What Causes Cracking In Concrete?
What Is Cracking in Concrete?
Cracking in concrete is caused by a variety of factors such as shrinkage, settlement, thermal movement and corrosion.
Shrinkage occurs when the concrete loses moisture over time and begins to deteriorate in size.
Settlement is when the underlying ground moves causing the slab of concrete to move with it which can lead to cracking.
Thermal movement occurs due to the daily temperature fluctuations that cause the concrete to expand and contract leading to cracks on its surface.
Corrosion happens due to exposure of steel reinforcement bars within the concrete structure which react with oxygen leading to rusting and subsequent cracking of its surface.
What Causes Cracking In Concrete?
Cracking in concrete occurs primarily due to the shrinkage of the material during its setting and curing process.
As the material dries out, it shrinks slightly, often leading to excessive cracking due to tension caused by moisture loss.
Additionally, extreme temperatures and environmental changes can cause concrete to crack as well.
Poorly mixed or manipulated concrete is also prone to cracking because it may contain voids and air pockets which expand when exposed to heat or cold.
Lastly, certain materials used in construction are too rigid for use with concrete and can cause cracking if not done correctly.
Is Concrete Cracking Normal?
Concrete cracking is a common problem and is normal to some extent. Minor surface cracks generally do not impact the structural integrity of the concrete and often do not require repair.
The causes of these cracks can include drying shrinkage, thermal movement, overloading of the concrete or settlement within the soil.
It is important to distinguish between cosmetic cracking in which only the surface of the concrete has been damaged and structural cracking that could be indicative of larger underlying issues.
If minor cosmetic cracking occurs, it may be possible to fill or seal it without any risk.
However, if there is significant evidence of wide or deep cracks along with crumbling and disintegration then immediate professional need to intervene for repairs should be sought in order to prevent further damage from occurring.
What Are The Types Of Cracking In Concrete?
Cracking in concrete is a common issue and there are several types of cracking that can occur due to a variety of factors.
Plastic shrinkage cracks form due to rapid drying of the freshly laid concrete and decrease in moisture content faster than the concrete paste can readjust itself.
Drying shrinkage cracks occur over time as the cement paste continues to try to draw moisture out of the environment, leading it to crack once it has come into contact with an area that is not sufficiently moist.
Thermal contraction cracks are caused by temperature differences between two areas of the concrete slab, causing them to pull apart from each other and cause fractures when they become too great.
Another type is settlement cracks which occurs because the soil under or near a concrete slab has been overloaded, resulting in some subsidence which causes fracturing.
Finally, corrosion related cracking happens when metal reinforcement inside the slab begins corroding, producing pressure on the material around it and causing fractures.
What Are The Effects Of Cracks In Concrete?
Cracks in concrete can cause serious damage to the structural integrity of buildings, pavements, and other concrete structures.
They are a sign of underlying problems in the foundation and cement mix used in the concrete.
Cracks can weaken the strength of a building or pavement, creating an unstable surface that can collapse. This can cause serious injuries or even death.
In addition, cracked concrete allows water seepage which could lead to decay, mold growth, and corrosion of reinforcing steel underneath.
This weakens the structure further and can eventually lead to its collapse. Furthermore, cracks also make buildings and pavements aesthetically unpleasing; they reduce property values significantly.
How Do You Stop Concrete From Cracking?
To prevent concrete from cracking, proper installation is key. First, ensure the project is based on an appropriate mix design and that the cement to water ratio is correct- too much water can cause shrinkage cracks or high shrinkage stress leading to surface cracks.
Secondly, ensure the subbase and foundation are prepared properly as they play a crucial role in spreading load evenly over a larger area and avoiding large concentrated loads which can localize stress and lead to cracking.
Additionally, reinforcing with steel bars or mesh provides additional strength to decrease the chance of cracking due to heavy load bearing or heavy impact forces.
Finally, allow for proper curing time – this ensures all moisture has been removed from the concrete before it dries so that no quick loss of water occurs which can cause micro cracks.
How Do You Treat Cracks In Concrete?
To treat cracks in concrete, the first step is to make sure that the surface of the crack is clean and free from dust and debris.
Then, use a stiff-bristled brush to fill any larger cracks with mortar mix. Once filled, allow for sufficient drying time before continuing.
For smaller cracks, fill them with a liquid cement repair material and allow it to dry completely before painting or sealing the area.
If treating more severe structural damage, then consulting with a professional may be necessary.