Keeping It Green

In an unusual assignment Hahn & Weilbächer from Hochheim/Main, Germany was called upon to lay a 3000 m2 ring of green-coloured asphalt at Frankfurt's Commerzbank Arena (formerly Waldstadion) to blend in with the central football pitch.

Achieving this colour in the asphalt, which was a chip mastic 0/5 with a layer thickness of 25 mm, meant using a colourless binding agent and a coloured powder pigment. It was also necessary to clean the pavers thoroughly with hot natural sand and individual washes.

“Within two days we achieved a very good result. The only thing that made installation difficult was the fact that the football field is square and the stadium is oval”, said Thorsten Hahn, the junior manager of the 45-strong company. A further complication was that the surface abutted the concrete stands, so low vibration compaction had to be used.

A 10 tonne Bomag BW 174 AD tandem roller, fitted with the company's ‘Asphalt Manager’system, and a 1,5 tonne BW 80 AD carried out the compaction work. The Asphalt Manager system controlled the intensity of compaction, and in this case it was necessary to select a gentle, horizontally directed vibration. Particular attention also had to be paid to cleanliness during laying - the rollers, equipment and tools were all continuously cleaned of black tar.