Technological advances are changing just about everything humans do, and structural engineering is no exception. New techniques and new materials are being used to create buildings and other structures. Carbon fiber, polymer and even biological materials are opening new possibilities in structural engineering and construction. They allow us to build structures that were impossible just a decade ago.

Last month, we wrote about new formulations and uses for concrete. This time, we’re taking a deeper look at how carbon fiber is allowing us to explore new frontiers in structural engineering.

Carbon fiber

Carbon fiber is a very thin, long strand made by bonding carbon atoms in crystals oriented parallel to the long axis of the fiber. The result is a high strength-to-volume ratio, which means it is very strong for its size.

Several thousand carbon fibers are bundled together in a form called a tow, which can be woven into fabrics to make them stronger, or combined into completely different materials to increase their strength.

Carbon fibers impregnated with plastic resin form carbon fiber-reinforced polymer, which has a very high strength-to-weight ratio. Tennis rackets, skis and other sports equipment are some of the more common uses today.

Carbon fiber combined with graphite or other materials can form reinforcing composites that have a very high heat tolerance.

Structural engineering applications

Carbon fiber also can be used to reinforce steel, concrete, masonry and timber. Carbon-reinforced polymer rebar is an extremely strong and light alternative to steel rebar, and is used in bridge decks, parking structures and other applications that are susceptible to corrosion and magnetic fields. In addition, polymer rebars are not thermally or electrically conductive.

Carbon fiber-reinforced polymer compounds have been used to construct foot bridges since the 1990s. The advantages of carbon-polymer over regular concrete include less weight and longer life.

Manufacturers began embedding carbon fiber in precast concrete as far back as 2003. Replacing steel mesh in concrete makes the concrete lighter and more durable. It also allows less use of concrete, reducing weight and cost.

Carbon fiber in construction

Carbon fiber-reinforced steel, concrete and other materials can make building materials lighter. Composite building materials are easier to work with and can speed up construction without increasing costs.

The increased strength and lighter weight of carbon-reinforced materials allows architects and structural engineering professionals to make higher skyscrapers than was possible before, with less material. It also allows different shapes, such as the fanciful twisting, curving outlines of the most innovative new buildings recently erected around the world.

Closer to home, carbon fiber reinforcement of concrete, steel and other building elements makes homes and other structures stronger, more able to withstand tornados, earthquakes and other extreme events. This is already having an impact right here in the United States.

Carbon fibers in robotics

Carbon fiber reinforcement is also changing the way structural engineering and construction professionals produce buildings.

Reduced weight and increased structural stiffness allows machinery to work faster with less energy consumption, leading to higher productivity and longer maintenance cycles.

One construction-related application was a wall-climbing robot built by International Climbing Machines of Ithaca, New York. Its machines allow for inspection of hydroelectric dams and other high structures by remote control, protecting human operators from exposure to heights, chemicals or other hazards. By building a new model with a cassis made from carbon fiber reinforced material, it increased the machine’s carrying capacity and performance.

Imagine using robots like this to inspect walls and perform other maintenance duties.

Robots are already being used to perform a number of assembly, inspection and maintenance functions in the construction industry. This is only going to accelerate.

Find out more

It’s an exciting time in structural engineering and construction. If you have some thoughts about new materials for construction, we’d love to talk with you about them.