Although concrete is known for its strength and durability, like any other building material it’s also susceptible to wear and tear. Over time concrete can start to crack, which can be a cause for concern.
At best, their unsightly appearance can spoil the aesthetic of a structure. At worst, cracks may threaten the integrity of a structure, posing a serious safety hazard.
In this post we’ll take you through the various types of concrete cracks, what causes them and the different methods we use to fix the damage.
Reasons For Concrete Cracks
Concrete cracks can range in severity from insignificant cosmetic wear to dangerous structural damage and they’re caused by a variety of factors, including:
Shrinkage Cracks
One of the most common reasons for concrete cracks is the natural drying and curing process. As the concrete dries, it undergoes shrinkage, which can lead to surface cracks.
Although these are typically small and not structurally significant, they can still be unsightly and may widen over time.
Settlement
Settlement cracks occur when the soil beneath the concrete shifts or compacts unevenly. There are a number of reasons this may happen including changes in moisture levels, inadequate compaction during construction or natural soil movement.
Freeze-Thaw Cycles
In colder climates, freeze-thaw cycles can play a major factor in concrete cracking. When water penetrates the concrete and then freezes, it will expand, putting pressure on the concrete, which can cause it to crack.
Overloading
Excessive weight on a concrete surface can cause stress and lead to cracks. This is a common issue in areas where concrete regularly comes into contact with heavy machinery or vehicles.
Corrosion Of Reinforcement
In structures with reinforced concrete such as rebar, corrosion of the internal metal can cause the surrounding concrete to start to crack and deteriorate.
Chemical Exposure
Exposure to certain chemicals, especially those commonly found in industrial or chemical processing facilities, can weaken the concrete and make it susceptible to cracking.
The Importance Of Timely Repairs
Although some cracks obviously require more urgent attention than others, it’s a good idea to tackle any signs of wear and tear in their early stages. There are a number of reasons for this, including:
Preventing Further Damage
If left unattended, small cracks can quickly become more significant structural issues. So fixing them early can prevent the need for extensive and costly repairs in the future.
Safety
Depending on the severity of the damage, cracked concrete surfaces could be hazardous. Timely repairs enhance safety.
Preventing Water Intrusion
Cracks in concrete allow water to penetrate, potentially leading to more significant structural problems and even mould growth, which can produce an acid that deteriorates concrete.
Preserving Aesthetics
Even when cracks aren’t affecting the structural integrity, cracked surfaces can be unsightly and diminish visual appeal. Timely repairs help maintain a well-kept appearance and stop small cracks turning into big ones!
Effective Repair Methods
There are a number of ways to fix cracks. Obviously, the severity of the crack will usually determine the course of action taken so here are the most common remedies for cracked concrete and when you can expect them to be used:
Epoxy Injection
For this repair, epoxy is used to fill and seal cracks in concrete. This versatile method is suitable for both structural and non-structural cracks and it also offers excellent bonding and waterproofing properties.
Concrete Resurfacing
For surface-level cracks and insignificant cosmetic issues, resurfacing can be an effective solution. This involves applying a new layer of concrete over the existing surface, creating a fresh and smooth finish that should vastly improve the aesthetic of the structure.
Polyurethane Sealants
For dynamic or moving cracks, polyurethane sealants are particularly useful as they’re flexible and durable materials that are used to seal and waterproof cracks in concrete.
Reinforcement And Strengthening
If cracks are appearing as a result of corrosion to the internal reinforcement, structural strengthening methods may well be required. This involves repairing and reinforcing the concrete which is a much bigger job than some of the other treatments.
Crack Stitching
This clever method involves drilling holes across the cracks and inserting steel bars or rods, which are then bonded with epoxy. This is an effective way to restore the structural integrity of the concrete.
Concrete Crack Repair Step By Step
If you’ve spotted some cracks in a concrete structure that you feel needs addressing, this is the course of action that would usually follow:
Assessment
The first step to making any repair to concrete is to assess the extent and severity of the damage. A professional company like ourselves would be in the best position to assess the damage and advise on the best course of action.
Surface Preparation
Once the damage has been assessed, the next step is to clean the surface, removing any loose debris or contaminants. This is an essential part of the process as proper surface preparation is required for a successful repair.
Crack Filling
Depending on the type of crack and the repair method that’s being administered, the crack is filled with epoxy, polyurethane sealant or other suitable materials. This effectively seals the crack and prevents further damage occurring.
Curing And Protection
The repaired area is allowed to cure and harden properly. It’s essential to protect the repaired section from moisture and extreme temperatures during this period or the concrete’s integrity will be in jeopardy.
Sealing And Finishing
Depending on the specific repair method, the surface may be sealed or finished to restore its appearance and protect against future damage.
So those are the different types of cracks you’ll find in concrete, as well as what causes them and how they’re usually remedied.
If you’ve spotted some cracks starting to appear in your concrete structure then it’s probably best to nip the issue in the bud before it becomes much worse. Or if the damage is already significant, don’t put it off any longer as it could become a danger to you and the public.
Even before cracks appear there are ways to assess the condition of your concrete to help give you an idea of whether your structure is likely to deteriorate. This is done with a concrete condition survey.
A concrete condition survey looks at the state of your concrete and tells you how strong it is, which can ensure safety and save money in the long run.