Short Notes: Mortar | Short Notes for Civil Engineering - Civil Engineering (CE) PDF Download

 Page 1


 
CHAPTER 5 
MORTAR 
 
 The term mortar is used to indicate a paste prepared by adding 
required quantity of water to a mixture of binding material like cement or 
Lime and fine aggregates like sand. The two components of mortar 
namely the binding material and fine aggregates are some times referred 
to as matrix the durability, quality and strength of mortar will mainly 
depends on quantity and quality of the matrix. The combined effect of 
the two components of mortar is that the mass is able to bind the bricks 
or stones firmly 
 
5.1  Properties – Uses: 
 
 The important properties of a good mortar mix are 
mobility, placeability and water retention. The mobility is used to 
indicate the consistency of mortar mix, which may range from 
stiff to fluid 
 The mobility of mortar depends upon composition of 
mortar and mortar mixes to be used for masonry work, finishing 
works, etc are made sufficiently mobile. 
 The placeability or the ease with which the mortar mix 
can be placed with minimum cost in a thin and uniform layer 
over the surface depends on the mobility of mortar. The 
placeablity of mortar mix should be such that a strong bond is 
developed with the surface of the bed. 
Page 2


 
CHAPTER 5 
MORTAR 
 
 The term mortar is used to indicate a paste prepared by adding 
required quantity of water to a mixture of binding material like cement or 
Lime and fine aggregates like sand. The two components of mortar 
namely the binding material and fine aggregates are some times referred 
to as matrix the durability, quality and strength of mortar will mainly 
depends on quantity and quality of the matrix. The combined effect of 
the two components of mortar is that the mass is able to bind the bricks 
or stones firmly 
 
5.1  Properties – Uses: 
 
 The important properties of a good mortar mix are 
mobility, placeability and water retention. The mobility is used to 
indicate the consistency of mortar mix, which may range from 
stiff to fluid 
 The mobility of mortar depends upon composition of 
mortar and mortar mixes to be used for masonry work, finishing 
works, etc are made sufficiently mobile. 
 The placeability or the ease with which the mortar mix 
can be placed with minimum cost in a thin and uniform layer 
over the surface depends on the mobility of mortar. The 
placeablity of mortar mix should be such that a strong bond is 
developed with the surface of the bed. 
Mortar                                                                            
  
 A good mortar mix should posses the ability if retaining 
adequate humidity during the transportation and laying over the 
porous bed. 
If water retention power of mortar mix is low it separates 
into layers during transportation and when it comes contact with 
the porous bed like brick, wood, etc, it gives away its water to 
that surface. Thus the mortar becomes poor in a amount of water 
and remaining water proves to be insufficient for its hardening. 
Hence required strength of mortar will not be achieved with such 
a mortar mix will. 
 
Properties of good mortar 
1. It should be capable of developing good adhesion with the 
building units such as bricks, stones etc. 
2. It should be capable of developing the designed stresses. 
3. It should be capable of resisting penetration of rainwater. 
4. It should be cheap. 
5. It should be durable. 
6. It should be easily workable. 
7. It should not affect the durability of materials with which it 
comes into contact. 
 
Uses: 
1. To bind the building units such as bricks, stones etc. 
2. To carry out painting and plaster works on exposed surfaces 
of masonry 
3. To form an even bedding layer for building units 
Page 3


 
CHAPTER 5 
MORTAR 
 
 The term mortar is used to indicate a paste prepared by adding 
required quantity of water to a mixture of binding material like cement or 
Lime and fine aggregates like sand. The two components of mortar 
namely the binding material and fine aggregates are some times referred 
to as matrix the durability, quality and strength of mortar will mainly 
depends on quantity and quality of the matrix. The combined effect of 
the two components of mortar is that the mass is able to bind the bricks 
or stones firmly 
 
5.1  Properties – Uses: 
 
 The important properties of a good mortar mix are 
mobility, placeability and water retention. The mobility is used to 
indicate the consistency of mortar mix, which may range from 
stiff to fluid 
 The mobility of mortar depends upon composition of 
mortar and mortar mixes to be used for masonry work, finishing 
works, etc are made sufficiently mobile. 
 The placeability or the ease with which the mortar mix 
can be placed with minimum cost in a thin and uniform layer 
over the surface depends on the mobility of mortar. The 
placeablity of mortar mix should be such that a strong bond is 
developed with the surface of the bed. 
Mortar                                                                            
  
 A good mortar mix should posses the ability if retaining 
adequate humidity during the transportation and laying over the 
porous bed. 
If water retention power of mortar mix is low it separates 
into layers during transportation and when it comes contact with 
the porous bed like brick, wood, etc, it gives away its water to 
that surface. Thus the mortar becomes poor in a amount of water 
and remaining water proves to be insufficient for its hardening. 
Hence required strength of mortar will not be achieved with such 
a mortar mix will. 
 
Properties of good mortar 
1. It should be capable of developing good adhesion with the 
building units such as bricks, stones etc. 
2. It should be capable of developing the designed stresses. 
3. It should be capable of resisting penetration of rainwater. 
4. It should be cheap. 
5. It should be durable. 
6. It should be easily workable. 
7. It should not affect the durability of materials with which it 
comes into contact. 
 
Uses: 
1. To bind the building units such as bricks, stones etc. 
2. To carry out painting and plaster works on exposed surfaces 
of masonry 
3. To form an even bedding layer for building units 
 
4. To form  joints of pipes 
5. To improve the appearance of structure. 
 
5.2  Types of Mortar 
The mortar are classified on the bases of the following 
1. Bulk density 
2. Kinds of binding material 
3. Nature of application 
4. Special mortars 
 
5.2.1 Bulk density:  
According to bulk density of mortar in dry state, the mortars are 
two types  
a. Heavy mortars bulk density is more than 1500kg/m3 and 
prepared from heavy quartz 
b. Lightweight mortars – bulk density is less than 1500/mg3 
and prepared from light porous sands. 
 
5.2.2.  Kinds of binding Material 
 According to the kinds of binding material, several factors 
such as expected working conditions, hardening temperature, 
moisture conditions, etc should be considered. The mortars are 
classified into four categories. 
a. Lime Mortar -  in this motor, lime is used as binding material. 
Lime may be fate lime or Hydraulic lime. Fat lime mortar 1:2 to 
1:3 and hydraulic lime mortarmay be1:2 by VOLUME. 
Page 4


 
CHAPTER 5 
MORTAR 
 
 The term mortar is used to indicate a paste prepared by adding 
required quantity of water to a mixture of binding material like cement or 
Lime and fine aggregates like sand. The two components of mortar 
namely the binding material and fine aggregates are some times referred 
to as matrix the durability, quality and strength of mortar will mainly 
depends on quantity and quality of the matrix. The combined effect of 
the two components of mortar is that the mass is able to bind the bricks 
or stones firmly 
 
5.1  Properties – Uses: 
 
 The important properties of a good mortar mix are 
mobility, placeability and water retention. The mobility is used to 
indicate the consistency of mortar mix, which may range from 
stiff to fluid 
 The mobility of mortar depends upon composition of 
mortar and mortar mixes to be used for masonry work, finishing 
works, etc are made sufficiently mobile. 
 The placeability or the ease with which the mortar mix 
can be placed with minimum cost in a thin and uniform layer 
over the surface depends on the mobility of mortar. The 
placeablity of mortar mix should be such that a strong bond is 
developed with the surface of the bed. 
Mortar                                                                            
  
 A good mortar mix should posses the ability if retaining 
adequate humidity during the transportation and laying over the 
porous bed. 
If water retention power of mortar mix is low it separates 
into layers during transportation and when it comes contact with 
the porous bed like brick, wood, etc, it gives away its water to 
that surface. Thus the mortar becomes poor in a amount of water 
and remaining water proves to be insufficient for its hardening. 
Hence required strength of mortar will not be achieved with such 
a mortar mix will. 
 
Properties of good mortar 
1. It should be capable of developing good adhesion with the 
building units such as bricks, stones etc. 
2. It should be capable of developing the designed stresses. 
3. It should be capable of resisting penetration of rainwater. 
4. It should be cheap. 
5. It should be durable. 
6. It should be easily workable. 
7. It should not affect the durability of materials with which it 
comes into contact. 
 
Uses: 
1. To bind the building units such as bricks, stones etc. 
2. To carry out painting and plaster works on exposed surfaces 
of masonry 
3. To form an even bedding layer for building units 
 
4. To form  joints of pipes 
5. To improve the appearance of structure. 
 
5.2  Types of Mortar 
The mortar are classified on the bases of the following 
1. Bulk density 
2. Kinds of binding material 
3. Nature of application 
4. Special mortars 
 
5.2.1 Bulk density:  
According to bulk density of mortar in dry state, the mortars are 
two types  
a. Heavy mortars bulk density is more than 1500kg/m3 and 
prepared from heavy quartz 
b. Lightweight mortars – bulk density is less than 1500/mg3 
and prepared from light porous sands. 
 
5.2.2.  Kinds of binding Material 
 According to the kinds of binding material, several factors 
such as expected working conditions, hardening temperature, 
moisture conditions, etc should be considered. The mortars are 
classified into four categories. 
a. Lime Mortar -  in this motor, lime is used as binding material. 
Lime may be fate lime or Hydraulic lime. Fat lime mortar 1:2 to 
1:3 and hydraulic lime mortarmay be1:2 by VOLUME. 
Mortar                                                                        
  
b. Cement mortar: In this mortar, cement is used as binding 
material. Depending upon the strength required and importance 
of work, the proportion of cement to sand varies from 1:2 to 1:6 
or more.  
c. Gauged Mortar or composite mortar: 
The process of adding cement to lime mortar to improve the 
quality of lime mortar is known as gauging. It makes lime mortar 
economical, strong and dense. The usual proportion of cement to 
lime by volume is about 1:6 to 1:8 
d. Gypsum mortar: 
These mortars are prepared from gypsum binding material such 
as building gypsum and anhydrite binding materials. 
 
5.2.3  Nature of Application:  
 According to the nature of application, the mortars are 
classified into two categories. 
A. Brick laying mortars: Mortars for brick laying are intended to 
be used for brick works and walls. Depending up on the working 
conditions and type of construction, the composition of masonry 
mortars with respect to the kind of binding materials is decided. 
B. Finishing Mortars: these mortars include common plastering 
work and mortars for developing architectural or ornamental 
effects. Generally cement or lime is used as binding material. 
Page 5


 
CHAPTER 5 
MORTAR 
 
 The term mortar is used to indicate a paste prepared by adding 
required quantity of water to a mixture of binding material like cement or 
Lime and fine aggregates like sand. The two components of mortar 
namely the binding material and fine aggregates are some times referred 
to as matrix the durability, quality and strength of mortar will mainly 
depends on quantity and quality of the matrix. The combined effect of 
the two components of mortar is that the mass is able to bind the bricks 
or stones firmly 
 
5.1  Properties – Uses: 
 
 The important properties of a good mortar mix are 
mobility, placeability and water retention. The mobility is used to 
indicate the consistency of mortar mix, which may range from 
stiff to fluid 
 The mobility of mortar depends upon composition of 
mortar and mortar mixes to be used for masonry work, finishing 
works, etc are made sufficiently mobile. 
 The placeability or the ease with which the mortar mix 
can be placed with minimum cost in a thin and uniform layer 
over the surface depends on the mobility of mortar. The 
placeablity of mortar mix should be such that a strong bond is 
developed with the surface of the bed. 
Mortar                                                                            
  
 A good mortar mix should posses the ability if retaining 
adequate humidity during the transportation and laying over the 
porous bed. 
If water retention power of mortar mix is low it separates 
into layers during transportation and when it comes contact with 
the porous bed like brick, wood, etc, it gives away its water to 
that surface. Thus the mortar becomes poor in a amount of water 
and remaining water proves to be insufficient for its hardening. 
Hence required strength of mortar will not be achieved with such 
a mortar mix will. 
 
Properties of good mortar 
1. It should be capable of developing good adhesion with the 
building units such as bricks, stones etc. 
2. It should be capable of developing the designed stresses. 
3. It should be capable of resisting penetration of rainwater. 
4. It should be cheap. 
5. It should be durable. 
6. It should be easily workable. 
7. It should not affect the durability of materials with which it 
comes into contact. 
 
Uses: 
1. To bind the building units such as bricks, stones etc. 
2. To carry out painting and plaster works on exposed surfaces 
of masonry 
3. To form an even bedding layer for building units 
 
4. To form  joints of pipes 
5. To improve the appearance of structure. 
 
5.2  Types of Mortar 
The mortar are classified on the bases of the following 
1. Bulk density 
2. Kinds of binding material 
3. Nature of application 
4. Special mortars 
 
5.2.1 Bulk density:  
According to bulk density of mortar in dry state, the mortars are 
two types  
a. Heavy mortars bulk density is more than 1500kg/m3 and 
prepared from heavy quartz 
b. Lightweight mortars – bulk density is less than 1500/mg3 
and prepared from light porous sands. 
 
5.2.2.  Kinds of binding Material 
 According to the kinds of binding material, several factors 
such as expected working conditions, hardening temperature, 
moisture conditions, etc should be considered. The mortars are 
classified into four categories. 
a. Lime Mortar -  in this motor, lime is used as binding material. 
Lime may be fate lime or Hydraulic lime. Fat lime mortar 1:2 to 
1:3 and hydraulic lime mortarmay be1:2 by VOLUME. 
Mortar                                                                        
  
b. Cement mortar: In this mortar, cement is used as binding 
material. Depending upon the strength required and importance 
of work, the proportion of cement to sand varies from 1:2 to 1:6 
or more.  
c. Gauged Mortar or composite mortar: 
The process of adding cement to lime mortar to improve the 
quality of lime mortar is known as gauging. It makes lime mortar 
economical, strong and dense. The usual proportion of cement to 
lime by volume is about 1:6 to 1:8 
d. Gypsum mortar: 
These mortars are prepared from gypsum binding material such 
as building gypsum and anhydrite binding materials. 
 
5.2.3  Nature of Application:  
 According to the nature of application, the mortars are 
classified into two categories. 
A. Brick laying mortars: Mortars for brick laying are intended to 
be used for brick works and walls. Depending up on the working 
conditions and type of construction, the composition of masonry 
mortars with respect to the kind of binding materials is decided. 
B. Finishing Mortars: these mortars include common plastering 
work and mortars for developing architectural or ornamental 
effects. Generally cement or lime is used as binding material. 
 
 
5.2.4.  Special Mortars: 
A. Fire resistant mortar- This mortar is prepared by adding 1:2 
ratio of aluminous cement with crushed powder of fire bricks 
used for fire brick lining furnaces, fire places, ovens etc. 
B. Light weight mortar – This mortar is prepared by adding 
sawdust, wood powder to lime or cement mortar for sound 
proof and heat proof construction 
C. Packing Mortar – To pack of oil wells, special mortars 
possessing the properties of high homogeneity, water 
resistance, predetermined setting time, ability to form solid 
water proof plugs in cracks and voids of rocks, resistance to 
subsoil water pressure etc. have to be formed with cement 
sand, cement loam and cement sand loam mortars. 
D. Sound absorbing mortars: To reduce the noise level, sound 
absorbing mortars with Portland cement, lime, gypsum, slag 
Portland cement etc as the binding materials employed in its 
composition. The aggregates re selected from lightweight 
porous material such as pumice, cinders etc. 
E. X-ray shielding mortar: This type of mortar is used for 
providing the plastering coat to walls and celling of x-ray 
cabinets. This is heavy mortar with bulk density over 
2200kg/m
3
 is used. The aggregates are obtained from heavy 
rock and suitable admixture are added to enhance protective 
property of such a mortar.