CONSTRUCTION OF REINFORCED CONCRETE

STRUCTURES OF BUILDING

PROJECT DETAILS

Company Name: JVR Infra Tech (India) Pvt. Ltd., Banjara Hills, Hyderabad.Project Location: JVR Blossoms, Bibi nagar road, Ghatkesar.

Layout plan of JVR Blossoms

OVERVIEW:

INTRODUCTION FOUNDATION COLUMNS BEAMS SLABS

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.

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.

Stepped Isolated rectangular Single footings

Combined footings were also constructed in some cases where the gap between two columns is less to construct two footings separately.

Fe500 Rebars were used at the site.Reinforcement details of the footings were:

Isolated footing:

Footings NoFooting Size Reinforcement Grade

of concret

e for Footing

s

A 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

Cover provided for Footing is 50mm.

Reinforcement of Footings

COLUMNSColumn 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.

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.

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.

Size of columns, C1 – 300X900, C2 – 300X1200Fe500 grade steel is used, and M40 grade concrete is used.Reinforcement details

C1- 14Nos 25TorC2- 8Nos 25Tor, 10Nos 20Tor

Stirrups used forC1- 8Tor@200c/c (3 sets)C2- 8Tor@200c/c (3 sets)

Reinforcement of Column

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 beamii. Concealed beamiii. Deep beam

1. Inverted Beam:The beam whose bottom level is same as that of

slab is called as an inverted beam.

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 beamsSimply supported BeamFixed 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)

Inverted Beam

2. Concealed Beam:The beam whose depth is same as the depth of the

slab.

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

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.

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 slab2. Two way slab1) 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.

Reinforcement in One way slab

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.

Thickness of One way slab – 150mmThickness of Two way slab – 150mmFe500 grade steel and M20 grade concrete is usedReinforcement details:

One way slab:Along short span- 8Tor@150c/c at top supports

8Tor@150c/c at bottom mid spanAlong long span - 8Tor@230c/c at top supports

8Tor@230c/c at bottom mid spanTwo 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

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.

Two Way SlabTwo 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 SlabOne 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.