Physics of cultural heritage preservation: from moisture transport and salt crystallisation to biomineralisation and nanoscale consolidation

Historic masonry, archaeological stone and monumental surfaces deteriorate through coupled physical, chemical and biological processes whose quantitative description draws on continuum mechanics, thermodynamics, colloid science and microbiology. This review presents a unified physics-centred framework spanning the deterioration–diagnosis–intervention chain. We first analyse moisture and soluble-salt transport in porous stone as a poromechanical boundary-value problem, alongside thermal-stress coupling and freeze–thaw fatigue. We then extend the physics envelope to microbial colonisation, examining biofilm-mediated alteration of capillary suction, lichen-induced mechanical wedging and biodecalcification kinetics as potential modifiers of transport boundary conditions. Consolidation interventions spanning microbially and enzymatically induced carbonate precipitation, nanolime dispersions and organosilane sol–gel systems are evaluated through nucleation theory, polymorph-selection thermodynamics and pore-network cementation models, and benchmarked against a common set of performance metrics. Machine-learning damage classification and digital-twin architectures for predictive risk mapping conclude the review. The framework is finally specified as a coupled scheme in which each parameter is mapped to its determination route, suggesting that the principal obstacle to predictive, physics-informed preventive conservation is a measurement gap rather than a theoretical one.