Metsä Group’s Bioproduct Mill, Finland
Finnish forest industry group Metsä Group’s Äänekoski mill is the first next-generation bioproduct mill in the world. In addition to high-quality pulp, it produces a broad range of bioproducts, such as tall oil and turpentine, bioelectricity, and wood fuel. The massive mill project required thousands of precast concrete elements – made from more than 31.500 metric tons of concrete.
|Gross building area||142 000 sqm|
|Total building volume||1 200 000 m3|
|In-situ concrete||100 000 m3|
|Load-bearing concrete arches||80 000 sqm|
|Steel structures||7 000 t|
|Precast products||15 000 pcs|
When the Finnish forest industry group Metsä Group constructed a new bioproduct mill in Äänekoski, Central Finland, precast concrete elements played an important part in making sure that the tight schedules were met.
Speed of construction was one of the primary benefits of using precast concrete elements in the frames of the mill buildings. But Samu Ristolainen, the project’s main structural engineer, does not hesitate to cite other reasons: adaptability, strength, durability, and fire safety.
The massive size of the mill structures and the special requirements of a bioproduct mill tested the limits of concrete element production. The mill’s barking plant building posed the biggest challenges with its 45-meter long primary braces, which were at the limits of what prestressed concrete can do. Also the framework of the causticizing plant was demanding to build. It required massive pillars to support the weight of the lime silo located on the building roof.
Despite the challenges, the schedules stayed on target: excavation work in the mill area began in the spring of 2015, and test use will commence a mere two years later, in the spring of 2017.
Most of the mill’s precast concrete elements were supplied by six different factories of Parma, the largest precast concrete element manufacturer in Finland. Parma belongs to Consolis Group, the largest precast concrete solution provider in Europe, which operates in 30 countries.
Sweco Industry Oy and Sweco Rakennetekniikka Oy were responsible for the detailed engineering of the mill. Sweco is Europe’s leading architecture and engineering consultancy.