Characterization of concrete from Roman buildings for public spectacles in Emerita Augusta (Mérida, Spain)

Abstract

The present study focuses on the compositional characterization of Roman concrete from Roman buildings for public spectacles, theatre and amphitheatre, from Emerita Augusta, Mérida, Spain. An advanced knowledge of the Roman concrete composition is required to get a reliable restoration and preservation of these ancient monuments. The concrete was studied through mineralogical (petrographic microscope and X ray diffraction) and petrophysical (bulk and real density, open porosity, mercury intrusion porosimetry, compressive strength and ultrasonic pulse velocity) analyses. With this work, it is possible to fill the gap which exists in this field, the characterization of the materials used in the Roman concrete from these two buildings, never previously studied, despite the significance of this archaeological ensemble, declared a World Heritage Site by UNESCO in 1993. The obtained results of the studied samples, allowed us to determine the composition of the concrete and to infer the provenance of the aggregates used in it.

Multi-technical characterization of Roman mortars from Complutum, Spain

“…Similarities and differences in mortar can be used to estimate the construction period of buildings, bearing in mind that for the precise results, cross-referencing with archaeological data is necessary [1]. Recent studies have presented detailed information about different construction phases and technologies in historic buildings based on mortar characterizations [2-8], especially Roman mortar, due to its outstanding durability [8][9][10][11][12][13][14][15][16]. The main issue was the addition of pozzolan which makes mortar highly durable which was previously mentioned by Vitruvius and proved by researchers [12][13][14][15][16][17][18][19][20][21].…”

“…Recent studies have presented detailed information about different construction phases and technologies in historic buildings based on mortar characterizations [2-8], especially Roman mortar, due to its outstanding durability [8][9][10][11][12][13][14][15][16]. The main issue was the addition of pozzolan which makes mortar highly durable which was previously mentioned by Vitruvius and proved by researchers [12][13][14][15][16][17][18][19][20][21]. The construction technique of the Roman builders who used concrete with both natural and artificial pozzolanic materials in accurate proportions, are identifiable markers of the empire's presence.The Complutum archaeological site is a complex of remains from the eponymous Roman city located on the Henares River terrace.…”

A field guide to mortar sampling for radiocarbon dating*

“…[Colour figure can be viewed at wileyonlinelibrary.com] sample's spatial distribution of elements can be mapped. SEM can identify recrystallization and aggregate grains, for example, limestone and dolomite with dead carbon (Michalska et al 2017;Mota-Lopez et al 2018;Ponce-Anton et al 2018).…”

“…Cocciopesto is hydraulic, waterproof and has greater compressive strength than lime mortar (Pavia and Bolton 2000;Ringbom et al 2014;Mota-Lopez et al 2018). Smaller domestic buildings rarely used volcanic pozzolana mortar but used cocciopesto instead (Harden 1962).…”

“…Aluminosilicates are abundant in both clays and volcanic pozzolana ash, and the two materials have chemical similarities (Massazza 2003;Hobbs and Siddall 2011). Firing clay, at a not too high temperature (450-900°C), followed by crushing to increase fineness, can activate pozzolanic properties in clay (Dodson 1990;Mota-Lopez et al 2018). Similarly to pozzolana, cocciopesto hardened in the presence of air has the potential for radiocarbon dating on account of the excess Ca(OH) 2 reacting with atmospheric CO 2 .…”