Cracking on concrete is normal especially in the first 30 days while the concrete is settling or curing.
If the weather conditions are ideal and your contractors do it right, the cracking should be unnoticeable.
Before we discuss ways to keep driveway concrete from cracking, it is important that you understand why concrete cracks.
- Shrinkage – the water in the concrete evaporates as it hardens causing it to shrink. When it shrinks, the concrete cracks. Some people add too much water to their concrete mix because it is easier to apply. However, if the concrete dries too quickly, it also shrinks and cracks.
- Weather – the weather plays an important role in how well concrete cures. Extreme weather (too hot or too cold, too to dry or too wet) and rapid temperature changes affect the concrete and can cause severe cracking.
- Incorrect spacing of control joints – concrete joints are placed to anticipate and prevent cracking of the concrete. When they are not properly placed and spaced, they don’t work properly which means that cracking will still occur.
Preventing Concrete Driveway Cracking
Concrete is one of the most durable and long-lasting building materials available. You just have to make sure that you follow the proper procedures so it is done right to avoid cracking and other damage.
Here are some things you can do during and after the concrete is poured to avoid mistakes and reduce cracking in the future.
Let the concrete cure properly. Cement (the binding ingredient in concrete) takes a long time to cure so concrete naturally takes a long time to cure. It takes 28 days for it to be completely cured.
Cement needs moisture while curing to fully achieve its maximum strength. This is why concrete cracks easily when it is drying, whether is it drying slowly or quickly.
It will help to spray the concrete with water a few more times a day for seven days so it does not dry up too easily. If the weather is too hot, spray more often.
This will help the cement to gradually build its strength without cracking until the concrete is fully cured.
During cold weather, there is no need to spray on water, instead, cover the concrete to keep it from the cold weather for seven days.
After the seven day period, the concrete should be dry and strong enough not to be affected by harsh weather conditions.
Add control joints. Even if concrete is cured properly, there is still a chance of cracking. Temperature changes and drying can still cause it to crack. This is why control joints are crucial.
Control joints anticipate the cracks by putting strategic cracks in advance. These are intentional weak spots to direct future cracks.
Control joints are done in three ways:
- They can be made while the concrete is still wet using a concrete grooving tool.
- You can insert joint strips made of flexible wood fibres during the pouring process.
- Concrete cutting. You can cut them a few hours or a day after the concrete is poured using a diamond saw.
While the first two options are okay but the best way to add control joints is by cutting them in using a concrete saw a day after the concrete is laid.
Cutting concrete must be timed so that you do not cut too soon or too late. When you cut too soon, it will not work since the concrete is still wet.
When you cut too late, the joints will be rendered useless because the concrete has most likely already cracked.
Use the proper amount of water in the concrete mix. Do not be tempted to add more water than what is required just because it is easier to apply concrete when it is wet.
More water content in the mix means more shrinkage. More shrinkage means more cracks. Make sure the base is compact. Concrete cracks because of soil or ground movement.
Avoid this by making sure the ground where you will pour the concrete is compact and can securely support the concrete slab.
Use reinforcements. Concrete is strong on its own but you can make it ten times stronger by using rebar or steel reinforcements.
Adding steel reinforcements is not complicated and can easily be done. Yes, you may spend extra money on the rebar but this will make up for the cost of fewer cracks and much stronger concrete.
Concrete driveways take on heavy loads and regular traffic. It is important that you keep it strong and crack-free.
Although small unnoticeable cracks are okay, larger ones can damage the integrity of your concrete. Consult your structural engineer on the proper ways to cut concrete to prevent cracking.
If you are looking for a specialist concrete cutting company who uses only the best practices to get the job done right, then please call us at Megasaw on 1300 920 419 or contact us through our website.