Modern Concrete: A Double-Edged Sword

Concrete has become a cornerstone of modern construction. In 2021, it ranked as the second most used material globally, following water. Its widespread use in roads, buildings, and bridges is due to its durability and affordability.

However, there’s a downside. Concrete is composed of various materials, including water, sand, gravel, chemicals, and cement. Many people conflate cement with concrete, but they are distinct—cement serves as a binder in concrete. The demand for cement has surged, with production increasing by 20% between 2011 and 2020, solidifying cities' reputation as "concrete jungles." Unfortunately, concrete contributes significantly to greenhouse gas emissions, ranking as the third largest emitter globally. Additionally, climate change threatens the material's effectiveness.

Fortunately, the exploration of alternative techniques offers a promising path. For example, researchers at MIT developed emissions-free concrete in 2019, but the Romans had their own effective method.

The first video, Ancient Solutions for Modern Problems [VIDEO PODCAST], delves into how ancient practices can provide insights into solving today's issues.

Roman Concrete: A Timeless Marvel

Having traveled to the Pantheon in Rome, I was struck by its grandeur. Over 2,000 years old, it features the largest unreinforced concrete dome globally, standing resilient against time. The durability of the Pantheon has puzzled experts until recently.

Research from MIT suggests that the Roman concrete's longevity is due to "lime clasts," small white fragments within the mixture that enable "self-healing" properties. This discovery was published in Science Advances in January 2023. These lime clasts, once dismissed as signs of poor quality, actually contribute to the material's strength over time.

The process used by the Romans involved mixing water with quicklime and volcanic ash at high temperatures, resulting in unique compounds that enhance durability. When cracks appear in the concrete, exposure to water allows lime clasts to recrystallize, effectively "gluing" the cracks shut.

Geologist Marie Jackson noted the Romans created a durable concrete capable of thriving in seawater, showcasing a potential for resilient coastal structures.

The second video, Solving Modern Problems with Ancient Greek Philosophy - YouTube, examines how ancient wisdom can influence modern solutions.

Air Conditioning: A Temporary Fix

As global temperatures rise, air conditioning has become a common household necessity. However, it consumes vast amounts of energy and contributes to carbon emissions. In fact, air conditioners account for about 6% of the total electricity consumption in the U.S., leading to the release of approximately 117 million metric tons of CO2 each year.

While air conditioning cools our spaces, it also exacerbates the climate issue, creating a cycle of dependency. Rather than relying solely on air conditioning, we should consider adapting architectural designs to naturally cool our environments.

Innovative Cooling Solutions: Wind Catchers

One ancient technique is the use of wind catchers. These chimney-like structures capture and direct wind into buildings, providing effective cooling without energy consumption. This method has been successfully employed in modern constructions, such as the Kensington Oval stadium in Barbados and various projects in Dubai.

Building with Cob: A Sustainable Alternative

Cob, a traditional building material, offers a low-cost solution for sustainable construction. This mixture of soil, water, and straw can create durable structures that withstand extreme conditions. Cob houses have proven resilient, even surviving hurricanes.

Although cob is not an ideal insulator, its benefits in warm climates are noteworthy. Its biodegradability, breathability, and compatibility with other materials make it an attractive option for sustainable architecture.

Shifting Perspectives on Longevity

Today's manufacturing often prioritizes short-term profits over longevity, leading to a decline in product quality. However, innovative thinkers are revisiting ancient solutions to create more sustainable practices.

For example, ancient Indian techniques involved growing tree roots into bridges that improve over time, and recent developments in floating cities showcase self-repairing materials that gain strength as they age.

In conclusion, we have the potential to reshape our future by embracing ancient wisdom and integrating it with modern creativity. By stepping away from traditional constraints, we can forge new paths toward sustainability and resilience.

This article was originally published in the author's newsletter, Curious Life, and has been edited and republished on Medium with permission.