Roman Concrete (Pantheon)

• Upon the death of Emperor Trajan in 117 CE, Rome was the capital of a government ruling territories on three continents
• Romans carried out extensive building programs to accommodate their expanding territory and growing population
• Concrete is a significant technological innovation of the Romans
• At its height, the Roman Empire ruled nearly all of Europe, North Africa, and West Asia
• Modern concrete differs significantly from Roman concrete, but the basic elements remain the same
• Technological advances in the early modern era

  • Pigments harvested from the earth used to color glass, ceramics, and paints
  • Technological developments like concrete and flying buttresses advanced architectural projects
  • Advances in kiln technology in China allowed firing clay at high temperatures to produce porcelain
  • In Northern Africa, advanced practices in mummification based on scientific and biological learnings
• Roads, bridges, and aqueducts facilitated travel, trade, and communication between regions of the Roman Empire
• If the Romans had been satisfied with the building materials used by the Greeks and Etruscans, our world today would likely look very different
• The Romans used art and monumental public architecture as political tools to glorify emperors and advance political agendas
• Concrete was crucial for the widespread dominance of the Roman Empire
• Concrete production in Ancient Rome

  Basic elements: broken stone, sand, lime mortar, and water
• Advantages of concrete

  • Incredibly strong and durable, relatively inexpensive and convenient to mix on site, workable by unskilled laborers, incredibly adaptable
• Although the Romans were not the first to create concrete, they were the first to utilize the material on such a widespread scale
• Concrete made buildings of great stability, durability, and flexibility, a true departure from the buildings of the past
• Impact of concrete construction on stability in earthquake-prone environments

  Created stabilizing layers within buildings, enabling the concrete portions to shift slightly with earth movements, making structures more stable
• Use of concrete in Roman architecture

  Initially used as filler material between walls, enhanced durability with pozzolana sand, increasingly used from the second century CE onward
• Development of arch, vault, and dome by Romans

  Basic architectural forms that could be combined and recombined in any number of ways
• Advantages of concrete vaults over timbered vaults

  Concrete vaults were relatively fireproof, giving them a major advantage over timbered vaults
• Concrete revolutionized Roman architecture

  Allowed for new shapes at expanded scales to be incorporated into building plans, shaping the contours of human civilization
• Comparison between concrete barrel vaults and traditional ashlar masonry vaults

  Concrete barrel vaults were more stable and allowed for better lighting due to the ability to place windows at any point along the vault
• Concrete mixing and pouring

  Mixed concrete according to a changing recipe, poured it into wood frames, left it to harden, removed wood molds to reveal a strong mass
• Many extant buildings from ancient Rome still stand today, an incredible feat for structures more than two thousand years old
• The Pantheon stood at the south end of a long rectangular court in Roman times
• The Pantheon's dome was an engineering marvel in its day and remained the largest dome in the world until the sixteenth century
• Pantheon


  • One of the most technically advanced concrete structures built by Roman architects
  • Built as a temple dedicated to the five planetary gods—Jupiter, Mars, Mercury, Saturn, and Venus
  • Converted into a church in the early seventh century
  • Exists today as one of the best-preserved temples from ancient Rome
  • Has the world's largest unreinforced concrete dome
• The oculus, a circular opening twenty-seven feet in diameter at the top of the dome, is the only light source for the interior space