In the construction industry, there are many types of concrete cracks. Some can be minor and easily repaired, while others are more serious and need to be addressed immediately. They can occur anywhere, but are most likely to appear in walls, columns, or slabs, and are usually the result of tensions not accounted for in the design. They can also occur if the reinforcement steel or section is insufficiently shaped, or if the reinforcement is corroded.
Concrete cracks are not all the same, contrary to popular belief. Knowing what type of concrete crack it is can actually help you to properly correct it. In this article, we’ll look at what these various cracks are and how they can affect the strength and durability of your concrete.
Shrinkage Cracks
Once concrete has been poured, it hardens and shrinks a little, leading to shrinkage cracks. In most cases, these cracks are not a cause for concern, but they can signal problems in the future.
In most cases, shrinkage cracks do not pose a structural threat, though they can lead to water leaking in through the crack, which can cause problems later on. Shrinkage cracks in poured concrete foundations are often caused by poor concrete mix and rapid curing. Regardless of the cause, shrinkage cracks can eventually cause internal stresses to develop in the concrete. Unless control joints are incorporated into the slab design, these stresses will likely cause a wall or floor to crack as the concrete cures.
Ideally, no cracks should be visible after the concrete has hardened. If you notice any cracks after the concrete has set, you should contact a concrete professional right away. This is because once concrete has set, it is very difficult to repair. If the crack is large enough, you may have to completely remove the concrete and start over.
Corrosion Cracks
Another type of crack in concrete is due to corrosion. Indeed, the corrosion of reinforcement steel is a common cause of concrete cracking. When reinforcing steel rusts, it causes the steel to expand, which puts stress on the concrete surrounding it. This results in cracking and spalling of the concrete, compromising the durability of a structure.
Coastal, tropical, and areas with high salt levels can accelerate corrosion of steel in concrete. Of course, the most exposed elements deteriorate first, but the actual corrosion of the reinforcement is often hidden from view. Because of this, it may take five to ten years of active corrosion before cracks begin to appear in the concrete.
Steel with minor corrosion might be fixed with a rust remover and won’t need to be replaced. However, when corroded steel has already lost considerable sectional area due to corrosion, it may be necessary to replace it with rebar/lap method.
Expansion Cracks
It is common for concrete slabs to expand outward when heated. If there is not enough room for slabs to expand, cracks form. Most premature cracks are caused by poor planning and wrong material selection.
Expansion joints are designed to allow for the expansion and contraction of concrete. They are typically placed in concrete slabs or floors that are subject to thermal changes. This allows the slab to expand and contract without causing damage. Unfortunately, expansion joints are not always installed correctly, and when they are not properly placed, they can actually cause concrete cracks.
If you need to replace or repair concrete floor expansion joints, you should contact a professional. A professional team will ensure you get the best service and that the job is done right and safely. If you try to do it yourself, you run the risk of making mistakes that will be costly to fix.
Cracks Due To Overload
Concrete slabs are subjected to various loads. These include the weight of people walking on them, the weight of furniture being placed on them, and the weight of vehicles driving over them. Even after curing, concrete may crack if it is subjected to too much pressure for a prolonged period of time.
Concrete slabs must be able to withstand these loads without breaking or cracking. Unfortunately, sometimes the load is too much for the slab to handle. This is why concrete slabs are reinforced with steel bars. The steel bars transfer the load from the slab to the foundation.
The load that a concrete slab can withstand depends on the size of the slab and the amount of reinforcement. For example, a floor slab that is designed to support a load of 100 pounds per square foot will probably be fine if it is not subjected to more than 100 pounds of pressure. However, if a 200 pound weight is dropped onto the slab, it may crack. The same is true if the slab is subjected to a force that is applied at an angle.
Overloading concrete can be a problem if you need to use a heavy piece of equipment, such as a forklift, on your floor. It is important to be aware of the maximum weight limit for your concrete floor. This is usually specified in the building codes for your area.
Settlement Cracks
Settlement cracks can occur when the underlying soil has not been appropriately prepared or compacted.
They can also be caused by uneven settling of a concrete slab. If the slab was poured improperly, it may not have been allowed to cure evenly. As the slab settles, the outer edges settle faster than the center. This creates a void into which water can seep and cause a crack.
The best way to avoid settlement cracks is to make sure that the ground underneath the slab is properly level and compacted before the concrete is poured.
Seeing Cracks in Your Concrete?
You need to get them fixed right away. Don’t wait until it gets worse before you call a professional.
Brandon Concrete Services is the top contractor for all things concrete in Brandon, Florida. We specialize in residential and commercial concrete installation and repair, and we have the experience and expertise to help you get the job done right. Call us today!