Roman vs. medieval crushed brick lime mortars: A comparative study

Author(s): Martin Schidlowski, Tobias Bader, Anja Diekamp
Paper category: Proceedings
Book title: Proceedings of the 5th Historic Mortars Conference
Editor(s): José Ignacio Álvarez, José María Fernández, Íńigo Navarro, Adrián Durán, Rafael Sirera
ISBN: 978-2-35158-221-3
e-ISBN: 978-2-35158-222-0
Publisher: RILEM Publications SARL
Publication year: 2019
Pages: 468-481
Total Pages: 14
Language : English

Abstract: A detailed material description of medieval crushed brick lime mortars from the Alpine
region has not yet been performed. The present study focuses on the mineralogical
characterization of mortars of this type in comparison to Roman age mortars. The samples
were studied by polarized light microscopy, SEM-EDS, XRPD and TG-DTG in order to assess
material characteristics.
First results of petrographic investigations revealed that the medieval as well as the Roman
binders are inhomogeneous concerning their colour and structure, which is attributed to
differences in the chemical composition of the binders, transformation of binder phases over
time and a varying extent of alteration. Calcite, aragonite, lizardite and brucite as well as C-S-
H phases and M-S-H phases were identified as components of the binder. The STA results
indicated a hydraulic character of the mortars most likely resulting from a pozzolanic
reaction between the slaked lime and the crushed bricks. The frequent occurrence of Mg-
bearing phases, such as lizardite, brucite and M-S-H phases, suggests the widespread use of
dolomitic lime as raw material for the binder production. Based on the results obtained,
most of the samples can be classified as hydraulic dolomitic lime mortars.

Online publication : 2019
Publication type : full_text
Public price (Euros) : 0.00