3. PCC
The Plain cement
concrete consists of
cement, sand and a
coarse aggregate mixed it
in suitable proportions in
addition to water.
4. PCC IS MAINLY USED FOR FOLLOWING
PURPOSES
It is used as a protective layer for the RCC above so that
water from the RCC is not absorbed by the earth below.
Provides a base for the concrete and also helps workers to
set out the structure above in a easier way
Act as a cover to reinforced cement concrete i.e. Resist
corrosion of steel bars in footings
Moisture available in soil should not absorbed by R.C.C
footings which causes corrosion of reinforcement
5. 0 the aggregate size is 40mm down size
0 the concrete should be mixed in the top & placed
it where we want it may be machine mixed or
manual
6. 0 The depth of PCC depends on SBC of soil
0 In our site they provided 150mm thick cement
concrete bed
0 In the ratio of 1:4:8 i.e., 1 part of cement, 4 parts
of fine aggregates and 8 parts of coarse aggregates
by volume were used in it.
7. FOOTINGS
0 Footings are pads or strips that support columns
and spread their load directly to the soil.
0 At our site, spread footing and one combined
footing are provided
0 Spread footing are provided to support an
individual column, it is called isolated footing
0 Depending on the size and configuration of the
building, spread footers can be buried just below
ground level or several feet below the surface
8. 0 This type of footer design is highly beneficial to
builders and homeowners
0 This design helps to minimize cracks and other
signs of damage that occur as a building settles
over time
0 There are 44 footings and dimension of
2400 x 2000 x 600mm
0 At our site we learnt how the centering for footing
been done. First applying oil and checking for all
tight joints at the corners.
9.
10.
11. 0 Combined footing are provided when the two
columns are so close to each other that their
individual footings would overlap.
0 A combined footing is also provided when the
property line is so close to one column that a
spread footing would be eccentrically loaded
when kept entirely within the property line. By
combining it with that of an interior column, the
load is evenly distributed.
0 A combine footing may be rectangular or
trapezoidal in plan.
0 Trapezoidal footing is provided when the load on
one of the columns is larger than the other
column.
12. 0 The use of combined footings helps spread out
the loads out to the adjacent footings in order to
minimize stresses in the footings and reduce the
differential settlement between them.
14. COLUMN
0 Columns are vertical members that support loads
from the beam or slabs. They may be subjected to
axial loads or moments
0 In our site they provided rectangular and circular
columns
0 The sides of rectangular column varies from
230mm to 600mm.
0 The diameter of circular column is 450mm.
17. SSM- SIZE STONE MASONARY
0 The SSM is a substructure is the lower portion of
the building, which transmits the load of the
superstructure to the subsoil
0 SSM distributes the loads of the super structure,
to a larger area so that intensity of load at its base
does not exceed the SBC of the subsoil
18. 0 SSM provide levelled and hard surface over which super
structure can be built
0 The stability of the building ,against sliding and
overturning ,due to horizontal forces such as wind
earthquake etc. Is increased due to SSM
0 The ratio of cement mortar is 1:6 i.e., 1 part of cement
and 6 parts of fine aggregates(sand)
0 Stepped SSM are provided in our site.
0 In our site undressed stones are used.
0 The grade of concrete used in SSM is M10
0 In SSM as per code(IS1597 PART 1:1992) we have to
provide break @every 1m or 2m
21. PLINTH BEAM
0 It's the sheer wall load that needs to be transferred to
the foundation; as such, 4” thick plinth concrete is
adequate
0 In RCC frame structure, plinth acts as a tie, as a beam
at ground level itself. More recently, after few disasters
we have faced, RCC plinth beams are being
recommended for their earthquake-resistant
properties.
0 In our site they used plinth beam of size 230 x 530mm
