Project Description

The National Opera House is a 310 Mio. € project situated at Bjørvika in Oslo. The construction period is over 5 years with completion scheduled in 2008. It will cover an area of 36‘000 m² with 1‘350 seats in the main auditorium and 400 seats in the smaller hall. The unique appearance of the Opera House arises from the icicle shaped precast concrete columns which support the roof structure.

Project Requirements

These columns have a length of between 4 m and 21 m, and weigh between 4 tonnes and 24 tonnes respectively. The precast volume comprises a total of 12‘000 m³ concrete, with an additional volume of 120 m³ for the special white precast feature columns. The architects design requirements for the icicle shaped precast columns were to achieve a reflective, snow white concrete surface with a very high quality finish. In order to achieve such a snow white appearance, white cement was combined with bright white marble aggregates from western Norway.

Sika Solutions

A Self Compacting Concrete based on Sika® ViscoCrete® technology was developed for the white precast columns. The Sika® ViscoCrete® ensured sufficient fresh concrete stability coupled with a powerful water reducing effect. The required dosage was 1,5% by weight of cement. The admixture reduced bleeding, and subsequently reduced the formation of pores in the surfaces.

To achieve the ideal Self Compacting Concrete a white dolomite filler was added to compensate for a low content of fi ne materials in the crushed marble aggregates. The hardened precast columns were also treated after demoulding and curing with Sika® Antigrafi tti-15 as a clear, non yellowing, protective impregnation to prevent future surface contamination.

Sika Products

In addition the following Sika products were used in the project

  • Sika® ViscoCrete®
  • Sika® Antigrafitti-15