Post-solidification features in granite natural stone and implication for its possible use and re-use in construction

Granitoids are among the most common rock types used in construction. Along with their typical dominant mineralogical composition and rock microfabric, these rocks contain numerous minor/accessory phases and microfabric features that can be attributed to post-solidification development associated with e.g. hydrothermal alteration (HA). HA can be manifested both by microcracking, and by discrete changes in mineralogical composition – e.g., alteration of more basic cores of plagioclases, recrystallization of quartz aggregates, and/or by formation of clay mineral fillings of microcracks. Additional changes can occur due to various decay processes, and interactions with other construction materials (such as mortars) and/or conservation agents. Current study aims to show how these changes can influence physical and mechanical properties specifically when considering granitic natural stone used in important load-bearing infrastructural structures such as bridges. This issue can be of great importance for structures where individual stone elements were re-used from older ones or for those structures which require current repair.