The construction industry has always had to deal with material issues. For decades, homes and commercial buildings have been purged of asbestos and lead, formaldehyde and other volatile organic compounds in everything from paint and carpeting to insulation. Currently, the manufacture and use of building materials accounted for 39 percent of all energy-related carbon dioxide emissions in 2018, according to the Global Alliance for Buildings and Construction. Those types of numbers are fueling concerns over the built environment’s effects on the natural world and human health. These pain points have driven a demand for projects that deliver innovative building materials that are safer for both the planet and its people.
PHOTOS COURTESY OF, CLOCKWISE FROM TOP LEFT, CARBONCURE, COMPANY NEW HEROES AND HE INDIAN SCHOOL OF DESIGN AND INNOVATION
Construction companies are launching projects to make concrete less carbon intensive—a big deal, considering manufacturing the material accounts for about 8 percent of global carbon dioxide emissions each year.
CarbonCure, a startup in Dartmouth, Nova Scotia, Canada, has partnered with more than 100 concrete producers for over a decade to reduce their carbon footprints by sequestering emitted carbon dioxide in concrete.
CarbonCure’s technology allows manufacturers to inject waste carbon dioxide from industrial emissions into their concrete mix, where it reacts with calcium ions to form a limestone-like material. In this mineral form, the carbon is permanently embedded into the concrete and is prevented from being released back into the atmosphere. The material combination also reduces the need for cement and other energy-exhausting and expensive concrete ingredients.
The project team designed the product so engineers can install it in hours without disrupting operations or cycle times. Since the technology integrates into the plant’s existing software, additional staff training isn’t needed. Following each installation, CarbonCure’s technical services team works with the plant’s quality control staff to identify the optimal mix of carbon dioxide and other ingredients that will maintain the manufacturer’s requirements for strength and other properties.
Dutch design firm Krown has been experimenting for years with building products out of fungi, specifically the mushroom root system known as mycelium. After years of designing furniture and packaging, the company last year added building products to its focus industries. For one project, it partnered with Dutch creative agency Company New Heroes to design and produce a mycelium building installation for Dutch Design Week.
The project used mycelium panels as the wall and insulation material for the all-natural pavilion—panels between timber framing and above flooring made from cattails. Typical insulation materials, such as extruded polystyrene panels (EPS), emit three times their weight in carbon dioxide on most buildings, says Krown co-founder Jan Berbee, Hilversum, the Netherlands. The mycelium prototype, on the other hand, offsets its own carbon footprint by extracting carbon dioxide from the air. And although mycelium remains more expensive than EPS, that price is rapidly coming down.
“Mycelium used to be 20 times more expensive than EPS, but today that factor is between three and nine times, depending on the application,” Mr. Berbee says.
To build the pavilion, the team grew mycelium in 6-foot-by-3-foot (2-meter-by-1-meter) molds filled with local organic waste, such as sawdust or hemp husks. The mycelium envelops and binds the waste. After about five days, the new mycelium structures are cured at 176 degrees Fahrenheit (80 degrees Celsius) to halt growth and make them available for use.
Mycelium holds a number of properties that make it ideal for building structures: It’s “insulating, light, water repellent, carbon dioxide negative and fire retardant,” Mr. Berbee says. “The material is also known for acoustical properties,” he says, and it can be reused or composted at the end of its life cycle.
—Jan Berbee, Krown, Hilversum, the Netherlands
One way to ditch traditional, carbon-intensive concrete construction is to develop an all-new material to replace it. Case in point: A team at the Indian School of Design and Innovation in Mumbai, India is combining loofah, charcoal, soil and cement to make bricks that replace concrete in buildings and other structures. The material reduces the need for coarse aggregate, a major ingredient in concrete, by 90 percent.
The team chose natural loofah for its fibrous properties, which strengthen the bricks while also adding flexibility, eliminating the need for steel beams typically found in concrete construction. Another advantage of the porous design is that it stimulates plant growth and can provide a safe habitat for insects, fulfilling the team’s goal of creating a biophilic design that encourages urban biodiversity.
The bricks also hold water, allowing them to regulate a building’s temperature. Charcoal, which appears in small amounts on the brick’s surface, purifies the air by absorbing nitrates. At the end of its life cycle, the sustainable charcoal can be crushed and returned to the soil.
Since the team first showcased its technology in 2018, it has continued to iterate with different compositions, shapes and natural coloring, along with customized mixtures for different climates. PM