The large cistern

RUDI RANESI

The large cistern at the Roman villa of Els Munts or “Castel deposit”

IN THE NORTH-EASTERN SECTOR OF

THE VILLA ENCLOSURE IS THE MAIN TANK for rainwater collection, also called “Castel deposit”, which was part of the pipe system in the rustic villa, from a period before the paintings in the residential area.

Its floor plan is rectangular and is divided internally into eight compartments separated by strong walls, connected to each other through semicircular arches. It is a solid, robust structure. The Roman concrete walls have a remarkable thickness, in this case 55 cm. They are coated with signinum hydraulic mortars, up to 4 cm thick, made of lime, sand and broken ceramic elements, of different sizes. On the perimeter plinth, between the flooring and the vertical structures, there is a considerable rounded groove that prevented the accumulation of dirt in the corners, following a technique commonly used in the Roman world.

Although it is a solid structure, the state of conservation of the ensemble presented many deficiencies when starting work. These were concentrated in the coatings, both of the walls and the pillars of the cistern, given that the mortars were partially detached from the support and showed significant dents and separations, which often turned into material

Partial view of the cistern before the intervention. Photo: Rudi Ranesi

Overview of the cistern before the intervention. Photo: Rudi Ranesi

Plant of the main cistern at Els Munts

losses. At the same time, the presence of biological agents in the form of lichens, algae and higher plants was prevalent, which could end up weakening the structures and constituent materials. Insect and animal nests (such as lizards) as well as saline efflorescences were also common.

The intervention fundamentally consisted of an urgent action to solve the most serious problems and avoid the subsequent loss of original coatings. For practical and budgetary reasons, management at the Archaeological Museum of Tarragona decided to intervene in the lowest area of the flooring and the first meter and a half of the walls (which was the most accessible area and also the most deteriorated).

We started cleaning the surfaces with brushes and brooms , and then continued with vacuum cleaners and palettes, to remove items deposited on the floor, such as dry leaves, dust and fallen stones from the outside. Cleaning allowed us to recover the original loose material, which had fallen to the ground, to reuse it in the successive reintegration phases. Biotin® T, from CTS, was applied to remove the biological

Detail of a cistern wall showing the loss of opus signinum coating. Photo: Rudi Ranesi

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Extraction of biological elements from the cistern floor. Photo: Rudi Ranesi

Cleaning phase with water, sponges and brushes. Photo: Rudi Ranesi

Consolidation phase with hydraulic mortar injections. Photo: Rudi Ranesi elements, and the salts were extracted both dry and using distilled water dressings.

The deepest cleaning was done with hydroalcoholic solution and brushes, but occasionally, AB57 dressings were also applied.

The consolidation of the coatings was done with injections of CTS PLM ® hydraulic mortars, in all areas where there was a danger of falling.

Crack and fissure reintegrations were made with lime mortars and aggregates of different types, and whenever possible, with previously recovered recycled materials. In a specific case, at the base of a pillar, we had to tear off part of the coating, in order to be able to put it back in its original place, re-attach it and support it until the mortar dries.

The intervention carried out expected to include planning periodic maintenance, in order to preserve the objectives achieved in the intervention, but unfortunately financial problems have not made this possible.

Cleaning phase of the rounded groove area. Photo: Rudi Ranesi

DETAILS

GENERIC CLASSIFICATION: archaeological and palaeontological material | OBJECT: main cistern. Hydraulic coating with opus signinum | MATERIAL/TECHNIQUE: plaster made with lime, crushed ceramic elements and sand: opus signinum (flooring, side walls and pillars) | TITLE / TOPIC: main cistern, also known as “Castel deposit” | DATE/ERA: Roman era; mid1st century and first half of the 2nd century | SIZE: 21.50 × 5.5 × 3.5 m, divided into eight parts connected to each other by arches | LOCATION: northeastern side of the villa. Highest sector of the site in the Roman villa of Els Munts, Altafulla (Tarragona) | CRBMC REGISTRY NO: no number | RESTORATION: Arcovaleno Restauro, SL. Rudi Ranesi (coordinator), Davide Belfiore, Renzo Saporetti and Manuel Uzandizaga | YEAR OF THE RESTORATION: 2008