443304310431 Reinforced Concrete DesignReinforced Concrete Design

Welcome to

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Instructor: Mongkol JIRAVACHARADETInstructor: Mongkol JIRAVACHARADET

School of Civil EngineeringSchool of Civil Engineering

SuranareeSuranaree University of TechnologyUniversity of Technology

Lecture 1 - Introduction

� Class Locations

Lecture: B3101

General Information

� Instructor

Asst.Prof.Dr. Mongkol jiravacharadet

� Office: 4th Floor, C Building

� Phone: (044-22) 4327

� Email: mongkol@sut.ac.th

� Class Time

� TUE 10:00 - 12:00

� THU 10:00 - 12:00

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TEXTBOOKSTEXTBOOKS

Reinforced Concrete: Mechanics and Design, 4th Edition

James G. MacGregor, James K. Wight, Prentice Hall, 2005.

Design of Concrete Structures, 13th Edition

Arthur H. Nilson, David Darwin, Charles W. Dolan, McGraw-Hill, 2003.

Reinforced Concrete: A Fundamental Approach, 5th EditionEdward G. Nawy, Prentice Hall, 2005.

Building Code Requirements for Structural Concrete,

ACI318-05,American Concrete Institute, 2005.

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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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:

Conduct of Course

Design Projects 20 %

Midterm Exam 40 %

Final Exam 40 %

Grading Policy

Final Score Grade

100 - 90 A

89 - 85 B+

84 - 80 B

79 - 75 C+

74 - 70 C

69 - 65 D+

64 - 60 D

59 - 0 F

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

� An Introduction to Structural Systems

� Reinforced Concrete Structures

� Mechanical Properties of Concrete

� Steel Reinforcement

11 Reinforced Concrete DesignReinforced Concrete Design

Introduction, Materials and Properties

Mongkol JIRAVACHARADET

S U R A N A R E E INSTITUTE OF ENGINEERING

UNIVERSITY OF TECHNOLOGY SCHOOL OF CIVIL ENGINEERING

Cantilever ConstructionsCantilever Constructions

CN Tower, Canada

Column

Typical Structure (1)

1st Floor

2nd Floor

Beam Joist

Spandrel

beam

Wall footingSpread footing

Typical Structure

Foundation

(Footing)

Spandrel

beam

Pier

Column

Floor slab

Main beam

(Girder)

Structural Design Concept

�������� Stability

�������� Safety

�������� Serviceability

��������Economy

��������Environment

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

Reinforced Concrete (RC) Structures

Steel bars

Concrete

Section A-A

P

A

A Steel bars

compression zone

tension 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

Review of Concrete Properties

Concrete is a mix of :

Water Cement Ratio (W/C) :

Low W/C

High Strength

Low Workability

High W/C

Low Strength

High Workability

0.3 0.7

Optimal ratios obtained

by trial and experience

30

cm

∅ 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

Co

mpre

ssiv

e s

tre

ng

th,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

′≈ −

′≈ −

Standard Beam Test (ASTM C78):

P

r

Mcf

I= = Modulus of rupture

Tensile Strength in Flexure

7.5 psi 2.0 kscr c cf f f′ ′= =

Practical choice for design purposes

Stress-Strain Relationship of Concrete

0.003≈

Ultimate strain

εASTM

σ

cf ′

0.5 cf ′

Initial modulus

Secant modulusat = Ec0.5 cf ′

εεεεcu

Concrete & Steel StrengthConcrete & Steel Strength--DeformationsDeformations

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

Failure

Strain

fy

0.85f’c

Modulus of elasticity

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:

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 ("#$%��$&'()"�*+)

SR24: Fy = 2,400 ksc, Fu = 3,900 ksc

Deformed Bar ("#$%�012212*)

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)