page_title: Roman concrete
section_title: Historic references
hierarchical_section_title: Roman concrete / Historic references
caption_attribution_description: Italy, Rome, Via Appia Antica, tomb. The remains show the internal core of the building, made in roman concrete (cementizio: opus caementicium) Personal photo (march 2002) by MM in it.wiki
context_page_description: Roman concrete, also called opus caementicium, was a material used in construction in Ancient Rome. Roman concrete was based on a hydraulic-setting cement. It is durable due to its incorporation of pozzolanic ash, which prevents cracks from spreading. By the middle of the 1st century, the material was used frequently, often brick-faced, although variations in aggregate allowed different arrangements of materials. Further innovative developments in the material, called the concrete revolution, contributed to structurally complicated forms, such as the Pantheon dome, the world's largest and oldest unreinforced concrete dome.
  Roman concrete was normally faced with stone or brick, and interiors might be further decorated by stucco, fresco paintings, or thin slabs of fancy colored marbles. Made up of aggregate and cement, like modern concrete, it differed in that the aggregate pieces were typically far larger than in modern concrete, often amounting to rubble, and as a result it was laid rather than poured. Some Roman concretes were able to be set underwater, which was useful for bridges and other waterside construction.
context_section_description: Vitruvius, writing around 25 BC in his Ten Books on Architecture, distinguished types of aggregate appropriate for the preparation of lime mortars. For structural mortars, he recommended pozzolana (pulvis puteolanus in Latin), the volcanic sand from the beds of Pozzuoli, which are brownish-yellow-gray in color in that area around Naples, and reddish-brown near Rome. Vitruvius specifies a ratio of 1 part lime to 3 parts pozzolana for cement used in buildings and a 1:2 ratio of lime to pozzolana for underwater work, essentially the same ratio mixed today for concrete used in marine locations.
  By the middle of the first century, the principles of underwater construction in concrete were well known to Roman builders. The city of Caesarea was the earliest known example to have made use of underwater Roman concrete technology on such a large scale.
  For rebuilding Rome after the fire in 64 AD, which destroyed large portions of the city, Nero's new building code largely called for brick-faced concrete. This appears to have encouraged the development of the brick and concrete industries.
caption: Example of opus caementicium on a tomb on the ancient Appian Way in Rome. The original covering has been removed.
exif: {"Image ImageDescription": "File Name : DSCN0027.JPG\n File Size : 500.3KB (512312 bytes)\n Date Taken : Dom 3 mar 2002 14:48:16\n Image Size : 1280 x 960 pixels\n Resolution : 300 x 300 dpi\n Bit Depth : 8 bits/channel\n Protection Attribute : Off\n Camera ID : N/A\n Camera : E995\n Quality Mode : FINE\n Metering Mode : Matrix\n Exposure Mode : Programmed Auto\n Speed Light : No\n Focal Length : 11.3 mm\n Shutter Speed : 1/101.8 seconds\n Aperture : F3.8\n Exposure Compensation : 0.0 EV\n White Balance : Auto\n Lens : Built-in\n Flash Sync Mode : N/A\n Exposure Difference : N/A\n Flexible Program : N/A\n Sensitivity : Auto\n Sharpening : Auto\n Image Type : Color\n Color Mode : N/A\n Hue Adjustment : N/A\n Saturation Control : Normal\n Tone Compensation : Auto\n Latitude(GPS) : N/A\n Longitude(GPS) : N/A\n Altitude(GPS) : N/A", "Image Make": "NIKON", "Image Model": "E995", "Image Orientation": "Horizontal (normal)", "Image XResolution": "300", "Image YResolution": "300", "Image ResolutionUnit": "Pixels/Inch", "Image Software": "Adobe Photoshop CS Macintosh", "Image DateTime": "2005:08:14 04:00:55", "Image YCbCrPositioning": "Centered", "Image ExifOffset": "1004", "Thumbnail Compression": "JPEG (old-style)", "Thumbnail XResolution": "72", "Thumbnail YResolution": "72", "Thumbnail ResolutionUnit": "Pixels/Inch", "Thumbnail JPEGInterchangeFormat": "1562", "Thumbnail JPEGInterchangeFormatLength": "10614", "EXIF ExposureTime": "491159/50000000", "EXIF FNumber": "19/5", "EXIF ExposureProgram": "Program Normal", "EXIF ISOSpeedRatings": "100", "EXIF ExifVersion": "0210", "EXIF DateTimeOriginal": "2002:03:03 14:48:16", "EXIF DateTimeDigitized": "2002:03:03 14:48:16", "EXIF ComponentsConfiguration": "YCbCr", "EXIF ExposureBiasValue": "0", "EXIF MaxApertureValue": "0", "EXIF MeteringMode": "Pattern", "EXIF LightSource": "Unknown", "EXIF Flash": "Flash did not fire", "EXIF FocalLength": "113/10", "EXIF FlashPixVersion": "0100", "EXIF ColorSpace": "sRGB", "EXIF ExifImageWidth": "1015", "EXIF ExifImageLength": "817", "EXIF FileSource": "Digital Camera", "EXIF SceneType": "Directly Photographed"}