Damage of porous building stone by sodium carbonate crystallization and the effect of crystallization modifiers Ruiz Agudo, Encarnación Ibáñez Velasco, Aurelia María Ruiz Agudo, Cristina Bonilla-Correa, Sarah Elert, Kerstin Rodríguez Navarro, Carlos Manuel Sodium carbonate Salt crystallization Salt damage Salt crystallization is an aggressive weathering mechanism affecting porous building materials. The extensive use of Portland cement, a source of alkalis, in modern buildings and restoration interventions makes sodium carbonate salts important weathering agents. Herein, we study salt damage to a porous stone commonly used in the Andalusian built heritage (Santa Pudia limestone) due to stress generation associated with the precipitation of natron (Na2CO3⋅10 H2O). We performed cyclic crystallization tests combined with thermodynamic and poromechanical calculations to determine salt crystallization pressure and effective tensile stress suffered by the material. The outcome reveals that in-pore natron crystallization during cooling/evaporation generates stresses exceeding the tensile strength of the wet substrate, leading to extensive damage by fracturing and material loss. Damage is reduced using aminotris(methylenephosphonic) acid (ATMP), a common phosphonate-based crystallization modifier that induces non-damaging efflorescence growth as opposed to damaging subflorescence growth, which takes place in its absence. 2024-06-13T07:04:36Z 2024-06-13T07:04:36Z 2023-12-27 journal article Ruiz-Agudo, Encarnación, et al. Damage of porous building stone by sodium carbonate crystallization and the effect of crystallization modifiers. Construction and Building Materials 411 (2024) 134591 [10.1016/j.conbuildmat.2023.134591] https://hdl.handle.net/10481/92549 10.1016/j.conbuildmat.2023.134591 eng http://creativecommons.org/licenses/by-nc/4.0/ open access Atribución-NoComercial 4.0 Internacional Elsevier