In an ever-industrializing world, landscapes turn from forests and plains to concrete roads and high rises as cities expand and develop. But 21st century urban architecture doesn’t resemble the dull and dreary factory lanes of Europe during the Industrial Revolution. In modern, global cities around the world, innovators are finding ways to use concrete that are better for the environment, safer, and more aesthetically pleasing.
There’s nothing more frustrating to a construction professional than when a concrete project cracks. Cracks are not just unattractive, but potentially unsafe. Concrete cracks are sites for future leakages, meaning unhappy clients and in extreme cases, collapsed buildings. Unfortunately, all concrete structures will crack eventually, whether in one year or one thousand.
In fact, the architects of the Roman Empire, which is admired to this day for its splendour, used a unique concrete that allowed for sightly structures that withstood the test of time through the chemical properties of the concrete. According to American Mineralogist journal, the use of lime and volcanic ash in these ancient structures added a rare mineral to the concrete called aluminum tobermorite. It crystallizes in lime while curing, under exposure to sea water. Even though water is traditionally thought of as an agent of erosion in the construction sector, water exposure actually reinforced these Roman wonders.
Concrete that works with nature
Today, modern scientists are finding other ways to work with nature, rather than against it, as we build our concrete jungles. Research has shown us that there is more than one way to make self-healing concrete. For instance, Henk Jonkers, a professor and microbiologist at Delft University of Technology in the Netherlands has invented “living concrete,” also known as bioconcrete.
CNN Business reports that Jonkers’ concrete – like regular concrete but with an extra “healing ingredient” – is made with a resilient kind of bacteria that can survive the harsh and dry environment of concrete, becoming active only if the concrete cracks and water leaks into it. Jonkers hopes that this concrete could be “the start of a new age of biological buildings.”
Because concrete is very dry and basic, the bacillus bacteria was chosen, as it thrives in basic conditions. Bacillus is usually found near active volcanoes, and their spores can live for decades without sustenance. The bioconcrete also contains calcium lactate capsules to feed the bacteria. When water enters a bioconcrete crack, the capsules are released, the bacteria feed on the calcium lactate, and they create calcium carbonate (limestone), which plugs the cracks. Interestingly, IndustryTap writes that spraying a liquid containing the bacteria onto concrete cracks is also an effective solution.
“It is combining nature with construction materials,” Henk Jonkers told CNN. “Nature is supplying us a lot of functionality for free – in this case, limestone-producing bacteria.”
Using bacillus bacteria might not be the only way. Trichoderma reesei, which is actually a type of fungus that also produces limestone, may be another method of creating self-healing concrete, according to researchers from Rutgers University and Binghamton University. In Technology Review, it is mentioned that the mushroom spores can survive in extreme basicity, up to pH 13. However, they’re not as resilient as bacillus, and will need to live in bubbles in the concrete. Further research is needed to see whether this alternative is viable.
More than just shades of grey
Gone are the days when graffiti was dismissed as a public nuisance. Now, it is appreciated as a legitimate art form with the potential to transform otherwise plain concrete street corners.
One of the most famous street artists is Banksy, a mysterious (and still anonymous!) 45-year-old English multimedia artist who has been active since the 90s. Though his identity has never been confirmed, his work has been featured in countless art shows, he was profiled in The Guardian, and his documentary even received an Academy Award nomination. Banksy is known for his eye-catching, edgy, and sometimes iconoclastic style. As USA Today writes, many celebrities, including Bono, Angelina Jolie, and Christina Aguilera own Banksy originals, so it is safe to say that this elusive artist’s work has gone mainstream.
Moreover, in 2014, Google launched the Street Art with Google Art Project, a partnership with art experts to bring Google users a virtual exhibition of graffiti from around the world. “The transient nature of street art means it can be at risk of being scrubbed out and lost forever to its legions of fans. But long after the paint has faded from the walls, technology can help preserve street art, so people can discover it wherever and whenever they like,” Lucy Schwartz, Program Manager at Google Cultural Institute wrote for the Google Blog.
When the hydrophobic NeverWet® spray entered the market in 2013, Atlanta-based artist Nathan Sharatt saw an opportunity for innovation in the graffiti world. He created a rain drawings project with stencils. Then, he submitted the work as part of a Home Depot contest for creative uses of the waterproofing spray system, beautifying the city at the same time. Though the spray does wear off with soap and abrasion – you can think of the works as temporary tattoos for the inanimate – the technique puts a smile on pedestrians’ faces. When residents see unexpected messages like Sharatt’s “The sun’ll come out tomorrow” or “I’m only happy when it rains” pop up on wet sidewalks, they can’t help but feel that their day has just gotten a little brighter.
What’s next in store for the genre of street art? Quartz Media believes people will soon be doing graffiti in augmented reality (AR). AR technology means people can look at (and create) the world around them through the lens of an app on their smartphone, as we saw with the Pokémon GO craze a couple of years ago. As Quartz Media states, “AR turns physical sites into a blank canvas for the creation of new content.”
The use of robotics on modern construction sites
It isn’t just the way that concrete looks or is made – indeed, even the way it is applied is completely changing in the modern metropolis. Tech startups funded by venture capital firms are developing robots to make construction work both faster and safer.
For instance, Built Robotics is a new business on the block that is developing technology for unmanned construction vehicles, including self-driving bulldozers. Meanwhile, AutonomouStuff provides autonomy systems components to make mega-machines for miners that can control them from thousands of miles away. Construction Junkie notes that this equipment is a boon in an industry where workers have braved hostile, remote work environments. Of course, such conditions can also be dangerous to one’s long-term health, which is another reason we are seeing an automation push in the industry.
Other trades within the construction umbrella are also getting a makeover. A bricklaying robot was created by Construction Robotics in 2016, which received early stage R&D funding from the National Science Foundation. The SAM (Semi-Automated Mason) robot works alongside masons to ease the traditionally backbreaking labour that comes with the trade.
The changes are coming fast, and have made some people within the field feel a bit uneasy. However, such changes also bring about newer, safer jobs in a booming industry with an abundance of work to be done. “We need all of the robots we can get, plus all of the workers working, in order to have economic growth,” Michael Chui, a partner at McKinsey Global Institute in San Francisco, told The Associated Press. “As machines do some of the work that people used to do, the people have to migrate and transition to other forms of work, which means lots of retraining.”
Construction has come a long way since the famous, vertigo-inducing Lunch atop a Skyscraper photo was captured at New York’s Rockefeller Center circa 1932. Just a look at the sidewalks of Manhattan reveals the leaps in construction that were taken by the city that Jay-Z dubbed the “concrete jungle where dreams are made.” It’s interesting to witness cities around the world as they change their look, and what’s more, change the very way that they grow.