Bendy concrete to go into field trials

The invention of tough yet flexible concrete could halve the duration of road and paving works

Conventional concrete vs bendable concrete developed at NTU, Singapore.
Conventional concrete vs bendable concrete developed at NTU, Singapore.

Scientists in Singapore have developed a form of bendable concrete they say is stronger, lighter and more resistant to cracking than regular concrete made of sand and cement.

Researchers at Nanyang Technological University (NTU) successfully tested tablet-sized slabs of ConFlexPave, which is made from a combination of hard materials and polymer microfibres that allow the concrete to flex under tension.

The material’s improved strength will enable the formation of slimmer, precast pavement slabs, say researchers, potentially halving the time needed to complete road works and lay new pavements. They claim it lasts longer, requires less maintenance than conventional concrete widely used today, and enhances skid resistance.

  • NTU Asst Prof Yang En-Hua holding the bendable concrete developed by his team.
    NTU Asst Prof Yang En-Hua holding the bendable concrete developed by his team.
  • NTU Asst Prof Yang En-Hua holding the new bendable concrete in his right hand and the conventional concrete which broke on the left.
    NTU Asst Prof Yang En-Hua holding the new bendable concrete in his right hand and the conventional concrete which broke on the left.

Assistant Professor Yang En-Hua, at the School of Civil and Environmental Engineering, NTU, says: ‘Traditional concrete comprises cement, water, gravel and sand, which makes it hard and strong, but also brittle. The higher strength of our material is a result of the enhanced toughness which prevents brittle failure under bending. The major advantage is the enhanced safety and durability of structures.’

The key breakthrough was understanding how components of the materials interact with one another mechanically on a microscopic level. This allowed ingredients to be selected and engineered to create a material tailored for specific road and pavement applications.

The hard components create a non-slip surface texture and the microfibres, each one thinner than a human hair, distribute the load across the entire slab, resulting in a concrete that is as tough as metal and at least twice as strong as conventional concrete under bending.

‘The challenge of scaling up the technology to create larger slabs suitable for use in buildings, is to control the rheology [the physics of deformation and flow] and mixing so we can obtain consistent and reliable material using conventional mixing equipment,’ says En-Hua Yang.

The next phase of the development will be field trials. Over the next three years tests will be scaled up for vehicular traffic, working in partnership with JTC Corporation, Singapore’s state developer of infrastructure technology.