Trowel blades are the components fitted on power trowels in concreting works used by construction companies, contractors and architects. They have the function of enabling the concrete to set and for the slab to have a smooth and fine finish. There are several companies making trowel blades and supplying them to power trowel manufacturers. They are also supplied as spares and replacement to contractors as and when required by them. Many of them are on their regular list of suppliers to original equipment manufacturer.
Trowel blades have three different functions, all essential for a durable and well finished concrete slab. The three different functions are leveling of the concrete surface, then smoothing and giving it a good finish. Because of the nature of their duty, trowel blades differ in constructional details though not very much. They are the float blades, finish blades and combination blades. Essentially the application of trowel blades is only as contributory factor in the use of power trowel to effect the three operations on a concrete slab, mentioned above.
The first application of the trowel blade of the power trowel is the leveling of the concrete also called the floating operation and uses the floating blade. This is done after the concrete is set enough to bear the weight of the trowel without a dent being created. The floating blade makes contact on the concrete slab surface, when the trowel is run. This process opens up the surface crust and enables it to set. Floating removes humps and also fills up all the pits on it. Compaction of the concrete is also achieved by large aggregate being pushed beneath the surface. They are clip on devices and do not require bolts and nuts to fit them on the trowel. The same is the case with the other two blades also. Float blades are broad one with the edges turned up and used flat. The floating operation brings the water to the top.
The second and third application of smoothing and finishing is done by finish blades. They are narrow six inch blades. The length varies according to the diameter of the machine on which it is to be fitted. They are reversible and can be turned end for end. Finish blades are tilted to small angle and are usually run with the machine at full speed. Used when the concrete has just begun to set, they make the concrete surface hard and give it smooth finish and sometimes glossy. Usually, trowel with the blades is run as many times as required, from one end to the other. It is also run across, with a motor at a higher speed and the blades exerting more pressure. This operation is done to cover any filling which might have been missed in the earlier run. Combination blades are used for doing both floating and finishing operation. This blade is not reversible.