Why Green Materials and Methods are Gaining Ground
It’s sobering to realize that cement is responsible for almost a tenth of global carbon emissions. If the cement industry were a country, it would be the third-largest carbon dioxide (CO2) emitter in the world, behind China and the United States. According to Chatham House, cement contributes more CO2 to global warming than aviation fuel, and is not far behind the global agriculture business.
Also, construction and demolition projects generate tons of bulky, heavy debris and waste — like concrete, wood, asphalt, gypsum, metal, brick, trees, and stumps. In one year, 2015, the EPA estimated there were nearly 550 million tons of debris generated in the U.S. alone — more than twice the amount generated by municipal solid waste.
As a result, green and sustainable construction methods and materials are gaining a lot of buzz. Not only can choosing the right raw materials reduce construction waste and lower greenhouse gas emissions, but they could end up saving contractors money — especially if they qualify for tax breaks.
Think Outside the (Concrete) Box
More and more general contractors (GCs) are starting to think outside the concrete box to reimagine how projects are conceptualized, designed, and executed. You only need to skim the headlines to discover scientists researching how cigarette butts can conduct energy in bricks and pavement, and paint developers rethinking chemicals and colors for more energy-efficient homes.
There is also a growing interest in using recycled glass, drywall, and steel, and renewable resources like bamboo. According to the World Business Council for Sustainable Development, businesses pay less than 2% extra, on average, for green building features. And they’re estimated to recoup as much as seven times that initial expense over the life of the building.
More than ever, the concrete trade is front and center as builders and contractors look for potential solutions that could lower costs, speed up construction, and improve quality and safety. As such, everything from 3D printing to self-healing concrete is gaining momentum as new materials are needed to lower carbon footprints and improve cost efficiency.
Transparent Wood for Mass Production
Many of these new materials get their start as scientists reexamine how to repurpose materials. For instance, researchers at Stockholm’s KTH Royal Institute of Technology developed a new transparent wood material that is suitable for mass production.
Experts say transparent wood is made through a process that chemically removes lignin from wood, causing it to become very white. Then, a transparent polymer is added, evening out both of their optical properties. Ultimately, it can be used to create windows and solar panels.
At the University of Maryland, researchers are creating transparent wood that they believe has better insulating properties, and is stronger than glass and more biodegradable than plastic. In China, researchers have brought see-through wood one step closer to a commercial application by creating panels of transparent wood that are bigger, thicker, and more transparent than their predecessors; while at the same time using a manufacturing process that is more environmentally friendly, according to the Journal of Materials Research. While experts say it may be a while before transparent wood becomes a mainstream construction material, they believe it could be used for solar panel cells, to bring more light into buildings, and even for load-bearing windows.
Graphene Could Play a Major Role
Researchers are also excited about the possibility of using graphene to create a new type of concrete that is much stronger, water-resistant, and greener. It is viewed as an excellent material for construction, as it is lightweight, but stronger than steel or carbon fiber.
The biggest hurdle has been how to scale the production of graphene concrete. However, researchers at the University of Exeter have discovered a way to suspend flakes of graphene in water before mixing them with water and traditional concrete.
This Process May Allow it to be Produced More Easily
What’s exciting about graphene-enhanced concrete is its potential strength — a 146% increase in compressive strength as compared to regular concrete, and a 79.5% increase in flexural strength. The real “wow” factor is found in that it has an almost 400% decrease in water permeability, according to xeter researchers.
What does it mean? Not only would structures last longer, but they wouldn’t need to be replaced as often. Carbon dioxide emissions would also be reduced as a result of having used less concrete.
Cigarette Butts and Breathable Bricks
Scientists and researchers are also finding new alternatives for using bricks in construction. Students at the Institute of Advanced Agriculture of Catalonia are studying how adding a new material to bricks can deliver a cooling effect on indoor buildings. Called “hydroceramics,” the cooling effect comes from hydrogel inside the clay bricks which absorbs rainwater up to 500 times its weight. During hot days, the water is then released to reduce the indoor temperature. Incorporating an innovative system in a building structure has made hydroceramics into one of the “coolest” materials to revolutionize construction.
Another type of brick being developed is called “Breathe Bricks.” These bricks borrow their cyclone filtration from vacuum cleaners, which separates heavy pollutant particles from the surrounding air and drops them into a removable hopper at the base of a wall.
One of the most interesting developments involves using cigarette butts in the making of bricks. There are 1.2 million tons of cigarette butts thrown away each year, making up approximately 5% of our overall global waste. Not only do they make a lot of waste, but they also release harmful chemicals into the air and soil, such as arsenic, chromium, nickel, and cadmium.
Researchers at RMIT University in Australia discovered that by infusing 1% of cigarette waste in fired-clay bricks, the resulting bricks are lighter and require less energy to produce. The researchers found that if just 2.5% of the world’s annual brick production incorporated 1% cigarette butts, they would completely offset annual worldwide cigarette production.
Turning Science Fiction into Reality
Driving much of this demand for new materials are zero net energy (ZNE) buildings, which generate as much renewable energy as a building consumes in a year. Whether they feature solar panels, wind turbines, or some other material, these buildings are designed to minimize the amount of required energy. Some states, like California, are pushing both residential and commercial builders to embrace ZNE.
As traditional materials and methods give way to cuttingedge materials, it will be interesting to see how owners and general contractors adapt how projects are designed and built.
Will new projects feature a mix of old and new? Will everything old be recycled into new, greener building materials? With so much technological disruption occurring in the construction industry, contractors can expect to see these futuristic green and renewable building materials play a bigger and bigger role in the coming years.
Want to learn more about how technology is helping contractors realize major gains in speed, accuracy, and efficiency? Don’t miss On Center’s free white paper, “Step Outside Your Tech Comfort Zone.”
About the Author: Conley Smith is a senior business writer with On Center Software by ConstructConnect. She has been writing about technology and its impact on business for more than 15 years.