Artfully: Designing with colored concrete

The color concrete by pigments is not a new procedure. But thanks to technological progress, concrete color concrete delight of architects, planners and builders today particularly popular. With colored concrete made it a far more lasting color results than with a subsequent painting and much more intense colors than by colored aggregates alone. This corresponds to the color of concrete ideas, but experience and know-how are essential in the production of concrete, because it applies different factors to control properly.


Stone hits concrete: the expansion of the mediaeval Lukasklause Magdeburg (see Google Maps) are made of colored, highly flowable concrete. (Photo: CEMEX Germany AG)


Cement and color pigment choice
Even if the concrete is colored with pigments, the brightness of the cement used plays a large role because it determines the basic color of the concrete. With bright cements, as a rule with portland cement or blast furnace, so CEM II and CEM III, there are, in principle, be made deeper, purer colors. These cements are mainly in bright colors such as pastels and of course recommended for very white. Dark red, ocher, brown and black on the other hand can also be set well with darker cements. are pigments for coloring concrete is targeted in various forms such as powders, granules, beads or liquid paint. Each has its advantages in certain applications. The mostly inorganic pigments are added to the formulation of concrete production and color the cement paste which surrounds the mineral aggregates and connects.


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With iron oxide pigments, for example, concrete can be colored red, yellow, black and brown.
With the mineral pigment ultramarine and cobalt blue are achieved various degrees of blue.
Chromium oxide and chromium hydroxide green result.
Titanium oxide pigment colors the white concrete.
Even with relatively low pigment added a great color effect is achieved. Depending on the nature of the pigment and the desired color result dose the employees of the concrete manufacturer is usually between 2 and 6% of the share of cement color pigments into the concrete. The color intensity initially increases linearly with the amount of pigment, stagnating at a certain percentage, the color saturation level - the addition of other pigments will show hardly any effect. Since the pigments represent a not underestimate the cost, knowledge about the optimal dosage avoids unnecessary expenditure. be expected, however, must be below the saturation level more with fluctuations in the shade. The timing of the addition of the pigment has to be right:

Powder and granules are about before,

Liquid color by the addition of water in the mixer.
Manufacture and installation
For colored concrete is the same as for any concrete vision: the establishment of a stable, well-processed formulation is an important basis for making desired end result. But it is not enough. At each step, from planning to installation and after-treatment should the project partners to vote in detail in a concrete team.

The "data sheet for Concrete" is a valuable basis for agreements. Prior to the execution of the production of plots is strongly recommended. Only this test under harsh conditions provides information on the project-specific best combination of concrete, plywood and release agents. The customer can select one of the plots, which is regarded as reference surface. The tolerance limits for color variations should necessarily be discussed in advance. Many parameters in the production, installation and surface treatment affects the color results. Variability from batch to batch can be largely avoided if you have a ...

uniform mixing time attaches,
consistently the same starting materials and formulation compositions selected and
especially water-cement ratio and cement content has very consistent.
The mold surface is also important: An absorbent panel formwork for example, takes in air and excess water from the building, which the uniformity of the color creation. A professional, as consistent processing of the concrete, a substandard, but also exposed concrete equitable treatment and a subsequent protection of the young concrete at the construction site are essential to achieve a high quality colored concrete surface.

The concrete and air temperatures, humidity, and general site conditions are taken into account in the interest of an optimal outcome in the planning of concrete works well. Especially in the outer area may help prevent impregnation of the concrete surface water flags and streaks and so the color result in the long term.