Cracks, cracks bloody cracks.
They’re ugly, unwanted and sometimes a sign that your concrete is falling apart. But not always….
We as concreters do very little during an installation to prevent cracking of the concrete, rather, we put a lot of effort into controlling that cracking.
- With proper installation of steel reinforcing, we aim to control the crack from being able to pull apart from itself.
- Installation of Abel Flex allows for the concrete to move hard against another solid structure, which in turn removes excess tension from the slab attempting to help the concrete crack less.
- Control joints create a weak point in the concrete depth which it is hoped, that the concrete when under tension will find the weakest spot to crack along inside our cut or tooled line, subsequently controlling where the concrete cracks.
- Installation of crack inducers are installed under the concrete (usually where a control joint will be cut, to again assist in this area being a weaker spot to find under tension.
As you can see, the majority of tactics we undertake to combat cracking, are actually for controlling the cracking and not stopping it. It is fundamentally shallow thinking to believe your concrete, being a solid structure placed on soft ground, will not find a point where the tension is too great and over the length of the concrete and cause a fault.
Apart from the ways we as contractors go about your structural project, lets go into a little more detail of the 3 main types of cracking and how serious they actually are.
These cracks occur during the pour due to the concrete surface setting too quickly. The water evaporates to fast out of your materials, then the surface sets too quickly causing it to shrink and crack.
These cracks usually happen when pouring on extremely hot days or overly windy days. Unfortunately, there is very little a contractor can do to stop and fix this once it is happening. The only real two ways to go about this is to use an Alcohol based vapor on the surface to re-add some moisture, then continuing to work the surface keeping the small cracks closed and holding together.
These cracks are not structurally a problem for your concrete, they are unfortunate, but will remain small hairline spiderweb cracks without pulling further apart.
Non Structural Cracking
Non structural cracking is where your concrete has started to tension either from the ground underneath moving under the weight of the concrete, or by heavy vehicles / items being placed on the concrete.
This type of cracking is called non structural because although the concrete itself is cracking, our preventative and controlling measures are working and the crack is not separating any further.
There is typically no need for any rectification work for this type of cracking, as they are considered normal and just unfortunate that they haven’t found the control joints to crack along that have been installed.
Structural cracking is caused by the same reasons I mentioned in “non structural cracking”, however in difference, these cracks are not being controlled by our preventative measures and are not only beginning to pull apart further than they should, they can lead to lifting or dropping of the two section of concrete surrounding the crack and have serious consequences for your concrete slab.
If you have this type of cracking occur, it is normally due to failure during the installation by the contractor and they must be dealt with immediately to rectify the problem.
After you’ve had your new concrete installed you get some cracking, take a little further investigation into what kind of cracking it is.
Most of the time, cracking in concrete is considered normal however unfortunate it is to both client and contractor, nobody likes to see them.
If you do however, notice that your cracking is starting to pull apart more than say a $1 coin in width, then it could be structural. Give you installer a call to come and inspect and if required, for rectification to begin.