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Classics and World Religions, Ohio University, Athens, Ohio 45701, USA
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- PublicationRestrictedPROVENANCING OF LIGHTWEIGHT VOLCANIC STONES USED IN ANCIENT ROMAN CONCRETE VAULTING: EVIDENCE FROM ROME(2011)
; ; ; ; ;Lancaster, L.; Classics and World Religions, Ohio University, Athens, Ohio 45701, USA ;Sottili, G.; Dipartimento di Scienze della Terra, Università degli Studi di Roma ‘La Sapienza’, Piazzale Aldo Moro 5, 00185 Roma, Italy ;Marra, F.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma1, Roma, Italia ;Ventura, G.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma1, Roma, Italia; ; ; Some of the most structurally innovative concrete vaults built in imperial Rome employed lightweight volcanic rocks to reduce the lateral thrust on the supporting walls, the most famous being the Pantheon. Roman concrete (opus caementicium) was made up of mortar binding together pieces of large aggregate (caementa) usually ranging from 10 to 20 cm long, which were hand laid in the mortar (as opposed to being poured as is typical in modern concrete), so that it resembles mortared rubble. A key aspect of the development of large-scale concrete vaulting was the ability to regulate the weight of the ingredients in order to reduce the weight of the vaults and to control the forces within the structure. The volcanic environment along the west coast of Italy provided numerous stones of different weights and physical properties from which the builders could choose (Fig. 1), including pumice and scoria, which were the most common choices for the lightweight caementa of the most innovative vaulted structures. Because these materials were produced by many of the Italian volcanoes, our goal was to establish the provenance of those used in vaults in Rome in order to understand better the supply network. We first used thin sections to narrow the potential sources and then we submitted selected samples to X-ray fluorescence113 20 - PublicationOpen AccessProvenancing of Lightweight Volcanic Stones Used in Ancient Roman Concrete Vaulting: Evidence from Turkey and Tunisia(2010)
; ; ; ; ;Lancaster, L.; Ohio University, Department of Classics and World Religion ;Sottili, G.; Universitò La Sapienza Roma ;Marra, F.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma1, Roma, Italia ;Ventura, G.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma1, Roma, Italia; ; ; The mastery of the use of lightweight rocks in concrete as a means of controlling the thrusts of large scale vaults was among the most important contributions of the Roman builders to the development of vaulted architecture. The string of volcanoes along the Tyrrhenian coast of Italy produced a variety of lightweight rocks, which allowed the builders in Rome to develop highly sophisticated ways of manipulating form and mass to create stable structures. The use of lighter rocks in vaults and heavier in foundations occurs from the mid first century B.C. in Rome, but the systematic use of imported lightweight rocks only began in the early second century A.D. under Trajan (Lancaster 2005, 59-64). Soon thereafter the technique of using lightweight stones to build large vaults spread throughout the empire, usually to areas that had a local source of lightweight volcanic material. However, there was also a seaborne trade in lightweight rocks to areas that did not have local sources of such material. The intention of our analysis is to determine as precisely as possible the provenance of the lightweight stones used in vaulting of two areas of the Mediterranean, modern Turkey (ancient Cilicia) and Tunisia (ancient Africa Proconsularis), and thus to provide a better understanding of the nature of this trade.170 446