It is an unfortunate truth that our world is almost entirely built from materials that are mostly unsustainable. Wherever you are — if you are indoors — take one look around and the chances are your eyes will fall on substances that are all practical and relatively cheap to produce but are, ultimately, finite in origin.
I am referring of course to the bricks, concrete, steel, glass and wood that makes up our world. With our planet in a state of climate emergency, there is growing public awareness to act on the other fronts and reduce environmental damage elsewhere.
Not that the construction industry is separate from the climate crisis. In fact, it is estimated that production of these unsustainable building materials stacks up to about five percent of all manmade carbon emissions. To make things even worse, nearly two-thirds of all of these materials are not even recycled and, after use, are dumped in our ever-growing landfill sites.
So with the current zeitgeist focused on sustainability, perhaps it is time to look beyond the traditional bricks-and-mortar; steel and concrete, and at the innovative solutions currently in development that are paving the way for a cleaner, greener, future:
Cement that can be ‘programmed’ into shape
Of all the traditional building materials we have, cement is perhaps the most ubiquitous. But cement is not without its problems. It is extremely tough, except for when its under strain — then it becomes brittle and liable to collapse. That is why the partnership of steel and cement is one of the great triumphs of the architectural world — one that has allowed our generation to build architects that our grandfathers could only dream of. But cement has a big drawback. As it sets, the molecules leave big, porous gaps that invite in water that then rusts the steel.
Fortunately, a team of engineers at Rice University in Texas think they might have solved this problem of porosity. They have invented a way to ‘programme’ the cement. To tweak the molecular content, take control of the cement and ‘move’ the particles into positions that close it off to water.
The final result is a type of cement that sets harder, tighter, and will protect the steel from rust. And, because it is more efficient, it means less cement will have to be manufactured in the first place — reducing our emissions and over-reliance on it.
Buildings that ‘breathe’
In hot countries, air conditioning can be very expensive. It is also a massive drain on energy. Fortunately, engineers at Barcelona’s IAAC architecture school have invented what they call ‘hydro-ceramic’ panels that may cut bills by up to a third.
These panels are designed to cover the facades of the outsides of buildings. They have an ingredient called ‘hydrogel’ — an insoluble polymer that can absorb 500 times its weight in water.
The panels cool the building by absorbing the humidity in a hot country and then letting it evaporate. This is what the IAAC staff means by ‘breathing’. As the collected water evaporates the temperature inside the building drops by as much as six degrees.
Reefs of ‘coral’ bricks
Bricks requires a lot of energy because very high temperatures are needed to make them. But, thanks to a research team in North Carolina, USA, there may now be another alternative: bricks that grow at very low temperatures, and a bit like how coral grows in the ocean.
The scientists have done this by placing sand into rectangular moulds and then adding bacteria to the mould. The bacteria then ‘wraps’ around the sand which encourages the growth of calcium carbonate crystals. These crystals later develop into stone-like substances that are just as tough as bricks.
If coral bricks ever become the standard, they will be much eco-friendlier, as nowhere near enough energy is required for their production.
Plastics made from plants
Engineers in the Netherlands (working for a private enterprise called Aectual) have succeeded in creating a plastic that is actually 100 per cent renewable and from plant-based polymers. The ingenious thing about these plant-plastics is that they can be destroyed and re-assembled again without any waste.
As if that wasn’t impressive enough, these engineers have constructed giant 3D-printers that can print off entire floors and facades of buildings — made entirely out of these plant-based ‘bioplastics’.
Conclusion: the beginnings of a green revolution in construction business?
Although these new, innovative materials are exciting and promising, we have to be realistic. The traditional materials of today are not likely to disappear overnight. But it is heart-warming and optimistic to see so many potential replacements already in development.
If we are ever going to achieve full sustainability on Earth, then innovations such as those listed here should be celebrated, and encouraged.
There is a long way to go, but we are getting closer to equilibrium.
This is a guest article, written by Neil Wright of Weldwide. Weldwide is an architectural steel and structural engineering company, based in London, UK.