Fixing materials of Czechoslovak “socialistic” mosaics

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F68378297%3A_____%2F25%3A00638610" target="_blank" >RIV/68378297:_____/25:00638610 - isvavai.cz</a>

Result on the web

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DOI - Digital Object Identifier

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Result language

angličtina

Original language name

Fixing materials of Czechoslovak “socialistic” mosaics

Original language description

Monumental mosaics from Czechoslovakia’s socialist era (1948–1989) have long faced societal rejection due to their perceived association with political propaganda. However, recent shifts in cultural heritage perspectives have led to their recognition as historical monuments, underscoring the need for precise material characterization to develop appropriate conservation strategies. This research addresses the existing gap in knowledge regarding the composition and fixation techniques of these mosaics using standard analytical methods, including scanning electron microscopy (SEM-EDS), thermal analysis (TG/ DTG), X-ray powder diffraction (XRD), gas chromatography (GC), and infrared spectroscopy (FTIR). During the latter half of the 20th century, numerous monumental mosaics were created across socialist countries. In Czechoslovakia, most mosaic installations were produced by two state-run companies due to the absence of private art and craft studios. The largest mosaic studio existed within the so-called Central Art and Craft Studio (Ústředí uměleckých řemesel - ÚUŘ). It developed standardized techniques for mosaic fixation3. However, until now, no scientific verification has been conducted to assess the extent to which these standardised procedures were consistently applied in practice. Fixing materials, i. e. mosaic beds of 10 mosaics designed by outstanding artists of the time (Martin Sladký, Radomír Kolář, Sauro Ballardini, Eva Kmentová etc.) were investigated within this study. Detailed examination of the mosaic samples, including those assembled by state-run studios as well as rare works produced directly by independent artists, reveals both uniformity and notable exceptions in material composition. Scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) analyses demonstrate that the chemical composition of the mortars generally aligns with expectations for Portland cement binders, with characteristic levels of CaO, SiO₂ and Al₂O₃, and the presence of unhydrated clinker residues. The binder of the ÚUŘ mosaics can be characterised as a blended cement as it contains unreacted blast furnace slag grains apart from clinker residues. This finding is in accordance with contemporary literature. In several samples, a relatively low degree of carbonation was observed, while others exhibited pronounced decalcification and secondary formation of CaCO₃ polymorphs such as vaterite and aragonite. In particular, the mortars associated with some state‐run projects display a standardised, nearly uniform aggregate composition, whereas authorial exceptions—such as the mosaic sculpture by Eva Kmentová and Olbram Zoubek—reveal the deliberate incorporation of asbestos cement and tailored binder modifications.

Czech name

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Czech description

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Type

D - Article in proceedings

CEP classification

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OECD FORD branch

20501 - Materials engineering

Project

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Continuities

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Publication year

2025

Confidentiality

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Article name in the collection

7th Historic Mortars Conference (HMC 2025), Padova. International conference

ISBN

978-88-5491-636-4

ISSN

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e-ISSN

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Number of pages

3

Pages from-to

331-333

Publisher name

Edizioni Quasar

Place of publication

Roma

Event location

Padova

Event date

Sep 2, 2025

Type of event by nationality

WRD - Celosvětová akce

UT code for WoS article

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