Concrete pouring is an important process of construction. Concrete is used in structural elements like columns, beams and slabs. It can also be used in the walls, roofing and others. While concrete pouring seems like a very common process that most builders would use, there is always a risk of the formation of cracks. Hence, concrete saw cutting is done.
Concrete cutting is done to create a control joint. A control joint, also known as a contraction joint, are small cuts or ridges that are intentionally placed in concrete slabs to control random cracking. After the pouring of concrete, the mixture tends to shrink and lose volume as it dries up. These cracks are made to prevent the slab from cracking additionally that can have adverse effects on the structural integrity of the slab.
These control joints make it possible to control where and how the cracking will occur, its orientation or if it should be in a straight line. Many specifications go into ensuring that the control joint is an effective one, like when to cut it, how to cut it, depth and placement of the joint.
What is important is that the control joint cut must be made at a specific period after the concrete has dried to obtain sufficient strength but before the internal cracking begins. Hence, the timing to cut is very critical and depends on the type of admixtures used, the concrete mix design and climatic conditions. The recommended period for cutting concrete is 6-18 hours after casting and never after 24 hours, after 6 hours during summer and 12 hours during winters. To know more, visit https://www.proconcretecutting.net.au/.
Cutting the joint too early can cause ‘ravelling’ which is when the aggregates are moved from their position, leaving a weakened edge on the cut. If the joint is cut too late, it can cause unforeseen cracks that cannot be controlled during the curing of concrete.
After ascertaining the time, the position of the joints needs to be decided. Usually, joints are created at the centre lines of columns, spaced 24-36 times the thickness of the slab. If the concrete is more likely to shrink excessively, the cuts can be placed closer together. Other considerations are areas that do not have continuous steel rebars from one slab to another or creating them in a square pattern. The location of the cuts must be marked with a chalk line.
Finally, after assessing all the factors like time, location, the thickness of slab etc. are decided and using a concrete saw the joints can be created. Following the chalk line, the joint must be carefully cut according to the decided depth. One must walk or move around the slab to cut it and not stay in a single position.
Without twisting or spinning the blade, the depth of the joint must not be increased. When cutting concrete that has heavy steel reinforcement, blades with soft metal segment bonds can be used. Another aspect is to take proper safety measures during the process.
As a finishing step, the joint must be completely cleaned of all the concrete dust and filled with filler material to prevent water damage to the interior reinforcements.
So, the process of concrete cutting seems simple enough but must be done carefully and with precision. Its accuracy can be achieved only by professionals which will ensure a crack-free concrete surface that is strong and will sustain for a longer period of time. To know more, visit https://www.proconcretecutting.net.au/.
Thanks to proconcretecutting.net.au for consulting on this post.
