What is the difference between Roman concrete and modern concrete?

The article aims to answer the question “What is the difference between roman concrete and modern concrete?”. It will also discuss what roman concrete is, the composition of roman concrete and why we don’t use it anymore:

What is the difference between Roman concrete and modern concrete?

The article has mentioned all the differences between roman concrete and modern concrete below:

When exposed to salt water, today’s concrete quickly deteriorates due to its porous structure. The salts crystallize after the plant is dried out after being exposed to seawater. Stresses may form fractures and spalls due to the salts’ crystallization pressure. 

Modern concrete deteriorates due to a number of chemical processes, including sulfate assault, lime leaching, and alkali-aggregate expansion. Some concrete artifacts buried in water may only survive 10 years, yet Roman concrete is still holding firm after 2000 years. 

Researchers from all around the world, led by geologist Marie Jackson of Utah University, set out to determine the cause of this phenomenon. While it has long been known that Roman concrete is made from a combination of volcanic ash, quicklime (calcium oxide), and volcanic rock, the science underpinning its resistance to saltwater has only recently been uncovered. 

The Romans saw ash from volcanoes solidify into hard rock, so they reasoned that this must be the substance being utilized. While contemporary concrete is designed to be inert, the study team found that the Roman version reacts with its surroundings. 

Rare minerals aluminous tobermorite and phillipsite are formed when saltwater reacts with the combination, and they are thought to fortify the substance. This finding has promising implications for the creation of stronger concrete for usage in salty areas.

Limestone is the main component of most modern concrete, while additional materials including sandstone, ash, chalk, iron, and clay are also sometimes used. It is intended that the resulting combination will have no discernible effect on its surroundings. 

Even if the kind of concrete and water-cement ratio must adhere to strict guidelines in coastal areas, concrete is still permeable and may be damaged by saltwater corrosion and structural deterioration.

Why is Roman concrete better than modern concrete?

Continue reading the article to understand why roman concrete is better than modern concrete:

The remarkable endurance of some of Ancient Rome’s concrete harbor constructions is one of the city’s greatest mysteries. Even after being washed about by the ocean for two millennia, these objects are still standing, but our contemporary inventions only last a few decades before they crumble.

Scientists are now one step closer to discovering the long-lost formula for this phenomenon after discovering the remarkable chemistry at its heart. It turns out Roman concrete is not only stronger than modern concrete, but it also grows stronger as it ages.

After years of study, scientists have finally mapped the crystalline structure of Roman concrete, providing a detailed account of the material’s aging hardening process. Portland cement, a combination of silica sand, limestone, clay, chalk, and other elements melted together at high temperatures, is the main constituent in most modern concrete mixes. 

This paste is used in the production of concrete, where it is used to bind the “aggregate” – the various rock and sand particles that make up the material. Any chemical interaction with this aggregate might lead to fractures in the concrete, which in turn could lead to erosion and the collapse of the buildings. Because of this, natural rocks tend to outlast concrete.

However, it is not how Roman concrete operates. Theirs took use of a chemical reaction the Romans may have witnessed in naturally cemented layers of volcanic ash (known as tuff rocks) by combining volcanic ash with lime and salt water.

What is Roman concrete?

Opus caementicium, or Roman concrete, was a building material in Ancient Rome. The Romans used hydraulic-setting cement for their concrete. Durability is ensured by the use of pozzolanic ash, which stops fractures from propagating. 

By the 1st century B.C., the material was widely used, usually with a brick façade, but differences in aggregate allowed for a variety of design options. The Pantheon dome is the biggest and oldest unreinforced concrete dome in the world, and it was made possible by further innovations in the material during the period known as the concrete revolution.

Interiors of Roman concrete buildings were often embellished with stucco, fresco paintings, or thin slabs of fancy coloured marbles, while exteriors were often clad in stone or brick. It’s a lot different from today’s concrete since it’s made using aggregate and a two-part cementitious system. 

Since the particles were so much bigger than in contemporary concrete, the material was often put in place rather than poured. When building bridges and other structures near water, the Romans took use of concrete that could be laid underwater.

Although the precise date of Roman concrete’s invention is debated among historians, it was obviously in use as a standard building material from about 150 BC.

What was Roman concrete made up of?

Aggregate and hydraulic mortar, or a binder combined with water that hardens over time, are the two main components of Roman concrete. The aggregate was a heterogeneous mixture of materials such as rock fragments, broken ceramic tiles, and debris from destroyed brick houses.

A combination of gypsum and quicklime was utilized as a binding agent. When available, pozzolana, often known as “pit sand,” is a kind of volcanic dust that was chosen. Adding pozzolana to concrete makes it more resistant to salt water than regular concrete. 

The alumina and silica concentration of the pozzolanic mortar utilized was rather high. As an aggregate, tuff was widely used. Because of its rheological flexibility in the paste stage, concrete—and more specifically the hydraulic mortar responsible for its cohesion—was a useful kind of structural ceramic. 

The chemical and physical reactions that take place after materials hydrate. This results in the setting and hardening of hydraulic cement. Setting slaked lime mortars, the most prevalent cement of the pre-Roman era, was different. After setting, Roman concrete was not very flexible but still had a degree of tensile strength.

Pozzolanic cement, like Portland cement, has many similarities in its setting processes. Cement made today from blast furnace slag, fly ash, or silica fume has a similar high silica content to ancient Roman pozzolana cement.

It is believed that the combination of saltwater with volcanic ash and quicklime produces a rare crystal called tobermorite, which may resist breaking, contributing to the strength and durability of Roman “marine” concrete. 

Aluminous tobermorite crystals were formed when salt water seeped through microscopic fractures in the Roman concrete and interacted with phillipsite in the igneous rock. The product is perhaps “the most long-lasting construction material in human history.” However, contemporary concrete erodes in a matter of decades when submerged in seawater.

Conclusion

More than two thousand years of pounding seawater have not damaged the concrete sea barriers that the ancient Romans constructed. Now, an international group has found evidence that the chemical interactions between concrete and saltwater contribute to the material’s durability.

It’s possible that structural engineers may utilize this information to develop more durable and environmentally friendly forms of concrete. Contrarily, tiny pebbles are held together by a paste made of Portland cement and water in today’s concrete. 

In severe maritime settings, it breaks down in a matter of decades. Roman concrete was made by binding rock pieces together with a mixture of volcanic ash and lime, rather than Portland cement.

Frequently asked questions (FAQS): What is the difference between roman concrete and modern concrete?

What is the difference between Roman concrete and modern concrete?

When exposed to salt water, today’s concrete quickly deteriorates due to its porous structure. The salts crystallize after the plant is dried out after being exposed to seawater. Stresses may form fractures and spalls due to the salts’ crystallization pressure. 

Modern concrete deteriorates due to a number of chemical processes, including sulfate assault, lime leaching, and alkali-aggregate expansion. Some concrete artifacts buried in water may only survive 10 years, yet Roman concrete is still holding firm after 2000 years. 

Why is Roman concrete better than modern concrete?

The remarkable endurance of some of Ancient Rome’s concrete harbor constructions is one of the city’s greatest mysteries. Even after being washed about by the ocean for two millennia, these objects are still standing, but our contemporary inventions only last a few decades before they crumble.

Scientists are now one step closer to discovering the long-lost formula for this phenomenon after discovering the remarkable chemistry at its heart. It turns out Roman concrete is not only stronger than modern concrete, but it also grows stronger as it ages.

What is Roman concrete?

Opus caementicium, or Roman concrete, was a building material in Ancient Rome. The Romans used hydraulic-setting cement for their concrete. Durability is ensured by the use of pozzolanic ash, which stops fractures from propagating. 

By the 1st century B.C., the material was widely used, usually with a brick façade, but differences in aggregate allowed for a variety of design options. The Pantheon dome is the biggest and oldest unreinforced concrete dome in the world, and it was made possible by further innovations in the material during the period known as the concrete revolution.

Bibliography

Why is Roman concrete more durable than modern concrete?. Risk frontiers. Retrieved from: https://riskfrontiers.com/insights/why-is-roman-concrete-more-durable-than-modern-concrete/