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  2. 2. MORTAR Mortar is a workable paste used to bind construction blocks together and fill the gaps between them. The word comes from Latin moratorium meaning crushed. Mortar may be used to bind masonry blocks of stone, brick, etc. Mortar becomes hard when it sets, resulting in a rigid aggregate structure. Mortar can also be used to fix, or point, masonry when the original mortar has washed away
  3. 3. MORTAR • Mortars are usually named according to the binding material used in their preparation. • They are essentially required for masonry work, plastering and pointing etc. FUNCTIONS OF MORTAR: • To bind together the bricks or stones 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.
  4. 4. Composition of Mortar Modern mortars are typically made from a mixture of  sand, a binder such as cement or lime, and water.
  5. 5. An ideal mortar:  Adheres completely and durably to all the masonry unit to provide stability.  Remains workable long enough to enable the operative to set the masonry unit right to line and level; this implies good water retentivity.  Stiffens sufficiently quickly to permit the laying of the units to proceed smoothly, and provides rapid development of strength and adequate strength when hardened.  Is resistant to the action of environmental factors such as frost and/or abrasion and the destructive effects of chemical salts such as sulfate attack.  Resists the penetration of rain.  Accommodates movement of the structure.  Accommodates irregularities in size of masonry units.  Contributes to the overall aesthetic appearance.  Is cost effective
  6. 6. Mortar as Binding Material Pointing Masonry joint Plastering Cement Slurry
  7. 7. Nature of application Brick Laying Mortars Finishing Mortars
  9. 9. Workability Workability may be defined as the behavior of a mix in respect of all the properties required, during application, subsequent working and finishing. Ease of use, i.e. the way it adheres or slides on the trowel.  Ease of spread on the masonry unit. Ease of extrusion between courses without excessive dropping or smearing. Ease of positioning of the masonry unit without movement due to its own weight and the weight of additional courses
  10. 10. Water Retentivity & Air content This is the property of mortar that resists water loss by absorption into the masonry units (suction) and to the air, in conditions of varying temperature, wind and humidity. Water retentivity is related to workability. The air content of the mortar in its plastic state is also important. In order to achieve good durability it is necessary that there is sufficient air content (entrained air) to enable freeze-thaw cycles to be resisted without disrupting the matrix of the material.
  11. 11. Stiffening and hardening The progression of stiffening, defined in the European Standard as workable life, refers to the gradual change from fresh or plastic mortar to setting or set mortar. Hardening refers to the subsequent process whereby the set mortar progressively develops strength.
  12. 12. Properties of hardened mortar  Durability of mortar may be defined as its ability to endure aggressive conditions during its design life. A number of potentially destructive influences may interact with the mortar: these include water, frost, soluble salts and temperature change. In general, as the cement content increases so will durability. Air entrainment of mortars improves resistance to freeze-thaw damage.
  13. 13. Compressive strength The use of too much cement will produce a more rigid mortar, which may result in vertical cracking passing through units and mortar joints as stresses are imposed Use of the appropriate mortar should not result in cracking, but any that does occur, (e.g. due to movement), will tend to follow the joints, which will be much easier to repair
  14. 14. Flexural strength  Traditional masonry construction tended to be massive relative to modern structures, typically with very thick walls. This meant that the mass or bulk generally resisted the various forces applied to it.  The development of modern masonry units and advances in mortar technology have led to more slender structures which are more vulnerable to lateral forces e.g. wind loads.
  15. 15. MIXING THE MORTAR: •The sand and the cement have to be thoroughly mixed by hand or in a mechanical mixer before adding any water - do not use dirty water, or water from puddles or ponds, as this could impair the final strength of the mortar. •Similarly, keep any sugarcontaining liquids, such as soft drinks, well away from the mix sugar, even in small amounts, seriously impairs the setting ability of the cement.
  16. 16. Types of Mortars Mortars are classified on the basis of the following  BULK DENSITY KIND OF BINDING MATERIAL NATURE OF APPLICATION SPECIAL REQIREMENTS
  17. 17. By Bulk Density According to the bulk density of mortar in dry state , there are two types of mortars. Heavy Mortar Bulk Density =/> 1500 kg/m3 Lightweight Mortar - Bulk Density < 1500 kg/m3
  18. 18. Kind of binding material Lime Mortar Lime – Surkhi Mortar Mud Mortar Cement Mortar
  19. 19. FUNCTION OF SAND AND SURKHI IN MORTARS: Functions of sand: •It reduces shrinkage of the building material. •It prevents development of cracks in the mortar on drying. •It helps in making mortars and concretes of desired strength by varying its proportions with the binding material. •A well graded sand adds to the density of mortars and concretes. Functions of surkhi: •It provides brick color and make the mortar economical
  20. 20. LIME MORTAR
  21. 21. LIME MORTAR Lime mortar is a type of mortar composed of lime and an aggregate such as sand, mixed with water. Lime mortar is primarily used in the conservation of buildings originally built using lime mortar, but may be used as an alternative to ordinary portland cement. A lime kiln is used to produce quicklime through the calcination of limestone (calcium carbonate). CaCO3 + heat → CaO + CO2
  22. 22. Quick Lime Calcium oxide (CaO), commonly known as quicklime or burnt lime, is a widely used chemical compound. It is a white, caustic, alkaline crystalline solid at room temperature usually obtained from limestone. Slaking of Lime When water is added to quick lime in sufficient quantity, lime cracks, swells and falls into powder form due to the chemical reaction thus forming calcium hydrate Ca(OH)2.
  23. 23. 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. •This type is used for construction work above ground level i.e. exposed positions.
  24. 24. Ht: 40 cm 6 – 9 m Dia BULLOCK DRIVEN GRINDING MILL Width: 30 cm
  25. 25. Pivot Roller Roller Revolving Pan 180- 240 CM Dia Power POWER DRIVEN GRINDING MILL
  26. 26. MUD MORTAR
  27. 27. Mud mortar: •The paste is prepared by mixing suitable clay, 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.
  28. 28. PREPARATION OF CLAY Mixing With Hand Ramming Homogenous Mixture Clay Mortar
  29. 29. MUD wall
  30. 30. Applications of MUD MORTAR Walls Mud wall Mud being Plastered to wooden Framework Mud Plaster
  31. 31. Wall with Mud Blocks Binding Material
  33. 33. Clay Blocks / Tiles
  34. 34. TERRACOTTA – Burnt Clay Solar Panels embedded in clay tiles Shingles Tiled Roofs Roof Tiles Pot Tiles
  37. 37. Decorative Motifs in Terracotta
  39. 39. Cement mortar: •The paste is prepared by mixing cement and sand in suitable proportions in addition to water. •The general proportion is 1 part of cement to 2-8 parts clean sand. •These mortars must be use within half an hour, i.e.; before initial setting time of the cement. •This type is used for all engineering works where high strength is desired such as load bearing walls, deep foundations, flooring etc.
  40. 40. •When mixing by hand, the sands and cement are heaped up on a mixing board or in a wheel barrow and repeatedly turned over and over until thoroughly mixed. •The color of the dry mix will change as the cement is distributed throughout - there should be no 'streaking' of cement, and no clumps of pure sand or pure cement. •Once the dry ingredients are mixed, the water can be added.
  41. 41. Dry sand and cement in wheelbarrow Begin to mix sand and cement Mix to evenly distribute cement The dry mix should be all one colour Add water and plasticiser Mix to required consistency
  42. 42. •When using a mechanical mixer, add half a bucket (2 or 3 liters) of clean cold water to the empty drum before adding the dry ingredients in sequence. • Add 4 measures of sand then 1 of cement, followed by 4 sand, then another cement and so on until the required quantity is in the mixer. •This ensures a more thorough mix than adding, say, 20 measures of sand and then 5 measures of cement. •Again, the water is added to the revolving drum once the dry ingredients are thoroughly blended, a bit at a time until the required consistency is achieved.
  43. 43. For wide joints in paving or for stonework, either as paving or as walling, a coarser mortar is often preferred - replace half of the building/soft sand with grit/sharp sand. You will probably find that a coarse mortar such as this requires less gauging water to achieve a working consistency than does a bricklaying/general purpose mortar. Mortar for Wide Joints 2 x Building Sand plus 2 x Grit Sand plus 1 x cement
  44. 44. SPECIAL MORTARS Fire – Resistant Mortar Lightweight Mortar Packing Mortar Sound Absorbing Mortar X-Ray Shielding mortar
  45. 45. Fire resistant mortar: •The paste is prepared by mixing aluminous cement and finely crushed fire bricks (1:2) in suitable proportions in addition to water. •The usual proportion are 1 part aluminous cement to 2 parts of finely crushed fire bricks. •These are generally used for lining furnaces, ovens and fire places with fire bricks.
  46. 46. Light weight mortar: •The paste is prepared by mixing wood powder, wood sawing or saw dust with cement or lime mortar. •In such mortars fibers of jute coir or asbestos fibers can also be used. •These are generally used as fiber plasters in sound and heat proof construction.
  47. 47. THANK YOU