Believe it or not, one of the best ways to increase the structural integrity of a slab is to saw concrete and add control joints. Put simply, control joints allow concrete slabs to develop cracks in a controlled fashion where the contractor wants them along a cut in the surface.
Control joints add strength by controlling inevitable cracking
Control joints are one of the most effective techniques for maximizing concrete strength over time. These strategically placed lines or grooves are sawed into the concrete surface, which enables the concrete to crack in a pre-determined and controlled way.
This allows the cracks to be more uniform and predictable, preventing them from occurring where they are not wanted, and reducing the risk of potential structural failures, such as slab collapses.
How do you saw concrete to create control joints?
One of the most common methods of creating control joints is with a saw cut, which can be done using a special saw with diamond blades specifically designed for concrete. This method produces better results compared to using a blunt saw, as it will create a cleaner edge. Saw cuts are also able to be made deeper than scoring with a blade, allowing the full depth of the control joint to be accessed.
When saw cutting control joints, it is important to ensure that the concrete is hard enough to be able to withstand the sawing process. If the concrete is too soft, the saw will likely not make the desired cuts and could cause damage to the concrete slab. Experienced concrete specialists use methods such as the Schmidt hammer test to determine when a slab is ready to saw. Concrete that is allowed to set up properly will be easier to work with than when trying to make the cuts too early in the finishing process, or too late.
Control joint planning
Before beginning to saw concrete, an expert should determine the size and placement of control joints, based on the slab thickness and area. Control joints should be spaced at least three times the thickness of the slab, and a maximum of eight times the slab thickness to ensure that any expected slab cracking is properly distributed.
It is also important to position the control joints around any changes in the direction of the concrete, such as corners, so that the stress created by these changes is handled properly.
Finally, when saw cutting control joints into concrete slabs, it is important to remember to keep the saw angle consistent. This will ensure that the cuts are straight and the control joint depth is even throughout. Any problems that occur due to uneven cuts can potentially cause structural problems with the slab.
Trust your slab to commercial concrete experts
Control joints are an important part of constructing commercial concrete slabs and ensuring their structural integrity. By using saw cutting to create the control joints, with the correct saw angle and depth, it is possible to achieve uniform and predictable cracking that will help to protect the slab against structural failure.
The experts at H3 Construction work to produce quality, lasting concrete results based on our years of experience and current industry best practices. Each slab is different, and planning features such as control joints requires attention to the slab’s makeup, location, substrate, projected use and load, and client goals for the project. You really can create more structural integrity when you saw concrete, and H3 Construction can help you maximize the strength and durability of your slab for years to come.