Basic Civil Engineering- Components of building

1. COMPONENTS OF
BUILDING
By,
Ms. Priya Sarita Mane

2.  The structure of a building essentially consists of
two parts namely the sub-structure and
the super-structure.
1. Sub-structure
2. Super-structure
 1. Sub-structure:-
 It is that part of the structure which is below
the ground level i.e.
foundation.
 It also includes the portion below the ground
level since the height between the ground floor
level and the ground level is negligibly small as
compared to the height of the building.

3. 2. Super-structure:-
 It is that part of the structure which is above the
ground level or ground floor level.
 The principal parts of the super-structure which
carry the structural or superimposed
loads are,
(i) Masonry walls, (ii) Pillars or columns, (iii) Beams,
(iv) Lintels, (v) Arches, (vi) Floor slabs and (vii) Roofs
etc.
 The other parts of the super-structure which do not
carry any structural loads are,
(i) Curtain or partition walls, (ii) Doors,
(iii) Windows and (iv) Parapet wall etc.

4. A TYPICAL CROSS
SECTION THROUGH
DOOR AND WINDOW
SHOWING ALL BUILDING
COMPONENTS

5. Basic building components
Super Structure
Plinth
D.P.C
Walls and columns
Floors
Beams
Roofs and slabs
Lintels and Archers
Doors and Window
Chajjas
Parapet
Steps and Stairs
Cupboard and Shelves
Substructure
Foundation

6. COMPONENTSOFSUB-STRUCTUREAND THEIR
FUNCTIONS
 The various components or elements of sub-structure
are as given below:
1. Foundation-
 It is the lowermost part of the building below the
ground level and it forms the base of the building.
It mainly consists of the base-course in cement
concrete to fill all the pockets in foundation
 Functions or Purpose: (a) To transfer the load of the
building uniformly to a larger area
of sub-soil to reduce the intensity of load.

7. (b) To sustain the load of the building without yielding.
(c)To provide a level surface for concreting and masonry
work.
Materials :-
Plain concrete, Reinforced Cement Concrete (R.C.C.),
Stones are used.

8. TYPES OF FOUNDATIONS
 Foundations can broadly be classified in two types,
such as Shallow and Deep foundations.
(I) Shallow Foundation
 When the depth of foundation 'D' is less or equal to the
width 'B' it is called as Shallow Foundation or open
foundation . Generally it is 3 to 4 m.
 The various types of shallow foundations are as
follows.
(i) Wall Footing (Strip), (ii) Column Footing,
(iii) Inverted Arch Footing, (iv) Raft or Mat Footing
(v) Grillage Foundation.

9. (II)Deep Foundation -
 When a stratum of good bearing capacity is not
available at reasonable depth i.e. D > B and where
other types of foundations such as grillage or raft
foundations are not suitable, then deep foundation
must be adopted to attain a bearing stratum which
will be suitable in all respect.
 They are generally provided when depth of foundation
is more than 5 meters.
 Types of Deep Foundations: Important types of deep
foundations are-
(i) Pile Foundation,(ii) Pier Foundation,(iii) Caisson

10.  2. Plinth-
 It is the portion of the sub-structure between the
level of the surrounding ground and the
level of ground floor.
 The filling between the ground floor level i.e.
plinth level and ground level is known as plinth
filling.
 Minimum height of plinth should be 45 cm above
the ground level.

11.  Functions:-
 To support the super structure and provide
stability and strength.
 To transfer the load from the building to the
foundation layer.
 To provide adequate grip or hold to the structure on
the subsoil.
 To retain the plinth filling.
 To provide safety against rats, rodents, flood on
roads, etc.
 To give aesthetic aspect to the elevation of the
building.
Materials: Stones, bricks are used.

12. 3. Damp Proof Course ( D.P.C.)-
 It is the layer provided in between the sub-
structure and super-structure
 Functions: It prevents the entry of moisture into
the foundation below and super-structure
above and vice-versa.
 Materials: Stone slabs of impervious variety, plain
cement concrete are used for damp
proof courses.

13. COMPONENTSOFSUPER-STRUCTUREAND THEIR
FUNCTIONS
 Different components or elements of the super-
structure are as given below.
1. Walls-
There are two types of walls.
(1) Load bearing walls and
(2) Non-load bearing Walls
 Functions:
 To enclose or divide the space to make it functional
and useful.
 To transfer the load of floors to foundation.
 To provide privacy, security and protection against
weathering conditions.

14. 2. Pillars and Columns-
 These are the structural vertical members of a
building.
Functions :-
 These are constructed at suitable intervals to provide
lateral stability to the wall.
 Pillars and columns are constructed to provide
support to the beams, slabs and transfer the loads to
the foundation.
Materials: These are constructed in bricks, stones,
steel and reinforced cement concrete.
 These are constructed in various sizes and shapes
such as square, rectangular, circular, etc.

15. 3. Doors-
 These are the movable panels constructed in the
openings through a wall.
 Functions : They provide horizontal circulation. or
movement of the inmates from one
room to another of the building.
 Materials: They are made up of wood. ply-wood,
plastic. metal and glass.

16. 4. Windows -
 These are the openings built in the walls.
 Functions: They provide light, air, cross
ventilation etc. They also provide privacy and
security. They should be built considering the
direction of wind, exterior view i.e. aspect,
prospect etc.
 Materials: They are made up of wood, ply-wood.
plastic, steel and glass.

17. 5. Window-sills -
 These are provided below the windows
 Functions: They provide a uniform surface and
support to the window and also protect
the top of the wall from wear and tear.
 Materials: Materials used are stone-slabs and
cement. concrete.

18. 6. Lintels and Arches –
 These are provided over the openings of doors
and windows.
 Functions: Lintels support the load of the wall
above the opening since the frame of the
door or window is not strong to bear it.
 Materials: Lintels are constructed with sound
timber and R C. C.

19. 7. Ceiling-
 It is the lower part of upper floors.
 Functions: They are used as insulators against
sound and vibrations of upper floors.
They are provided to look more pleasing and
beautiful.
 Type: False ceiling made of plaster of paris,
plastics etc'

20. 8. Beams-
 Beams are structural horizontal members of a
building.
 Functions : These are constructed to support the
floors and transfer their loads to the columns.
They give lateral rigidity to framed structures.
 Materials: Materials used are timber, steel and
R.C.C.
 Types: Beams may be simply supported, fixed or
cantilever type

21. 9. Slabs -
 These are the horizontal surfaces supported on
beams and columns.
 Functions:
 It provides space for the occupants to live, move and
keep their materials.
 It distributes the load of the floors, uniformly and
transfer it to the columns and walls through beams. It
acts as floor or roof for multi storied buildings.
 Materials: The material used is R.C.C.

22. 10. Roof:
 This is the top most part of the building.
Functions: It protects against sun, wind, rain,
snow, thefts etc.
 Materials: It is covered with a suitable material
such as country tiles, Mangalore tiles,
Allahabad tiles, Asbestos sheets, Galvanized iron
sheets or reinforced cement concrete.

23. Types of roof
Flat Sloped Domes
Lean-to-roof King post trussQueen post truss
Cylindrical Spherical

24. 11. Finish For Walls-
 It is done by plastering, pointing with cement
mortar or even painting.
 Functions: They protect the exposed surface,
conceal the bad workman ship and give a
pleasant look.

25. 12.FLOOR - A floor provides a plane surface to support the
occupants, furniture and any equipment.
Types of floor
(1) Ground floors
(2) Upper floors
The different types of floor which are commonly used for
floor construction is
(1)Mud and Muroom
(2)Stone
(3)Terrazzo
(4)Tiles
(5)Timber
(6)Rubber
(7)Mosaic tiles
(8) Brick
(9)C.C
(10)Marble
(11)Asphalt
(12)Glass
(13)Granite
(14)Plastic or PVC

26. TYPES OFSOILAND ROCKSAS FOUNDATION
STRATA
1.Types of Soils-
(a) Non-cohesive soils
(b) Cohesive Soils
2. Types of Rock-
There are three types of rocks such as-
(i) Igneous rocks, (ii) Sedimentary rocks and
(iii) Metamorphic rocks.

27.  Igneous rocks: Rocks that are formed by cooling of
Magana (molten or pasty rocky material) are known as
igneous rocks. Ex. Granite, Basalt and Dolerite etc.
 Sedimentary rocks: these rocks are formed by the
deposition of production of weathering on the pre- existing
rocks. Ex. gravel, sandstone, limestone, gypsum, lignite
etc.
 Metamorphic rocks: These rocks are formed by the
change in character of the pre-existing rocks. Igneous as
well as sedimentary rocks are changed in character when
they are subject to great heat and pressure. Known as
metamorphism. Ex. Quartzite, Schist, Slate, Marble and
Gneisses.

28. CONCEPTOFBEARING CAPACITY
 The terms bearing power, bearing value and bearing
capacity are used to denote the ability of the soil to
sustain the total load of the structure without yielding
or showing any settlement.
 Bearing capacity of the soil depends upon the
physical properties of soil such as shape, size,
density, surface texture, voids, frictional resistance,
cohesion and moisture retaining
capacity.

29. Ultimate bearing capacity
 The Ultimate bearing capacity is the theoretical
maximum pressure which can be supported
without failure.
 allowable bearing capacity or safe bearing
capacity is the ultimate bearing capacity divided
by a factor of safety.
safe bearing capacity

30. PLATE LOAD TEST
 Plate load test is done at site to determine the ultimate
bearing capacity of soil and settlement of foundation
under the loads for clayey and sandy soils. So, plate
load test is helpful for the selection and design the
foundation. To calculate safe bearing capacity suitable
factor of safety is applied.
 Apparatus for Plate Load Test on Soil
 Mild Steel plate
 Hydraulic jack
 Reaction beam or reaction truss
 Dial gauges
 Excavating tools

31. Procedure of Plate Load Test on Soil
 A Pit is excavated in the ground at which foundation is to
be laid. The size of pit is generally 5 times the size of the
plate. The depth excavated should be equal to proposed
foundation depth.
 The plate used is made of mild steel. It may be square
(0.3m x 0.3m) or circular (0.3m diameter) with 25mm
thickness.
 After excavation of pit, at center of excavated pit steel
plate sized hole with “Dp” thickness is excavated and
arrange the plate in it.
 The Thickness of plate Dp is calculated by formula

32.  After arranging the plate in central hole hydraulic jack is
arranged on top of plate to apply load. Reaction beam or
reaction trusses is provided for the hydraulic jack to take up
the reaction. Otherwise a loaded platform is created (using
sand bags etc.) on the top of hydraulic jack and provided
the reaction.
 After that seating load of 7kN/m2 is applied to set the
plate and released after some time. Now load is applied
with an increment of 20% of safe load.
 Dial gauges are arranged at bottom to record the
settlement values. At 1min, 5min, 10min, 20min, 40min,
and 60min and after that for every one-hour interval the
settlement is observed and noted. The observations are
made until the total settlement of 25mm has occurred.

33. Plate Load Test

34. Truss loading
 In case of reaction truss loading, a truss is arranged on
jack and both sides of truss are anchored to the ground
with strong support. Two ends of truss are loaded
uniformly, then truss transforms the load into the plate
and settlement occurs.
 Load is applied with an increment of 2kN at every interval.
Settlement is observed at different intervals as said in
above method. For clayey soils, the observations are
made until the rate of settlement is to be 0.2mm per hour.

36. Types of Foundation
Shallow Deep
Pile Pier Well or Caisson
Spread footing Strap footing Combined footing Mat footing
For walls for columns Rectangular Trapezoidal
Simple Stepped Grillage Single Stepped Sloped

38. Spread footing - which spread the super imposed load of
wall or column over larger area. Masonry walls have
stepped footing with a concrete base.
Suitable: when good bearing capacity available at shallow
depth

39. Strap footing - If the independent footing of two columns are
connected by a beam it is called a strap footing.
Suitable: when extreme column very close to boundary of
plot.

40. Combined footing - A spread footing which support two or
more columns is turned as.
Suitable- columns are close to each other

41. RAFT or MAT foundation – It is a combined footing that
covers the entire are beneath a structure and supports all
walls and columns.
Suitable- soft clay or marshy land or in case of chances of
differential settlement

42. Grillage Foundation – Grillage foundation is a special
type of isolated footing and it is provided for heavily loaded
steel stanchions. The depth of foundation is 1 to 1.5m
Suitable- if soil have low bearing capacity

43. Inverted Arch Foundation
this is either in brick or stone & built between two walls,
Suitability- at soft soil

44. Pile Foundation-Pile foundations are deep foundations
used when the site has a weak shallow bearing strata
making it necessary to transfer load to a deeper strata either
by friction or end bearing principles. Pile are formed by long
slender columnar elements.

45. Classification based on load transmission:
End bearing piles (Point bearing)
These transmit most of their loads to the load bearing
layer (which can be dense sand or rock). Most of the pile
capacity is inferred from the end bearing point.
Frictional Piles
These transmit their load through the layers through which
the piles pass which is mostly through the surface friction
(skin friction) with the surrounding soils.
End bearing piles Frictional Piles

46. Under reamed piles
These are bored cast-in-situ concrete piles having one or more
number of bulbs formed by enlarging the pile stem.
These piles are best suited in soils where considerable ground
movements occur due to seasonal variations, filled up grounds
or in soft soil strata.

47. Classification based on Material of Piles Construction:
Timber piles:
Timber can be used for manufacture of temporary piles
and also for permanent ones in regions where timber is
readily and economically available. It’s most suitable for
long cohesion piling and piling under embankments.
Steel piles:
Steel can be used for both temporary and permanent
works. They are suitable for handling and driving for
piles with prolonged lengths. there may occur a risk of
corrosion which can be eliminated by tar coating or
cathodic protection.

48. Well foundation
Well foundation is a type of deep foundation which is
generally provided below the water level for bridges.
Cassions or well have been in use for foundations of
bridges and other structures since Roman and Mughal
periods.