The document discusses various materials used in construction including cement, aggregates, water, bricks, steel, and concrete. It provides details on testing and quality standards for each material. Proper selection and testing of materials is important for ensuring quality of construction. The document also covers mixing, placing, finishing, and curing of concrete. Curing allows concrete to gain strength and durability over time.
1. Selection of materials
Selecting the right building material is
crucial for any construction. Although the
contractor may be arranging the material,
yet it is advisable for you as the house
owner to be aware of methods to ascertain
the quality of the material being used. This
is especially important if you are not
using ready-mix concrete.
2. Cement
The cement used shall be any of the following and the type
selected should be appropriate for the intended use:
33 grade OPC (IS 269)
43 grade OPC (IS 8112)
53 grade OPC (12269)
Other types,Portland slag cement conforming to IS 455
Portland pozzolana cement (fly ash based) IS 1489 (Part 1)
Portland pozzolana cement (calcined clay based)IS 1489 (Part 2)
Hydrophobic cement conforming to IS 8043
Low heat Portland cement conforming to IS 12600
Sulphate resisting Portland cement conforming to IS 12330
4. Different Tests on cement
Fineness (IS 4031 )
Soundness: Le-Chatelier
Consistency of Standard Cement
Paste
Initial & final setting time
Compressive Strength
5. Sand
In technical language, sand is referred
to as Fine Aggregates. Size of
particles is less than 5 mm. River sand
is cheapest source of natural
aggregates. It should be free from
dust, clay, silt and organic impurities.
You can conduct a simple field test for
sand: Hold some of the sand in hand,
rub it and just throw it. Check your
palm. Good sand will not stick to the
palm.
6. COARSE AGGREGATES
Crushed hard stone and gravel are
common materials used as coarse
aggregates for concrete work in India.
Aggregates are available in sizes of
40mm, 20mm and 10mm. For residential
slab, beam and column work, 20mm and
10mm size of aggregates are generally
used
8. Tests on Aggregates(IS 2386)
Part 1 particle size and shape
Part 2 Estimation of deleterious & organic
Impurities
Part 3 specific gravity, Density, Voids,
bulking
Absorption.
9. WATER
Municipal water supplied for drinking
purpose is generally considered fit for
construction purpose. Additionally, you
can check if the water is free of oil,
acids, salts and organic impurities. Sea-
water and ground water should
preferably not be used for construction
purposes.
10. IS Recommendations for
Water
To neutralize 100 ml sample of water,
using phenolphthalein as an indicator,
it should not require more than 5 ml of
0.02 normal NAOH IS 3025 (Part 22).
To neutralize 100 ml sample of water,
using mixed indicator, it should not
require more than 25 ml of 0.02
normal H2O,. The details of ‘test shall
be as given in 8 of IS 3025
11. BRICKS
Bricks should be sound, hard and well
burnt. They should be free from
effloresces and be uniform in size,
shape and colour.
The bricks when struck together
should produce a good metallic ringing
sound.
They must not break when dropped
from a height of approximately a
meter.
12. Steel
IS 432 Mild steel and medium tensile
steel bars and hard-drawn steel wire
for concrete reinforcement : Mild steel
and medium tensile steel bars
IS 1789 High Strength Deformed Steel
Bars and Wires for Concrete
Reinforcement
14. Concrete
Concrete is a composite construction
material composed primarily
of aggregate, cement, and water
admixtures.
Concrete has two main stages
1)Fresh Concrete
2)Hardened Concrete
15. Admixtures
Accelerating admixtures
Retarding admixtures
Water-reducing admixtures and
super plasticizers
Air-entraining admixtures
Foaming agents
16. Mixing, placing, finishing and
curing of concrete
MIXING
Involves weighing out all
the ingredients for a
batch of concrete and
mixing them together - A
six-bag batch contains
six bags of cement per
batch - Hand-mixing
(tools used) - Mixing
with stationary or paving
mixer - Mixing with truck
mixers - Rated
capacities of mixers
vary from 2cu.ft. to
7cu.yd.
18. Segregation & Bleeding
Segregation can be defined as
separating out of the ingredients
of a concrete mix, so that the
mix is no longer in a
homogeneous condition.
Bleeding is due to the rise of
water in the mix to the surface
because of the inability of the
solid particles in the mix to hold
all the mixing water during
settling of particles under the
effect of compaction.
20. POURING AND CONSOLIDATION
Formwork must be in good condition
to prevent leakage.
limit of vertical free fall not more then
.5m
Care was taken to ensure that
concrete is not over vibrated so as to
cause segregation
21. Pumping and placing
Concrete is conveyed to
the construction site in
wheel barrows, carts, belt
conveyors, cranes or
chutes or pumped (high-
rise building) - Pumps have
capacities to pump
concrete
Concrete should be placed
as near as possible to its
final position - Placed in
horizontal layers of uniform
thickness (6” to 20”) and
consolidated before placing
the next layer
27. Finishing:
The concrete must be leveled and surface made smooth/flat -
Smooth finish; Float/trowel finish; Broom finish; Exposed aggregate
finish
28. FINISHING CONCRETE SURFACE
a) All concrete while being poured
against form work was worked with
vibrator rods & trowels as required so
that good quality concrete is obtained.
b) All exposed surface of RCC lintels,
beams, columns etc. were plastered to
match with adjoining plastered face of
walls after suitably hacking the
concrete surface.
30. Terms related to concrete
Compressive Strength
Tensile Strength(8-12% CS)
Shear Strength (12-13% CS)
Bond Strength (10% CS)
31. RMC concrete Vs Site mix
concrete
The quality of concrete is a critical
factor in determining the durability and
life of your construction. In case of
site-mix concrete, the quality is
variable and depends upon the limited
expertise of the construction
supervisor. The process is manual and
non-standardised, and hence prone to
human error.
34. Methods of curing
Ponding and Immersion
Wet Coverings
Fogging and Sprinkling
Plastic Sheets
Steam Curing
Electrical, Oil, Microwave, and
Infrared Curing
35. Proportions of concrete
Use/Application Proportion on volumetric basis
Cement Sand Stone
Aggregates
Plain Cement Concrete (PCC) 1 3 6
RCC footing column, beam, slab, 1, 1 1.5, 2 3, 4(5,3)
(M20) etc.
Brick Masonry (23 cm and above) 1 6 -
Brick Masonry (Less than 23 cm) 1 3 -
Cement plaster on wall 1 4 -
Cement plaster on ceiling 1 3 -
Ceramic tiles fixing 1 4 -
Flooring 1 2 4
Cement concrete for 1 1.5 3
footpath/internal roads in housing
societies
36. Deshuttering period
Deshuttering period relates to the maturity of concrete and
depends on the ambient temperature. Forms shall not struck
until the concrete has reached strength at least twice the stress
of which the concrete may be subjected at the time of removal
of form work.
Assuming standard conditions of workmanship and quality of
materials, you can refer to the following time-frames for the
removal of forms.
37. Deshuttering period
Form Summers Winters (Temp <18°
C)
Walls, columns and vertical faces of 24 hrs. 48 hrs.
structural members
Removal of props under slab 7 days 14 days
Spanning up to 4.5 m
Removal of props under beams and 14 days 28 days
arches spanning up to 6 m
Editor's Notes
Aggregates should be hard, strong and durable. They must also be free of clay, loam, vegetable and other foreign materials. As far as possible, flaky and elongated pieces of stone should be avoided.