NATURAL BEAUTY

Colorpigments - natural beauty

The Hanze line, the new railway connection between Lelystad and Zwolle, will be completed by the end of 2012. This project also involved constructing a railway tunnel underneath Drontermeer (a lake). Other key features of this particular section are the tunnel buildings which not only house the technical installations, but also function as escape route terminals.

The project was commissioned by the railway management company Prorail.

The building on the west side is long and narrow, this to leave the woodland intact and enable wildlife to continue to move around. The three tunnel walls erected are made of reddish brown concrete and Cortens steel and blend in perfectly with the natural environment as the reddish brown volumes echo the large roof surfaces of the farmhouses in the surrounding countryside. The buildings look different every day because the natural materials used change in appearance according to the weather. This natural beauty is an essential quality of the design.

To obtain truly natural colours, much attention was paid to the composition of the concrete. White, reddish brown and black pigments are widely used in concrete. Nevertheless many of the reddish brown samples were rejected because the colour was not right. 

Eventually, the desired result was achieved in collaboration with Scholz Benelux. Scholz Benelux took a reddish brown brick as reference material and examined its colour in a laboratory at Recklinghausen, Germany. The colour was analysed, samples were made, and finally one sample was selected.

Black concrete was used for the bases of the buildings and the upper part of the tunnel entrance. The black colour was achieved by mixing iron oxide and carbon. The pigments used were iron oxides Bayferrox^® black 330 and Bayferrox^® red 503 and a mixture of iron oxide and carbon called Grapa Nero 8020. These pigments ensure that the building elements will retain their dark colour for a long time.

Project details:

Principal: ProRail

Architect: studioSK

Construction: Ballast Nedam

Contractor: Ballast Nedam / GTI

Subcontractor: Ballast Nedam Bouw, Groningen

Reddish brown elements: Eurobeton, Meppel

Black concrete elements: Waco Lingen Beton, Bergen op Zoom

Steel: Konstruktiebedrijf Visser B.V., Veenwouden