Damage processes: Difference between revisions
Jump to navigation
Jump to search
No edit summary |
No edit summary |
||
| Line 40: | Line 40: | ||
== [[Salt mixtures]] == | == [[Salt mixtures]] == | ||
In the presence of pure salts and with the particular phase diagram as a basis, it is always possible - through choice of the appropriate indoor air conditions - to prevent phase transformation, i.e., crystal growth. Unfortunately, in building materials it is seldom the case that pure salts are present, rather they are found in more or less complex mixtures. In most cases, the salts found in building materials are mixtures of chlorides, nitrates, sulfates and sodium carbonates. The behavior of salt mixtures is far more complicated than the behavior of pure salts and information can generally not be derived only from the properties of the salts present in the building material. For example, salt mixtures cannot be characterized by a single deliquescence relative humidity, rather a range of | In the presence of pure salts and with the particular phase diagram as a basis, it is always possible - through choice of the appropriate indoor air conditions - to prevent phase transformation, i.e., crystal growth. Unfortunately, in building materials it is seldom the case that pure salts are present, rather they are found in more or less complex mixtures. In most cases, the salts found in building materials are mixtures of chlorides, nitrates, sulfates and sodium carbonates. The behavior of salt mixtures is far more complicated than the behavior of pure salts and information can generally not be derived only from the properties of the individual salts present in the building material. For example, salt mixtures cannot be characterized by a single deliquescence relative humidity, rather a range of relative humidity, within which fluctuations lead to phase transformation and crystallization processes, depending on the composition of the mixture. Phase diagrams of salt mixtures are therefore more complex and the prediction of suitable climate conditions can usually only be made with appropriate models. This is discussed in more detail elsewhere[[Salt mixtures| salt mixtures]]. | ||
== Literature == | == Literature == | ||