A vast expanse of newly laid concrete is before you smooth and flat. Or is it? Not normally. In our experience new concrete can be anything but smooth and flat.
The surface of the concrete can be very rough with small lumps and grooves across the surface. If you want newly laid concrete to be completely smooth and flat and maybe to extend the life of the concrete then maybe what you need is Power Floated Concrete.
What is Power Floated Concrete?
Power Floated Concrete is a process applied to newly laid concrete to provide as flat and and smooth a surface as possible. It is achieved through the application of a Power Float Machine which literally cuts the top of the concrete surface away to leave a smooth flat finish.
A Power Float is an electric or petrol driven machine that, from a distance, looks rather like a rotary hover mower. Some machines you walk behind, like the Wacker Neuson CT36-5A, or sit on, like the Whiteman HHX. At the base of the machine are one or two rotating sets of adjustable steel blades. The machine spins at around 150 rpm and smooths the almost set concrete.
Why use Power Floated Concrete
Power Floating will make a concrete surface flatter and smoother but it will also make the surface denser too. This means the surface will last longer, be more attractive and easier to maintain.
Plower Floating is, therefore, ideal for manufacturing or commercial environments that need hard and attractive flooring. For example, warehouses, commercial centres, factories, airports, car parks, etc.
How to produce Power Floated Concrete
Timing is crucial in the process of Power Floating. If the surface is too dry the machine will find it difficult to remove the high spots and the floor will not be able to reabsorb the cement particles. Too wet and the machine will simply tear the surface to pieces.
At Becosan we like to wait until the surface is dry enough to support a person walking on it but wet enough so that the footprint will leave an indentation of between 3 and 5mm.
The Power Floating itself consists of two phases; floating and finishing. Special blades are used for each distinct phase.
In the Floating phase the machine is fitted with floating blades and the blades are set at a flat angle to induce a suction effect on the concrete surface. The machine then travels up and down the surface leaving a series of circular marks on the floor.
If using a walk behind machine the operator should walk backwards so that the footprints are eliminated.
Before the Finishing phase we must wait until the concrete has dried further, until walking on the surface leaves no footprint. Finishing blades are fitted to the Power Float. The finishing is a series of passes across the floor with the angle of the blades increased progressively. The larger the blade angle, the harder the finish. Finishing continues until we have the requisite smoothness and hardness.
The concrete floor is now left to Cure, this usually takes about 28 days.
How to make Power Floated Concrete better with the BECOSAN System.
So now the concrete is harder, flatter and smoother than it might otherwise have been, but it is still concrete and the surface will begin to disaggregate overtime and will create dust. Also, the floor is still open and will absorb any liquid spilled upon it.
These problems can be significantly reduced, once the concrete is cured, using the Becosan System. The Becosan System begins by micro-grinding the floor using a Power Trowel fitted with Becosan diamond studded abrasive pads opening the pores and eliminating the micro-roughness in the surface.
The Becosan Densifier is then applied to the floor penetrating into the substrate, chemically reacting and binding with the free lime and calcium hydroxide in the floor. The result is a harder surface which is resistant to wear and, hence, reduces dust.
After the application of the Becosan Sealant the floor is much more resistant to the absorption of liquids leaving the surface stain free for many years.
A final polish and we you have a hard, flat, smooth and beautiful concrete floor that will maintain its sparkle for many, many years.