ABSTRACT
This chapter discusses the main factors related to conservation, which is the art and science of maintaining, repairing and cleaning buildings, ranging from ancient monuments to humble dwellings, such that they maintain their appearance and continue to perform a useful function or can be adapted for a new role. It also explains deterioration, conservation and strengthening of masonry. Technological advances allowed the development of a large number of solutions for structural strengthening of masonry. Visible effects of sulphate attack on mortar are expansion of the masonry where it is unrestrained and stress increase where it is restrained. This is particularly critical concerning the seismic strengthening in earthquake-prone zones. In the chapter, examples of strengthening techniques are presented and some considerations for application are made. These techniques are divided in three categories depending on the purpose of a more localised or global effect: (1) strengthening of structural elements, (2) upgrading of connections and (3) improvement of the global building behaviour.
