From soaring skyscrapers to massive bridges, the constructed world around us is getting taller, bigger, and more ambitious with each passing year. Making these modern marvels a reality requires extremely strong, lightweight, and durable materials that can withstand intense forces and harsh environmental conditions over decades.
High-Strength Concrete Reinvented
We tend to think of concrete as a heavy, rigid material. But novel concrete formulations using specialized admixtures and alternative cements are producing ultra-high-performance concretes (UHPC) that are up to eight times stronger than conventional concrete mixes. Strategic placement of reinforcing steel fibers or polymer fibers creates extremely ductile UHPC that is both stronger and more flexible. This allows for thinner, lighter structures while enhancing seismic and impact resistance.
Towering with Steel Composites
For years, steel-reinforced concrete was a construction staple for building vertical support columns able to handle the massive downwards forces in high-rise structures. But steel is heavy and susceptible to corrosion over time. Fiber reinforced polymer (FRP) composites made from glass, carbon or basalt fibers set in a resin matrix provide a lighter, more durable, and non-corroding substitute. Some record-setting skyscrapers incorporate FRP composite reinforcements for both vertical columns and horizontal structural supports.
Shape-Shifting Concretes
Most concretes permanently harden and become rigid solids after curing. But researchers are developing smart, flexible concretes that naturally bend and adjust their shapes over time using shape-memory materials. One promising approach embeds shape-memory alloy fibers or polymers into the concrete mix. These materials have a programmed shape that can reactivate and morph the concrete upon heating or cooling cycles. Such deformable concretes could potentially reshape themselves to alleviate cracking or other damage.
Rebuilding Itself from Within
Even the strongest materials gradually deteriorate and develop cracks over years of use. A groundbreaking solution is self-healing concrete packed with special microorganisms or enzyme admixtures. When a crack emerges, these self-healing agents within the concrete naturally produce calcite minerals that seal the cracks before they spread further. Like self-repairing human bones, this biomimetic process continually rebuilds the structural integrity from within to extend the concrete’s usable lifespan.
Lighter Loads with Foams and Aerated Concretes
Using less concrete overall can lead to big sustainability gains and cost savings. Thanks to special chemical foaming agents, manufacturers can produce aerated concretes and lightweight foamed concretes. Their porous, air-filled structures provide sufficient compressive strength for many applications while using roughly 30% less material. The experts over at Aerodine Composites say that when reinforced with polymers or industrial composites, these ultralight concrete foams can even achieve the lightweight benefits of wood-frames while being far more fire and weather-resistant.
Building the Future with 3D Printing
Large-scale 3D printing is having an impact on construction too. Utilizing cements and polymer-based feedstocks means specialty 3D printers can build concrete structures on site with intricate features, hollow interiors and complex curvilinear forms that would be incredibly difficult or impossible using traditional techniques. 3D printing reduces material waste, construction timelines and allows never-before-seen architectural geometries.
Smart Sensing with Nanocomposites
Embedding nanomaterials like carbon nanotubes or graphene into concretes and polymer composites produces smart nanocomposites with integrated sensing and monitoring capabilities. These nanofillers can detect and wirelessly report information about structural stresses, cracks, corrosion, and temperature fluctuations in real-time during and after construction. Such smart materials give infrastructure continuous health checkups to preempt maintenance issues.
Conclusion
From smart self-healing concretes to 3D printed designs and nanocomposite sensors, innovative construction materials are pushing the boundaries of what is possible for the built world. The offices, bridges, and homes we inhabit will only get taller, lighter, smarter, and longer lasting as material science continues charting new frontiers.