Reinforced Concrete Vol. I – Part I By Dr. H. J. Shah

(2) Surface moisture
2-23-7. Bulking of sand
2-23-8. Deleterious substances in aggregates
(1) Organic impurities
(2) Surface coatings
(3) Salt contamination
(4) Weak or unsound particles
2-23-9. Soundness of aggregate
2-23-10. Alkali-aggregate reaction
2-24. Sieve analysis
Fineness modulus
2-25. Standard grading
(1) Coarse aggregate
(2) Fine aggregate
(3) All-in-aggregate
2-26. Use of grading curves
(1) Coarse aggregates
(2) Fine aggregates
WATER
2-37. Water for mixing concrete
2-28. Water-cement ratio and water-cementitious materials ratio
CHEMICAL ADMIXTURES
2-29. Admixtures
(1) Accelerators
(2) Retarders
(3) Water reducing admixtures
(4) Air-entraining agents
REINFORCEMENT
2-30. Steel as reinforcement
2-31. Types of reinforcement
(1) Plain bars
(2) High strength deformed (hsd) bars
2-31-1. Plain bars
(1) Mild steel bars
(2) Medium tensile steel bars
(3) Hard drawn wire or welded wire fabric
2-31-2. High strength deformed (hsd) bars
(1) Cold twisted deformed (ctd) bars
(2) Thermo-mechanically treated (tmt) bars
2-32. Corrosion–resistant steel
2-33. Grades of normal and enhanced quality
Hsd rebars for reinforced concrete
2-34. Bending and fixing of bars
2-35. Welding of reinforcement
2-36. General notes for site engineers
QUESTIONS II
EXAMPLES II

Chapter 3 STRUCTURAL CONCRETE

3-1. Proportioning of ingredients
(1) Design mix concrete
(2) Nominal mix concrete
Dosage of admixtures
3-2. Estimation of materials for nominal mix
3-3. Measurement of materials
(1) Mass-batching
(2) Volume-batching
3-4. Mixing and placing of concrete
(1) Batch mixers
(2) Ready mix concrete (rmc)
(3) Continuous mixers
3-5. Compaction

3-6. Curing
(1) Moist curing
(2) Membrane curing
(3) Steam curing
3-7. Formwork for R.C.C. members
3-8. Workability
(1) Slump test
(2) Compacting factor test
(3) Vee-bee test
3-9. Factors influencing workability
3-10. Strength of concrete and water-cement ratio
(1) Compaction
(2) Curing
(3) Fineness of aggregate
(4) Fatigue and impact
(5) Age
(6) Compressive strength of cement and concrete
3-11. Compressive strength of concrete
(1) Object
(2) Equipments
(3) Preparation
(4) Capping
(5) Testing
(6) Results
3-12. Tensile strength of concrete
(1) Split cylinder test
(2) Standard beam test — modulus of rupture test
3-13. Non-destructive tests
(1) Rebound hardness test
(2) Ultrasonic pulse velocity test
3-14. Stress-strain behaviour of concrete under short term loads
(1) Compressive loads
(2) Tensile loads
3-15. Short term static modulus of elasticity
Poisson’s ratio
3-16. Shrinkage
(1) Plastic shrinkage
(2) Drying shrinkage
(3) Carbonation shrinkage
(4) Autogenous shrinkage
3-17. Creep
3-18. Durability of concrete
(1) Use of inferior quality materials
(2) Improper compaction and curing
(3) Limits on cement content
(4) Requirements of concrete cover to steel reinforcement
(5) Improper design and detailing
3-19. Temperature change
3-20. Concrete quality control
3-21. Sampling and strength tests of concrete
(1) Sampling and frequency of sampling
(2) Strength tests
(3) Preparing sampling and testing records
(4) Checking the record
(5) Analyse the results
3-22. Statistical analysis of test results
(1) Density function
(2) Normal distribution
(3) Mean
(4) Standard deviation
3-23. Standard deviation
(1) Standard deviation based on test strength of sample
(2) Assumed standard deviation

3-24. Acceptance criteria
Design mix concrete
3-25. Introductory
3-26. Use of plasticizers and super-plasticizers
Efficiency of super plasticizer
Mix design for ordinary and
Standard grades of concrete
3-27. Basic assumptions
3-28. Data for mix design
3-29. Target strength for mix design
3-30. Assumed standard deviation
3-31. Selection of water-cement/
Water-cementitious materials ratio
Portland pozzolana cement
3-32. Estimation of air content
3-33. Selection of water content and admixture content
Note for site work
Type of aggregates
Workability required
Use of chemical admixtures
3-34. Calculation of cement/cementitious materials content
3-35. Estimation of coarse and fine aggregate
Proportion in all–in aggregates
Correction for w/c ratio
Correction for concrete of increased workability
3-36. Estimation of masses of various ingredients
3-37. Trial mixes
QUESTIONS 3
EXAMPLES 3

Chapter 4 DESIGN FOR FLEXURE: FUNDAMENTALS

4-1. Introductory
4-2. Review of theory of simple bending
4-3. Practical requirements of an r.C.C. Beam
4-4. Size of the beam
4-5. Cover to the reinforcement
4-6. Spacing of bars
4-7. Design requirements of a beam
4-8. Classification of beams
(1) Singly reinforced and doubly reinforced beams
(2) Rectangular and flanged beams
4-9. Effective width of a flanged beam
4-10. Cracking moment
4-11. Balanced, under-reinforced and over-reinforced design
(1) Balanced design
(2) Under-reinforced design
(3) Over-reinforced design
4-12. Bending of an r.C.C. Beam
(1) Uncracked concrete stage
(2) Concrete cracked-elastic stresses stage
(3) Ultimate strength stage
4-13. Design methods

Chapter 5 DESIGN FOR FLEXURE: WORKING STRESS
METHOD

5-1. Permissible stresses
Increase in permissible stresses
5-2. Modular ratio
5-3. Design for flexure–assumptions
Singly reinforced beams
5-4. Derivation of formulae for balanced design
5-5. Transformed area method
(1) To decide the type of the beam
(2) Balanced design

(3) Over-reinforced design
5-6. Types of problems in singly reinforced concrete
5-7. Analysis of the section
5-8. Design of the section
(1) Dimensions not given
(2) Dimensions are given
5-9. Use of design aids
Doubly reinforced beams
5-10. Introductory
5-11. Derivation of formulae for balanced design
5-12. Transformed area method
5-13. Types of problems for doubly reinforced concrete
5-14. Use of design aids
Flanged beams
5-15. Moment of resistance of a singly reinforced flanged beam
(1) Neutral axis lies in flange
(2) Neutral axis lies in web
5-16. Types of problems for flanged beams
5-17. Doubly reinforced flanged beams
5-18. Slabs
EXAMPLES 5

Chapter 6 LIMIT STATE METHOD

6-1. Inelastic behaviour of materials
6-2. Ultimate load theory
6-3. Limit state method
6-4. Limit state of collapse
6-5. Limit state of serviceability
Deflection
Cracking
6-6. Characteristic and design values and partial safety factors
(1) Characteristic strength of materials
(2) Characteristic loads
(3) Partial safety factors
(4) Design values
6-7. Limit state of collapse: flexure
Assumptions
Strain compatibility
Singly reinforced rectangular beams
6-8. Derivation of formulae
(1) With respect to compression
(2) With respect to tension
6-9. General values
(1) Limiting moment of resistance index
(2) Limiting reinforcement index
6-10. Types of problems
6-11. Failure of r.C.C. Beam in flexure
6-12. Code provisions to prevent the brittle failure
6-13. Computer programmes
Doubly reinforced beams
6-14. Derivation of formulae
6-15. Types of problems
6-16. Use of design aids
6-17. Computer programmes for doubly
Reinforced rectangular sections
Flanged beams
6-18. Introductory
6-19. Position of neutral axis
6-20. Derivation of formulae
6-21. Use of design aids
6-22. Doubly reinforced flanged beams
6-23. Sections subjected to reversal of moments
(1) Hogging moment

(2) Sagging moment
6-24. Computer programmes for flanged sections
Examples 6

Chapter 7 SHEAR AND DEVELOPMENT LENGTH

7-1. Shear in structural members
(1) Flexural shear
(2) Punching shear
(3) Torsion shear
7-2. Flexure and shear in homogeneous beam
7-3. Shear in reinforced concrete beams – elastic theory
7-4. Diagonal tension and diagonal compression
7-5. Limit state theory
7-6. Design shear strength of concrete for various member
Without shear reinforcement
(1) Beams
(2) Solid slabs
(3) Members under axial compression
7-7. Design for shear
7-8. Shear reinforcement in beams
(1) Vertical stirrups
(2) Inclined stirrups
(3) Bent bars
(4) Shear resistance capacity of a section
7-9. Practical considerations
(1) Distance of first bent bar from support
(2) Maximum spacing
(3) Minimum shear reinforcement
(4) Maximum shear stress
7-10. Critical sections for shear
(1) Tension in end region of a member
(2) Compression in end region of a member
7-11. Design of a complete beam for shear
Simplified approach
Using enhanced shear strength
Supplementary notes
7-12. Use of design aids
(1) Minimum shear reinforcement
(2) Vertical stirrups
(3) Bent bars
7-13. Shear design of beams with variable depth
Development length
7-14. Bond and bond stress
(1) Features of reinforced concrete attributed to bond
(2) Grip or bond attributed to various mechanisms
7-15. Flexural (local) bond and development (anchorage) bond
(1) Flexural or local bond
(2) Secondary effects
(3) Development or anchorage bond
7-16. Anchorage length and development length
(1) Anchorage length
(2) Development length
7-17. Development length: pull out test
Mechanism of bond failure
(1) Pull out failure
(2) Splitting failure
7-18. Code provision
7-19. Use of bundled bars
7-20. Anchoring reinforcements
(1) Anchoring bars in tension
(2) Anchoring bars in compression
(3) Anchoring bars in shear
7-21. Bearing stresses at bends
7-22. Reinforcement splicing
(1) Lap splices
(2) End bearing splices

(3) Welded splices
(4) Mechanical splices
7-23. Ensuring ductile failure
EXAMPLES 7
Long questions of chapter 7

Chapter 8 DEFLECTION AND CRACKING DEFLECTION

8-1. Limit state of serviceability
8-2. Deflections in a structure or structural members
(1) Structural damage
(2) Non-structural damage
(3) Discomfort to the occupants
8-3. Span/effective depth ratio
8-4. Control of deflection on site
(1) Cambering
(2) Controlling concrete work
(3) Removal of forms
(4) Controlling temporary loads
8-5. Deflection calculations
8-6. Short term deflections
(1) Modulus of elasticity of concrete
(2) Moment of inertia of the section
8-7. Long term deflections
(1) Deflection due to shrinkage
(2) Deflection due of creep
Cracking
8-8. Introductory
(1) Bar spacing controls
(2) Crack width calculations
8-9. Bar spacing controls
(1) Beams
(2) Slabs
8-10. Calculation of crack width
(1) Assumptions
(2) Approximate method
8-11. Computer programs
EXAMPLES 8

Chapter 9 SIMPLY SUPPORTED AND CANTILEVER BEAMS

9-1. Design procedure
(1) Estimation of loads
(2) Analysis
(3) Design
9-2. Anchorage of bars check for development length
9-3. Reinforcement requirements
(1) Tension reinforcement
(2) Compression reinforcement
(3) Cover to the reinforcement
9-4. Slenderness limits for beams to ensure lateral stability
Simply supported beams
9-5. Introductory
9-6. Design s.F. Diagram
9-7. Curtailment of bars
9-8. Design of a template
9-9. Design of a lintel
(1) Loads
(2) Size
(3) Cover
Cantilever beams
9-10. Design considerations
9-11. Computer programs
EXAMPLES 9

Chapter 10 SIMPLY SUPPORTED AND CANTILEVER SLABS

10-1. Introductory
(1) One-way spanning slabs
(2) Two-way spanning slabs
(3) Flat slabs
(4) Grid slabs
(5) Circular slabs
(6) Ribbed and waffle slabs
10-2. Analysis
(1) Elastic analysis
(2) Using coefficients
(3) Yield line method
10-3. One-way spanning slabs
(1) Effective span
(2) General
(3) Reinforcement requirements
(4) Shear stress
(5) Deflection
(6) Cracking
(7) Cover
(8) Development length
10-4. Simply supported one-way slab
10-5. Detailing of slabs
10-6. Inclined slabs
(1) Slabs spanning perpendicular to the slope
(2) Slabs spanning parallel to the slope
10-7. Straight slabs having a small length inclined along the span
10-8. Cantilever slab
10-9. Concentrated load on slabs
10-10. Two-way slabs
10-11. Simply supported two-way slabs
10-12. Computer program
EXAMPLES 10

Chapter 11 CONTINUOUS BEAMS AND SLABS

CONTINUOUS BEAMS
11-1. Introductory
11-2. Analysis parameters
(1) Effective span
(2) Stiffness
11-3. Live load arrangements
Arrangement of live load
11-4. Redistribution of moment
(1) Plastic hinge
(2) Fixed beam
(3) Code requirements
11-5. Reinforcement requirements
11-6. Flexure design considerations
11-7. Simplified analysis for uniform loads
11-8. Moment and shear coefficients for continuous beams
11-9. Typical continuous beam details
Continuous slabs
11-10. Continuous one-way slab
11-11. Restrained two-way slabs
11-12. Two-way slabs subjected to large shear force
11-13. Computer program
EXAMPLES 11
QUESTIONS 11

Chapter 12 TORSION

12-1. General
(1) Equilibrium torsion
(2) Compatibility torsion
12-2. Effect of torsion: provision of reinforcement
12-3. Code provisions
(1) General
(2) Design rules

12-4. General cases of torsion
(1) Cantilever slab inducing torsion in supporting beam
(2) Cantilever beam inducing torsion in supporting beam
(3) Beams curved in plan
12-5. Beams curved in plan
12-6. Circular beam
(1) Support moments mo
(2) Shear, moment and torsion at p
12-7. Circular arc fixed at ends
12-8. Design of beams curved in plan
EXAMPLES 12
QUESTIONS 12

Chapter 13 STAIRS

13-1. Stair slabs
13-2. Classification of stairs
(1) Straight stair
(2) Dog-legged stair
(3) Open well stair
13-3. Design requirements for stair
(1) Live loads on stair
(2) Effective span of stair
(3) Distribution of loading on stairs
(4) Depth of section
13-4. Reducing the span
13-5. Tread-riser staircase
13-6. Closure
EXAMPLES 13

Chapter 14 LOAD CALCULATIONS – 1

Slabs and beams
14-1. Introductory
14-2. Loads on slabs
(1) Self weight of the slab
(2) Floor finish
(3) Live loads
(4) Any other loads
14-3. Loading on beams from one-way slabs
14-4. Wall loads and self weight of beams
14-5. Loading on beams from two-way slabs
14-6. Unit loads
EXAMPLES 14

Chapter 15 SIMPLE DESIGNS

15-1. Introductory
15-2. Design s.F. Diagram
15-3. Loads from two-way slabs
EXAMPLES 15

Chapter 16 FRAMED BEAMS,

16-1. Structural joints
16-2. Fixed, cantilever and framed beams
(1) Fixed beams
(2) Cantilever beam
(3) Framed beams
16-3. Analysis and design of the framed beams
16-4. Single span portal frame
16-5. Substitute frame
Moment of inertia of framed beams and columns
EXAMPLES 16

Appendix A SHORT QUESTIONS WITH ANSWERS
Appendix B USEFUL TABLES
Moment and shear coefficients
Index