B.K.N GOVT. POLYTECHNIC . POLYTECHNIC , NARNAUL

BY- NISHA YADAV

Reinforced Concrete Structure

(IS 456

…

Concrete Structure

(IS 456 :2000)

Design of Different TypeStructural

Beam

Design of Different Type of Structural Elements

Slab

Column

� Topics are taught thoroughly and

concepts and fundamental principles without weakening

� Many example problems are solved to demonstrate or to provide

insights into the basic concepts and

� The solution of each example

to teach students to think about possible solutions to a problem before

Some Key Features of

to teach students to think about possible solutions to a problem before

begin to solve it.

� Each solution provides a step

problem-solving which really

for the conventional exam

are taught thoroughly and systematically to clarify the basic

concepts and fundamental principles without weakening technicalhardship.

are solved to demonstrate or to provide further

insights into the basic concepts and applications of fundamentalprinciples.

example is preceded by a strategy, which is intended

students to think about possible solutions to a problem beforethey

Some Key Features of this Course

students to think about possible solutions to a problem beforethey

step-by-step procedure to guide the student in

really help students for university examinations and

for the conventional exam like ESE (Engineering Services Examinations).

Design of Reinforced Concrete

For Full Course visit,…

www.machenlink.com

Concrete Structure (IS 456:2000)

01 || Introduction ||

02 || Analysis and Design of Beam || WSM ||

03 || Analysis and Design of Beam || LSM ||

04 || Design for Shear, Torsion and Bond ||

05 || Design for Slabs ||

06 || Design for Compression Members ||

What is “IS 456:2000

� IS 456: 2000 is Indian National Building

� Provide guidelines for the design

� Evolved from the collective wisdom

� Periodically revised to bring them in line with current research, and often, current� Periodically revised to bring them in line with current research, and often, current

01 || Introduction

456:2000” ?

Indian National Building Code.

design and construction of structures.

collective wisdom of expert structural engineers.

to bring them in line with current research, and often, currentto bring them in line with current research, and often, current

Introduction to RCC

01 || Introductionoduction to RCC

Objective of Structural DesignDesign

Objective of Structural Design

Tension

Design

compression

IS 456 - 2000

.. .. .. .. … ..

.. .. .. .. … ..

.. .. .. .. … ..

.. .. .. .. … ..

.. .. .. .. … ..

Objective of Structural Design

.. .. .. .. … ..

.. .. .. .. … ..

Disaster Management of India

� 2600People die every year due

to building collapse.

Design

2013

7 storey Building collapsed in

Thane , Maharashtra

Objective of Structural Design

Reason of Failure

Use of sub-standard

construction Material.

Design

IS 456 - 2000

.. .. .. .. … ..

.. .. .. .. … ..

.. .. .. .. … ..

.. .. .. .. … ..

.. .. .. .. … ..

1.

Objective of Structural Design

.. .. .. .. … ..

.. .. .. .. … ..

1. StrengthStresses should not exceed

the critical values.

Design

Objective of Structural Design

40m Curve

Ultadenga flyover in Kolkata

Design

2. Stability� Overturning

� Buckling

� Sliding

should be prevented.

Objective of Structural Design

prevented.

Design

3.

Objective of Structural Design

3. Serviceability� Stiffness

� Deflection

� Impermeability

� Durability

Design

2.1.Strength

Objective of Structural Design

3. Serviceability

2.Stability

Design

Planning phase

Structural Analysis And Design

Reinforced Concrete Construction

Are the safety& Serviceability Requirement Satisfied?

YES

Construction Phase

NO

Revised Structural Design

Construction

Planning Phase:

� Carried out by Architect/planner to plan the layout of structure

� Functional Requirement� Aesthetics Requirement� Budgetary Requirements

Structural Analysis And Design:� Selection of most appropriate Structural System to bring the architect concept into being

� Estimation of loads on structure� Structural analysis for estimationstresses.

� Structural Design of actual proportion( size, reinforcement etc.) for safety and serviceability.

� Submission of drawing.

Concrete & Reinforced Steel

Plain Concrete is made by mixing of :

Cement

Aggregate

Water

Admixture

Concrete is generally prepared at the site itself, Concrete is generally prepared at the site itself,

although ready-mixed concrete and precast

concrete are also used.

Concrete compressive strength is very high.

Concrete tensile strength is very low

(negligible) compare to its compressive

strength.

Steel

Hairline Crack Steel Bars Undergo

Steel Bars embedded

Concrete & Reinforced Steel

Hairline Crack (not Perceptible )

Steel Bars UndergoYielding

Ductile mode of failure under heavy load.

Steel

Steel embedded in concrete calledreinforced steel

� Usually manufactured in factoriesunder control conditions.

� It can effectively take up the tension

= RCC

that induced due to –� flexural tension� direct tension� diagonal tension� environmental effect

� Steel also impart ductility to materials

�Steel compressive strength is more than concrete.

Grade of Concrete

Design properties of concrete

This is measured by standard test

M20M 20

M refers to mix

Design properties of concrete are:

measured by standard test on concrete cube.

150 mm Cube

Characteristics compressive strength (28 Days) expressed in MPa (N/mm2 )

Grade of Concrete

Design properties of concrete

IS 456 -2000 TABLE NO.

This is measured by standard test

Types of concrete

High Strength concrete

Standard Strength concrete

Normal Strength concrete

IS 456 -2000 TABLE NO.

Design properties of concrete are:

NO. 02

measured by standard test on concrete cube.

150 mm CubeGrade

Above M 60

M25 to M 55

M 10 to M20

NO. 02

Characteristic Strength ( f

≠ ≠

Characteristic Strength ( fck )

Even we collect them from same mix but there

Compressive strength is not same.

Characteristic Strength (

Definition: Its is defined as the strength of material below which than 5% result are expected to fall.

� Subjected to considerable variation instrength.

� The variation in concrete is expressed terms of standard deviation and/or coefficient of variation.coefficient of variation.

Target

Coefficient of variation =����������������

��� �������ℎ

Strength ( fck )

the strength of material below which not more

in

expressed in and/or

Specimen

Compressive strength (28 days)5%Area

Target mean strength fm = fck + 1.65s

Characteristicstrength

1.65�Meanstrength

�

ℎ

Characteristic Strength (

Definition: Its is defined as the strength of material below which than 5% result are expected to fall.

Values of standard deviation ( �) 2000Grade M 10, M 15

� (N/2) 3.5

Strength ( fck )

the strength of material below which not more

) as per IS456-

M 20, M25 ≥ M 30

4.0 5.0

Modulus of Elasticity of Concrete

Concrete - Brittle material.-elastic-linear

Only initial portion of curve is linear.

�������� =

������

-term elastic strain (Instantaneous load)

2. Long-term elastic strain (creep & shrinkage)

��= short-term modulus of elasticity

���= effective modulus of elasticity

of Concrete (��)

of

Strain

Stress

term elastic strain

effective modulus

Modulus of Elasticity of Concrete

Possible type of ��(Short-term strain)Initial Tangent Modulus (ITM)Tangent Modulus (TM)Secant modulus (SM)

Empirical formula for static modulus Empirical formula for static modulus given by IS 456-2000 (Cl. 6.2.3.1)

��= 5000 fc�

Based on ITM

of Concrete (��)

IT

T

S SpecifiedS

Strain

Stress

Specifiedstress level

Tensile Strength

to 15% of compressive strength.

Tensile strength tests.Direct tension testSplitting testFlexural Tension test.

Secondary stresses induced due to induced due to gripping

Direct tension test

Tensile Strength

to 15% of compressive strength.

Tensile strength tests.Direct tension testSplitting testFlexural Tension test.

Splitting Test

Tensile Strength

to 15% of compressive strength.

Tensile strength tests.Direct tension testSplitting testFlexural Tension test.

100mm x 100

Loading pin

100mm x 500mm

Supporting pin

Three Point Method

Tensile Strength

to 15% of compressive strength.

Modulus of Rupture (fcr)

theoretical maximum tensile stressreached in extreme fiber.

Empirical Formula suggested by Code

fcr =0.7 fc�

Relation between tensile & compressive stress.

fcr =M

Z

Creep (�)

CrTotalstrain

Time dependent component of totalstrain

tantaneous strain

Creep strain

Crstrai

Total

depend on Stress level.

Creep coefficient:

� = ����� ����������� (�)������������ ������

Creep Ultimate creep

Instantaneousstrain

Creep strain

Ultimate creep strain

Time (t)

Creep (�)

Creep Coefficient for design:-2000 (Cl. 6.2.5.1)

Days �

7 2.2

28 1.6

1 year 1.1 CrTotalstrain

1 year 1.1

Effective modulus of Elasticity (���) long-term modulus

���=��

1+�

Crstrai

Total

Creep Ultimate creep

Instantaneorecovery

Creeprecovery

unloading

Instantaneousstrain

Creep strain

Ultimate creep strain

Time (t)

Residualcreep strain

Shrinkage

Concrete shrinks ( hardened state )Due to loss of moisture by Evaporation.

Shrinkage:– reduction in volume of concrete.

Similar to Creep – induced time dependent strain.

Shrinkage Restrain developed tensile stress – lead to cracking

Differential Shrinkage: due to moisture or thermal gradient,Differential Shrinkage: due to moisture or thermal gradient,OR due to unsymmetrically placed reinforced

Induced internal stressesCurvatureDeflection

Shrinkage strain for

Expressed as

Unlike Creep – independent of Stress level

cracking

gradient,gradient,OR due to unsymmetrically placed reinforced steel in beam

Shrinkage strain for Design:

as linear strain (mm/mm)

IS 456-2000 (Cl. 6.2.4.1)0.0003mm/mm

DurabilityWhat is durability of concrete ?

concrete is to serve the purpose for which it is designed

Some factors which effect the durability of

Internal factors External factors

� EnvironmentalProperties of ingredient used to

Effective way to Increase durability:Provide adequate clear cover to embedded steel.Using coated steelUsing appropriate minimum grade of concrete accordingenvironmental exposure condition.

� Environmentaleffectsingredient used to

make concrete

� Alkali-reactive aggregate� Salty water

it is designed during its intended lifetime.

which effect the durability of concrete.

factors

Environmental

according toNominal or clear cover

Environmental

Durability

osure

categoryDescription

ild Protected against weather or aggressive conditions, except in coastal area

Moderate Sheltered from severe rain or freezing whilst wet, or Exposed to condensation & rain, or continuously under water, or buried under non-aggressive soil or ground water, or sheltered from

Cl. 8.2.2.1 – Environmental Exposure

Severe

buried under non-aggressive soil or ground water, or sheltered from saturated ‘salt air’ in coastal area

Exposed to severe rain, alternate wetting and drying or occasional freezing whilst wet or severe condensation, or completely sea water, or exposed to coastal area

severe Exposed sea water spray, corrosive fumes or severe freezing whilst wet, or in contact with or buried under aggressive subwater

Extreme Members in tidal zone, or member in direct contact with liquid/solid aggressive chemicals

Min. Min. Min. Ma

except if located in

or freezing whilst wet, or Exposed to or continuously under water, or in contact with or

aggressive soil or ground water, or sheltered from

Grade Cover Cement Free

M20

(mm)

20

Kg/��)

300

content

0.55

M 25 30 300 0.50

Environmental Exposure Conditions

aggressive soil or ground water, or sheltered from

drying or occasional completely immersed in

freezing whilst wet, contact with or buried under aggressive sub-soil or ground

direct contact with liquid/solid

M30 45 320 0.45

M35 50 340 0.45

M40 75 360 0.40

Reinforced Steel

Rebars – Reinforcing Bars

of Bars…

Nominal diameters - 5 mm to 50mm.

Mostly used between – 8 mm to mm to 32mm

Reinforced Steel

Rebars – Reinforcing Bars

of Bars…

Nominal diameters - 5 mm to 50mm.

Mostly used between – 8 mm to mm to 32mm

Reinforced Steel

Rebars – Reinforcing Bars

of Bars…

Nominal diameters - 5 mm to 50mm.

Bars Deformed

Smooth Surface

DeformedBars

Lugs on surface

Lugs enhanced the bond betweenand

Reinforced Steel

Grade of Steel: Yield strength of steel

Cl. 36.1 – Specified yield strength may be treated as characteristic

Types of steel:

Mild steel (Fe 250): less commonly used becausetheir low strength.

Medium Tensile SteelCold twisted Bar: HYSD ( High Yield StrengthCold twisted Bar: HYSD ( High Yield Strength

Deformed ) Bars. e.g. Fe 415, 500TMT Bars: Thermo mechanically Treated(TMT)

inner core – soft and ductile

Cl. 5.6.3 specifies ��= 2 x 105 ���

outer shell – very high tensile strength

Anti-corrosive coating

Modulus of elasticity (��):

For all grade – initial lHinigehasrtreelnagstthic portionwithconstant slope

Ductile

characteristic strength.

250): less commonly used because of

(Expr�e�ssed in N/mm2)

Fe500

StrainStress

Fe415

��= 2 x 105 ���

Yield Strength of HYSD Bars

Strain

��

��

0.002 ����

�� = 0.002 + ��/��

Bars

Yield stress is read at 0.2% proof strain.i.e. at strain of 0.002

ONE WAY VS TWO WAY SLABONE WAY VS TWO WAY SLAB

RCC COLUMN

RCC 2D DRAWING WITH AUTOCADRCC 2D DRAWING WITH AUTOCAD

THANKSTHANKS