DESIGN OF REINFORCED MASONRY STRUCTURES

DESIGN OF

REINFORCED

MASONRY

STRUCTURES

This page intentionally left blank

DESIGN OF

REINFORCED

MASONRY

STRUCTURES

Narendra Taly, Ph.D., P.E., F.ASCE

Professor Emeritus

Department of Civil Engineering

California State University, Los Angeles

Second Edition

New York Chicago San Francisco Lisbon London Madrid

Mexico City Milan New Delhi San Juan Seoul

Singapore Sydney Toronto

Copyright © 2010, 2001 by The McGraw-Hill Companies, Inc. All rights reserved. Except as

permitted under the United States Copyright Act of 1976, no part of this publication may be reproduced

or distributed in any form or by any means, or stored in a database or retrieval system, without the prior

written permission of the publisher.

ISBN: 978-0-07-159367-0

MHID: 0-07-159367-5

The material in this eBook also appears in the print version of this title: ISBN: 978-0-07-147555-6,

MHID: 0-07-147555-9.

All trademarks are trademarks of their respective owners. Rather than put a trademark symbol after

every occurrence of a trademarked name, we use names in an editorial fashion only, and to the benefi t

of the trademark owner, with no intention of infringement of the trademark. Where such designations

appear in this book, they have been printed with initial caps.

McGraw-Hill eBooks are available at special quantity discounts to use as premiums and sales

promotions, or for use in corporate training programs. To contact a representative please e-mail us at

[email protected].

Information contained in this work has been obtained by The McGraw-Hill Companies, Inc.

(“McGraw-Hill”) from sources believed to be reliable. However, neither McGraw-Hill nor its authors

guarantee the accuracy or completeness of any information published herein, and neither McGraw-Hill

nor its authors shall be responsible for any errors, omissions, or damages arising out of use of this

information. This work is published with the understanding that McGraw-Hill and its authors are

supplying information but are not attempting to render engineering or other professional services. If

such services are required, the assistance of an appropriate professional should be sought.

TERMS OF USE

This is a copyrighted work and The McGraw-Hill Companies, Inc. (“McGrawHill”) and its licensors

reserve all rights in and to the work. Use of this work is subject to these terms. Except as permit￾ted under the Copyright Act of 1976 and the right to store and retrieve one copy of the work, you

may not decompile, disassemble, reverse engineer, reproduce, modify, create derivative works based

upon, transmit, distribute, disseminate, sell, publish or sublicense the work or any part of it without

McGraw-Hill’s prior consent. You may use the work for your own noncommercial and personal use;

any other use of the work is strictly prohibited. Your right to use the work may be terminated if you fail

to comply with these terms.

THE WORK IS PROVIDED “AS IS.” McGRAW-HILL AND ITS LICENSORS MAKE NO GUAR￾ANTEES OR WARRANTIES AS TO THE ACCURACY, ADEQUACY OR COMPLETENESS OF

OR RESULTS TO BE OBTAINED FROM USING THE WORK, INCLUDING ANY INFORMA￾TION THAT CAN BE ACCESSED THROUGH THE WORK VIA HYPERLINK OR OTHERWISE,

AND EXPRESSLY DISCLAIM ANY WARRANTY, EXPRESS OR IMPLIED, INCLUDING BUT

NOT LIMITED TO IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR

A PARTICULAR PURPOSE. McGraw-Hill and its licensors do not warrant or guarantee that the

functions contained in the work will meet your requirements or that its operation will be uninterrupted

or error free. Neither McGraw-Hill nor its licensors shall be liable to you or anyone else for any

inaccuracy, error or omission, regardless of cause, in the work or for any damages resulting

therefrom. McGraw-Hill has no responsibility for the content of any information accessed through

the work. Under no circumstances shall McGraw-Hill and/or its licensors be liable for any

indirect, incidental, special, punitive, consequential or similar damages that result from the use

of or inability to use the work, even if any of them has been advised of the possibility of such

damages. This limitation of liability shall apply to any claim or cause whatsoever whether such claim

or cause arises in contract, tort or otherwise.

To my wife, Trish, for her high-limit state of endurance,

to my daughters, Neena and Beena, for their love of teaching,

and to the memory of my parents, Sundar Bai and Bhagwan Das Taly,

this book is dedicated.

This page intentionally left blank

ABOUT THE AUTHOR

Narendra Taly, Ph.D., P.E., F.ASCE, is a professor (emeritus) of civil engineering at

California State University, Los Angeles. He has more than 50 years of experience in the

fields of civil and structural engineering design. Dr. Taly is the author of Loads and Load

Paths in Buildings: Principles of Structural Design and Design of Modern Highway Bridges.

He is a co-author of Reinforced Concrete Design with FRP Composites and has written

several technical papers in the field of structural engineering.

This page intentionally left blank

ix

CONTENTS

Preface to the Second Edition xiii

Preface to the First Edition xvii

Acknowledgments xix

Notation xxi

Acronyms xxvii

Chapter 1. Introduction 1.1

1.1 What Is Masonry? / 1.1

1.2 Plain and Reinforced Masonry / 1.1

1.3 A Brief History of Masonry Construction / 1.2

1.4 Evolution of Reinforced Masonry / 1.3

1.5 Unreinforced and Reinforced Masonry / 1.5

1.6 Historical Development of Building Codes and Standards for Masonry Construction / 1.6

1.7 Design Methods / 1.9

1.8 Load Combinations / 1.11

References / 1.14

Chapter 2. Masonry Units: Applications, Types, Sizes, and Classification 2.1

2.1 Introduction / 2.1

2.2 Application of Masonry Units in Construction / 2.1

2.3 General Description of Masonry Units / 2.2

2.4 Clay Building Brick / 2.4

2.5 Functional Aspects / 2.15

2.6 Concrete Masonry Units / 2.23

2.7 Bonds and Patterns in Masonry Work / 2.35

2.8 Structural Requirements for Masonry in Stack Bond / 2.41

2.9 Mortar Joints / 2.42

2.10 Types of Wall Construction / 2.43

2.11 Glass Unit Masonry / 2.46

2.12 Mortarless Block Systems / 2.51

2.13 Prefabricated Masonry / 2.51

2.14 Autoclaved Aerated Concrete / 2.54

References / 2.55

Chapter 3. Materials of Masonry Construction 3.1

3.1 Introduction / 3.1

3.2 Mortar / 3.1

3.3 Grout / 3.6

3.4 Differences between Mortar, Grout, and Concrete / 3.11

3.5 Compressive Strength of Masonry / 3.12

3.6 Steel Reinforcement / 3.15

3.7 Modulus of Elasticity of Masonry Materials / 3.22

x CONTENTS

3.8 Thermal Effects on Masonry / 3.23

3.9 Influence of Moisture on Masonry: Shrinkage / 3.25

3.10 Creep of Masonry / 3.27

References / 3.28

Chapter 4. Design of Reinforced Masonry Beams 4.1

4.1 Introduction / 4.1

4.2 Historical Development / 4.2

4.3 Strength Design Philosophy / 4.2

4.4 Assumptions in Strength Design Philosophy / 4.5

4.5 Analysis of Rectangular Sections in Flexure / 4.7

4.6 Modulus of Rupture and Nominal Cracking Moment of a Masonry Beam / 4.26

4.7 Design of Masonry Beams / 4.31

4.8 Procedure for Flexural Design of Beams / 4.41

4.9 Overreinforced Beams / 4.53

4.10 Design for Shear in Reinforced Masonry Beams / 4.56

4.11 Lateral Support of Masonry Beams / 4.69

4.12 Analysis of Doubly Reinforced Masonry Beams / 4.69

4.13 Lintels / 4.74

4.14 Masonry Wall Beams (Deep Wall Beams) / 4.101

4.15 Bond Beams / 4.109

4.16 Diaphragm Action / 4.111

4.17 Flexural Strength of a Wall due to In-Plane Loads / 4.115

4.18 Development Lengths for Reinforcing Bars / 4.117

4.19 Serviceability Criteria for Beams / 4.119

4.20 Service Load Analysis of Reinforced Masonry Beams / 4.120

4.21 Deflections of Reinforced Masonry Beams / 4.126

References / 4.139

Chapter 5. Columns 5.1

5.1 Introduction / 5.1

5.2 Behavior of Axially Loaded Columns / 5.4

5.3 Axial Strength of Reinforced Masonry Columns / 5.7

5.4 MSJC Code Provisions for Reinforced Masonry Columns / 5.10

5.5 Analysis of Reinforced Masonry Columns / 5.16

5.6 Design Procedure for Reinforced Masonry Columns / 5.21

5.7 Columns under Combined Axial Load and Bending / 5.28

5.8 Discussion and Interpretation of the Axial Load-Bending Moment Interaction

Diagrams / 5.57

5.9 Interaction Diagram for a Wall under Combined Loading

(Axial Load and Bending) / 5.58

5.10 Shear Strength of Masonry Columns / 5.60

5.11 Masonry Piers / 5.64

References / 5.68

Chapter 6. Walls under Gravity and Transverse Loads 6.1

6.1 Introduction / 6.1

6.2 Types of Masonry Walls / 6.1

6.3 Bond Patterns in Masonry Walls / 6.16

6.4 Analysis of Walls under Gravity and Transverse Loads / 6.23

6.5 Out-of-Plane Loads on Walls / 6.25

CONTENTS xi

6.6 Analysis of Masonry Walls for Out-of-Plane Loads / 6.38

6.7 Design of Walls for Gravity and Transverse Loads / 6.44

6.8 Axial Loads on Walls Subjected to Out-of-Plane Loads / 6.69

6.9 Pilasters / 6.69

6.10 Nonload-Bearing Walls / 6.77

References / 6.86

Chapter 7. Shear Walls 7.1

7.1 Introduction / 7.1

7.2 Fundamental Concepts / 7.2

7.3 Types of Shear Walls / 7.6

7.4 Rigidity and Relative Rigidity of a Shear Wall / 7.10

7.5 Rigidity of a Shear Wall with Openings / 7.17

7.6 Determination of Seismic Lateral Forces in Shear Walls / 7.39

7.7 Horizontal Diaphragms / 7.50

7.8 Influence of Building Configuration on Lateral Force Distribution in Shear Walls / 7.57

7.9 Analysis of Shear Walls and Diaphragms under Direct Shear and Torsional Moments / 7.69

7.10 Design Considerations for Shear Walls / 7.81

7.11 Analysis of Shear Walls under Flexure and Axial Loads / 7.95

7.12 Design of Multistory Shear Walls / 7.108

7.13 Failure Modes of Shear Walls / 7.110

References / 7.121

Chapter 8. Retaining and Subterranean Walls 8.1

8.1 Introduction / 8.1

8.2 Principal Types of Retaining Walls / 8.2

8.3 Lateral Pressures on Retaining Walls / 8.9

8.4 External Stability of a Retaining Wall / 8.25

8.5 Design Procedure for Masonry Retaining Walls / 8.29

8.6 Subterranean or Basement Walls / 8.35

8.7 Construction Considerations / 8.42

References / 8.48

Chapter 9. Construction Aspects 9.1

9.1 Introduction / 9.1

9.2 Placement of Steel Reinforcement / 9.2

9.3 Grouting / 9.7

9.4 Movements of Construction Materials, Their Causes and Effects / 9.23

9.5 Control of Cracking and Movement Joints / 9.33

9.6 Quality Assurance / 9.42

9.7 Flashing for Masonry Construction / 9.43

References / 9.46

Chapter 10. Anchorage to Masonry 10.1

10.1 Introduction / 10.1

10.2 Types of Anchor Bolts / 10.1

10.3 Placement and Embedment of Anchor Bolts in Masonry Grout / 10.2

10.4 Nominal Strength of Anchor Bolts / 10.3

xii CONTENTS

10.5 Nominal Axial Strength of Anchor Bolts Loaded in Tension and in Combined

Tension and Shear / 10.5

10.6 Nominal Shear Strength of Headed and Bent-Bar Anchor Bolts in Shear / 10.14

10.7 Headed and Bent-Bar Anchor Bolts in Combined Axial Tension and Shear / 10.15

10.8 Structural Walls and Their Anchorage Requirements / 10.16

References / 10.27

Appendix Design Aids: Tables A.1

Glossary G.1

Index I.1

xiii

PREFACE TO THE

SECOND EDITION

Why write?

“I hear, I forget;

I see, I remember;

I write, I understand.”

A Chinese proverb

The writing of this book was motivated by a professional need to update changes in the

reinforced masonry design philosophy that have occurred as a result of incorporation

of strength design philosophy in the 2008 Building Code Requirements for Masonry

Structures reported by the Masonry Standards Joint Committee (referred to in this book as

the MSJC-08 Code) and corresponding requirements of the 2009 International Building

Code (2009 IBC), and to update changes brought out by the ASCE/SEI 7-05 Standard,

Minimum Design Loads for Buildings and Other Structures (referred to in this book as

ASCE 7-05 Standard). While the fundamental principles of designing reinforced masonry

structures discussed in the first edition (2001) of this book remain valid, revisions in

codes, specifications, and reference standards applicable to design and construction of

masonry structures that have since occurred required updating that book in the form of this

second edition.

The allowable stress design (ASD) method of designing reinforced masonry structures

presented in the first edition of this book is still acceptable, and is expected to remain so for

the foreseeable future. However, the general trend in the structural engineering profession

is to move toward using the strength design philosophy for the design of concrete structures,

and load and resistance factor design (LRFD) for the design of steel structures. Readers of

the first edition of this book will note that the topic of strength design of reinforced masonry

was briefly covered in App. D. This second edition is a natural, follow-up publication that

focuses exclusively on strength design philosophy for reinforced masonry structures. In

addition, a new chapter on anchorage to masonry (Chap. 10) has been introduced.

Consistent with the first edition, this edition of the book is written in a stand-alone

format and independent of the ASD philosophy. While knowledge of and familiarity with

the strength design principles for design of reinforced concrete structures would enable

readers to quickly grasp the fundamentals of strength design of reinforced masonry, neither

that knowledge nor that of allowable stress design of masonry are considered prerequisites

for understanding the discussion presented herein. Each chapter of the book presents the

theory based on first principles and is supported by references and followed by numerous

examples that illustrate its application.

Like the first edition of this book, this edition is written for use by students and profes￾sionals of reinforced masonry design and construction. It is written in a simple, practical,

and logical manner, and is styled to suit as a text for teaching reinforced masonry design

and construction in a classroom environment at senior/graduate level. Frequent references

to the MSJC-08 Code and ASCE/SEI 7-05 Standard are made throughout all discussions

and examples in this book to acquaint readers with the design and specification requirements

that must be followed; readers will find it helpful to keep copies of these two references

handy while reading this book.

Chapter 1 introduces the topic of masonry design and construction—from ancient times

to modern times—a practice that began as the art of construction and evolved into the

modern engineered construction. Also presented in the chapter are brief discussions of the

governing building codes and specifications for masonry structures, and governing provi￾sions of ASCE/SEI 7-05 Standard that form the basis of load calculations for analysis and

design.

Masonry structures are built from units that are fabricated in production plants from

clay and concrete, and hand-laid by skilled masons, one unit at a time. Chapter 2 is devoted

to a detailed discussion of both clay and concrete units with respect to industry standards,

product availability, modular sizes, design properties, and applicable ASTM Standards.

Chapter 3 presents a discussion on materials of masonry construction: masonry units,

mortar, grout, and steel reinforcing bars. Reinforced masonry structures are built from

placing masonry units with mortar between them, placing horizontal and vertical reinforce￾ments, and grouting the cells of masonry units to accomplish the desired design objectives.

Adherence to the specifications of these materials is the key to acceptable performance of

as-built structures, hence the importance of this chapter.

Chapters 4 through 10 present analysis and design of masonry structures subjected to

flexure, shear, compression, and combined axial compression and flexure; walls subjected

to out-of-plane loads; shear walls (walls subjected to in-plane loads); retaining walls; and

anchorage to masonry.

Chapter 4 presents an exhaustive discussion of fundamentals of strength design philoso￾phy and their application to flexural analysis and design of masonry structures. This is the

longest and also the most important chapter in the book for it embodies principles of strain

compatibility and ductility, and requirements of the MSJC-08 Code pertaining to design for

flexure, shear, deflection, and cracking moment, concepts which are used in later chapters

of the book. The author has provided in-depth explanation of fundamental principles of

strength design in this chapter, followed by numerous examples designed to satisfy the

many “what if” questions and curiosities of readers, particularly students. The purpose

of this chapter is to encourage discussion and to develop confidence in understanding the

ramifications of improper designs.

Chapter 5 is devoted to design of compression members—reinforced masonry columns—

loaded axially or in combination with bending. Many examples are presented to illustrate

the design concepts and alternatives. An in-depth discussion of interaction diagrams for

columns subjected to combined axial load and bending, including detailed, step-by-step

calculations for developing such diagrams, forms the highlight of this chapter.

Chapter 6 presents analysis and design of reinforced masonry walls subjected to out-of￾plane loads due to wind or earthquakes. The chapter presents a discussion and calculation

of these forces based on ASCE/SEI 7-05 Standard. Also presented in this chapter are many

different types of masonry walls and their uses.

Chapter 7 deals with an all-important topic of analysis and design of reinforced masonry

shear walls which are used as systems for resisting lateral forces in building structures—

either as the main wind force–resisting systems (MWFRS) or as the seismic force–resisting

systems (SFRS). Because of the extreme importance of this topic, this chapter provides an

in-depth discussion of seismic load provisions of ASCE 7-05 Standard and design require￾ments pertaining to the many different types of shear walls as classified and permitted by the

standard for use as lateral force–resisting systems.

Chapter 8 describes analysis and design of reinforced masonry earth-retaining walls and

basement walls which are commonly used in practice.

Chapter 9 provides a discussion of masonry construction practices, with an emphasis

on grouting practices. Masonry construction involves hand placement of brick or concrete

xiv PREFACE TO THE SECOND EDITION