b.k.n govt . polytechnic , narnaul
TRANSCRIPT
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
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Objective of Structural Design
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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
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1.
Objective of Structural Design
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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