Aluminum air pipes

Mussel shells are clogging London’s water pipes, but a designer has found

About eight years ago, a invasive species called quagga mussel shells began clogging London’s water pipes and tunnels. Since then, Thames Water, the utility company responsible for the city’s public water supply and sewage treatment, has spent millions of pounds to remove them. Most of these shells ended up in landfills, but in a few years you might see them on the walls of your building, albeit in a different form.

[Photo: Patrick Seeger/Picture Alliance/Getty Images]

Lulu Harrison, a masters student at Central Saint Martins University in London, has created a bio-glass from crushed quagga mussel shells. The material was recently on display at London Craft Week, where Harrison teamed up with local architecture studio Bureau de Change to develop a series of textured glass tiles inspired by the designs of 19th century terracotta chimney pots. . It may be years before glass is commercially viable, but if it succeeds, it could become a rare example of an equally translucent sustainable building material.

[Photo: Bureau de Change]

Typical glass consists of 70% highly pure silica sand (i.e., not desert sand); soda ash, which helps lower the melting point of silica; and limestone, which acts as a stabilizer. Glass is infinitely recyclable, but sand mining can erode rivers and disrupt ecosystems.

[Photo: Bureau de Change]

Harrison says his version was inspired by old recipes for making glass. In the spirit of ‘celebrating the impurities’ she mainly used plain Thames sand, around 15-20% mussel shells with a little soda ash and locally sourced wood ash waste which , she hopes, will eventually replace soda ash entirely. . The result is what she calls “geo-glass,” an approach that could be used in other regions to help reduce transportation costs by incorporating local resources.

[Photo: Bureau de Change]

Making the tiles involved a “vigorous processing step” of washing the collected materials, allowing them to dry in the sun, then grinding and sifting them into a fine flour-like powder. The mixture is then processed using an ancient technique called sintering, which involves melting the glass, soaking it in cold water until it breaks into tiny granules, and then recast. Finally, the molten glass is poured into 3D-printed molds the size of a sheet of paper and allowed to cool slowly so it doesn’t crack.

[Photo: Sophie Maccorquodale/courtesy Bureau de Change]

Harrison’s early experiments resulted in a series of blown glass vases and decanters. But for the exhibition, organized by the design studio here, Harrison was paired with Bureau de Change and the material was turned into half a dozen tiles, the size of a sheet of paper. These were displayed on individual podiums. According to Katerina Dionysopoulou, co-founder of Bureau de Change, the textured nature of the tiles could create a much more interesting architectural coating, especially if the team moved away from the tiles and found a way to cast the glass into larger molds. She says the tiles could also open up a whole new world of bio-based, translucent materials. “There are so many eco-friendly alternatives to solid materials, but there’s nothing for anything transparent,” she says.

[Photo: Sophie Maccorquodale/courtesy Bureau de Change]

Architectural materials, of course, must meet an enormous amount of regulations, from durability to fire safety, to be deemed up to code. The process requires lengthy testing and expensive certifications that can vary from country to country. “But as we realized with the Covid vaccine, if R&D companies work together, things can actually happen much faster,” Dionysopoulou says.