Smart buildings are more and more on the agenda. For their elaboration, some materials have been developed to meet specific objectives during their use without the need to be operated by any person or equipment. Self-maintenance, cleaning the air, working with the comfort of space, energy efficiency, are just some of the benefits that can be achieved by adopting them.
Before presenting some examples, it is important to emphasize that most of these materials are in the development phase and deal with cutting-edge technology, which can increase their costs and, still, have little presence in the market. However, given the demand and need for more sustainable solutions in the face of the climate crisis, it is likely that products will be developed and improved over the next few years and become more accessible. Next, get to know some of them.
Regenerative Bioconcretes
Cracks or crevices, if left unrepaired, can enlarge and allow water to enter the interior of the concrete structure, leading to corrosion of the steel and compromising the mechanical qualities of the structure. Bioconcrete or bacterial concrete incorporates some species of bacilli (bacteria) in the cement mixture that minimize the need for maintenance in the material, as they produce spores that can survive up to five decades without food or oxygen, and are able to naturally close any cracks that may arise.
Carbon Concrete
Four times stronger and lighter than the usual reinforced concrete, this material uses carbon meshes instead of iron elements, signaling resource and financial savings, as well as less damage to the environment. Its manufacture takes place through a process of thermal decomposition (pyrolysis) in which ultrafine strands of carbon crystals are extracted and used to create a mesh where the concrete is spread before it hardens. Its advantage therefore lies in the approximately 50,000 individual fibers – much thinner than a human hair – processed to form a grid structure. In addition to allowing even larger spans without the risk of collapse, carbon concrete is capable of generating much lighter prefabricated parts, eliminating the need for large cranes.
Hydroceramics
The material developed by Spanish students is a ceramic with hydrogel bubbles that are capable of retaining up to 400 times their volume in water. Due to this property, the spheres absorb water and, on hot days, evaporate, cooling the environment. On a rainy and low temperature day, the bubbles increase in size, recompose themselves, and serve as a thermal insulator. Therefore, the thermal comfort and energy efficiency of buildings are improved.
Self-Cleaning Materials
It is already possible to find materials such as paints, glass and ceramics that are self-cleaning on the market. What they have in common is that they have titanium dioxide nanoparticles in their composition, an element that makes photocatalysis, that is, increases the speed of chemical reactions when exposed to light, eliminating microorganisms and dirt from the surface. In the case of paints, they offer savings in maintenance and repainting, and are suitable for use in external areas such as façades and roofs, after all, with the heat of light (natural or artificial), the paint releases free radicals that break down polluting agents such as nitrogen oxide and reduce odors, improving the quality of urban air. In Rome, a painting was carried out inside a tunnel, and that resulted in a 51% reduction in polluting gases in the area.
