Terrazzo floors in the look and feel of yesteryear

Eterno Minerals of The World combines age-old skills with innovative technologies. The floors in the new AFAS office in Leusden, the JuBi Rijkskantoren in The Hague and the ARTIS-Aquarium in Amsterdam are fine examples of this. Especially for the ARTIS-Aquarium, Eterno Minerals of The World supplied and installed approximately 1,900 m2 of Eterno Terrazzo floors with Arabescato, Norwegian White and Basalt natural stone fragments, combining the luxurious and atmospheric feel of yesteryear with functionality and durability.

At 144 years old, the ARTIS Aquarium is one of the oldest aquariums in the world. "Partly due to years of saltwater loading, the 1881 national monument has deteriorated considerably," knows Cor Hoogeveen, CEO of Eterno Minerals of The World. "Also when it comes to the floors. It is up to us the beautiful task of renewing these floors, with attention to history, functionality and sustainability."

Divergent substrates

On behalf of contractor Salverda Bouw, Eterno Minerals of The World realized approximately 1,900 m2 of Eterno Terrazzo flooring. "Because of the age and monumental character of the ARTIS Aquarium, we started with a thorough inventory," says Hoogeveen. "In fact, everywhere in the building the subfloor looked different. For example, we were dealing with vaults and varying spans. But also with substrates of foam concrete, facade masonry, wood, et cetera, over which our concrete had to be poured. In fact, ARTIS and OTH Architects wanted to achieve the same type of floor throughout the building, in the look and feel of yesteryear."

Hybrid concrete floors

A Terrazzo floor is a beautiful floor, provided the subfloor is sufficiently stable and level, Hoogeveen emphasizes. "For example, to prevent cracking due to subsidence and operation. For this reason, we mapped out all the floor details in advance. Based on this and in consultation with Salverda Bouw, hybrid concrete floors were selected as the subfloor, with traditional reinforcement combined with steel fiber reinforcement. In this way, we were able to give more structural strength to the building. Also with regard to the storey floors, where we poured hybrid floors over the Dovetail system floors." A 20 mm Eterno Terrazzo floor was poured over the subfloors, he says. "Once the cementitious floors had cured sufficiently, we sanded and polished the floors in six steps. By sanding from coarse to fine, we removed the cement skin and the natural stone fragments became more and more visible."

Appearance of yesteryear

The ARTIS Aquarium also originally had Terrazzo floors, a few pieces of which were still preserved, Hoogeveen says. "We tried to bring back the colors of these floors in the new floors. Together with the architect, client and contractor, we examined several color samples, based on which a somewhat whiter and an anthracite-colored floor with beige-like Arabescato natural stone fragments were selected. These very closely matched the color tones of the time." 

Brass strips

"Terrazzo floors are often dilated," Hoogeveen knows. "In this project, this was not done, but we divided the floors into large compartments/spaces that were poured in one go. In the process, brass strips were incorporated into the floors, enhancing the atmosphere of the past." A total of nearly 2 km of brass strips were set on the subfloors, he says. "In addition, the floors are equipped with underfloor heating and floor pots, in which the network cabling and electricity are finished."

High durability

In addition to functional and aesthetic properties, Eterno Terrazzo floors are distinguished by high durability, Hoogeveen concludes. "The floors are made from exclusively natural materials. In addition, the floors have a long lifespan of more than 150 years and are excellent to clean and maintain. Also, the Total Cost of Ownership is very favorable."