SB Brand-Led Culture Change 2024 - Prices go up March 17th! Register now!

Chemistry, Materials & Packaging
Clay-Based Concrete, Upcycled Waste Latest Innovations in Sustainable Building Materials

The days of conventional concrete and carbon-intensive building materials are waning.

The days of conventional concrete and carbon-intensive building materials are waning. Along with promising advancements such as concrete made from biofuel waste, carbonate rock made from captured CO2 emissions, and a smart gypsum board that can help regulate room temperatures, three recent innovations in material development illustrate the intensifying search for more sustainable materials — from city streets to cement production plants.

First, a new technology developed by California-based Watershed Materials promises high–strength masonry with a lower carbon footprint than traditional concrete. The company uses natural mineral-based geopolymers to achieve a sustainable material alternative with compression strengths of 7,000 psi — twice the strength of ordinary concrete — and a demonstrated resistance to water and chemical erosion.

Until now, geopolymers have mostly relied on the limited supply of byproducts from coal or heavy metal production. In place of these materials, Watershed Materials is drawing from globally abundant natural clay-based materials to yield strong geopolymer reactions.

This new geopolymer technology can be applied for:

  • Mass production of sustainable masonry made from locally sourced, often recycled mine and quarry waste.
  • On-site local production of structural masonry from excavation or demolition materials.
  • Disaster relief and remote production of reliable building materials from locally sourced materials.

Meanwhile, Dutch roads may soon be made from upcycled plastic. Through a project calledPlasticRoad, Dutch construction firm VolkerWesselsplans to pilot a road surface in Rotterdam made entirely from plastic materials.

“Plastic offers all kinds of advantages compared to current road construction, both in laying the roads and maintenance,” said Rolf Mars, director of VolkerWessels’ roads subdivision, KWS Infra.

The plastic roads are lighter than concrete and reduce the load on the ground, according to VolkerWessels. This quality makes it easier to install cables and utility pipelines below the surface. A simple delivery process of refabricated road sections will eliminate the need for on-site mixing while saving money and energy.

In addition, asphalt is responsible for 1.6m tons of carbon emissions annually, VolkerWessels says, emphasizing the need for lower-impact materials. Finally, the company estimates the roads will be able to be recycled into something else after their approximate 50-year lifespan.

While the PlasticRoad project is still in the conceptual stage, VolkerWessels hopes to install the first fully recycled thoroughfare within three years. Rotterdam provides a perfect launching place with a city council receptive to the idea.

“We’re very positive towards the developments around PlasticRoad, said Jaap Peters, from the city council’s engineering bureau. “Rotterdam is a city that is open to experiments and innovative adaptations in practice. We have a ‘street lab’ available where innovations like this can be tested.”

The next step for VolkerWessels is building and testing the roads for performance in diverse weather conditions.

“We’re looking for partners who want to collaborate on a pilot — as well as manufacturers in the plastics industry, we’re thinking of the recycling sector, universities and other knowledge institutions,” Mars said.

And even further east, building materials company Holcim is installing a Solid Recovery Fuel manufacturing (SRF) plant in Vietnam that repurposes solid footwear production waste to create a fossil fuel substitute that powers its cement. Technology from Austrian waste-to-energy shredding company Untha will process up to 10 metric tons of material per hour to produce 80 mm fuel with high calorific value.

The process uses 50 percent less power than traditional static electro-hydraulic shredders, Untha says. Metals will be extracted for recycling.

“Footwear production waste is an incredibly difficult product to shred, due to the mixture of notoriously tough materials contained within sports shoes,” said Christian Lanner, Untha’s Head of Engineering and Product Management. “We’re tackling rubber, textiles, plastics, metals, sponge, reinforcements and more. However, we extensively configured, re-engineered and trialled our flexible XR waste shredder — using the client’s own material — until it was perfectly suited to this application. We’ve also refined the cutting concept so that it is incredibly well-equipped to deal with this demanding waste stream.”

The Holcim plant is expected to be fully operational by September.

If a group of U.S.-based tech giants have their way, demand for innovations such as these might soon be the norm: A working group of The Building Health Initiative comprised of Google, Facebook, Genentech, Adobe, CalPERS, Kaiser Permanente, Troon Pacific and UCSF Mission Bay are actively using their collective market influence to create demand for new and innovative products that improve the health of the built environment.