5. INTRODUCTION
When we say concrete in the building trade, we actually mean reinforced
concrete. Its full name is reinforced cement concrete , or RCC. RCC is
concrete that contains steel bars, called Reinforcement Bars or Rebars.
Reinforced concrete elements of a building acts as a Skeleton to the
Structure. As they are they main component parts of a structure.
Horizontal members of the structure are called Beams, Vertical members
are called Columns, the flat planes which rest on these columns and
beams are called Slabs. The whole concrete structure rests on
Foundation.
6. FOUNDATION
A Foundation is the part of structure that is in direct contact with the
ground. It is the part of the structure that transmits the weight of the structure
to the ground.
Since the weight of the building rests on the soil, so we have to study
about the Safe Bearing Capacity of the Soil.
The safe bearing capacity at the site location is 45T/m2.
The type of foundation constructed at the site was Shallow Foundation.
Isolated Rectangular Stepped Footing was constructed.
8. Combined footings were also constructed in some cases where the gap
between two columns is less to construct two footings separately.
9. Fe500 Rebars were used at the site.
Reinforcement details of the footings were:
Isolated footing:
Footings No
Footing Size Reinforcement Grade of
concrete
for
FootingsA B C D Along ‘A’ Axis Along ‘B’ Axis
C1 2400 2700 450 450 10Nos 12Tor (top)
20Nos 16Tor (bot)
10Nos 12Tor (top)
18Nos 16Tor (bot)
M-20
C2 2550 2850 450 450 12Nos 12Tor (top)
24Nos 16Tor (bot)
10Nos 12Tor (top)
21Nos 16Tor (bot)
M-20
Combined footing:
Footings No
Footing Size Reinforcement Grade of
concrete
for
Footings
A B C D Along ‘A’ Axis Along ‘B’ Axis
CF-1 3150 4950 525 525 17Nos 10Tor (top)
34Nos 16Tor (bot)
11Nos 12Tor (top)
22Nos 16Tor (bot)
M-20
11. COLUMNS
Column is a structural member and also a compression member. It
takes axial load and also loads which are coming on structure and it transfers
to footings.
Pedestal:
The part of column which comes between the top of footing to
bottom of ground beam. The purpose of pedestal is to distribute the point
load as a uniformly distributed load.
12. A COLUMN CAN BE DEFINED AS A VERTICAL STRUCTURAL
MEMBER DESIGNED TO TRANSMIT A COMPRESSIVE LOAD. A
COLUMN TRANSMITS THE LOAD FROM CEILING/ROOF SLAB AND
BEAM, INCLUDING ITS OWN WEIGHT TO THE FOUNDATION.
HENCE IT SHOULD BE REALIZED THAT THE FAILURE OF A
COLUMN RESULTS IN THE COLLAPSE OF THE ENTIRE
STRUCTURE. THE DESIGN OF A COLUMN SHOULD THEREFORE
RECEIVE IMPORTANCE.
IN THE MODERN CONSTRUCTION INDUSTRY, COLUMNS ARE
MOSTLY CONSTRUCTED BY CONCRETE; APART FROM THAT
MATERIALS SUCH AS WOOD, STEEL, FIBRE-REINFORCED
POLYMER, CELLULAR PVC, AND ALUMINIUM TOO ARE BEEN
USED.
13. Starter:
The main purpose of starter is to fix the layout of the column. It is used
to maintain the verticality of the column.
Cover used for columns is 40mm.
14. Size of columns, C1 – 300X900, C2 – 300X1200
Fe500 grade steel is used, and M40 grade concrete is used.
Reinforcement details
C1- 14Nos 25Tor
C2- 8Nos 25Tor, 10Nos 20Tor
Stirrups used for
C1- 8Tor@200c/c (3 sets)
C2- 8Tor@200c/c (3 sets)
16. BEAMS
Beam is a horizontal member, it is tension member. Its takes the axial
load and shear force. Beam is rectangular in cross section. Beam transfers all
loads including self weight to the column.
Types of beams used in structure were:
i. Inverted beam
ii. Concealed beam
iii. Deep beam
1. Inverted Beam:
The beam whose bottom level is same as that of slab is
called as an inverted beam.
17. BEAM
A beam is a structural member which spans horizontally between supports and
carries loads which act at right angles to the length of the beam. They are small in
cross-section compared with their span. The width and depth of a typical beam
are “small” compared with its span. Typically, the width and depth are less than
span/10.
Generally a beam is subjected to two sets of external forces and two types of
internal forces. The external loads are the loads applied to the beam and
reactions to the loads from the supports. The two types of internal force are
bending moments and shear forces. The internal shear force and the internal
bending moment can be represented as pairs of forces. The Figure below shows
a Typical Beam with Internal and external forces acting on it.
There are several types of beams
Simply supported Beam
Fixed Beam (main bars & stripps are provided)
Cantilever Beam (top&bottom:tension&compressio zone)
Continuous Beam(more economical for span lengths)
Overhanging Beam(its end extends beyond the wall or
column. One side or both the sides of support)
20. 3. Deep Beam:
Deep beam is defined as the ratio of effective span to overall depth is
less than the
• 2.0 for simply supported
• 2.5 for Continuous
21. Sizes of beams:
1. Inverted beam: 350X750
2. Concealed beam: 950X150
3. Deep beam: 300X450, 400X600
Cover provided for beams is 25mm.
Reinforcement details
Top – 2Nos 16Tor
Bottom – 2Nos 16Tor
Top &Bottom Extra reinforcement – 1Nos 12Tor
Stirrups used – 8Tor@150c/c at corners
8Tor@230c/c in mid span
Fe500 grade steel and M25 grade concrete is used.
22. SLABS
(block consisting of thickness of something)
Slabs are plate elements forming floors and roofs of buildings and
carrying distributed loads primarily by flexure. A slab may be supported by
beams or walls.
Slabs are of two types:
1. One way slab
2. Two way slab
1) One way slab (l/b>2):
One way slab may be continuous or simply supported. The bars which
are parallel to the shorter span are called main bars. The bars which
are perpendicular to the shorter span are called distribution bars.
24. 2) Two way slab (l/b<2):
When slabs are supported on four sides, two ways spanning action
occurs. Such slabs may be continuous or simply supported on any or all
sides. The deflection and bending moments in a one way slab are
considerably reduced as compared to two way slab.
25. Thickness of One way slab – 150mm
Thickness of Two way slab – 150mm
Fe500 grade steel and M20 grade concrete is used
Reinforcement details:
One way slab:
Along short span- 8Tor@150c/c at top supports
8Tor@150c/c at bottom mid span
Along long span - 8Tor@230c/c at top supports
8Tor@230c/c at bottom mid span
Two way slab:
Along short span- 8Tor@150c/c at top supports
8Tor@150c/c at bottom mid span
Along long span - 8Tor@230c/c at top supports
8Tor@230c/c at bottom mid span
26.
27. One Way Slab Two Way Slab
One way slab is supported by beams in only 2 sides. Two way slab is supported by beams in all four sides.
The ratio of longer span panel (L) to shorter span
panel (B) is equal or greater than 2. Thus, L/B >= 2
The ratio of longer span panel (L) to shorter span
panel (B) is less than 2. Thus, L/B < 2.
Main reinforcement is provided in only one direction
for one way slabs.
Main reinforcement is provided in both the direction
for two way slabs.
28. Two Way Slab
Two way slabs are the slabs that are supported on four sides and the ratio of
longer span (l) to shorter span (b) is less than 2. In two way slabs, load will be
carried in both the directions. So, main reinforcement is provided in both
direction for two way slabs.
One Way Slab
One way slab is supported on two opposite side only thus structural action is only
at one direction. Total load is carried in the direction perpendicular to the
supporting beam. If a slab is supported on all the four sides but the ratio of longer
span (l) to shorten span (b) is greater than 2, then the slab will be considered as
one way slab. Because due to the huge difference in lengths, load is not
transferred to the shorter beams. Main reinforcement is provided in only one
direction for one way slabs.
