Reasons for color variations
in colored concrete

Figure: Schomburg

With the aid of pigments wonderful results can be achieved particularly in the field of concrete products and precast concrete elements

Figure: Schomburg

Figure: Harold Scholz

The industry provides pigments for the coloring of concrete as powder, as granules, in compact and liquid form

Figure: Harold Scholz

Depending on the inherent color of the concrete, the outcome can appear completely different when using the same pigment shade as well as same amount of pigment

Figure: Harold Scholz

The aggregates have a great influence on the inherent color of the concrete – in particular, if they are exposed by acid treatment

Figure: Harold Scholz

The higher the water/cement ratio, the brighter the concrete

Figure: Harold Scholz

Dirty snow affected this concrete block pavement

Figure: Harold Scholz

Colored concrete can be like a Diva – beautiful but susceptible to external influences. Only the slightest changes may result in an appearance of the colored concrete that is not as perfect as originally conceived or the color of slab A does no longer look like slab B. The reasons for this phenomenon can be quite different.

Frequently, the requirements on colored architectural concrete are very high. The appearance of the same is again and again compared with the uniformity of a metal surface painted in serial production and not with the individuality of natural stone. Almost everything that alters the visual appearance of normal architectural concrete also has an impact on the same when colored.

Aggregates: concealed or exposed

With an amount of about 70 vol.%, aggregates account for the largest proportion of the concrete composition. Consequently, they make an important contribution to the inherent color of the...