The multi-domed ceiling of the subterranean Amos Rex art museum pushes up through the surface of Helsinki’s Lasipalatsi plaza to create an interactive outdoor playscape. The concrete walls of the subterranean museum two storeys below rely on Canada’s Xypex Admix C-1000 NF waterproofing product to translate the design into reality.
Project planning began in 2013 when the Föreningen Konstsamfundet art foundation began to search for a new home for the Amos Anderson Art Museum. The nearby Lasipalatsi (glass palace) building offered an inviting project site but, due to its historic significance, could not be modified sufficiently.
Helsinki-based JKMM Architects proposed to renovate and incorporate the Lasipalatsi complex, including the 590-seat art deco Bio Rex theatre, with a new subterranean art museum under Lasipalatsi square. Plans for the newly dubbed Amos Rex art museum called for a two-storey deep excavation that required removal of nearly 14,000 cubic metres of soil and bedrock.
The $64-million museum features a main gallery floor and a lower level for art storage and mechanical equipment. Steel-reinforced concrete footers, floor slabs, and walls form the main structure. The roof is built with 20-centimetre-thick steel-reinforced concrete, a thick insulation layer, glass foam fill, and a top layer of exposed concrete.
The project required absolute moisture resistance in concrete foundation and walls. At a depth of 14 metres the foundation rested seven metres below the water table and faced constant hydraulic pressure. The plan to use the lowest level for art storage meant that any influx of water could result in disaster.
The design team considered many waterproofing options, including membranes, coatings, and concrete additives.
“Our track record on a global scale with similar deep-foundation projects convinced them that we were the right choice,” says Ronald Sulin, Xypex sales manager for Finland. “We also provided a 15-year warranty, which no other manufacturer could match.”
Xypex Admix C-1000 NF was selected to provide normal- to mildly-delayed set and was added to concrete at the time of batching. It consists of Portland cement and active, proprietary chemicals that react with moisture and the by-products of cement hydration to cause a catalytic reaction that results in the formation of non-soluble crystals that fill natural pores and capillary tracts. It becomes a permanent and integral part of the concrete structure and continues to prevent the ingress of water and other liquids for the life of the structure.
The product not only heals hairline cracks up to 0.4 mm, it also provides chemical resistance that mitigates the attack of chlorides and sulfates and the effects of carbonation and alkali-aggregate reaction.
“The project saved money by varying the dosage of Admix C-1000 NF based on the projected hydraulic pressure at different depths,” Sulin explains.
The footings, slabs and elevator pit received 5 kg/m3. Lower level walls were dosed at 4 kg/m3, and gallery level walls were dosed at 3 kg/m3. An estimated 1,500 cubic metres of concrete were treated.
By including primary waterproofing as an integral part of the foundation, the project also saved time and money that would have been required by other waterproofing systems. Because Xypex typically increases the compressive strength of concrete and crack tolerance, less reinforcing steel was used.
“Xypex not only met the immediate need for a concrete water-proofing solution,” notes Sulin. “It also delivers long-term benefits by providing a one-time application that never needs to be repeated or renewed throughout the service life of the concrete.”
This content is sponsored by Xypex in collaboration with ConstructConnect® Media. To learn more about Xypex, visit www.xypex.com.