BEYOND BENDING LEARNING FROM THE PAST TO DESIGN A BETTER FUTURE

When people look at modern buildings, they tend to describe them as boxes: rectilinear cubic volumes defined by vertical and horizontal lines and elements. It is true that we need flat horizontal surfaces to walk around and use rooms in a reasonably simple enough way, but we tend to assume that the lower side of such surfaces (slabs) and the associated structural components (beams) also have to be flat. For some reason, not only is a horizontal beam seen as something inevitable but it is even seen as structurally desirable.
A rectilinear horizontal beam tends naturally to bend. In this bending there are two forces at play: compression in the upper part (particles pushing against each other) and traction in the lower part (particles trying to pull away from each other). The invention of reinforced concrete consists in the introduction of rebars in the lower part of the beam in order to resist traction, a force that concrete alone can not support. The problem is that the mass needed in that lower part of the beam is not there to perform any structural operation, but only to protect the steel from rusting; structurally speaking, it is dead weight. This was the starting point of these three engineers’ research. They studied old structures like King’s College Chapel and the Guastavino vault, and concluded that if bending could be avoided and the structure could work only in compression, then something like 70% of the matter could be saved. This has huge consequences on the weight and amount of material used in the overall system, with potentially dramatic savings in direct costs. But it also has consequences in the amount of energy saved because less matter is needed—there is less energy spent in the fabrication and less energy spent in the transportation. It even saves time since less matter has to be put in place. Using state-of-the-art engineering, software, and robotic prefabrication technology, their research may open the path for a global shift in the building paradigm.