Are you worried that concrete cutting might cause the formation of cracks? Do you want to cut concrete without causing extensive damage to the slab? Read on for our guide on sawing concrete and cracking. In a nutshell, it is possible to crack and damage concrete by cutting it which is why this extremely hazardous task is best left to professionals.
Some of the main reasons for sawing concrete include:
- Sawing the concrete too late after setting
- Making too deep of cuts into the concrete
- Using poor cutting techniques
While concrete structures are durable and long-lasting, they are naturally susceptible to cracking. The expansion and contraction due to heating and cooling can cause microfractures to form, which expand over time. That’s why cutting control joints is a necessary part of maintaining the structural integrity of the concrete.
However, when, where, and how deep your cuts should be will determine whether your concrete cutting endeavour will cause cracks.
How The Timing Of Concrete Cutting Will Influence Slab Cracks
The timing of your cutting concrete is critical to the overall structural integrity of the slab. Depending on the concrete mix and the weather, you can saw your concrete 4 to 24 hours after pouring the concrete. The timing of things is the tricky part.
Cut the concrete too early, and the concrete will ravel – an effect of pulling aggregate out of position. The ravelling weakens the concrete structure at the edge of the cut. Moreover, the ravelling will yield an uneven cut along the edges.
On the other hand, cutting the concrete too late will cause uncontrolled cracking. When the concrete is too dry, uncontrolled cracks will form at the front of or beside the blade, damaging the concrete slab. To avoid structural issues, you should carefully choose your timing to prevent ravelling and cracking.
In hot weather, cutting concrete happens a little earlier. The hot and humid weather allows concrete to set and cure much faster, making it possible to cut concrete as little as 4 hours after curing the concrete. However, the concrete takes a tad longer to cure in cooler weather. However, sawing concrete usually happens within 24 hours.
How Deep Should You Cut Concrete To Cracks?
A rule of thumb is to cut the concrete between 25% to 35% of the slab thickness when making joints. However, you should ensure your cuts strictly adhere to the structural engineering specifications. Making too deep cuts into the concrete slab will reduce the aggregate interlocking, affecting load transfers. However, making shallow cuts makes the cuts ineffective, leaving room for random cracks to arise later on.
Using Poor Cutting Technique Can Cause Cracks
Using poor cutting techniques can increase the risk of cracks forming. To avoid the formation of cracks, consider the slab length, thickness, and base to determine the cut to make. Choose a cutting blade that suits the concrete slab you want to cut.
Start by cutting the desired depth before cutting the length of the slab. When cutting concrete with a water cutting saw, you should ensure the blade reaches the desired depth before moving the blade the length of the slab.
Additionally, when cutting the concrete, avoid twisting or tilting the blade. A smooth cut following chalk line marks reduces the risk of forming cracks.
While concrete is susceptible to cracking, taking caution when cutting concrete can reduce the risk of cracks forming. Consider the timing of the cuts, the depth of the cuts, and the cutting techniques. As a premier concrete cutting service provider, we have an intricate understanding of concrete cutting. We use the best industry practices to reduce the risk of concrete cracks.
If you are looking for a concrete cutting company in Sydney that is trustworthy and reliable, then don’t go past Sydney Sawing & Drilling. Please call us today on (02) 9158 6101 or leave an enquiry.