Flexible Concrete Won’t Crack Under Pressure

(Image courtesy of Nanyang Technological University.)

The ancient building material concrete is getting a performance boost thanks to a clever reformulation.

Sand, water, cement and gravel. Those are the ingredients that make up concrete, one of the most ubiquitous building materials on the planet. Since its invention millennia ago concrete has served as the foundation for buildings, roadways and all manner of infrastructure. Although it’s a useful material, it does have its flaws. Namely, concrete is brittle and will crack under pressure.

For two thousand years that’s been concrete’s Achilles’ heel. But things may be changing.

According to Nanyang Technological University (NTU) professor Chi Jian, “We developed a new type of concrete that can greatly reduce the thickness and weight of precast pavement slabs, hence enabling speedy plug-and-play installation, where new concrete slabs prepared off-site can easily replace worn out ones.”

Named ConFlexPave this reformulated concrete holds true to the age old recipe but adds a twist by including polymer microfibers to the cocktail. The introduction of these polymers means that loads which would traditionally cause concrete to crack can be distributed across a larger area of the material, giving ConFlexPave greater resiliency.

(Image courtesy of Nanyang Technological University.)

"The microfibers, which are thinner than the width of a human hair, distribute the load across the whole slab” said Assistant professor Yanf En-Hua. “[Thus] resulting in a concrete that is tough as metal and at least twice as strong as conventional concrete under bending."

While table-sized slabs of ConFlexPave have proven to be reliable in laboratory settings, NTU researchers will continue to scale up the volume of ConFlexPave they pour in order to confirm that the material will behave as expected once it’s released into the real world.

Though flexible concrete might seem like a mundane technological advance, the impact that it might have on global infrastructure can’t be overstated. If flexible concrete can be poured far and wide, billions, if not trillions of dollars in infrastructure maintenance could be saved.

What’s more, because flexible concrete can be poured in thinner layers, less material will be needed to repave roadways, thus saving money and energy. Concrete building might also be made more resistant to cracking under the pressure of earthquakes as well. The list of benefits goes on and on.

For more on the latest developments in the world of concrete, find out how engineers are developing smarter concrete with biomaterials.