PRODUCTION OF ARTIFICIAL STONES BETWEEN 1800 AND 1900: A PATENT REVIEW

The search for formulations of building products to replace cut natural stone materials, in terms of aesthetics, workability and strength, has constantly featured the history of construction. However, in the period between the 19th and 20th century, the practice of artificial stone was at its most widespread, boosted by the availability of novel cement-based conglomerates. Within this framework, the present research analyses the patents filed in Italy between 1870 and 1940 and stored at the Central State Archives in Rome, in order to provide in-depth historical, material and technological knowledge of the artificial stone manufacturing. The analysis was conducted through diligent reading and classification that allowed the patents to be catalogued according to the time sequence, the countries of production and the main mixtures, with particular reference to the binder. Within each typology, the reported defects/anomalies/failures and the declared causes were also pointed out, along with the proposed improvement strategies for each shortcoming, involving both the formulation of the mixtures and the production techniques and procedures. Nowadays, the results may constitute an useful baseline toward the analysis of alteration and obsolescence forms, as well as the identification of compatible maintenance and repair measures.