ABSTRACT
The governing factors in deciding a type of mortar for a specific structure depend upon the strength of masonry, resistance to penetration of rain water, immediate and long term appearance, hardening temperature, expected working conditions of the building and cost. Mortars are classified on the basis of their bulk density, kind of binding material, applications and, physical and mechanical properties. For most practical purposes a building mortar will fall in one of the following classes: cement mortars, lime mortars, gypsum mortars, mud mortars, and composite mortars. The chief properties of hardened mortar are strength, resistance to weathering and those of green mortar mixes are mobility, placability and water retention. Cement mortar of fluid consistency used to fill the voids and joints in masonry and to repair the cracks is known as grout. The application of mortar or concrete under pneumatic pressure through a cement gun is known as guniting; concrete becomes extremely strong and a high bond is achieved.
