The concrete that was used by the Romans is revered today for its long-term durability, with many even claiming it’s better than modern concrete. Why is Roman concrete not used today?
Roman concrete is not used today because it was often made by materials that aren’t abundant around the world, such as volcanic ash. It’s also not used today because of the tremendous success of Portland cement, which has been the prominent ingredient in concrete-making since the early 20th century.
Portland cement is durable, can be used in nearly every situation it is needed, and it easy and cheap to mass-produce.
The widespread success of Portland cement has made other forms of concrete obsolete.
Read on to learn about Roman concrete and why it no longer used in modern society.
Impressive works of Roman concrete architecture, such as the Pantheon, are a testament to the long-term durability of Roman concrete. While the concrete structures that were made by the Romans are awe-inspiring and represent a monumental phase of civilization and progress, there are several reasons why it was left in the past.
One major problem in using Roman concrete today is that the majority of the recipes for the concrete were lost to history. During the past few decades, scientists have been conducting in-depth research on the Roman structures, finding that most Roman concrete was made predominantly of a mixture of volcanic ash and lime.
Roman concrete is especially strong in marine environments, as the saltwater reacts with the volcanic ash, creating tobermorite crystals. Not only do these crystals keep the structure intact over time, but they actively harden over time, continually make the structure stronger.
While the higher durability of Roman marine structures over our modern marine structures may suggest that Roman concrete is inherently stronger, the disintegration of modern marine structures has more to do with the steel rebars that are used in their construction than the concrete itself.
Experts point out that for modern marine structures the corrosion of steel caused by constant chloride exposure is the most damaging, not the deterioration of the modern concrete itself. The rusting of the steel inside destroys the concrete within, and as Roman concrete had no steel in it, it is naturally going to last much longer.
While some have pointed to the survival of Roman concrete over thousands of years as a sign of its superiority, others have pointed that there was much more Roman concrete that didn’t survive that we may never know about. Due to the fact that we only have a few examples today of Roman concrete-made architecture, we don’t know its success rate in terms of durability.
This is especially true considering the scarcity of some of the ingredients used, namely volcanic ash. Roman concrete’s recipes were likely less uniform than our modern Portland cement, and a bad “batch” of Roman concrete could have spelled disaster for any major construction project.
It should also be emphasized that Roman concrete was only used in the subtropical Mediterranean climate and not exposed to colder elements that contribute to concrete disintegration. The Romans were in the perfect climatic conditions to test out the durability of their concrete, but it is doubtful that the durability of their concrete would be matched in parts of the world with less favorable conditions.
The Portland cement-made concrete of the 20th century and today is so widely used because it is durable, cheap, and easy to produce en masse. Portland cement can be used in a diverse number of ways, making it useful in nearly every situation that concrete is needed.
The use of volcanic ash and other specialized ingredients that were used to create Roman concrete would not be possible to produce on a large scale profitably, while the abundant ingredients of Portland cement can be found nearly anywhere.
Portland cement-made concrete has yet to be replaced because it is durable, easy to make, and can be used in nearly every situation that requires concrete. While the use of Roman concrete could be advantageous in certain situations, it simply could not beat out the practicality and efficiency of our modern concrete.
While Roman concrete has miraculously kept the Ancient Roman past alive for centuries, the urbanization and industrialization of the 20th and 21st centuries have made society seek efficiency rather than centuries-long durability. Despite the incredible resilience of Roman architecture, the modern world has certainly made the correct choice of concrete.