This document discusses the functions of sand and surkhi in mortars. It states that sand reduces shrinkage and cracking, helps lime set faster, and allows for varying strength by adjusting proportions. Surkhi acts as an adulterant to reduce costs, and provides strength and color to mortar. The document also provides strengths of different types of masonry constructed with various mortars, and recommendations for selecting appropriate mortars based on engineering application and stresses.

1. 7.4. FUNCTIONS OF SAND AND SURKHI IN MORTARS
7.4.1. Functions of sand.
• It is used as an adulterant just to make the mortar
economical. It does not provide any strength and
hydraulicity to the mortar.
• It reduces the shrinkage of the binding material.
• It prevents development of cracks in the mortar on
drying.
• It helps in hardening of fat lime by making it porous. It
allows carbon dioxide, present in the air, to reach
insider the mortar mass easily and thus helps in
earlier setting of the mortar.
• It helps in making mortars and concretes of any
desired strength by varying its proportion with the
binding material.

2. 7.4. FUNCTIONS OF SAND AND SURKHI IN MORTARS
• A well graded sand adds density to the mortars and
the concretes.
• It helps in forming a hardened mass of silicates as it
is now believed that some chemical reaction takes
place between silica and constituents of the
cementing materials, particularly of lime and surkhí.
 7.4.2. Functions of surkhi.
• It acts as an adulterant to make the mortar
economical.
• It provides strength and hydraulicity to the mortar.
• It provides brick colour to the lime mortar.

3. STRENGTH OF MASONARY LAID
DIFFERENT MORTARS
Brick masonry in 1 : 3 cement mortar
1000KN/ sq. m
Brick masonry in 1 : 4 cement mortar
880KN/ sq. m
Brick masonry in 1 : 6 cement mortar
500KN/ sq. m
Brick masonry in lime mortar.
440KN/ sq. m
Ashlar stone masonry in 1: 3 cement mortar
1700KN/ sq. m
Rubber masonry in 1 : 3 cement mortar
900 to 1100KN/ sq. m
Rubber masonry in lime mortar.
300 to 500KN/ sq. m
7.6

4. • Brick Masonry with
cement Mortar
• Brick Masonry with
Lime Mortar
• Ashlar Stone masonry
with cement mortar
• Rubber masonry with
cement mortar
• Rubber masonry with
lime mortar

5. 7.7 SELECTION OF MORTAR FOR DIFFERENT
ENGINEERING WORKS
• Very heavily stressed members of structure.
1:1 cement Sand mortar
• R.C.C. tanks, and other water retaining structures
1:1.5 cement sand mortar
• General R.C.C. works such as slabs, beams and columns; arch
work or ashlar work in stone masonry, cement concrete roads,
cement concrete flooring, pointing, plastering inside of
swimming pools etc.
1:2 cement sand mortar
• Massive works, dams and retaining walls, lining of reservoirs
and water channels, reinforced brickwork, half brick thick walls,
columns or pillars, cornices, drip courses damp-proofing
flooring, pointing, plastering etc. where fine finish is desired.
1:3 cement sand mortar

6. 7.7 SELECTION OF MORTAR FOR DIFFERENT
ENGINEERING WORKS
• Masonry work below ground level, especially in water logged
areas.
1:3 cement sand mortar or 1:3 lime
sand mortar (The lime should be eminently hydraulic)
• Mass concrete in foundations, seining of wells, paving tiles, iron
fixtures, cavity walls, plastering of ceiling and external plastering
1: 2 to 3 hydraulic lime mortar work, etc. where good finish is
desired.
1: 4 cement sand mortar
• Ordinary brick masonry
1: 5 to 8 cement sand mortar
• Stone masonry in foundations and super- structures of ordinary
buildings.
1 : 2 fat lime surkhii mortar

7. Loading...
Introduction to Good
Concrete
Good concrete is essential for a wide range of
construction projects. It provides the foundation for
durable and sustainable structures.
Presented to: Ar. Abdul Moeez.
Presented by: M.Junaid, Mian Awais & Muhannad Usama

8. Characteristics of Good concrete:
Crushing Strength
The crushing strength of concrete, determined by breaking a cube,
and often called the cube strength, reaches values of about
3 tons per square inch, that of granite 10 tons per square inch,
and that of cast iron from 25 to 60 tons per square inch.
Durability
Durability of concrete is defined as the resistance of concrete
against abrasion and deterioration.
It means that how much damage a concrete member of structure
can safely endure in its service life.
CTM Machine
Degradation of concerete due
to non- durability

9. Resistance to fire
Concrete provides the best fire resistance of any building material.
It does not burn, it cannot be 'set on fire' like other materials in a building and
it does not emit any toxic fumes, smoke or drip molten particles when exposed to fire.
workability
Concrete workability basically refers to how easily freshly mixed concrete can be
placed, consolidated and finished with minimal loss of homogeneity.
Generally the workability of concrete is determined by how fluid the mix is
(i.e. the cement to water ratio).
Compactness of concrete
Compaction is the process which expels entrapped air from freshly placed concrete
and packs the aggregate particles together so as to increase the density of concrete.
It increases significantly the ultimate strength of concrete and
enhances the bond with reinforcement.
Fire resistance
Compactness test

10. Impermeability of concrete
The impermeability of concrete refers to the property of concrete that cannot be pervaded by
water, oil and other liquids with pressures. It plays an important role in the durability of concrete.
Abrasion resistance of concrete
Abrasion resistance of concrete means how well it can handle
rubbing or friction without getting damaged.i.e, heavy things on them.
Creep:
Concrete creep is defined as: deformation of structure under sustained load.
Basically as long term pressure or stress on concrete can make it
change shape. This deformation usually occurs in the direction
the force is being applied. Like a concrete column getting more compressed,
or a beam bending.
Appearance of concrete:
The appearance of concrete can be varied by altering the proportions
of the materials used or by using special additives.
The material can also be coloured during the mixing process or after it is in place.
Abrasion testing machine.
Creep in Bridge beam

11. TOPIC 7.8
CONCRETE
An artificial stone resulting from hardening of a
mixture of a binding material, fine aggregate, course
aggregate, and water in suitable proportion is called
concrete.
Preparation of different types of concrete
Material required in the preparation of
different types of concrete :
Cement and lime are generally used as binding
material.
Sand, surkhi, clinder used as fine aggregate.
Crushed stones, broken bricks, slag pumice,
breeze, clinkers, are used as course aggregate.

12.  A good Portland cement or lime, clean sand, and strong course aggregates
are necessary for making a good concrete.
 The required strength of concrete can be obtained by :
• Careful selection of ingredients
• Correct grading of ingredients
• Accurate water measurement
• Good workmanship in mixing
• Transportation
• Placing
• Compaction and finishing
• Curing of concrete in the construction site.
 Concretes are usually named according to the binding material used in their
preparation.
 Various forms of concrete is being used in the construction field these days.
 When building strength and durability is prime important then cement
concrete is used.

13. “ Plain, reinforced and pre-stressed cement
concretes are replaced other building materials very
fast because ,
• Better appearance,
• high crushing strength,
• More durability,
• Greater resistance to fire,
• Imperviousness,
• Quickness,
• Easy of monolithic construction,
• Long life,
• Less maintenance cost,