Problems with concrete and how to solve them

Compared to other construction materials, concrete is much easier to maintain. However, there are some problems that you might experience if you haven’t worked on it properly. In fact, concrete problems may include scaling, discolouration, shrinkage, cracking, and other various issues.

Here are some common problems that you need to be aware of and how to solve them.

• Cracking

Concrete can easily crack, it’s inevitable, but it can be controlled if you act in a timely manner. In fact, this problem is one of the main issues when constructing concrete, and this is caused by various factors like thermal contraction, shrinkage, and subgrade settlement. The rule of thumb when it comes to cracking is if it’s not structural or not too wide and isn’t leaking with water; then it’s still considered acceptable.

To reduce the cracking on your concrete surface, you can remove the topsoil, organic material, and soft spots in the subgrade. You should also compact all loose soil under the concrete slab or install concrete joints by forming, tooling, and sawing a groove.

Most importantly, minimise the water content by maximising the amount of course aggregate, and avoid rapid drying or using retardant admixture since this could weaken your concrete and make it more prone to cracking.

• Discolouration

Discolouration often occurs if there are sudden changes to the cement material, especially during rushed finishing operations, or if the contractor added calcium chloride on their mix. This issue can be prevented if the contractor used the correct batch and materials from a ready mix, and the ingredients complied with industry standards.

To remedy concrete discolouration, you must first prepare a uniform subgrade and wait until all the water has evaporated before you do the finishing process. Also, avoid hard trowelling on the surface of the concrete since this could to more significant discolouration.

• Concrete Curling

Curling is caused by the difference in temperature and moisture of the top and bottom surface that it leads to a weaken slab on the surface since it’s no longer supported from the base. There are several ways to avoid this issue. The most popular one is to use proper curling techniques as well as using water-reducing admixtures.

The contractor should also ensure the proper bonding of materials when applying thin topping mixes, and they must use the right amount of steel reinforcement in the slab. Also, concrete must be placed on an absorptive sub-grade, so all the bleed water will not be pushed on the top of the slab.

·         Scaling
Another concrete problem is scaling, and this occurs when the surface of the concrete breaks off and peels away. This is usually caused by inadequate concrete strength or improper curing procedure, as well as the heavy exposure of concrete to freeze-thaw cycles.

To avoid this issue, you should only use low slump-air in your entrained mix. It’s also wise to wait for the water to evaporate from the surface before conducting the curing procedure. Also, you should not use salt or other harmful chemicals on your mix during the winter season. If you have this issue with your concrete, you might like to consider concrete resurfacing. 

       Crazing
Crazing is considered one of the most repeated problems in concrete. This usually happens when the surface shows various interconnected cracks, or when the cement paste is pushed up to the surface and shrinks.To avoid crazed concrete, you should properly cure the concrete in a timely manner. Also, wait until the water has evaporated before you do the finishing process. In addition, you must not sprinkle water over the concrete while finishing it.