Chapter 5 Construction Mortar

§5.2 The composites of Mortar Chapter 5 §5.2 The composites of Mortar Cement Sand Lime

The Composites of Mortar The composites of mortar do not include coarse aggregate, while other materials are similar to concrete Including Cement Sand Lime

The Composites of Mortar Cement Cement types The six common kinds of cement can all be used in mixing masonry mortar； But for special uses such as component adapter, structure reinforcement, crack mending, it can use expansion cement. Strength grade Low strength grade cement is usually used; However, right amount of mixed material can be added when the grade is too high

The Composites of Mortar Sand Sand used in mortar is different from the sand of concrete, the differences are: Limitations for maximum of sand particle diameter When used for rubble masonry Dmax<1/4～1/5 thickness of mortar layer When used for brickwork Medium Sand: Dmax≯2.5mm When used for smooth flour-milling jointing Fine Sand only

The Composites of Mortar Sand Limitations for clay content In order to ensure mortar quality, especially high strength mortar, there are the following limitations for clay quantity of sand Above M2.5, Impurity quantity of clay: 5% Below M2.5, Impurity quantity of clay: 10%

The Composites of Mortar Sand Limitations for clay content Furthermore, aggregate can be formed with manufactured sand, hilly sand, furnace slag and so on; The technical index of mortar can be fixed according to experience or experiment.

The Composites of Mortar Lime In order to save cement and improve workability, right amount of lime or clay can be added. Lime must be made into lime paste (consistency 120mm) first, and quicklime powder or slaked lime powder can sometimes be straightly used.