Ultra High Performance Concrete (UHPC) is making inroads in the construction industry, due to its increased sustainability and energy efficiency. But what exactly is it and how is it produced?
In essence, concrete is a mixture of aggregates of different sizes with cement as a binder. The keys to producing UHPC lie in the careful selection of high-quality raw materials, the exact proportioning of its components and a careful mixing process. Therefore, larger aggregates are removed and fine silica particles are incorporated, which act as an additional binding agent. This combination, together with the use of high-performance cements, contributes significantly to improving the mechanical properties of a higher density concrete.
However, ongoing research in the field of nanotechnology makes it possible to introduce nanoparticles into UHPC. These reinforce the structure of the mix and improve its toughness and compressive strength. As a result, construction becomes more efficient and bolder, and now relies on thinner and lighter structures, without sacrificing the structural integrity of its productions.
In qualitative terms, this technology achieves concretes with a strength of more than 150-200 MPa (compared to 20-50 MPa for conventional concretes). However, achieving this level of quality requires attention to detail, not only to the selection of materials, their proportioning or the mixing process; it is also necessary to monitor the curing process. In this case, the use of steam blankets accelerates the hydration of the cement and ensures the optimal formation of crystals in the concrete matrix during curing.
The end result is a high-performance concrete, challenging that of materials such as steel or carbon, whose use is spreading in our cities and offers architects and structural engineers the opportunity to explore innovative designs.
By Jorge Laguna, head of the structures section of Amusement Logic’s Architecture Department.
Images: The Moroccan Index.
