Building materials are the backbone of every structure, from homes to skyscrapers. These materials help protect against weather and natural disasters, while delivering strength, durability, and safety.
Many of the strongest materials are composites, which are made up of one material that surrounds and binds together a group of fibres or fragments of another. Engineers have been developing new types of composites to meet increasing demands.
CABKOMA
Thermoplastic carbon fiber composites are becoming increasingly popular. These materials can be shaped to suit various building applications and offer high strength, flexibility, and corrosion resistance. They can also be reformed even after hardening. Moreover, they can be used to reinforce steel-reinforced concrete. This can increase the lifespan of buildings by a significant margin.
One such example is CABKOMA, a thermoplastic carbon fiber composite that was developed by Komatsu Seiten Fabric Laboratory in Japan. The company has used this innovative material in the seismic renovation of its former head office. Its exterior is now “wrapped” with a network of spaced CABKOMA strand rods that resemble a soft, organic textile.
Using CABKOMA strands in this way can transfer earthquake forces to the ground, which helps reduce vibrations in buildings. The material is especially effective in protecting older buildings that were built without considering seismic forces. A roll of CABKOMA is 160 meters long and can be carried by hand, and weighs just 12 kg—that’s only a fifth of the weight of metal wire of the same strength.
However, the market for CABKOMA is restrained by its complex production process and limited availability of raw materials. These factors could lead to supply chain disruptions, which may limit its adoption in various industries. Nevertheless, the strong tensile strength and flexibility of CABKOMA makes it an ideal choice for seismic reinforcement in historic buildings.
StarCrete
Researchers at the University of Manchester have mixed a large portion of extraterrestrial soil with a dash of potato starch and salt to create a concrete-like material that is up to twice as strong as regular concrete. They called their invention StarCrete because the resulting construction material could be used to build buildings on Mars and other worlds, such as moon colonies.
The scientists published their findings in the journal Open Engineering. Previously, they experimented with blood and urine, but decided to switch to potato starch because it is readily available, requires no regular collection and has a much higher compressive strength – up to 72 megapascals (MPa).
A 25 kg bag of dehydrated potatoes contains enough starch to make nearly half a ton of StarCrete, or more than 213 bricks’ worth of material. They also found that adding magnesium chloride – a common salt that can be obtained from the Martian surface or even from astronaut tears – increased the strength of their material dramatically.
The team is working to bring their concept from the laboratory to the real world. They hope that it will be able to provide a cheaper and greener alternative to traditional concrete on Earth, as cement and its production accounts for around eight percent of global greenhouse gas emissions. They have already launched a start-up company called DeakinBio to explore the possibilities of applying their new construction material in terrestrial settings.
Graphene
Just one atom thick, this two-dimensional form of carbon has amazing properties that make it the strongest material in existence. It conducts electricity 13x faster than copper, is able to absorb 2.3% of light, and is impervious—even helium can’t pass through it.
It’s no wonder that this incredible material has captured the attention of scientists and industry specialists around the world. Graphene can filter salt from water, develop bullet-stopping body armor, create biomicrorobots, and much more.
Adding graphene to concrete can also reduce its environmental footprint. Using a process called chemical vapor deposition, researchers were able to add 0.03 percent graphene powder into concrete and roughly halve the amount of materials used in making it. The result was a stronger and more durable building with less waste and lower greenhouse gas emissions.
While the current application of this revolutionary material is limited, researchers are hoping that in the future it can be integrated into concrete to provide more functional and adaptive responses to structural loads. For instance, smart concrete composites could react to changes in temperature and humidity, allowing them to adjust their structural integrity in real time. They might even be able to detect damage and predict when a structure will fail, helping to ensure safety and durability. This could be particularly beneficial for structures in seismic zones.
Living Concrete
Researchers at Worcester Polytechnic Institute have created a new type of concrete, which not only makes buildings stronger but also absorbs carbon dioxide from the air and heals itself if it cracks. The scientists used a combination of gelatin, sand and nutrients to create the material, which contains bacteria that help form calcium carbonate when they’re exposed to warm water and sunlight. They’ve tested the strength of the bricks, demonstrating that they can support a person standing on them, and they have also shown that the bacteria can regenerate the material by splitting it into two bricks in seven days.
The team is also looking at ways to make the bacterial concrete even more effective. To get the best results, they need to keep the bacteria alive. These microbes, which are called cyanobacteria, require a very humid environment to thrive and will die quickly if they’re dehydrated, so the UC Boulder team has been working on ways to protect them.
One of the most interesting applications for this material is in space, where it could reduce the amount of materials needed to build structures in remote desert areas or on other planets. But for now, the team’s bacterial concrete is only useful in places with warm and humid weather. The team hopes to continue to improve the material’s ability to survive in dry conditions, so it may someday be able to help construct buildings in places like Mars, where it would be very difficult to grow plants.