ABSTRACT
This chapter reviews some of the problems and trends related to binders used in masonry construction and conservation. Evolving from the simple use of rock blocks with no use of binder, masonry has been the most widespread architectural achievement in the history of mankind because of its versatility, beauty, and durability. Lime-based, gypsum-based and hydraulic binders have been prime binders of mortars until in the 20th century they left the scene to Portland cement-based formulations. The chemical and engineering properties of the binder should be gauged towards those of the selected masonry units. In the frame of modern masonry, the binders used for mortar formulation are: Portland cement, non-hydraulic lime, hydraulic or semi-hydraulic lime. Portland cement is going to be reduced in future masonry work for sustainability needs. The substitution of cement with alternative binders will improve durability substantially.
