Stamped concrete | What is it?

Stamped concrete is the result of an embossing and texturing process that’s currently gaining many fans around the world.

This is due to the remarkable aesthetic benefits it grants concrete surfaces, accompanied by appealing economic benefits.

Stamped concrete also stands out for keeping the concretes most important properties intact. That is, its resistance and durability, requiring only a simple maintenance to guarantee its functionality in high traffic areas.

What is stamped concrete?

This type of concrete refers to the decorative technique of applying a “continuous hardening mortar” made “in situ” on a fresh concrete surface. Normally in some color and texture.

Its main function is completely aesthetic, taking advantage of the plasticity of the mixture during the setting process. 

To achieve stamped concrete, the appropriate pigment must be spread on the fresh concrete surface, and then the moulds must be placed, which will be pressed against the concrete.

The chosen shapes are made with different molds, usually defined by geometric shapes or imitations of wood, stone, bricks, tiles, paving stones, etc.

The printed concrete technique is finished with the application of a “resin” that will offer protection to the pavement.

The advantages of stamped concrete

Most of stamped concrete’s characteristics are, in practice, considered to be an advantage because it doesn’t vary the concrete in any way, after the setting and curing processes.

However, it should not be forgotten that it is an aesthetic treatment to give surface appeal and sophistication to ordinary concrete and that the advantages come mainly from the concrete product itself.

Here we highlight some of the most important stamped concrete advantages:

• High mechanical resistance to relatively frequent traffic.
• Durability.
• Waterproof.
• They have the ability to be anti-slip.
• Resistance to solar ultraviolet radiation.
• Thermal resistance to sudden fluctuations, especially during frost and thaw.
• It can be used in large lengths of continuous paving.
• El tiempo de ejecución es reducido, en comparación con otros procesos de acabado.
• Maintenance almost null, due to its simplicity.
• They have a wide selection of shapes, colours and designs.
• Molecular stability against the attack of aggressive and abrasive chemical substances, such as acids, fats and oils.

Stamped concrete floors are often compared to polished concrete floors, as both have effective results and provide an optimal surface for transit.

This comparison of pavements refers only to those effective results, because the printed concrete floor and the polished concrete floor are 2 types of floors used for different types of constructions.

Concrete stamping

Before proceeding with concrete stamping, it is necessary to establish some preliminary aspects related to the floor surface, the colorant and the resin for printed concrete to be used, all of which are explained in these points:

• The base must be stable against any external influences, as well as being properly levelled and compacted.
• The floor base mustn`t affect the concrete’s mechanical resistance or its volumetric stability. Furthermore, it must be chemically compatible with lime, but without being susceptible to decomposition during the setting process of the cement.
• It must provide uniformity to create regular colourings. Likewise, it must contribute to the rigid flooring’s surface resistance.
• The colouring mustn’t affect the properties of the concrete. Being stable and chemically compatible.
• The resin must fill the pores of the concrete to seal its surface, generating a durable and resistant layer to thermal changes and abrasion.

Now, regarding the concrete, it is worth taking into account:

• Its resistance must be higher than 220 kgf / cm2. In the worst case, a minimum compressive strength of 200 kgf / cm2 is allowed.
• The maximum value of the water / cement ratio should be 0.55, to avoid the adverse effects of shrinkage.
• The consistency of the concrete needs to be soft.
• It’s recommended that water used for mixing should be clean and potable, without traces of sulphates and carbohydrates.

Stages to stamped concrete

Once all the important preliminary aspects are known, it should be known that the stamped concrete process is mainly done in 3 steps, the first 2 consist of colouring processes and the last one, stamping.

Base colouring

To stamp the concrete, you first have to add the base colouring, which will be the primary colour that gives a natural appearance in order to achieve the coating which we want to replicate.

The base colouring is created by adding hardening colouring to the concrete, this is a powder pigment.

There are 2 ways to do the base colouring. The first is an integral coloration, in which the entire volume of concrete is coloured, whereby the pigment is added during the mixing of the concrete.

The second option consists of applying the pigment on the surface of the flooring, in a plastic state.

Definitive colouring

In order to achieve the desired colour, a second colouring is needed. This second colouring is a pigment that’s responsible for texturing and adding a more detailed finish, it’s also non-stick, making it impossible for the stamping moulds to stick to the surface.

Like the previous stage, to apply the dye there are 2 ways of doing so, in accordance with its state, since it can be a powder or a liquid (solvent).

Powder colouring is the most commonly used product, which only needs to be spread on the surface before stamping. The liquid pigment is part of the content of sprays, so it is sprayed on the molds, prior to stamping.

Stamping

This last stage consists of the pressure placement of the molds, each one with a particular geometric pattern, usually imitating a covering material, such as wood, tiles, paving stones, stone, slate, among others.

The moulds are generally made of polyurethane, although neoprene has recently been used, since it’s a material with greater versatility to simulate more varied shapes.

To finish the stamped concrete floor, resins are used to seal the entire surface of the concrete, to enhance its water resistance.

What is the price of stamped concrete?

The first thing to know is that the cost of stamped concrete is budgeted per m2 executed (labor and materials) and curbs on the other hand are budgeted per linear meter.

The average price of the printed concrete of 14 cm thickness is between 25€ – 35€ per m2.

If this price is within your budget, ask for several offers from different companies. However, we recommend that you discard those that do not include in the price the reinforcement with reinforcement, mesh or fibers. That is to say, the installation should be reinforced. 

Here you can learn more about concrete reinforced with metallic fibers.

How to maintain stamped concrete floors?

Maintenance is a key point of the benefits of stamped concrete, since the surface has such a high resistance and durability that it makes it almost unnecessary to perform any care on the concrete.

However, the pavements must be subject to a periodic revision, to renew the surface treatments, since the probability of defects will never be completely null; the joints are the structural elements to which the greatest consideration must be given.

Restorations are recommended to compensate for the accumulated abrasion.

Even the cleaning of the flooring must never be neglected, since spills of harmful liquids, such as oils, may occur, which can damage the appearance of the concrete. Also, the removal of miscellaneous dust and debris is necessary.