Myth 1: Concrete is bad for the environment.
Truth: Concrete can be sustainable.
While it is true that the production of cement, a key component in concrete, contributes to carbon dioxide emissions, these emissions correspond to 6-8 percent of global emissions. This is similar to the steel industry but less than the transport or textile industries. The cement and concrete industry has made significant strides in recent years to reduce its carbon footprint. Today, alternative binders such as fly ash and slag are used to replace a portion of the cement, significantly reducing emissions. This is referred to as low-carbon concrete. Additionally, concrete can be both recycled and reused, making it a sustainable choice. Another important aspect is concrete’s ability to carbonate, meaning it absorbs carbon dioxide from the air throughout its lifetime.
Marmier, A., Decarbonisation options for the cement industry, Publications Office of the European Union, Luxembourg, 2023, doi:10.2760/174037, JRC131246.
Myth 2: Low-carbon concrete compromises performance.
Truth: Low-carbon concrete can achieve the same or even better performance.
Through careful design and understanding of material properties, low-carbon concrete can achieve the same, or even better, performance compared to traditional concrete.
Myth 3: Concrete is brittle and breaks easily.
Truth: Concrete is a very strong material that can withstand enormous forces in compression.
Concrete, however, has low tensile strength but can become very ductile and flexible with the help of reinforcement.
Its durability, strength, and cost-efficiency are reasons why it is used in so many different types of buildings and infrastructures, from homes to bridges and roads. With proper maintenance, concrete structures can last for several decades, even centuries. Historical buildings like the Pantheon and the Colosseum, made of unreinforced concrete, are evidence of concrete’s long-lasting durability.
Myth 4: Concrete is just a gray and boring material.
Truth: Concrete is versatile and offers great design freedom.
Concrete can be shaped, colored, and textured in many different ways, making it a very flexible material for architects and designers. From polished concrete floors to decorative facades and sculptures, concrete can be both functional and aesthetically pleasing. Additionally, concrete can have many adaptable properties; for example, the density can vary from 400 to 4000 kg/m³, which the Romans utilized when building the Pantheon.
Manuela Roth, Concrete: Architecture & Design, Braun 2012, ISBN 3037681071, 978303768107.
Philip Jodidio, 100 Contemporary Concrete Buildings, Taschen GmbH 2015, ISBN: 9783836547673.
Myth 5: Concrete is expensive.
Truth: Concrete is actually very cheap and cost-effective in the long run
Initially, concrete projects may seem expensive, but concrete is actually cheap and its durability and low maintenance costs often make it an economically advantageous solution. Concrete structures can withstand weather and wear better than many other materials, making them a more long-term investment.
Myth 6: Concrete is an energy guzzler.
Truth: Concrete can save energy.
Producing concrete does require energy, but the energy required is quite low compared to most other building materials. A concrete building can also contribute to energy savings. Concrete has a high thermal mass, meaning it can absorb and store heat. This helps to keep buildings warm in winter and cool in summer, reducing the need for heating and cooling due to daily temperature variations.
Myth 7: Biochar from coffee grounds can make concrete stronger and more durable.
Truth: Biochar from coffee grounds, or any biochar, is an unsuitable additive in concrete.
There are claims that biochar from coffee grounds can improve concrete’s properties, but this is a misconception. Biochar has no binding effect and can weaken the strength and durability of the concrete. Biochar’s porous structure reduces strength and may lead to a shortened lifespan. The beneficial effect on compressive strength reported in various publications is due to biochar’s high water absorption (100 to 150 percent of its weight). This effect has not been properly accounted for, making the reported “improvement” invalid.
Additional Benefits of Concrete
- High strength: Concrete has enormous compressive strength and can be used to build everything from roads and bridges to skyscrapers.
- Resistance to natural disasters: Concrete structures are resistant to extreme weather such as hurricanes, making it a safe and reliable material choice.
- Fire resistance: Concrete is non-combustible, does not emit smoke or toxic gases, and prevents the spread of fires, enhancing building safety. It retains its properties even at high temperatures, meaning a concrete frame maintains its load-bearing capacity during and after a fire.
- Mold resistance: Concrete is an inorganic material that can withstand moisture and become completely waterproof. It cannot rot or mold, making it suitable for houses and environments exposed to high levels of moisture.
- Sound insulation: Concrete has excellent sound-insulating properties, making it ideal for use in noisy environments such as cities and industrial areas.
Conclusion
Concrete is a versatile, durable, and economically advantageous building material that plays an important role in modern construction. By understanding and spreading well-substantiated facts about concrete, we can continue to use this fantastic material in an even more efficient and sustainable way.
