welcome to 430431 reinforced concrete design -...
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443304310431 Reinforced Concrete DesignReinforced Concrete Design
Welcome to
Instructor: Mongkol JIRAVACHARADETInstructor: Mongkol JIRAVACHARADET
School of Civil EngineeringSchool of Civil Engineering
Suranaree University of TechnologySuranaree University of Technology
Lecture 1 - Introduction
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TEXTBOOKSTEXTBOOKS
Reinforced Concrete: Mechanics and Design, 5th EditionJames G. MacGregor, James K. Wight, Prentice Hall, 2009.
Design of Concrete Structures, 13th EditionArthur H. Nilson, David Darwin, Charles W. Dolan, McGraw-Hill, 2003.
Reinforced Concrete: A Fundamental Approach, 6th EditionEdward G. Nawy, Prentice Hall, 2009.
Building Code Requirements for Structural Concrete,ACI318-08,American Concrete Institute, 2005.
TA683.2 W53 2009TA444 N38 2009
TA683.2 N55 2004 TA683.2 H365 2005
TA683.2 M39 2009 TA683.2 R48 2008
Course ObjectivesCourse Objectives
More than just trial and error, design is based on built up experience
as well as a solid background in analysis and an understanding of the
parameters affecting a good design solution.
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Conduct of Course
Design Projects 20 %
Midterm Exam 40 %
Final Exam 40 %
Grading Policy
Final Score Grade
100 - 90 A89 - 85 B+84 - 80 B79 - 75 C+74 - 70 C69 - 65 D+64 - 60 D59 - 0 F
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WARNINGS !!!
1)1) Participation expectedParticipation expected,, check check 80%80%
2)2) Study in groups but submit work on your ownStudy in groups but submit work on your own
3)3) No Copying of ProjectNo Copying of Project
4)4) Submit Project at the right place and timeSubmit Project at the right place and time
5)5) Late Project with penalty Late Project with penalty 30%30%
6)6) No make up quizzes or examsNo make up quizzes or exams
Reinforced Concrete Design (RC Design)Reinforced Concrete Design (RC Design)
• Specifications, Loads, and Design Methods
• Strength of Rectangular Section in Bending
• Shear and Diagonal Tension
• Design of Stairs, Double RC Beam, and T-Beam
• Analysis and Design for Torsion
• Design of Slabs: One-way, and Two-way
• Bond and Achorage
• Design of Column, and Footing
• Serviceability
Content:Content:
� Structural Design Concept
� Mechanical Properties of Concrete
� Steel Reinforcement
� Reinforced Concrete Structures
Reinforced Concrete Design
Lecture 1 : IntroductionLecture 1 : Introduction
Topics Covered
Structural Design ConceptStructural Design Concept
Structural Engineering
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Structural Design Concept
�������� Stability
�������� Safety
�������� Serviceability
��������Economy
��������Environment
LIFE-CYCLE OF STRUCTURE
Lesscompetitors
Traditionalactivities
New Design
Construction
Maintenance / Repairs /Renovation
Removal / Failure
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Concrete & Steel PropertiesConcrete & Steel Properties
What is Concrete?
Concrete is a mix of :
Water Cement Ratio (W/C) :
Low W/C
High StrengthLow Workability
High W/C
Low StrengthHigh Workability
0.3 0.7
Optimal ratios obtainedby trial and experience
30cm
∅ 15 cm
ASTM BS15 cm
15 cm
15 cm
( ) ( )0.85c cASTM BSf f′ ′≅
Compressive Strength of Concrete
cf ′ compression test of standard cylinder at 28 days
Normal used: 210, 240, 280, 320 kg/cm2
High strength: 350 - 700 kg/cm2
�.�.�. ��������� �.�. 2522 : < 150 kg/cm2
200
250
300
350
400
450
500
Com
pres
sive
str
engt
h,kg
f/cm
2
0.4 0.5 0.6 0.7
Water-cement ratio, by weight
Air-entrained concrete
Non-air-entrained concrete
For type Iportland cement
Effect of water-cement ratio on 28 days compressive strength
Tensile Strength of Concrete
- Greatly affects cracking in structures.
- Tensile strength is about 10-15% of compressive strength.
Splitting Tensile Test (ASTM C496):
L
P
P
D2
ct
Pf
LDπ=
2
2
1.59 1.86 kgf/cm for normal-weight concrete
1.33 1.59 kgf/cm for light-weight concrete
ct c
ct c
f f
f f
′≈ −
′≈ −
แรงกด
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แรงดึง
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Standard Beam Test (ASTM C78):
r
Mcf
I= = Modulus of rupture
7.5 psi 2.0 kscr c cf f f′ ′= =
Practical choice for design purposes
Tensile Strength in Flexure
P
Stress-Strain Relationship of Concrete
0.003≈
Ultimate strainASTM
ε
σ
εεεεcu
Initial modulus
0.5 cf ′
Secant modulusat = Ec0.5 cf ′
cf ′
Concrete & Steel Strength-Deformations
REINF.ROD
CONCRETE
L
∆L
εc = ∆L/L = εs
Strain
σCompression Steel
Tension
Concrete
ε1
fs
fc1
ε2
fy
εy
fc2
ε3
fy
εcm
f’c
εcu
FailureStrain
fy
0.85f’c
Concrete: 1.533 psic c cE w f ′=
lb/ft3 psi
1.54, 270 kscc c cE w f ′=
t/m3 ksc
315,100 ksc for 2.32 t/mc c cE f w′= =
62.04 10 kscsE = ×Steel:
Modulus of elasticity
Concrete Weight
Plain concrete = 2.323 t/m3
Steel = 7.850 t/m3
Reinforced concrete = 2.400 t/m3
Lightweight concrete = 1.6 - 2.0 t/m3
Steel Reinforcment
Round Bar (����กก����������)
SR24: Fy = 2,400 ksc, Fu = 3,900 ksc
Deformed Bar (����ก$%&&%&�)
SD30: Fy = 3,000 ksc, Fu = 4,900 ksc
SD40: Fy = 4,000 ksc, Fu = 5,700 ksc
SD50: Fy = 5,000 ksc, Fu = 6,300 ksc
Stardard Reinforcing Bar Dimension and Weight
RB6
RB9
DB12
DB16
DB20
DB25
DB28
DB32
0.28
0.64
1.13
2.01
2.84
4.91
6.16
8.04
0.222
0.499
0.888
1.58
2.23
3.85
4.83
6.31
1.89
2.83
3.77
5.03
5.97
7.86
8.80
10.06
BAR SIZE(mm)
AREA(cm2)
WEIGHT(kg/m)
PERIMETER(cm)
Reinforced ConcreteReinforced Concrete
Reinforced Concrete (RC) Structures
Steel bars
Concrete
Section A-A
PA
A Steel bars
compression zonetension zone
Neutral axis
Concrete: high compressive strength but low tensile strength
Steel bars: embedded in concrete (reinforcing)provide tensile strength
Steel and Concrete in Combination
(1) Bond between steel and concrete prevents slip of the steel bars.
(2) Concrete covering prevent water intrusion and bar corrosion.
(3) Similar rate of thermal expansion,
Concrete: 0.000010 - 0.000013
Steel: 0.000012
WHY Reinforced Concrete?
� Concrete is cheaper than steel
� Good combination of Concrete & Steel
� Durability from concrete covering
� Continuity from monolithic joint
Disadvantages of RC
� Construction time
� Concrete Quality Control
� Cracking of Concrete
Column
Typical Structure
1st Floor
2nd Floor
Beam Joist
Spandrelbeam
Wall footingSpread footing
Typical Structure
Foundation(Footing)
Spandrelbeam
Pier
Column
Floor slab
Main beam(Girder)
รอยแตกราวเนื่องจากการดัด
รอยแตกราวเนือ่งจากการเฉือน
คาน
แรงดึง
แรงอัด
รอยแตกราว
บริเวณเกิดแรงดึงสูงสุด
บริเวณเกิดแรงอัดสูงสุด
1/6 W
2/6 W
3/6 W
4/6 W
5/6 W
W
ขนาดแรงดึง kPa
การขยายตัวของแรงดึง ตามการแอนตัวของคานจากน้ําหนักที่เพิ่มขึ้น
แรงดึงสูงสุด
แรงดึงต่ําแรงอัด
ลูกศรแสดงทิศทางของแรงดึง ณ จุดตางๆ
ระนาบของรอยราวที่เปนไปได ซึ่งตองตั้งฉากกบัทิศทางของแรงดึง
ลูกศรแสดงทิศทางของแรงดึงในเนื้อคอนกรีต
รอยแตกราวเนื่องจากการดัดตัวของคาน
เหลก็เสนรับแรงดึง
รอยแตกราวเนือ่งจากการเฉือน
เหล็กปลอกท่ีใชรับแรงเฉือน
รอยแตกหลังคาน
รอยแตกใตทองคาน
ฐานรากทรุดรอยแตกใตทองคาน
รอยแตกหลังคาน
การแตกราวที่ผนัง เปนอาการของการทรุดตัวโครงสราง