What Is Concrete Finishing in Construction Works?
What Is Concrete Finishing in Construction Works?
Concrete finishing is a process that involves creating a smooth, durable surface. It is important to pay close attention to the timing and condition of the concrete during this process, as using improper techniques can result in a weak, damaged, or unattractive slab.
There are three main steps involved in finishing concrete: screeding, floating, and trowelling.
Screeding involves striking off excess concrete to achieve the proper grade. A tool called a screed is used to move the concrete in a sawing motion along the side forms.
If the distance between the side forms is more than 2 meters, two people may be needed to operate the screed.
Any voids on the surface should be filled with concrete and the process repeated until a uniform surface is achieved. It is important to avoid overworking the concrete, as this can result in low strength.
Floating involves removing any irregularities on the surface left after screeding. This is done with a tool called a float, which is a wooden board about 1.5 meters long and 20 centimeters wide with a handle.
Low spots are filled with concrete and worked with the float. If the area of the slab is large and there are no walls or posts, a tool called a bull float may be used.
It serves the same purpose as a float but has a longer handle and is operated without the operator standing on the concrete.
Trowelling is the final step in the finishing process and involves providing a smooth, hard, and abrasion-resistant finish. It may be necessary to trowel certain areas that were not satisfactorily finished by floating.
Trowelling should be done after all excess water has evaporated, and can be done with a steel float or a power trowel for larger works.
How Do You Use Concrete Finishing Tools?
Pouring concrete can be a DIY project if the proper tools and precautions are taken. It is important to wear gloves to prevent concrete burns and to understand the various tools used to achieve a professional finish.
These tools can be divided into four categories: leveling, smoothing, crack prevention, and final touches. Timing is crucial when using these tools, as it can affect the quality of the finished product.
To level the concrete, a screed or straight edge can be used to cut high spots and fill voids until the surface is even with the form boards.
For smoothing, a hand float, power trowel, or fresno can be used to make the surface as flat as possible. To prevent cracks, jointing tools such as a groover or saw can be used to create control joints in the concrete.
Finally, for the final touches, a trowel or edger can be used to give the edge a clean, finished look.
It is important to follow the proper steps and use the appropriate tool for each stage of the process to achieve a professional-quality finish on your concrete slab.
What Is A Finishing Trowel For Concrete?
Finishing trowels are a type of tool used to smooth and finish the surface of concrete. They have a large, flat blade that is rectangular in shape and designed specifically for this purpose.
The blade may also have a rounded edge to prevent gouging and a pointed edge for reaching corners.
These trowels are typically made of aluminum or steel and are not intended for cutting, but the straight edges of the blade may become rough and sharp with use.
It is important to wear gloves and apply pressure only to the handles when using a finishing trowel.
These tools come in various sizes, with the most common being about 10 inches long, but they can also be as long as 50 inches.
Smaller sizes are useful for reaching tight spaces and angles or for finishing smaller surfaces. To use a finishing trowel, wait until the “bleed water” on the surface of the concrete has been reabsorbed but before the concrete dries.
Then, grip the tool firmly and use back-and-forth strokes to smooth the surface in long straight motions.
Lift the blade slightly to avoid dragging the material, and wipe off any concrete that becomes caked onto the blade with a wet rag.
For the best results, allow the concrete to dry slightly before making additional passes. When finished, the surface should be smooth with no visible lines or grooves. Cover the concrete with plastic to allow it to cure properly over the next several days.
How Long Do You Let Concrete Set Before Finishing?
Standard concrete, also known as full strength concrete, typically takes one or two days to set, depending on the conditions in which it is placed.
After approximately 25-28 days, it reaches its full strength. While you can walk and perform normal activities on the concrete one week after it is applied, it is only at around 70-80% of its full strength at this point, so it is not recommended to drive heavy machinery on it during this time.
It is worth noting that concrete continues to cure and harden over time, even after it has reached its peak strength around a month after installation. While this ongoing curing process can strengthen the concrete to some extent, it is not necessary for the structure of the concrete and does not significantly benefit it.