The beginning of civilization as we know it, started with a series of material innovations; the Bronze Age and the Iron Age set us on the path to where we are now. Skyscrapers would have never reached such heights without developments in steel and high-performance concrete, and facades would have never slimmed down without thin-shell concrete.
The great downfall of concrete—the world’s most widely used building material—is unavoidable cracking, caused by exposure to water and chemicals.
But a new development from a team in the Netherlands could extend the life of concrete, by infusing it with bacterial spores that patch up cracks when water seeps through. Plans are in place to make this self-healing concrete commercial in the coming years.
NanotechnologyNanotechnology is one of the most active research areas that encompasses a number of disciplines, including civil engineering and construction materials. It is the art and science of manipulating matter at the nanoscale. It is an enabling technology that allows us to develop materials with improved or totally new properties. Nanotechnology is the use of very small particles of material. A nanometer is a billionth of a meter.
Use of nano fillers in concrete improves its weakness in tension and results in concrete with greatly improved stress-strain behaviour. The addition of nano silica fume improves durability of concrete structures.
TiO2 is a white pigment that can be used as an excellent reflective coating. It is hydrophilic and therefore gives self-cleaning properties to the surfaces to which it is applied. The addition of small amounts (1% wt) of CNT’s can improve the mechanical properties of samples consisting of the main Portland cement phase and water.
In “Concrete Planet: The Strange and Fascinating Story of the World’s Most Common Man-Made Material” (Prometheus Books, 2011), author Robert Courland writes: “If the Romans had used steel-reinforced concrete—which they did not have—to build the beautiful bridge in Alcántara, Spain, the bridge would have been rebuilt at least 16 times by now.”
The production of construction materials requires energy and generates greenhouse gases. In order to increase the service life of structures, innovative materials offer opportunities to change the way in which we construct and retrofit buildings. They give added value in terms of increased performance and functionality.
Transparent WoodWood is being used widely for architectural facades and in some other fields. Combining the properties of glass and wood theoretically, has proved to be a marvel in the field of engineering and architecture - it’s wood, but not as we know it.
Researchers have found a way to strip the lignin out of wood and replace it with a synthetic polymer, meaning that a strip 1 mm thick becomes 85 percent transparent. Crucially, even though it is see-through, it retains its strength. By making wood transparent it is possible to achieve thermal properties which are much better than that of glass. Efforts are on to create large panels so that they could be used as curtain walls.
Bamboo-Reinforced ConcreteBamboo is a strong, lightweight material that has been used for a long time in traditional construction across Asia – particularly for applications such as scaffolding, and in the construction of bridges and houses. Bamboo takes less energy to harvest and transport, therefore, it has low manufacturing costs compared to steel.
Test results have shown that bamboo has a similar characteristic as that of steel. Bamboo can be used as an alternative material for reinforcing concrete. However, the characteristic of bamboos show high water absorption and low bonding strength between bamboo’s surface and concrete. The material is a mix of bamboo fibres and an organic resin, ensuring the bamboo will not degrade or rot. Bamboo absorbs large amounts of CO2, adding to its potential as a sustainable alternative to steel.