Fiber-Reinforced-Plastic (FRP) Reinforcement for Concrete Structures. Properties and Applications

436 Pages·1993·11.982 MB·English

by  David A.Hensher and L. Anselin (Auth.)

Developments in Civil Engineering
Vol. 1 The Dynamics of Explosion and its Use (Henrych)
Vol. 2 The Dynamics of Arches and Frames (Henry ch)
Vol. 3 Concrete Strength and Strains (Avram et al.)
Vol. 4 Structural Safety and Reliability (Moan and Shinozuka, Editors)
Vol. 5 Plastics in Material and Structural Engineering (Bares, Editors)
Vol. 6 Autoclaved Aerated Concrete, Moisture and Properties (Wittmann, Editor)
Vol. 7 Fracture Mechanics of Concrete (Wittmann, Editor)
Vol. 8 Manual of Surface Drainage Engineering, Volume II (Kinori and Mevorach)
Vol. 9 Space Structures (Avram and Anastasescu)
Vol. 10 Analysis and Design of Space Frames by the Continuum Method (Kollär and Hegedüs)
Vol. 11 Structural Dynamics (Vertes)
Vol. 12 The Selection of Load-Bearing Stuctures for Buildings (Horväth)
Vol. 13 Dynamic Behaviour of Concrete Structures (Tilly, Editor)
Vol. 14 Shells, Membranes and Space Frames (Heki, Editor)
Vol. 15 The Time Factor in Transportation Processes (Tarski)
Vol. 16 Analysis of Dynamic Effects on Engineering Structures (Bata and Plachy)
Vol. 17 Post-Buckling of Elastic Structures (Szabo, Gäspär andTarnai, Editors)
Vol. 18 Fracture Toughness and Fracture Energy of Concrete (Wittmann, Editor)
Vol. 19 Pavement Analysis (Ullidtz)
Vol. 20 Analysis of Skeletal Structural Systems in the Elastic and Elastic-Plastic Range (Borkowski)
Vol. 21 Creep and Shrinkage of Concrete Elements and Structures (Smerda and Kfistek)
Vol. 22 Theory and Calculation of Frame Structures with Stiffening Walls (Pubal)
Vol. 23 Time Effects in Concrete Structures (Gilbert)
Vol. 24 Stresses in Layered Shells of Revolution (Kovarik)
Vol. 25 River Intakes and Diversion Dams (Razvan)
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Vol. 27 Reinforced-Concrete Slab-Column Structures (Ajdukiewicz and Starosolski)
Vol. 28 Finite Models and Methods of Dynamics in Structures (Henrych)
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Vol. 30 Shells of Revolution (Mazurkiewicz and Nagorski)
Vol. 31 Structural Load Modeling and Combination for Performance and Safety Evalution (Wen)
Vol. 32 Advanced Analysis and Design of Plated Structures (Kfistek and Skaloud)
Vol. 33 Regular Lattice Plates and Shells (Sumec)
Vol. 34 Combined Ultrasound Methods of Concrete Testing (Galan)
Vol. 35 Steel-Concrete Structures for Multistorey Buildings (Kozäk)
Vol. 36 Analytical Methods in Bin-Load Analysis (Drescher)
Vol. 37 Design of Welded Tubular Connections - Basis and Use of AWS Code Provisions (Marshall)
Vol. 38 Fresh Concrete - Properties and Tests (Bartos)
Vol. 39 Stability, Bifurcation and Postcritical Behaviour of Elastic Structures (Pignataro, Rizzi and Luongo)
Vol. 40 Cable-Stayed Bridges (Ito, Fujino, Miyata and Narita, Editors)
Vol. 41 Numerical Analysis of Reinforced Concrete Structures (Avram, Bob, Friedrich and Stoian)
Vol. 42 Fiber-Reinforced-Plastic (FRP) Reinforcement for Concrete Structures: Properties and
Applications (Nanni, Editor)
Advisory Editor to this Series:
Professor Isaac Elishakoff, Center for Applied Stochastics Research, Department of Mechanical
Engineering, Florida Atlantic University, Boca Raton, FL, U.S.A.
FIBER-REINFORCED-PLASTIC
(FRP) REINFORCEMENT FOR
CONCRETE STRUCTURES
Properties and Applications
Edited by
ANTONIO NANNI
The Pennsylvania State University
University Park PA, U.S.A.
y
ELSEVIER
Amsterdam - London - New York -Tokyo
1993
ELSE VIER SCIENCE PUBLISHERS B.V.
Sara Burgerhartstraat 25
P.O. Box 211, 1000 AE Amsterdam, The Netherlands
Library of Congress Catalog1ng-1n-PublIcatIon Data
Fiber-reinforced-plastic (FRP) reinforcement for concrete structures :
properties and applications / edited by Antonio Nannl.
p. cm. — (Developments 1n civil engineering ; v. 42)
Includes bibliographical references.
ISBN 0-444-89689-9
1. Reinforced concrete construction. 2. Fiber reinforced
plastics. I. Nannl, Antonio. II. Series.
TA683.F45 1993
624. 1 '8341—dc20 93-25585
CIP
ISBN: 0 444 89689 9
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V
PREFACE
The idea of preparing this book originated in October of
1991 during the American Society of Civil Engineers (ASCE)
Convention in Orlando, Florida. At that time, it was recog-
nized that the use of fiber reinforced plastic (FRP) compos-
ites for prestressed and non-prestressed concrete reinforce-
ment had moved from the stage of an "exotic subject" to that
of a technology with serious and substantiatable claims for
the advancement of construction materials and methods.
Research and development (R&D) efforts on the subject were
being undertaken world-wide. This included several demonstra-
tion projects. A considerable number of publications was
already available in technical journals and conference pro-
ceedings. Two symposia specifically dedicated to the subject
were in the planning stage (JSCE, Tokyo, Japan in April '92;
and ACI, Vancouver, Canada, in March '93.) Two other sympo-
sia, one eight-month old (ASCE, Las Vegas, Nevada, February
'91) and the other in the planning stage (CSCE, Sherbrooke,
Quebec, October '92,) had FRP reinforcement for concrete as
the major thrust. With all of these activities taking place,
it appeared necessary to offer a comprehensive picture of the
international situation. The idea was that of a book intended
for engineers, researchers, and developers with the objective
of presenting a world-wide cross-section of initiatives,
representative products and significant applications.
Based on personal experience and contacts, I invited the
leaders in this field to contribute a paper. The response to
the invitation was enthusiastic. The book collects 20 contri-
butions subdivided into three parts. Part I (three papers)
introduces FRP reinforcement for concrete structures and
describes general material properties and manufacturing
methods. Part II (four papers) covers a three-continent
perspective of current R&D, design and code implementations,
and technical organizations' activities. Part III (13 papers)
presents an in-depth description of commercially-available
products, construction methods, and applications.
I am grateful to the authors and co-authors for their
collaboration, and to Elsevier Science Publishers B.V. for
publishing the book. It is my hope that this book make a
significant contribution in advancing knowledge and acceptance
of FRP composites for concrete reinforcement.
Antonio Nanni
State College, PA
March 1993
Fiber-Reinforced-Plastic (FRP) Reinforcement for
Concrete Structures: Properties and Applications
A. Nanni (Editor) 3
© 1993 Elsevier Science Publishers B.V. All rights reserved.
FRP reinforcement for prestressed and non-prestressed concrete
structures
A. Nanni, Ph.D., P.E.
Department of Architectural Engineering, The Pennsylvania
State University, University Park, PA 16802, U.S.A.
Abstract
This paper provides the overall introduction to the subject
of FRP reinforcement for concrete structures. It explains the
organization and contents of the book and outlines a vision
for future work.
1. INTRODUCTION
In the last decade, the use of f iber-reinf orced-plastic
(FRP) composites for reinforcement to concrete members has
emerged as one of the most exciting and promising technologies
in materials/structural engineering. There is a wide range of
potential applications of FRP reinforcement that covers new
construction as well as strengthening/rehabilitation, pre-
stressed as well as non-prestressed members, and prefabricated
as well as cast-in-place construction. The justification and
motivation for this interest in FRP reinforcement appears to
be a world-wide phenomenon with some peculiar geographical
connotations. For example, in Japan, the driving interest
appears to be in construction materials and methods that may
enhance prefabrication, automation, labor savings, and in
general, a cleaner, more efficient construction process. In
North America, the major interest is to find a solution to the
durability problems caused by steel reinforcement corrosion,
particularly in the infrastructure. Europe may have a combi-
nation of all the above, coupled with a keen interest in
strengthening/rehabilitation as a result of its large number
of invaluable historical structures in need of repair.
As different nations have different organizational/ econom-
ical structures, the approach to research and development
(R&D) has also a regional nature. In Japan, general contrac-
tors and fiber manufacturers are forming the alliances neces-
sary for the development of this new technology. In North
America, the construction industry has been totally absent
from the R&D process related to FRP reinforcement. Only
pultruders have had some involvement up to now. Their origi-
nal interest was in the production of FRP structural shapes
for construction applications. Subsequently, FRP
4
reinforcement to concrete has become an extension of that
initial interest. The need to convert U.S. military-oriented
industries to civilian-type applications may have some inter-
esting developments in the near future. In Europe, contrac-
tors were directly involved in the R&D of two of the earliest
and the most successful FRP products. These differences in
priorities and structure among nations (or blocks of nations)
has also resulted in specializations within the wide range of
FRP reinforcement types. With a certain degree of approxima-
tion, it can be said that Japan excels in prestressed rein-
forcement (pre-tensioned type) and multidimensional reinforce-
ment; North America excels in non-prestressed reinforcement
and gratings; and Europe excels in prestressed reinforcement
(post-tensioned type) and bonded plates. In any case, the
success and the adoption of FRP reinforcement in the market
place will depend on the creativity and resourcefulness of
scientists and engineers and in their ability to disengage
their thinking and approach from traditional construction
procedures and systems. In other words, the realization of
the full potential of FRP composites for construction is yet
to come.
As FRP reinforcement for concrete structures moves from the
R&D phase to the demonstration and commercialization phases,
the need for a comprehensive document addressing background,
approach, expectations, products, and uses has emerged. This
book is to serve this need and complement the body of litera-
ture already available on the subject. Presently, the techni-
cal literature consists primarily of papers collected in the
proceedings of specialty symposia [1-5] and conferences of
various professional societies (e.g., Architectural Institute
of Japan (AIJ,) Canadian Society for Civil Engineering (CSCE,)
Federation Internationale de la Precontrainte (FIP,) Interna-
tional Association for Bridge and Structural Engineering
(TABSE,) Japan Concrete Institute (JCI,) Japan Society of
Civil Engineers (JSCE,) Society for the Advancement of Materi-
al and Process Engineering (SAMPE,) Transportation Research
Board (TRB,) etc.) The aim of this paper, the first of 20
collected in the book, is to provide an overall introduction
to the subject, to explain the organization of the work, and
to highlight the specific topics dealt with in the three main
sections of the book.
2. BOOK ORGANIZATION
2.1 Part I - Introductory topics
Part I consists of three papers (including this one.) The
objective of this section is to familiarize the reader with
fundamental concepts, material forms and properties, and
manufacturing methods that relate to advanced composites and
FRP reinforcement, in particular. In terms of nomenclature,
advanced composites encompass all kinds of systems that are a
combination of two or more materials acting in concert and
exhibiting significant mechanical properties [6]· For
5
advanced composites made of continuous, non-metallic, rein-
forcing fibers, fillers, and a resin binder and used as the
reinforcing elements in concrete structures, the term fiber
reinforced plastic (FRP) reinforcement is generally adopted.
In the paper on "Materials and Manufacturing", Bakis
presents a summary with extended bibliography of various
fundamental subjects relative to FRP composites. This de-
scription reviews of the developments that have occurred in
the last half century. The intention is to educate the reader
on: a) material forms and associated terminology; b) composite
constituents classification, grades, and properties; and c)
manufacturing processes. It is likely that some of the
constituent materials (e.g., thermoplastic) and manufacturing
methods (e.g., compression molding) mentioned in this paper
may not find immediate application in the field of FRP rein-
forcement to concrete structures. However, there is a need to
draw from these experiences in order to address construction
industry-related issues without the constraints of traditional
forms and approaches.
The paper on "Properties of FRP Reinforcements" by Bank
reviews all physical and mechanical properties pertinent to
FRP composites for use as reinforcement to concrete. This
description is a necessary background to the reader as it
provides a key to understand what follows in the book relative
to testing procedures, design methods, and specific products
and applications. Some of the important facts that need
recognition are: anisotropy (i.e., directional dependency)
and the relationship (or lack of it) between longitudinal and
transverse properties; stress rupture (i.e., decrease in
static strength under constant stress over time); and stress
corrosion (i.e., accelerated deterioration caused by the
combined effect of load and adverse environment.) For exam-
ple, the longitudinal shear modulus of FRP bars cannot be
computed on the basis of the corresponding elastic modulus and
Poisson's ratio. Furthermore, in traditional reinforced
concrete members, the effects of thermal and moisture expan-
sion of steel reinforcement are negligible. This is certainly
not the case for FRP reinforcement.
2.2 Part II - International perspective
The objective of Part II is to present a collection of four
regional experiences (Canada, Europe, Japan, and U.S.A.)
These presentations include background, R&D efforts in acade-
mia, government and industry, work by professional organiza-
tions, code implementation, design guidelines, and research
needs.
The "Canadian Perspective" offered by Erki and Rizkalla
presents the highly coordinated efforts taking place in this
country. The fact-finding missions organized by CSCE to
Europe and Japan have produced two valuable publications and
set the stage for the Canadian approach to advanced materials
for construction. The creation of a network or umbrella
organization for industry, government, universities, and
6
professional societies interested in advanced materials for
construction is another novel approach being tried in Canada.
The overview of the R&D work in this country seems to indicate
that bridge-type applications have the highest priority.
"FRP Developments and Applications in Europe" by Taerwe
provides the historic perspective of the major accomplishments
in the area of FRP reinforcement to concrete occurred in
Europe since 1974. Some of the products and applications
introduced in this paper are presented in more detail in Part
III of the book (see papers by Wolff and Miesseler; Burgoyne;
and Meier et al.) It is worth noting that a European, coordi-
nated, 4-year project started in 1991. This effort involves
universities, contractors, and industry with the financial
support of Commission of the European Communities.
The "Overview of R&D in Japan" offered by Sonobe points out
the two fundamental events that have spurred the considerable
R&D work on FRP reinforcement undertaken in this country. The
first event is the establishment of the 5-year National
Research Project that, among other topics, includes FRP
reinforcement. The second event is the formation of the
39-member strong industry association known as "CCC Society"
(Association of Composite Materials Using Continuous Fiber for
Concrete Reinforcement) to promote FRP reinforcement for
concrete. Some of the results of the National Research
Project have been collected in a design guide published by
JSCE. In 1993, it is expected that additional conclusions
about this coordinated effort be made public through AIJ.
These results will certainly shape the R&D strategy of Japan
for the next decade.
Dolan summarizes U.S. activities in his paper entitled "FRP
Development in the United States". This fourth and last
regional review covers historical developments, university and
government research, and demonstration projects. In addition,
the paper presents a discussion on mechanics and design of FRP
reinforced concrete members with and without prestressing.
This review is based primarily on U.S. contributions even
though - the author notes - some works are influenced or
supported by international activities. In the U.S.A., the
first consensus-based document on this subject is expected to
be the State-of-the-Art Report being developed by the American
Concrete Institute (ACI) Committee 440 - FRP Reinforcement.
2.3 Part III - FRP Reinforcement Products
Part III is a collection of 13 papers describing FRP
reinforcement products available on the market or in advanced
state of R&D. All papers follow a similar format in that they
present: the primary constituent materials, the manufacturing
method and configuration of the FRP reinforcement, the
physico-chemical and mechanical properties of the reinforce-
ment, the performance in concrete members, the
constructability, and the demonstration projects/applications.
Part III is artificially subdivided into three sub-sections
based on the geometrical configuration of the reinforcement
and its application. The three sub-sections are:
7
Part III·a: 1-D Reinforcing Systems (eight papers) deals
with mono-dimensional systems that are suitable for non-
prestressed reinforced concrete (RC) applications and
prestressed concrete (PC) applications. Of the eight
papers, the first two address RC construction and the
remaining six, PC construction. The six papers describing
FRP tendons include pre-tensioned and post-tensioned
(bonded and un-bonded) applications, and, in some cases,
pre-bent shapes for use as shear reinforcement.
Part Ill.b: 2-D and 3-D Reinforcing Systems (three paper)
deals with two-dimensional (one paper) and three-dimension-
al systems (two papers.) At present, all applications
including these systems are RC-type.
Part III.c: External Reinforcing Systems (two papers)
addresses bonded plates (one paper) and wrapping (one
paper,) which are primarily repair procedures.
It may be added that the FRP products presented in Part III
are a significant sample rather than a complete list. In
terms of fiber systems, six papers deal mainly with carbon,
three with aramid, three with glass, and one with polyvinyl
alcohol (PVA.) Hybrid fiber systems are also proposed in one
paper. In terms of resin binders, all FRP products make use
of thermoset resins (i.e., epoxy, polyester, and vinylester)
with the exception of one that is not impregnated (and strict-
ly speaking not FRP.) Insufficient information is available
on the plastic used in FRP reinforcement, in terms of composi-
tion, additives, fillers, etc.
2.3.1 Part III.a: 1-D Reinforcing Systems
The paper on "Glass FRP Reinforcing Bars" by Faza and
GangaRao describes material properties and performance of
glass FRP bars produced in the U.S.A. by four different
manufacturers. These bars, intended for non-prestressed con-
crete members, are pultruded and have surface deformations
made with a strand helically wrapped around the bar. Three
manufacturers have agreed to follow the same common fabrica-
tion standards in order to facilitate product acceptance in
the market place.
The paper on "Vinylon FRP Rod (CLATEC Rod)" by Okazaki
introduces the use of a relatively new fiber material for FRP
reinforcement to concrete. The fiber of reference is a PVA
fiber known in Japan under the generic name of vinylon (in the
U.S.A. the generic term is vinal.) The paper describes
physico-mechanical characteristics that can make vinylon a
desirable choice, particularly in non-prestressed concrete
applications. Mechanical properties and chemical stability
compare favorably with those of other organic fibers and
E-glass. Temperature sensitivity may be a drawback with
respect to fire resistance.
Santoh, in his paper on "CFCC (Carbon FRP Cable)," presents
a detailed description of the constituent materials,
8
manufacturing, quality control, and FRP product properties
related to CFCC. CFCC is a carbon FRP prestressing cable for
primary use in stranded form (7, 19, and 37 wires.) The
properties of the cable presented in the paper include tensile
strength and modulus, conductivity, expansion, creep and
relaxation, fatigue, and durability. Properties relative to
the use of CFCC as concrete reinforcement include shear
capacity, bond to concrete, effect of temperature on bond,
flexibility, anchorage, and strength of a bent profile. Some
demonstration projects relative to pre-tensioned PC construc-
tion are described.
With reference to the same CFCC cable presented by Santoh,
Katou and Hayashida describe "Testing and Applications" of
post-tensioned, fully-grouted PC construction. The first part
of the paper is devoted to laboratory tests on beams with
straight and bent cables subjected to fatigue loading. The
second part of the paper addresses the application of post-
tensioned CFCC three-strands cables in a gateway building.
"Technora, an Aramid FRP Rod" by Noritake et al. outlines
the physico-mechanical characteristics of FRP elements made of
single or multiple pultruded FRP rods for primary use in
prestressing. The rods consist of aramid fibers impregnated
with vinylester resin. Surface deformation by means of a
spirally wound fiber strand is added to provide mechanical
bond with concrete. Several anchorage devices have been
developed for Technora rods, including wedge and bond types,
single and multi-tendon types, metallic and non-metallic
types. The authors recognize that the strength of the pre-
stressing system depends on anchorage type selection. The
paper describes the performance of this FRP cable in pre-
tensioned and post-tensioned PC construction, and introduces
some significant demonstration projects.
Tamura in his paper on "FiBRA" points out that this braided
epoxy-impregnated rod can be manufactured with different fiber
types depending on the intended application. The rod is also
available in a flexible and rigid form. Because the original
development work was based on the use of aramid fibers, FiBRA
is optimized for PC-type applications. In contrast with the
majority of the mono-dimensional FRP elements that are
pultruded, FiBRA is manufactured by braiding. This fabrica-
tion method offers two advantages: a deformed external
surface for mechanical bond with concrete, and efficient large
diameter sizes. Demonstration projects using FiBRA are dis-
cussed.
In the paper on "Glass Fiber Prestressing System", Wolff
and Miesseler describe the FRP prestressing system known under
the trade name of Polystal. This is a post-tensioned system
of glass FRP tendons with polyamide coating for chemical and
mechanical protection. It is stated that the resin matrix
cannot assure protection of the glass fibers from alkali
attack when the strain level in the tendon is above 0.2
percent. The paper describes the several field applications
that have been undertaken over a period of 13 years. It also
emphasizes the sensor technology that is made possible with