The headline spelled it out best, loud and clear, bolded and all: “Concrete: The most destructive material on Earth.”
Traditional concrete, that is—not its more
sustainable alternative, green concrete.
The
article of discussion appeared in
The Guardian, a daily British newspaper, in 2019. The exposé underscored many environmental statistics that made the construction sector and concrete manufacturing industry cringe.
First among the alarming data points was how traditional concrete is the second-most widely used substance on the planet, second only to water. About
10 billion tons of it is poured annually.
Second, enough concrete to fill 19,000 bathtubs will have been poured by the global industry by the time you finish reading a single sentence, probably this one.
Third, if it were a single nation, the concrete industry would be the world’s third-largest carbon dioxide emitter, the International Energy Agency (IEA)
reports, behind only China and the U.S.
The sector already ranks rank third globally in another daunted category, the
IEA adds: anthropogenic emissions of carbon dioxide, right after fossil fuels and land-use change.
Other glaring statistics include:
Do the math. Constructing just one mile of a single interstate lane emits about 8.1 million pounds of carbon dioxide, the
National Ready Mixed Concrete Association reports.
Concrete is the foundation of our modern world. The number of architectural wonders it has created is infinite.
Look at the Pantheon and Colosseum in Rome, two ancient, still-standing examples that serve as testaments to concrete’s enduring strength.
See New York City’s Empire State Building, which utilized modern binder Portland cement with steel rods and mesh.
Witness the tunnels you drive through, the bridges and elevated expressways you go over, the runways your planes land on, the floor slabs your walk across, the groundwork your homes are built on—all concrete.
More than 70% of the world’s population
lives in a concrete structure, the Pennsylvania Aggregates and Concrete Association (PACA) says.
But one undeniable truth lingers: While concrete built the world we live in, it’s also turned our blue-and-green world much grayer.
The concrete and construction industries have taken note, and together, they have created a helpful solution: green concrete. Invented in
Denmark in 1998, it has nothing to do with its color.
Instead, it’s what it can do to help the world keep its color.
We’ll explain how below, plus detail what eco-friendly green concrete is and how it can give your infrastructure project a green thumbs-up—environmentally and economically.
Get Durable Concrete That Can Take The Heat for You
Green concrete— also called eco-friendly cement or geopolymer concrete—offers two advantages that old-fashioned concrete using only Portland cement cannot match.
One is that it gains strength faster. The other is how it offers a lower rate of shrinkage.
It can also take the heat, almost any heat—literally—upping its chances of surviving a fire. Green concrete using industrial byproducts is more tolerant of fire, enduring temperatures up to 2,400 degrees. Green concrete’s industry-best resistance to soaring temperatures makes it a must-have for the construction of infrastructure projects such as tunnels.
Green concrete is also resistant to something equally important: corrosion. Elements such as salt and pollution, which wane on traditional building materials' longevity, have less impact on projects that use eco-friendly concrete.
Add those advantages together, and you have yourself a more robust, longer-lasting structure that, unlike ordinary concrete, can withstand the test of time.
One Easy Way to Reduce and Reuse Industrial Waste
Traditional concrete uses 100% Portland cement made by pounding limestone and clay, then adding iron ore or ash.
Eco-friendly concrete flips this by substituting a portion of that cement sand with waste or residual materials from different industries that would normally end up in the landfill. Examples include:
- Fly ash
- Silica fume
- Waste glass
- Sawdust
- Rice husk ash
Waste from quarries, power plants, foundries, and even food mills produce by-products that can replace cement sand during green concrete production.
Per the PACA, green concrete also reuses wash water to reduce consumption, systemically checking off two boxes: Using fewer natural resources and expanding the use of recyclable materials.
One Concrete Method to Cut Your Energy Use
The next step to the previously mentioned process—crushing the limestone and clay, then adding iron ore or ash—includes heating the mixture to more than 2,600 degrees in a kiln, a process that uses massive quantities of fossil fuels. So, too, does mining and transporting these minerals.
However, green concrete knocks down the energy use required with industrial waste products already on hand, like fly ash.
Furthermore, green concrete can act as the thermal insulation of a structure. Infrastructure built with eco-friendly concrete allows architects to design concrete structures that better utilize heating and cooling systems more efficiently.
Make The Environment Say "Thank You"
Let's go back to traditional concrete’s heating process and the vast amounts of natural gas or coal it often utilizes.
Using that much energy is the primary reason why traditional concrete is an environmental no-no.
Burning pulverized limestone, clay, and sand releases 5% to 8% of the world’s carbon dioxide emissions. Per some accounts, the tally can creep up to 10%.
Alternatively, the manufacturing of green concrete
releases up to 80% fewer carbon dioxide emissions.
How Green Concrete Leads to Green Bottom Lines
Add up the above four benefits, and what do you get? Fewer expenses.
Think about it: When buildings don’t need to be fixed or rebuilt because they’re made with more durable concrete, leading to fewer materials and resources being required, not only is it less of an impact on the environment, it’s also less of a hit to your bottom line.
“Over and above all, green concrete has greater strength and durability than the normal concrete,” researchers from the International Journal of Advance Reacher and Development (IJARnD)
said in a multipage analysis in 2017.
Also, when that concrete uses less energy because it utilizes waste products as a partial substitute, pollution isn’t the only thing that plummets. So, too, do your costs.
In other words, using green concrete does not increase your costs.
Researchers
say green concrete is economical compared to conventional concrete and serves as an “excellent substituent” for traditional cement “as it is cheaper,” utilizing waste products and saving energy consumption.
Why Your Sustainable Future Starts with Green Concrete
Global efforts are underway to rethink how concrete is manufactured and transported and how end-users use it to increase safety, lower costs, ensure more extended durability, and reduce infrastructure projects' environmental footprint.
But finding the right alternative to traditional concrete is a process, one that requires the right insight into sustainable construction. The
options are limitless. So are the factors.
Experienced
concrete commercial contractors will steer you in the right direction and ensure your project creates the kind of feel-good headlines that the industry is in dire need of seeing more.