Handbook of Analytical Techniques in Concrete Science and Technology. Principles, Techniques, and Applications

973 Pages·2000·20.01 MB·English

by  V.S. Ramachandran and James J. Beaudoin (Eds.)

Foreword
Material sciences have always been a leading driver in construction
innovation. This is still true today with new technologies producing new
materials and advancing the performance and applications of old ones. Many
issues have to be addressed and resolved before such materials are
confidently accepted in practice. Issues such as durability and long-term
performance, design methods to allotwh eir integration in construction, and
new or modified standards to facilitate acceptance in the marketplace are
often mentioned. This book on analytical techniques in concrete science and
technology is a valuable addition to thel iterature addressing these subjects.
Over the past three decades, material scientists at IRC have contrib-
uted extensively to the advances on construction research through the
development of experimental techniques. Their work is based on innovations
in many areas including differential thermal methods, x-ray diffractometry,
electron microscopy, petrography and design of special miniature techniques
for determining mechanical behavior of cement systems. It is, therefore,
natural to see that seven ofthe book' s chapters are written by IRC scientists.
To add to this strength, the other thirteen chapters are written by world-class
experts in their respective fields.
The book is the first of its kind addressing technologies associated with
thues e ofboth organic and inorganic products and composite materials. The
principles of the techniques are explained and applications clearly described.
In addition, a wide selection of references are provided to give the reader
ready access to more detailed information should it be required.
Vll ~
Foreword
The techniques described in the book are useful for analysis and
prediction of many material-related issues such as: (i) resolving durability
issues related to the mechanisms of reaction, (ii) determining parameters
that influence reaction kinetics of processes that affect material properties
and service life ofbuilding elements, (iii) developing and characterizing new
materials for durable structures, (iv) establishing reasons for structural
failures and conducting related forensic investigations, (v) providing a basis
for the development of relevant standards and methods for advancing
aspects of objective based codes, and (vi) validating numerical methods for
predicting long-term performance of construction materials.
The result is a handbook that presents up-to-date information in the
form that makes it valuable to read and come back to frequently. It should
become a valuable reference source for students and practitioners as well
as professionals engaged in standards writing.
Sherif Barakat
Director General
Institute for Research in Construction
National Research Council Canada
Ottawa, Canada
Preface
Concrete is a composite material formed by mixing and curing
ingredients such as cement, fine and coarse aggregates, and water. Most
concretes, however, contain additional ingredients such as chemical admix-
tures including air-entraining admixtures, fly ash, fibers, slag, and other
products.
The physical, chemical and durability characteristics of concrete
depend on many factors such as the type and amount of the components,
temperature, pore and pore size distribution, surface area, interfacial
features, exposure conditions, etc. Consequently, a good understanding of
various processes occurring in cementitious systems necessitates the
application of diverse techniques.
Several physical, chemical, and mechanical techniques are applied in
concrete research and practice. They provide importanitn formation, includ-
ing characterization of raw materials and cured concrete, quality control,
quantitative estimation of products, prediction ofperformance, development
of accelerated test methods, study of interrelationships amongst physical,
chemical, mechanical, and durability characteristics, development of new
materials, etc. In most instances, no single technique provides all the needed
information and hence application of several techniques becomes neces-
sary. Information on the application of various techniques in concrete is
dispersed in literature, and few books are available that serve as a source or
reference. Hence a handbook incorporating the latest knowledge on the
application of various investigative techniques in concrete science and
/x
x Preface
technology has been prepared. Standard test methods are not covered in this
book as they are well described in publications ofnational and international
standards organizations.
The book is divided into twenty chapters. Each chapter describes the
technique and its application and limitations for the study ofconcrete,. Each
chapter also contains a list of important references that should serve as a
useful guide for further information.
The first chapter on concrete science describes the essential concepts
so that information presented in subsequent chapters can be easily followed.
The chapter deals with the formation of cement, its hydration behavior,
physicochemical processes related to the cement paste, and several impor-
tant properties of concrete and durability aspects.
Chapter 2 deals with the description of a number of specialized
techniques used in conjunction with petrography for the evaluation and
analysis of aggregates of concrete.
Chemical analysis methods have been applied extensively to analyze
the components of concrete, chemical and mineral admixtures, raw mate-
rials for making cement and also to estimate cement contents. Modem
analytical tools enable much faster analysis than the wet chemical methods.
In Chapter ,3 chemical analysis techniques reviewed include atomic absorp-
tion, x-ray emission and plasma spectroscopy. The chapter also contains
information on chemical (wet) methods of analysis.
Thermal analysis techniques based on the determination of physical,
chemical, and mechanical changes in a material as a function of temperature,
habveee n routinely used in concrete science taencdh nology. Identification,
estimation of compounds, kinetics ofreactions, mechanisms of the action of
admixtures, synthesis of compounds, quality control and causes leading to
the deterioration of cementitious materials are investigated by these tech-
niques. Various types of thermal techniques and their applications and
limitations are included in Chapter 4.
Although comparatively recent, IR spectroscopy is gaining importance,
especially with the development of user-friendly equipment as described in
the fifth chapter. This technique has been applied for identification of new
products and characterization of raw materials, hydrated materials, and
deteriorated products., Discussion on Raman spectroscopy, a complemen-
tary technique to IR, also forms a part of this chapter.
Nuclear Magnetic Resonance spectroscopy (NMR) is a effective tool
to probe atomic scale structure and dynamic behavior of cementing
materials. The application of NMR for determining the pore structure and
Preface xi
transport properties of cement and concrete via relaxation and imaging
methods and its application to anhydrous cement and hydrated cement
phases form some of the contents of Chapter 6.
Scanning Electron Microscopy and its adjunct, microanalytical unit,
known as Energy Dispersive X-ray Analyzer, have been accepted as
important investigative techniques in concrete technology. Chapter 7 com-
prises discussion on the microstructure of hydrated cement paste, C-S-H
phase, calcium hydroxide, aluminateh ydrate phases, paste-aggregate inter-
face, admixtures, slags, and fly ashes. Also included are studies on the
correlation ofmicrostructure with durability.
The eighth chapter on the application of x-ray diffraction focuses on
some of the fundamental aspects of the technique, the hardware and
software developments, and its applications to cement and concrete.
An understanding of the rheology of fresh cement paste and concrete
is essential for following the behavior of concrete in the fresh state.
Additions and admixtures in concrete alter its rheological behavior. Chapter
9 deals with rheological techniques and their application to fresh cement
paste and concrete.
Dimensional changes occur in cement paste and concrete due to
physical, chemical, and electrochemical processes. A discussion ofenerget-
ics of surface adsorption and volume changes forms the scope of Chapter
.01 Relevance of length changes to concrete deterioration is also highlighted
in this chapter.
The use of miniature specimens in cement science investigations has
proven to be very valuable because it assures a greater homogeneity of the
sample and increased sensitivity to the dimensional changes resulting from
physical and chemical processes. Chapter 11 provides results on compacted
powder used as a model system and includes discussion on creep and
shrinkage, volume stability, workability, and surface chemical changes.
Corrosion ofreinforced concrete is a major destructivep rocess. Many
electrochemical techniques have been developed to study corrosion. Chap-
ter 21 presents a comprehensive treatment of the principles of corrosion,
factors responsible for corrosion, and corrosion assessment techniques
relevant to concrete.
Surface area has an important influence on the rate of reaction of
cement to water and other chemicals. Many physical and mechanical
characteristics of cement and concrete are modified by changes in the
surface area. In Chapter ,31 the techniques that are used for measuring
surface area are given with respect to their application to systems such as
2tx Preface
raw materials for cement, hydrated cement, concrete mix, and also to
durability studies.
The porset ructure of hydrated cement systems influences significantly
the physicomechanical and chemical behavior of concrete. Several experi-
mental techniques have been employed to evaluate the microstructure of the
cement paste. Chapter 41 presents a description of six techniques that have
been developed for the determination of pore structure. The relationship
between pore structure and strength/permeability is also included.
The application of silica polymerization analysis for an understanding
ofthe hydration process and structure of calcium silicate hydrates is detailed
in Chapter .51 Three major techniques used for polymerization studies are
described.
In concrete, the physical structure and the state of water in the matrix
influences the permeation process. In Chapter ,61 test methods that are
employed to measure various transport characteristics of concrete are
evaluated. The applicability and limitations of these techniques is also
reviewed.
Inspection and testing of placed concrete may be carried out by
nondestructive testing methods. Sonic and pulse velocity techniques are
commonly used. Nondestructive methods are also applied to estimate
strength, surface hardness, pullout strength, etc. Details of various nonde-
structive techniques and their applications are included in Chapter .71
There is evidence of a significant impact of computer and information
technologies on concrete sciencea nd technology. General development of
these technologies in recent years is reviewed in Chapter .81 The treatment
includes computer models, databases, artificial knowledge-based and com-
puter-integrated systems.
In Chapter ,91 entitled "Image Analysis," steps needed to identify
reactions of interest eaxntdr act quantitative information from digital images
are reviewedI.n image analysis, multiple images are acquired and analyzed.
The prine ip e 1 steps required for image analysis o fcemen ti ti ous materials are
described in this chapter.
Some of the more commonly used techniques in concrete studies are
presented in Chapters 2 to .91 There has been continued interest in
developing new techniques for the investigation of cement and concrete.
Chapter 20 comprises the description and application of fourteen of these
specialized techniques. They include such techniques as Auger Electron
Microscopy, Chromatography, MasSsp ectrometry, X-Ray Absorption Fine
Preface xiii
Structure Analysis, Synchrotron Orbital Radiation Analysis, M6ssbauer
Spectrometry, Radio Tracer Technique, and Photoacoustic Spectroscopy.
Although every attempt has been made to cover the important
investigative techniques used in concrete technology, is it quite possible that
some information has been excluded or is missing. In addition, some
duplication of information occurs in some chapters. This was intentional
because some specific chapters may only be of interest to specialized
groups, and they provide enough self-contained information so that gleaning
through other chapters will not be needed.
This comprehensive handbook should serve as a reference material to
concrete technologists,m aterials scientists, analytical chemists, engineers,
architects, researchers, manufacturers of cement and concrete, standards
writing bodies, and users of concrete.
Ottawa, Canada V. .S Ramachandran
May ,21 2000 James J. Beaudoin
Contributors
Xu Aimin David Darwin
and Sarkar Associates University of Kansas
Houston, Texas Lawrence, Kansas
P. A. Muhammed Basheer Geoffrey Frohnsdorff
The Queen's University of Belfast National Institute of Standards and
Belfast, Northern Ireland ygolonhceT
Maryland Gaithersburg,
James J. Beaudoin
National Research Council of S. N. Ghosh
Canada Structural Waterproofing .oC
Ottawa, Canada P.O.- Shibpur, Howrah
West India Bengal,
A. K. Chatterjee
Cement House P. E. Grattan-Bellew
India Mumbai, National Research Council of
Canada
James R. Clifton Ottawa, Canada
National Institute of and Standards
ygolonhceT
Maryland Gaithersburg,
XP
xvi Contributors
Gordon Ping Gu Vangi S. Ramachandran
National Research Council of National Research Council of
Canada Canada
Ottawa, Canada Ottawa, Canada
Nataliya Hearn Shondeep L. Sarkar
Consultant Sarkar and Associates
Maryland Timonium, Houston, Texas
William G. ttime Jan Skalny
Erlin, Hime and Associates Consultant
,koorbhtroN Illinois Maryland Timonium,
Dipayan Jana Leslie J. Struble
Sarkar and Associates University of Illinois
Houston, Texas Illinois Urbana-Champaign,
Xihuang Ji Guokuang Sun
University of Illinois at Urbana- University of Illinois
Champaign Illinois Urbana,
Illinois Urbana,
Hiroshi Uchikawa
R. James Kirkpatrick Kanazawa Institute of Technology
University of Illinois Nonlchi, Ishikawa, Japan
Illinois Urbana,
J. Francis Young
V. M. Malhotra University of Illinois
Canada Centre for Mineral and Illinois Urbana,
Energy Technology
Ottawa, Canada
Jacques Marchand
Laval University
Quebec, Canada
1
Concrete Science
Vangi .S Ramachandran
1.0 INTRODUCTION
Concrete, made from cement, aggregates, chemical admixtures,
mineral admixtures, and water, comprises in quantity the largest of all
man-made materials. The active constituent of concrete is cement paste
and the performance of concrete is largely determined by the cement
paste. Admixtures in concrete confer some beneficial effects such as
acceleration, retardation, air entrainment, water reduction, plasticity, etc.,
and they are related to the cement-admixture interaction. Mineral admix-
tures such as blast furnace slag, fly ash, silica fume, and others, also
improve the quality of concrete.
The performance of concrete depends on the quality of the ingredi-
ents, their proportions, placement, and exposure conditions. For example,
the quality of the raw materials used for the manufacture of clinker, the
calcining conditions, the fineness and particle size of the cement, the
relative proportions of the phases, and the amount of the mixing water,
influence the physicochemical behavior of the hardened cement paste. In
the fabrication of concrete, amount and the type of cement, fine and coarse
aggregate, water, temperature of mixing, admixture, and the environment
to which it is exposed will determine its physical, chemical, and durability
behavior. Various analytical techniques are applied to study the effect of