Evaluation of salt weathering equations. – a review

Salt weathering of building stone is a major cause of loss of historic structures. Many geoheritage sites including stone heritage and geomorphosites have been damaged by this process. In nearly two centuries, research and observation relating salt weathering have accumulated. These studies could be organized focusing on theories, mechanisms, experimental methods, and research tools. This presentation introduce by reviewing many, though not enough, studies to summarize the research history of salt weathering, including the results of subsequent studies, especially focused on an important mechanism of salt weathering, crystallization pressure. Since the concept of crystallization was first proposed in the early 20th century, many equations have been proposed. However, in order to apply them correctly, it is important to consider the type of salt weathering and the surrounding environment, as well as the type and properties of salt and rock (rock properties), and to select and apply the proposed model according to the situation. Although salt weathering studies have been done in a wide variety of research fields, appropriate collaboration among disciplines will lead to meaningful conservation and will be used for practical problems in the future.