Subject: Civil Engineering Material Program : Civil Engineering Year/Part : II/I Class Load : 2 period/week By: Assistant Professor, Er. R.P. Neupane

MORTARS – 2 Hours

Outlines  Introduction  Classification of mortar  Function of Mortar  Selection of Mortar for Civil Engineering Works  Test of Mortar  Evaluation Last two topics will discuss in next class

Assistant Professor, Er. Ram Prasad Neupane 5/21/ Binding Material GENERAL INTRODUCTION: Fine Aggregate Water

Mortar:  Binding material, fine aggregate and water are mixed together in suitable proportions, they form an easily workable paste which is termed as Mortar.  Mortar is a workable paste used to bind masonry units (construction blocks) together and fill the gaps between them Assistant Professor, Er. Ram Prasad Neupane 5/21/ GENERAL INTRODUCTION:

MORTAR………..  For preparing mortars: cement and lime are generally used as binding materials; sand and surkhi as fine aggregates.  Mortars are usually named according to the binding material used in their preparation.  i.e.; Cement Mortar, Lime Mortar Etc.  They are essentially required for masonry work, plastering and pointing etc. Assistant Professor Er. Ram Prasad Neupane 5/21/2019 6

Assistant Professor Er. Ram Prasad Neupane 5/21/ Classification of Mortar & Their Uses as per Binding material

Cement mortar:  prepared by mixing cement and sand in suitable proportions with water.  The general proportion is 1 part of cement to 2-6 parts of clean sand.  These mortars must be use normally within half an hour, i.e.; before initial setting time of the cement.  used for all engineering works where high strength is desired such as load bearing walls, foundations, Plastering, Pointing etc. Assistant Professor Er. Ram Prasad Neupane 5/21/ Classification of Mortar & Their Uses as per Binding material

Dry sand and cement in wheelbarrow Begin to mix sand and cementMix to evenly distribute cement The dry mix should be all one colour Add water and plasticiserMix to required consistency Assistant Professor Er. Ram Prasad Neupane 5/21/ Preparation of Mortar

Lime mortar:  The paste is prepared by mixing lime and sand or surkhi in suitable proportions in addition to water.  If surkhi is to be added in lime mortar the equal proportions of sand and surkhi should be mixed with lime.  These mortars are inferior to cement mortars in strength as well as water tightness.  These mortars should not be used for underground works as they set in the presence of carbon dioxide and break up in damp conditions.  used for construction work above ground level i.e. exposed positions. Assistant Professor Er. Ram Prasad Neupane 5/21/

Mud mortar:  The paste is prepared by mixing suitable clayey soil with water.  The soil which is used for preparing mud mortar should be free from grass, pebbles etc.  These are the cheapest mortars but weakest in strength.  These mortars are used for brickwork of ordinary buildings and for plastering walls in rural areas. Assistant Professor Er. Ram Prasad Neupane 5/21/

PREPARATION OF CLAY Mixing With HandRamming Homogenous Mixture Clay Mortar Assistant Professor Er. Ram Prasad Neupane

Applications of MUD MORTAR Walls Mud Plaster Mud being Plastered to wooden Framework Mud wall Assistant Professor Er. Ram Prasad Neupane

FUNCTIONS OF MORTAR:

 To bind together the bricks or stones (Masonry units) properly so as to provide strength to the structure.  To form a homogenous mass of the structure so as to resist all the loads coming over it without disintegration.  To provide a weather resisting i.e., a durable layer between the different courses of masonry in the structure.  To do pointing and plastering to the structure. The mortar used for plastering is known as plaster. Assistant Professor Er. Ram Prasad Neupane 5/21/ FUNCTIONS OF MORTAR:

Mortar as Binding MaterialPlastering PointingMasonry jointCement Slurry FUNCTIONS OF MORTAR: Assistant Professor Er. Ram Prasad Neupane

 Special types of Mortar

 Selection of Mortar for Civil Engineering Works

 Selection of Cement Sand Ratio for different category of works