A research team has developed a fracture-resistant cement using lessons learned from aquatic creatures.
A project by physical chemistry teams from the University of Konstanz and University of Stuttgart, led by Professor Helmut Cölfen, may have found a way to make cement that is much stronger and more fracture resistant than current versions – using lessons learned from sea urchins. Sea urchin spines are made mostly of calcite, a mineral that is usually very brittle. However, the urchin spines are interspersed at the nano level with softer disordered layers. When force is applied to the brittle calcite, the energy is transferred to the soft layer, which prevents cracking.
As each component in cement sticks to all the others, Cölfen’s team needed to reorganise the cement at the nano-level in order to duplicate the type of fracture resistance found in the sea urchin spines. The team achieved this by identifying molecules that acted like mortar within the cement, allowing the creation of nano-layers within the cement which assembled themselves in an ordered manner. Cölfen describes the process as “encoding fracture-resistance at the nano-level.”
When tested, the new material was found to be more than one hundred times more fracture resistant than the concrete commonly used. To put this in perspective, a pillar made from this new cement could be built 8,000 metres high, or ten times as high as the current tallest building in the world, before the material at its base would be destroyed by its weight. Cölfen explains, “Our cement, which is significantly more fracture-resistant than anything that has been developed thus far, provides us with completely new construction possibilities”. We have already seen construction embracing new types of building materials, such as concrete reinforced with old tyres and drywall made from recycled materials. What new possibilities for building and construction could take place using the new super-strong cement?