RILEM WEBINAR: Stone deterioration and conservation

We are pleased to announce that the next ROC&TOK webinar will take place on  March 7th, 2024 at 3PM CEST/Paris Time and will be one hour long (30-minute presentation + 30-minute interaction). The registration for this webinar is free.

Speaker: Prof. Enrico Sassoni, University of Bologna, Italy

Hosts: Dr Prannoy Suraneni, University of Miami, United States and Prof. Karen Scrivener, EPFL, Switzerland

Title : Stone deterioration and conservation

Stone has been extensively used in historic buildings and sculptures, both for structural and decorative purposes. When exposed outdoors, stone suffers from several deterioration processes (dissolution in rain, thermal cracking, bowing of thin slabs, soiling, stress from crystallization of salts and ice, swelling of clays), many of which are predicted to be worsened by climate change. To arrest and prevent stone deterioration, conservation treatments may include the application of consolidants and protectives, namely liquid products that, after hardening, re-establish the cohesion of the stone and form a surface layer with reduced solubility, respectively. Although in several cases satisfactory results can be obtained, still traditional products (such as ethyl silicate, dispersions of lime nanoparticles, organic polymers) often exhibit limitations, especially when applied onto carbonate stones such as marble and limestone. For this reason, research on innovative treatments is ongoing. In the last 10 years, very encouraging results have been obtained by a new approach, based on aqueous solutions of ammonium phosphate. In this talk, after reviewing the main causes of deterioration of stone, the performance of traditional products and ammonium phosphate will be presented and discussed, in terms of the most important requirements (effectiveness, compatibility, durability and sustainability), considering both laboratory studies and field experiences.