Bricks have been a staple building material since ancient times. But these days, engineers are experimenting with different materials to create eco-friendly and extreme buildings.
One of the most innovative materials is carbon fiber, which can reinforce traditional bricks and concrete blocks to improve their strength. Also, researchers have developed a bone-like material that is lighter than water and stronger than some types of steel.
Carbon Fiber
Carbon fiber is an extremely strong and stiff material with a high modulus of elasticity (the ability of a material to absorb a set amount of strain). It can be used in place of more traditional building materials like steel. Carbon Fiber is also very lightweight. The combination of its strength and lightness make it a very desirable material for building structures that need to be both stiff and strong.
Carbon Fiber is created through a complex manufacturing process. The first step is to create a precursor material, such as polyacrylonitrile (PAN) or rayon. The precursor material is pulled into long fibers that are then heated at incredibly high temperatures in an environment without oxygen to ensure they don’t burn. This energizes the atoms of the material and drives off any non-carbon atoms to create carbon fiber. The new carbon fiber is then treated to improve bonding with epoxies and other resins. Careful oxidation of the carbon fiber allows for better chemical bonding, while roughening improves mechanical bonding.
Once the carbon fiber is bonded with other material, it’s ready to be used in a variety of different applications. The material can be used in structural applications, such as making stronger and lighter airplanes and automobiles, or to reinforce composites that are more resistant to heat and corrosion. It can also be used to build load-bearing walls and supports for bridges.
Bio-Concrete
Scientists have been working hard to develop eco-friendly materials that can function just as well as their non-green counterparts. One such material is bacteria-impregnated concrete. They have found that bacterial concrete is more durable than its traditional counterpart, and it can self-heal cracks in a much quicker way.
To make this concrete, researchers imbue it with bacteria from the genus Bacillus. The bacteria are amalgamated within clay pellets that are then embedded in the concrete. When the concrete cracks, the bacteria are ‘awakened’ by water and oxygen that infiltrate the crack. The bacteria metabolise calcium lactate to produce insoluble calcium carbonate that fills the crack. The resulting limestone seals the crack, preventing further damage and increasing the strength of the concrete.
The bacteria also improve the concrete’s compressive and tensile strengths. The tensile strength is improved by up to 50%, meaning that more stress is needed to cause a crack to form. The compression strength is increased by up to 24%.
The bacterium is also able to reduce the amount of water that the concrete absorbs. By limiting the flow of water, it is possible to prevent corrosion of steel reinforcement bars in the concrete and increase its durability. To test the concrete’s acid resistance, Srinivasa Reddy et al exposed both control and bacterium-treated specimens to 5% hydrochloric acid for 90 days. The control sample lost
Solid Wood
Wood has always been a popular building material. It’s durable, versatile and looks beautiful. But now scientists have found a way to make it even stronger. They’ve created a new method that could turn any type of wood into a material that can rival steel and titanium alloys in strength.
The key to making the wood stronger is changing its structure. Currently, most wood is made from a combination of different types of lumber. The resulting product is called a composite material. These are usually made by binding together wood strands or veneers using chemical adhesives. This is a lot cheaper and faster to produce than solid wood. But it also doesn’t have the same strength as solid wood.
To change the composites into something that is more like solid wood, researchers are experimenting with chemical modifications to the natural wood scaffolding. One of the most promising methods is called delignification. This removes the lignin from the cell walls without damaging them or changing their hierarchical organization.
These changes can greatly improve the properties of the wood, giving it a wide range of new applications. These include transparent and optical materials, catalytic materials, materials for waste water treatment and energy storage and conversion, and materials with outstanding mechanical properties. Unfortunately, most of these wood-based functional materials rely on treatments that don’t adhere to the principles of green chemistry and often result in hybrid products that can’t be separated or recycled. As such, they end up in landfills or burnt as fuel for electricity generation.
CABKOMA Strand Rod
In Japan, where earthquakes are a part of daily life, the Komatsu Seiten Fabric Laboratory has developed a new thermoplastic carbon fiber composite called CABKOMA Strand Rod to save buildings from damage. This strand rod looks like a bunch of carbon fibre noodles, and it has the power to prevent buildings from collapsing in an earthquake by transferring the force of an earthquake directly to the ground.
Its inner layer is made of thin oriented carbon fiber, and the outer layers are covered in synthetic and inorganic fiber and then impregnated with thermoplastic resin. The resulting product has the highest tensile strength of any other seismic reinforcement in the world, yet it is the lightest in weight.
The strand rods are so lightweight they can be easily strung from the top of a building to its foundation, making it easy for engineers to design earthquake-resistant structures. This means that buildings will be safer and can be used for years to come.
In addition to its earthquake-resistant properties, CABKOMA strand rod can also be used in the construction of roofs and façades, lighting ducts, and even green roofing panels. Its flexibility allows it to be woven into fabrics that can give buildings an organic appearance and reduce their environmental footprint. A 160 meter roll of CABKOMA strand rod weighs only 12 kg, so it can be easily carried by hand and is one-fifth the weight of metal wire of the same strength.