Concrete is a very durable and long-lasting material. If it is mixed and installed correctly, it can last hundreds of years. It also fairs well against harsh weather conditions, abrasion and chemicals. Despite its durability, concrete can develop cracks, which makes concrete crack repair necessary.
There are different types of concrete cracks. Some are evidence of structural failure while others are for the most part just eyesores.
Random crack – A slow-spreading crack that branches off into multiple directions.
Settling crack – If the ground under the concrete is uneven or was not properly compacted, settling cracks could appear.
Heaving cracks – Cracks caused by freezing and thawing of the concrete during winter months.
Impact cracks – Cracks that are caused by impact.
There are a number of conditions and situation under which concrete starts to crack.
Too Much Water – Concrete can achieve a high level of strength without using much water. However, non-professionals often add excessive amounts of water to the concrete mix in order to increase work ability, which makes installation easier. Although this saves time in the short-term, it will cost more time in the long run when there is a need for concrete crack repair or the concrete has to be replaced altogether.
Shrinkage is one of the number one causes of cracks in concrete. Due to water evaporation, concrete shrinks as it goes through the process of drying and hardening. The more water there is in the mix, the greater the amount of shrinkage. Shrinking causes concrete to pull apart, thus causing cracks. We use techniques which allow us to determine the ideal amount of water for the structure that is being made and the location it is in.
Drying Too Quickly or Unevenly – If concrete dries too quickly the chances of developing cracks are significantly higher. When concrete turns from a liquid to a solid, it goes through a chemical process that requires water. If the water evaporates before the process has fully run its course, cracking will most likely occur. Concrete is also prone to crack if it dries unevenly due to inconsistencies in the mix. Our machinery mixes the concrete to an even consistency and keeps mixing it (which prevents settling) until it is ready to be installed.
Inappropriate Concrete Strength – Not every construction job requires maximum-strength concrete. It is for this reason that concrete is manufactured in different strengths, which allows it to be sold at different prices. This allows consumers to purchase concrete at the adequate strength and to avoid overpaying for strength they don’t really need. Needless to say, if the strength of the concrete is too low for the job, it is prone to failure. If the strength is too high, the concrete could potentially be too heavy for the job or the project will cost more money than it has to.
Insufficient Control Joints – Control joints preserve structural integrity by giving the concrete a predetermined place to crack. The joints should be just as deep as the slab and should not be spaced too far apart.