Nano Concretes - The Building Materials of the Future
Safety Fabrications are continuing with our series on concrete – one of the most used substances. We’ve looked at the history of concrete, how it was first discovered by the Romans at the Campi Flegrei super volcano. Then we moved on to an overview of modern concrete, followed by descriptions of reinforced concrete and pervious concrete – how they’re made and what these materials are used for. Today we’re going to take a look at Nano concrete which is a quite fascinating material that doesn’t get used as much as it should.
Nanotechnology is an emerging field of science that aids the development of materials with improved or new properties and allows us to examine the nature of our world on an ever smaller scale. A nanometre is one billionth of a metre and nano particles are defined as a particle that has at least one dimension less than 100nm. Particle size is crucial because at the length scale of the nanometre (10¯⁹ m) the properties of the material itself become affected.
Nanotechnology is a dynamic field of research that applies to a large number of disciplines, including the construction industry. Concrete is the material that is most widely used in construction and interest in nanotechnology in concrete is steadily growing. The use of finer particles results in a higher surface area and this has advantages in terms of filling the concrete matrix, densifying the structure and offering higher strength and faster chemical reactions (e.g. hydration reactions). Nano cement particles can accelerate cement hydration due to their high activity. This means that the incorporation of nano-particles will fill pores more effectively and enhance the overall strength and durability of a structure. This means that nano particles can lead to the production of a new generation of cement composites that are stronger and longer lasting than current materials.
Researchers at MIT (the Massachusetts Institute of Technology, whose mission is to advance knowledge and educate students in science, technology and other areas of scholarship) have been studying the nanostructure of concrete and made an exciting discovery that could result in lower carbon-dioxide emissions during cement and concrete production.
The researchers predict that the construction industry could benefit from nanotechnology in the following areas:
- Replacing steel cables in suspension bridges and cable-stayed bridges with carbon nanotubes which are much stronger.
- Incorporating restive carbon nanofibers in concrete roads in snowy areas.
- Using nano-silica to produce dense cement composite materials.
- Incorporating nano-titania to produce photocatalytic concrete (concrete that is self-cleaning) that would lead to reduced maintenance costs.
- Using nano-clays in concrete to enhance its flowability and plasticity (this could be helpful to the engineers who are studying ways of pumping concrete more than half a mile into the sky when building the new Kingdom Tower in Jeddah).
- Using nano-calcite particles in sealants to protect structures from the aggressive elements of the surrounding environment.
- Urban air quality could be greatly improved if buildings and other structures are treated with nano Ti0₂
While the construction sector is notorious for resisting change, we’re now living in the 21st Century and the industry as a whole will benefit from the use of nanotechnology in years to come.