TYPES OF MORTAR

2.  Building mortars are mixtures used for the
jointing of bricks, stones, blocks etc.,
 Mortar may be defined as a paste, capable of
setting and hardening, obtained by adding
water to a mixture of fine aggregates such as
sand and binding material e.g., clay, gypsum,
lime or cement or their combination.
 It is used in vertical joints in brick and stone
masonry.
 It is used to cover exposed walls in plastering.

3.  Clay-gypsum, lime-gypsum & lime mortars

4.  Lime Mortar

5. To bind together the bricks or stones properly
so asto provide strength to thestructure.
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 hold coarse aggregate together in any
concrete so as to form a solid mass. The mortar
used in aconcrete is termed as matrix.

6. To do pointing and plastering to the
structure.
The mortar used for plastering is known
as plaster.
To fill up empty joints in
brick and stone masonry. The mortar
used for such purposes is a thin liquid
mortar which is termed as grout and the
process is known as grouting.

7.  Bulk density.
 Binding material.
 Applications
 Physical properties
 Mechanical properties

8.  Heavy weight
› Density > 1500 kg/m3
› Heavy quartz
› Sand
 Light weight
› Density < 1500 kg/m3
› Light porous sand
› Pumice, tuffa, slags

9.  Cement mortars – cement, sand & water
 Lime mortars – lime, sand & water
 Gypsum mortars – gypsum & binding
materials
 Mud mortars – clay & water
 Composite mortars
› Surkhi, lime, water
› Lime, surkhi, sand mortar
› Cement, lime, mortar
› Cement, clay mortar

10.  Brick laying mortars
 Finishing mortars – architectural or
decorative purposes
 Special mortars – acoustics, x – ray
shielding etc.,

11.  On the basis of compressive strength.
 Subdivided into 9 grades from 0.4 to 30
N/mm2

12.  Strength
 Development of good bond
 Resistance to weathering
 Mobility
 Placeability
 Water retention
 Should be Cheap & durable
 Should not develop cracks

13.  Depends upon activity of binding materials, W/C ratio,
quality of sand & amount of binding material.
 Strong mortar with weak building units & vice versa will
be of no use.
 Strong cement mortars are most likely to lead to
shrinkage cracks.
 Weak mortars leads to less workability, less cohesion.
 Increase in fine aggregate reduces density & strength of
mortar.
 Increase in water reduces density & strength & also
placeability.
 Small % of mica considerably lowers tensile strength &
adversely effects compressive strength.

14.  Mortar for plastering should protect the
masonry joints & units by forming an
impermeable sheet.
 A satisfactory bond should be ensured
between building units, mortar & plaster.

15.  Mobility indicates consistency of mortar.
 Placeability is the ease with which the mortar
mix can be applied with a thin & uniform layer
on the surface.
 Mortar may have a consistency ranging from
stiff to fluid.
 Mortars for masonry & finishes are made
sufficiently mobile.
 Mobility determines placeability.
 Mortars from OPC alone are deficient in cement
paste, stiff & non placeable and often
plasticizers are used.

16.  Ability of mortar not to stratify during
transportation & to retain adequate humidity
in a thin layer spread over a porous bed.
 A mix of low water retention will show the
defects after hardening.
 Amount of water left out may be insufficient
for its hardening & strength.
 Mineral & organic plasticizing agents may be
added to enhance water retention.

17.  When mixing by hand, the sands and cement
are heaped up on a mixing board or in a
wheelbarrow 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.

18. used, such as a•If any additives are being
plasticizer or a frost-proofer, they are normally
added to the water, and then mixed in, rather than
being directly added to the dry ingredients.
•A "well" is formed in the centre of the mixed heap,
water added to it and then folded in.
•More water is added a bit at a time and folded in
until the required consistency is attained.
•This should be when the mortar is thoroughly
mixed but is able to stand in peaks, like whipped
cream; too wet and it just makes a mess, too dry
and it's almost impossible to work.

19. Dry sand and cement in
wheelbarrow
Beginto mix sand andcement Mix to evenly distributecement
Thedry mix should be allone
colour
Add water andplasticiser Mix to requiredconsistency

20. •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.

21.  Cement, lime & clay used as binding materials
impart adhesive power & strength.
 Sand is an adulterant, but increases crushing
strength & reduces shrinkage.
 Water lubricates the surface of aggregate,
spreads binding material uniformly. pH value
should not be less than 6.
 Surkhi is used for economy.
 Flyash & cinders are used as fine aggregate in
lime mortar.

22.  Prepared by mixing cement, sand & water.
 OPC & GGBFS cement form excellent mortars
for walls built with stones or bricks.
 PPC & sulphate resisting cement form mortar
are used for constructions exposed to
aggressive & waste waters.
 Cement mortars are used for plastering,
rendering smooth finishes & damp proof
courses.

23.  Cement mortar should be placed within 30 mins from the
instant of adding water to the mix.
 MANUAL MIXING OR MECHANICAL MIXERS

24.  Prepared by mixing lime, sand & water.
 Fat lime or hydraulic lime.
 Fat lime has high calcium oxide content. Its
hardening depends on loss of water and absorption
of carbon di oxide from the atmosphere.
 Hydraulic lime contains silica, alumina & iron oxide
in small quantities. When mixed with water it forms
putty or mortar having the property of setting and
hardening under water.
 Fat lime is used for plastering while hydraulic lime
is used for masonry construction.

25.  Lime mortar is not suitable for water logged
areas & damp situations.
 Plasticity & placeability & little shrinkage.
 Harden & develop strength slowly.
 Lime mortar should be kept moist till use.
 Should be consumed within one day.

26.  Same like lime mortar except that sand is
replaced by surkhi.
 Surkhi should pass through 4.75 mm.
 Sand is also mixed some times.
 It provides brick color and make the mortar
economical.

27. •The sands 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 sugar-containing liquids,
such as soft drinks, well away from the mix -
sugar, even in small amounts, seriously
impairs the setting ability of the cement.

28.  Also known as guarded or guaged mortar.
 Prepared by mixing lime and cement.
 Increased water retention, workability,
bonding properties & frost resistance.

29.  Cheapest type, prepared with locally
available ingredients & are used for masonry
works, floors & plastering in low cost houses.
 The top 15 to 20 cm is removed & clay dug
from the ground is wetted & allowed to
mature for a day or two. Cow dung is added
to prevent shrinkage cracks. Ingredients
should be properly kneaded.

30.  Mortars for filling joints between
prefabricated reinforced concrete sections.
 Packing mortars.
 Damp proofing mortars.
 Sound absorbing mortars.
 Fire shielding mortars.
 X- ray shielding mortars.
 Light weight mortars.

32.  CRUSHING STRENGTH
 SOUNDNESS
 INITIAL & FINAL SETTING TIME TESTS
 PERMEABILITY

33.  Cement mortar of fluid consistency used to fill
the voids & joints in masonry & to repair the
cracks is known as grout.
 Also used to increase SBC of soil by injection.
 Extensive use in dams, to fill the cracks formed
after the concrete sets & hardens.
 Grout differs from mortar in its fluidity as it is to
be poured & not to be spread into place with
trowel.
 Composed of cement, sand, water , if needed
grouting mixture.

34.  Application of mortar or concrete under
pneumatic pressure through a cement gun is
known as guniting, concrete becomes
extremely strong & a high bond is achieved.
 Composed of cement & sand conveyed
through gun.
 Water is added at high velocity & the mix
strikes the surface.