Viaduct

WHAT IS IT FOR

dating

morphology

technology

origin

composition

alteration

APPLICABLE MATERIALS

Mortar

Stone

Mortar & Plaster
A mortar is characterized by its 2 major components: the lime binder and the aggregates.
Granulometric analysis of the aggregate grains allows the typological differentiation of mortars as well as building phases within a building.
In some unusual cases it may offer direct assignment of mortars in a wider chronological and architectural period.

BRIEF DESCRIPTION

Granulometry graph. Image by Nora Pérez Castellanos

Granulometry is a simple physical method for particle size analysis of granular materials, very diffused in mortar characterization as it can measure the included aggregates’ size in order to identify the type of mortar we are dealing with. Especially useful also for earthen architecture (earthen mortars, earth blocks, adobe, rammed earth, cob) both for analyses of original materials and for the determination of the granulometric distribution of restoration materials. Produces a granulometric curve, expressing weight percentage of the grain size range.

Granulometry graph. Image by Nora Pérez Castellanos

Metrics

accuracy
time
cost

TIPS

Useful to distinguish mortars from the same building without performing compositional analysis
For extra information use complementary methods

HOW DOES IT WORK?

A way to investigate granular materials is by measuring their grain sizes by means of mechanical sieving. Sieves display meshes* of diff erent sizes through which grains of different diameters pass. This way grains are separated and categorized according to both their size and their weight distribution. Once the grains have been separated, a granulometric curve, expressing weight percentage as a function of grain size range, is obtained

References

Biscontin, G., Pellizon Birelli, M., Zendri, E., 2002. Characterization of binders employed in the manufacture of Venetian historical mortars. Journal of Cultural Heritage 3, pp. 31-37.

Büttner, S., 2010. L’analyse des liants de maçonnerie et son apport à la compréhension chronologique et technique de la construction. In: L’Archéologie des Bâtiments en question – un outil pour les connaître, les conserver et les restaurer, Actes du colloque ICOMOS, Liège 2010,pp. 1-12. [online] Available at https://www.academia.edu/13048931/B%C3%BCttner_S._2014_L_analyse_des_liants_de_ma%C3%A7onnerie_et_son_apport_%C3%A0_la_compr%C3%A9hension_ chronologique_et_technique_de_la_construction_dans_L_arch%C3%A9ologie_des_b%C3%A2timents_en_question._Un_outil_pour_les_conna%C3%AEtre_les_conserver_et_les_restaurer_Li%C3%A8ge_2010_SPW_Namur_p._103_114 [Accessed 15 May 2015].

Franzini, M., Leoni, L., Lezzerini, M., 2000. A procedure for determining the chemical composition of binder and aggregate in ancient mortars: its application to mortars from some medieval buildings in Pisa. Journal of Cultural Heritage 1, pp. 365-373.

Von Konow, T., 2003. Aggregate grain size distribution – A major infl uence on many properties of lime mortars for restoration. In: EUROMAT 2003, Symposium P2 – Materials and Conservation of Cultural Heritage, EPFL – Lausanne, pp. 1-9.

GRANULOMETRY