A Story of Concrete

From standing the test of time in the Roman Pantheon to being used as a quick-fix material in modern construction, here is the story of how concrete has become the most ubiquitous building material in our urban fabric today.

Meher V
Min Read

The Secret Birthplaces of Concrete

Concrete, or “artificial stone” is typically a mix of cement, sand, water and aggregate (crushed stone) and is the most prevalent building material in the world today, second only to water in its use. [1] The origins of the word “concrete” are derived from the action of the material itself. Concrete has its roots in the Latin concretus meaning compact or condensed and is rooted in the meaning together and to grow. But where did this material come from and how did it become what it is today?

Well, here’s a hot news flash!

The first concrete experiments were undertaken as early as the 4th century BC by the mystic Mayans and roaming Bedouin tribes of Syria. The Bedouins used self-hardening hydraulic lime to build and hide water containers under the deserts’ surface (think underground oases). Later, the Romans formed the first concrete as we know it today by mixing volcanic ash (excavated from the Italian city of Pozzuoli) with quicklime and pumice. Ancient Rome reveled in the material’s strength and created domes, arches, and vaults with construction details that leave us awestruck to this day. Even more astonishingly, Roman concrete was not poured but layered and was not reinforced by metal bars as done today. Pozzolana ash is still preferred to make Portland cement—a core ingredient in concrete and cause for its large environmental footprint. Researchers today, to replace cement, are looking for waste materials with similar pozzolanic properties to keep the wonders of concrete going.

Cementing a Colony: A Tale of Hand-Me-Down Architecture

In the second half of the 19th century, experiments in strengthening concrete led to the invention of reinforced cement concrete (RCC) by William Wilkinson in 1854 [2]. Reinforcement means steel bars (that have high tensile strength) and, hence reinforced concrete becomes concrete (great compressive strength) combined with steel (great tensile strength) which makes it great for both columns and beams! You’d think this winning combination would mean superior buildings than historically found, but our experience tells us otherwise.

Reinforced concrete soon caught on and was brought to India enmeshed within formulaic designs that contractors merely had to follow to produce building foundations made of the same material. Before 1915 though, sandstone (a material more suited to the Indian climate) and unreinforced concrete buildings were being built in India and are still standing.

After the 2nd World War, the West needed a cheap building material to enervate its demolished landscapes. Concrete was a simple, inexpensive answer.

Figure 2: Gorton Castle, Shimla is built of un-reinforced concrete. Source: Thrillophilia

After the Indian Independence in 1947, it was time to rebuild the nation. While the modernist movement organically took the West by storm, India largely remained an inheritor of the movement’s leftovers. Contractors used reinforced concrete to build  dams, bridges, water tanks & towers, roads, houses & public buildings. Concrete was used for repair and, in some cases, even decoration, with vast gaps in quality of construction, a mismatch between material and Indian climate, and a lack of forethought about structural integrity over time. These oversights of the past impede building functionality to this day.

Concrete Isn’t the Bad Guy

In the heat of the climate crisis (quite literally) - it has become easy to make materials the scapegoat rather than question the system at large. For example, plastic seems to have become the common enemy of the planet. But plastic is not an evil material, with its non-biodegradability being an asset for applications where you want the object to last for centuries. Only single-use plastics disregard this material's best quality.

Similarly, concrete is not a villain either. Its ability to flow makes it a versatile material that can be cast-molded. The Bedouins had the right idea while using concrete cisterns to store water underground. Concrete is more water-resistant than steel or wood and can withstand higher temperatures than both. It affords architects the creative freedom to design structures that otherwise would have been very hard to create. It even absorbs carbon dioxide from the air through the entirety of its life through a process called Carbonation! At the end of its life, concrete is recyclable and can be processed back to make more concrete. However, its short-term large-scale application as RCC shortens its life by compromising its ability to deal with moisture. [4]

Le Corbusier and the Birth of City Beautiful

We mentioned that India seemed to be picking on the remnants of the major art movements that were constantly reshaping the West, which was the case until Le Corbusier designed Chandigarh in the 1950s. Unlike Lutyens' New Delhi, its style more inclusive of Indian architecture, Corbu the Crow (as his friends called him) wove modernist architecture into India for the first time through Chandigarh. Using concrete as a chief building material, Corbusier and his cousin, Pierre Jeanneret, together brought to life their vision of a city of trees, flowers, and water, of houses as simple as those at the time of Homer. [5]

Figure 3: The High Court of Justice, Chandigarh, features concrete grill sunshades (Source: ArchDaily); Figure 4: The Palace of Assembly under construction (Source: CCA); Figure 5: The Palace of Assembly, Interior. (Source: Chandigarh Tourism)

Using light, shadow, and a unique Vitruvian man of his own—Modulor to use as a scale for his buildings, Corbu locked the poetry of his architectural vision in concrete. He incorporated promenades into official government buildings like the High Court of Justice, which still stand resplendent today. He described his functional sculptures as cold, grand and, magnificent. Complemented by trees or pops of color like in the image above, concrete seemed like the best medium to model the vision of modern India.

When Corbusier finished his work, he had succeeded in turning a grey strip of land between two streams into a small gem that would in 2016 become a UNESCO world heritage site. The grey landscape of concrete also worked as a dynamic canvas that could incorporate a series of experimental aesthetics as trends came and went, something that residents of Chandigarh can relish to this day.

But while it is easy to romanticize the cold, grey aesthetic of exposed concrete and celebrate the renunciation of ornamentation by modernism,  it seems near impossible to talk about malba—a form of broken concrete.

Are we too afraid to address this brokenness? To address what happens next? The death of concrete was left unconsidered during its conception. After all, we had the Pantheon as proof that our buildings would stand the test of time.

Concrete and the Disrepair of City Beautiful

In the 1930s, the builders of the Hoover Dam claimed that it would outlast human civilization. However, over time, thermal expansion, corrosion, water entrapment, bacterial and fungal infestation, leaching, erosion, and rainwater damage can scar concrete beyond its functional lifespan. The story of concrete in Chandigarh is similar.

As the concrete ages and begins to show its years, Corbusier’s edicts for Chandigarh's architecture remain intact even today, and Grade-1 heritage buildings like the Sector 17 shopping plaza remain untampered with as per strict by-laws.

As a result of time and lack of maintenance, molding concrete is now an eyesore, and dubious cracks in the concrete raise questions about the structural integrity of the buildings. Hence, these irreplaceable but equally inflexible buildings are proving to become a sustainability issue for the City that, in other respects, remains Beautiful.

Figure 6: The Sector-17 market in Chandigarh falls into disrepair (Source: Hindustan Times)
More Details