Scientist Search for Clues to the Formula for Roman Concrete

One of the mysteries that continue to baffle scientists and engineers is how the ancient Romans produced the strongest concrete in the world.  Typically modern concrete buildings last about 50 to 60 years while ancient Roman concrete structures have survived through 2,000 years of environmental damage.   

Historical Timeline of Concrete

The history of concrete is actually quite interesting. For example, did you know that the art and science of concrete was almost entirely lost after the fall of the Roman Empire? Concrete is, in fact, an ancient material dating back thousands of years. From the earliest use of cement some twelve million years ago to the rediscovery of cement in the early 1700s, let’s review the little-known history of cement. 

12 Million Years ago: Earliest known occurrence of cement. Deposits of cement were formed due to oil shale burning next to a bed of limestone. Although these deposits dated back millions of years, they were not discovered and researched until the 1970s. 

6500 BC: The earliest concrete structures were built by the Nabataea or Bedouins traders who, literally, built an empire in Syria and northern Jordan. 

5600 BC: Homes were being built along the Danube River (in what was formerly Yugoslavia) which used concrete floors. 

700 BC:  Kilns were being used to create mortar for the construction of homes, concrete floors, and water cisterns.  

200 BC: The Romans built an empire out of concrete. Although their concrete was very rudimentary (almost plastic-like), they were also creative and created cement from volcanic sand.  

125 AD: The Pantheon is erected. The structure has one the largest un-reinforced concrete domes ever created in history.

After the fall of the Roman Empire, the art of Concrete was lost to mankind.

1756: The building blocks of concrete begin to re-emerge and John Smeaton rediscovers hydraulic cement. 

1824: Joseph Aspdin invents Portland cement! The material was aptly named “Portland” cement because it resembled the building materials found in Portland, England. 

1825: The commercial demand for concrete begins to soar. In the United States, the Erie Canal was commissioned to be built out of cement. 

The Conco Companies one of the foremost suppliers of concrete services for the Western U.S. We got our start in 1959 in the Bay Area by offering clients the best value on a broad range of concrete services and products.  Since that time, we have taken a leading role as top concrete contractors in the region. We have four regional offices serving California, Oregon, Nevada, Colorado and Washington.

Classical Greek Architecture

As leading commercial concrete contractors, The Conco Companies have been honored to be involved in many distinguished construction projects over the last several decades.  As many of these projects represent exciting accomplishments in our today’s world, it got us thinking about architectural wonders from ancient times.  Our post is an acknowledgement of the enduring influence of Greek architecture. 

The terms we use to describe the five orders of classical architecture, Doric, Ionic, Corinthian, Tuscan, and Composite, were given to us by the Romans.  The Ancient History Encyclopedia defines an order as, “a combination of a certain style of column with or without a base and an entablature (what the column supports: the architrave, frieze, and cornice).”   

The Greek’s architectural style embraced “simplicity, proportion, perspective and harmony” and inspired the building style of the Roman Empire.  Together this laid the foundation for the classical architectural orders that dominated the Renaissance period right up to today.   

Along with the Parthenon, which we wrote about in an earlier post, other significant ancient Greek temples that exemplified Doric and Ionic order include the Temple of Zeus at Olympia, completed c. 460 BC; and the Temple of Artemis at Ephesus, which was one of the wonders of the ancient world completed c. 430 BC.  The Temple of Poseidon at Sounion, built between 444-440 BC, is an example of the Greeks’ desire to not only build structures that were beautiful on the inside as well as close-up but also to construct temples that would be admired from a distance. 

On the Architecture of the Capitol website, they list a few examples of modern day buildings in Washington, DC that reflect the classic Greek orders.  These include the U.S. Capitol, the Supreme Court Building and the exterior of the Longworth House Office Building.  The old Senate Chamber located in the U.S. Capitol “is a two-story room modeled after the amphitheaters of antiquity.”  The eight Ionic columns that support the Chamber’s gallery on the east wall are inspired by the columns of the Erechtheion in Athens.

The Conco Companies are a leading supplier of concrete services for the Western U.S. and got our start in the Bay Area in 1959 by offering clients the best value on a wide range of concrete services and products.  Since that time, we have taken a leading role as one of the top concrete contractors in the region. Our offices serve California, Colorado, Oregon, Washington and Nevada.

Sources: ancient.eu/Greek_Architecture/, aoc.gov/capitol-hill/architecture-columns/ionic-columns

The Parthenon Restoration Project

At The Conco Companies, we have extensive experience as commercial concrete contractors and have been fortunate to be involved in many noteworthy structures built over the last several decades.  As some of our projects have been pretty amazing achievements even for modern times, we got thinking about some of the world’s remarkable projects built many centuries in the past.  One such project is the Parthenon, which is a part of the Acropolis in Athens, Greece. 

Built between 447 - 438 BC, although some of the decorative features were not completed until 432 BC, the Parthenon has been under renovations for more than 30 years.  In fact summer 2016 will be the first time since 1983 that tourists will be able to see the temple without scaffolding. 

The decades-long $90 million repair and restoration project is expected to be fully completed in 2020.  So why is it taking so long to complete the project when the original structure was built over a period of only nine years?  Led by the Greek architect, Manolis Korres, he states that the project is like “trying to assemble a 100,000-ton, three-dimensional jigsaw puzzle with 70,000 individual pieces.”   Also the team has struggled to find the proper balance between reassembling the temple and leaving it as a majestic ruin.

One of the difficulties of the project has been to undo mistakes made in the past such as during an earlier restoration in the late 1800’s to the mid-1900’s that incorrectly rebuilt parts of the structure.  Korres’ project has included taking apart and repairing almost every piece of the Parthenon.  Another challenge has been to locate original pieces, some of which were spread around the Acropolis site while others had been removed and were in other parts of the world.  For pieces the team could not locate, they had to be recreated.   

Other problems in the large undertaking include determining where each piece goes, finding a source of marble to match the blocks and then shaping new pieces, and employing age-old techniques to finish the marble surface.  Furthermore, since the column drums had been incorrectly replaced during the earlier restoration process, today’s team had to work out a system for realigning and correctly placing the drums.  The end product will be a testament to the survival of the two and a half thousand year-old ruin.     

The Conco Companies have built a reputation on superior concrete formwork, reinforcing, place and finish, shotcrete and other ancillary services that benefit from our vast experience.  Conco’s concrete services include commercial, educational, parking and other construction development along with public works projects and highways.  Our four regional offices serve California, Colorado, Oregon, Washington, and Nevada. 

Source: pbs.org/wgbh/nova/parthenon/rest-nf.html

One Enduring Example of Greek Architecture – The Parthenon

The Conco Companies are experienced commercial concrete contractors who have had the privilege to be involved in many exciting construction projects built over the last several decades.  In recognition of outstanding construction projects throughout the centuries, we are doing a series of posts on ancient Greek architecture.   

    

Since the word “acropolis,” means high city, it was used to describe many buildings throughout Greece, but in recent times, it has been used to describe the temples overlooking Athens.  There are several buildings that make up the Acropolis that still survive in some part.  The buildings include the Parthenon that was constructed in 447 to 438 BC (some of the decorative features were completed in 432 BC).  The Propylaea, constructed around 437 BC. The Temple of Athena Nike, constructed from 427 to 423 BC.  In addition the Erechtheum, which was started in 421 BC but had construction interrupted, was finally completed in 407 BC.  

 

The Parthenon, considered to be the most important surviving structure that exemplifies Classic Greece architectural style, was built in honor of the goddess Athena, patron of the people of Athens.  Constructed in the Doric order, the Parthenon is “regarded as an enduring symbol of Ancient Greece, Athenian democracy and western civilization, and one of the world's greatest cultural monuments.”  The temple was originally used as a treasury, but in the last decade of the sixth century, it was used as a Christian church.   

The Parthenon measures 45 ft. high and the cella, which is the inner chamber of a temple, is 98 ft. by 63 ft.  The rectangular shaped building is surrounded by a colonnaded portico of columns on all four sides.  Comprised of 8 columns along the front of the building, it has 15 columns on each side, with the two corner columns on each end to total 17.  Originally the structure contained many brightly painted sculptures but they were removed in 1802 and now reside in the British Museum.  Owned by the Greek government, the structure has been under renovation for decades, but this summer visitors to the Acropolis will have the chance to see the Parthenon without scaffolding for the first time since 1983,  

The Conco Companies are a leading supplier of concrete services for the Western United States. We have built a reputation on superior concrete formwork, reinforcing, place and finish, shotcrete and other ancillary services that benefit from our vast experience.  We have four regional offices to serve Southern and Northern California, Oregon, Washington, Nevada and Colorado. 

Source:  famous-historic-buildings.org.uk/greece_4.html, en.wikipedia.org/wiki/Parthenon

Mesopotamia’s Mud-Brick Building Material

Archaeological evidence indicates that some of the very earliest large-scale buildings were in ancient Mesopotamia; however, in many cases, the only thing that has survived is traces of their foundations.  We have better examples of the impressive buildings constructed by the later civilizations of Mesopotamia, Persia and the rest of the ancient Near East of which some of them remains partially intact. 

Since wood was scarce in the area and the climate is extremely dry and hot, the most common building material was brick formed from mud.  The bricks were easy to make as well as to use and varied from small hand-sized bricks to large slabs used for paving.  They were made from mud or clay from the river, and then mixed with sand or chopped straw to provide additional strength.  Once formed the bricks were laid in a wide variety of elaborate and sophisticated patterns. 

Although the earliest bricks were shaped by hand, Wikipedia states by 3500 BC, “fired bricks came into use and surviving records show a very complex division of labor into separate tasks and trades.”  The fired bricks were used to build walls and also used with stone to make pavement.  Sometime around 2700 BC, rectangular wooden molds were introduced that produced bricks twice as long as they were wide.  In addition during that same period the Mesopotamians started producing plano-convex bricks, which have flat bottoms and sides but tops that curve out to form a convex surface.  The plano-convex bricks were used to construct walls of buildings, which had the convex side on the exterior wall of the structure.  This type of brick lost its popularity sometime around 2400 BC and bricks makers started to make every surface a flat plane.   

The Conco Companies are one of the foremost suppliers of concrete services for the Western U.S. We got our start in 1959 in the Bay Area by offering clients the best value on a broad range of concrete services and products.  Since that time, we have taken a leading role as top concrete contractors in the region. We have four regional offices serving California, Oregon, Nevada, Colorado and Washington.

Sources: en.wikipedia.org/wiki/History_of_construction, fofweb.com/