value of the structure.
Prevension of Concerete Spalling
- Concrete should be mixed properly to get homogenous mixing.
- The cement should be checked for expiry date.
- The proper clear cover should be provided in the concrete structure.
- Curing should be done for at least 12 to 14 days to get the proper strength of concrete.
- Overload should be avoided on the structure.
How to repair Spalling?
- At first, the whole surface of the spalling should be cleaned with the help of water and dried properly.
- After that, Some chemicals or bonding agents should be applied to the cleaned surface.
- Now, pour the concrete with proper shuttering by mixing the concrete ingredient properly.
- Finally, curing should be done after 1 day till ten to fifteen days regularly twice a day.
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