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ICUS/INCEDE NEWSLETTER
International Center for Urban Safety Engineering

Institute of Industrial Science
The University of Tokyo

VOLUME 1 NUMBER 4
JANUARY -MARCH 2002

International Center for
Urban Safety Engineering

Maintenance of Concrete Infrastructure- A New Challenge for Civil Engineers by
Taketo Uomoto and Sudhir Misra
Civil Engineers have been
traditionally involved in design andconstruction of infrastructure road networks, buildings, bridges,
industries, or any other structure.
Even as engineers have endeavored
to develop innovative design
methods, materials andconstruction techniques, a lot moreneeds to be done. Shown below areclippings from the local press
expressing alarm at some of thedeterioration observed in concrete
structures. Also shown is a now

well-known collapse of a section of
the Hanshin expressway, after the
Kobe earthquake of January 26,
1995. Such failures of engineered
structures and the public outcry
associated with that, only highlightthe effort that still needs to be put
in to create a safe environment.
Now, creating a safe urban
environment needs,- a better understanding of the forcesof nature,- building the structures in a mannerthat their performance remains

satisfactory during the service
life, and,- m e t h o d s t o eva l u a t e a n dstrengthen existing structures interms of their ability towithstand loads. Initiation of
appropriate maintenance action
is a necessary corollary to this.
Traditionally, a civil engineer istrained to deal with forces of naturein terms of structural loads andadopt appropriate tools for designand construction. A new dimension

Warning of safety problems of concrete structures in Japan (left)
and failure of Hanshin Expressway due to Kobe Earthquake of 1995

ICUS/INCEDE Newsletter Vol. 1, No. 4

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- nondestructive testing andevaluation of existing structures,
initiating appropriate maintenanceaction, understanding
environmental conditions in termsof ‘loads’, and trying to better
understand the performance ofstructures over the period of time,
is being added to the
responsibilities of a civil engineer.
Efforts are being made all over
the world to train civil engineers forthe new role, and given Japan’sv u l n e r a b i l i t yt oearthquakes,typhoons, etc. theissue has been taken up on war
footing here. This article briefly
discusses some of the actions being
taken, citing examples in the areaof concrete structures.
Developments
in concrete engineeringThough concrete has been usedin the last 50 years in various
structures - bridges, tunnels,
nuclear power plants, dams, roads,
and of course buildings, better
construction materials andtechniques along with an improved
understanding of its mechanicalbehavior, has only widened its
applications as a construction
material.
Use of fibre-reinforced plastic
materials, as a possible
replacement for steel reinforcementin cases where corrosion could not
b e a l l owe d, o r i n e x t e r n a lprestressing especially in the caseof repair of deteriorated structures,is an example of use of alternative

Shotcreting using
automated equipment

Use of FRP rods along withconventional steel reinforcement

construction materials for
specialized use. There have also
been advances in the use of concrete
reinforced with short discrete fibres
when cracking in concrete needs tobe controlled and to improve thepost-cracking load-carrying
capacity of concrete. Air port
runways and tunnel linings areexamples where fibre-reinforced
concrete has been often successfully
used.
High performance selfconsolidating concrete is anotherdevelopment that has contributed to
improve the quality of concrete
construction, especially in areas
where it would otherwise be
extremely diff icult to ensure
adequate vibration andconsolidation of concrete. Though
use of such concretes is still less than
5%, it is increasing rapidly. The
figure above shows an example ofshotcreting using automatedequipment, and utilization of FRP
rods in conjunction withconventional reinforcement in aparking lot (where presence of steel
reinforcement hampers the workingof operating equipments).

Development in nondestructive
testing and evaluation methods
The construction of structures at
any time reflects the state-of-art indesign and construction at thattime, and the construction during
the 50s and 60s in Japan is no
exception. These structures werebuilt with only limited knowledgeo f t h e e f f e c t o f d i ff e r e n tenvironmental conditions. Viewed
in that light, it is not surprising thata lot of these structures have begun
to show signs of deterioration.
Efforts are being made to develop
new techniques for an accurate
assessment of the levels of
deterioration, so that corrective
steps, as may be required, can beinitiated.
Given that concrete structures
are often quite large, it is importantto narrow down smaller areas,
which could be used for‘representative’ testing. Use of
i n f ra re d t h e re m og ra p h y i s
emerging as a valuable tool in thisarea. An example of a photographic
and thermographic images of abuilding is shown below. The
presence of air pockets under the

Application of infrared thermography in non-destructive testing and evaluation of buildings

ICUS/INCEDE Newsletter Vol. 1, No. 4

page 3surface causes a difference in theheat absorption and conductivity
characteristics of the concrete
leading to a difference in thesurface temperatures in portions
with voids and delaminations,which is captured in at h e r m og r a p h i c i m a g e . T h etechnique can also be used toindentify areas that may have voids
behind an apparently smoothconcrete surface. The two figuresin righthand side show examples
where infrared theremography has
been used to ‘look’ at an H-shaped
void in a 150 mm thick concrete
block. It may also be pointed outthat in this study, the depth of thevoid (in the regions A, B and C,
the thickness of the concretebehind the smooth surface), isvarying, and that is also reflectedin the varying ‘clarity’ with which
the void is mapped.

- extent of removal of concrete
required (all loose concrete, or that
contaminated with chlorides, etc.,
should be removed)

Use of infrared thermography to detect voids hidden bihind smoothconcrete surfaces- need to provide additional used by doctors during the period
reinforcementof allowing broken bones to- properties of the material to be used repair!!
and method of repair- compatibility of the repair material
An extensive repair material
with the parent concrete
evaluation programme involving- b e h av i o u r o f t h e r e p a i r e d more than 15 companies is(composite) structural member presently in progress. The figure
under the action of loads
on the next page is a view of the
exposure site where specimens
In the last about 15-20 years, prepared under varying conditions
several method have been developed and using different materials arelargely on a ‘trial and error’ basis. being tested to test the durability
From among those documented in of repair materials.
literature, the following methods
have perhaps been more commonly
Steps by professional bodies
used:
The Japan Society of Civil- reinforcement with a steel plate
Engineers and the Japan Concrete-reinforcement with continuous Institute are among the several
fibre-reinforced plastic sheets
professional bodies in Japan, that- application of (cementitious or have taken steps in the recent past
epoxy based) repair mortar or i n r e s p o n s e t o t h e n e w
concrete by shotcreting
responsibilities that civil engineers- jacketing the affected members or are being asked to shoulder increasing the cross-section
whether they work for construction
companies, government and semiThe figures below show examples government organization, orof using external prestressing cables consulting organizations. Several
as a means for strengthening beams publications brought out in the lastin a bridge deck and an example of ten years dealing with testing andusing flexible sheets made of u s e o f n ew m a t e r i a l s a n dcontinuous f ibres woven in two techniques. This shows the
directions around columns in several importance being placed onlayers and applying binder material development of specifications andin much the same manner as making standardization of use of new
a rigid cast in the case of a plaster materials and methods.

Using external prestressing
for strengthening structures

Jacketing of columns with continuous fibre sheets
for strengthing structures

Development of repair
and rehabilitation methods
Minor repair and maintenanceaction are often undertaken locallyand with locally available materials
and expertise. However, in addition
to such minor actions, formal
rehabilitation works are needed
when it is desired to extend theser vice life or upg rade theperformance level of the structure,
or at the time of change in the(design) loading for the structure,o r d u r i n g p o s t - ev e n t ( e . g .
earthquake) rehabilitation. In suchcases, it is important that thefollowing are carefully examined:

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Two photographs of the Izu exposure site showing a bird's eye view and the specimens in place
Design of new structures
In the Standard Specification for
Design and Constr uction ofConcrete Str uctures (JSCE)
presently in force, a performancebased durability design approach has
been adopted. Most standards in the
wo r l d l ay d ow n l i m i t s f o r
parameters, such as, the maximum
flexural crack width, grade ofconcrete used and cover to thereinforcement, which are known toplay a part in the susceptibility of astructure to future deterioration.
However, the new approachsuggested in the Japanese standards
provides a framework to model
deterioration processes in a mannerthat during the service life of thestructure, a predetermined level ofdeterioration is not exceeded.
In other words, as recognition of
the fact that concrete structures are
not maintenance free, a certain
amount of deterioration has been‘allowed’. Now, on the basis ofquantitatively defined parameters, acertain critical level of (acceptable)
deterioration has been fixed (Alim).
Thus, the designer is required tocheck that the extent of likely
deterioration during the service lifeof the structure, Ad, (called ‘designed
deterioration’, because, that is theamount or extent of deterioration,
estimated to occur over the sevicelife at the time of design) does notexceed this critical level. Further, theextent of difference between thedesigned deterioration and thecritical deterioration needs to berelated to level of importance of thestructure. In other words, it should
be ensured that,
γi

Ad
<1.0
Alim

wh e r e , γ i i s a c o e ff i c i e n t
representing the importance of thestructure. It may be taken to be 1.0
in most cases, but may be increased
to 1.1 in case of important structures.
Efforts are now being made to
publish some of the important
standards in English, to enable nonJapanese speaking professionals
better understand the thinking
among Japanese designers, andpromote a fruitful exchange of ideas.
It is hoped that the volumes will beavailable for wider circulation by
May 2003.
Introductionof professional examination
A s m e n t i o n e d a b ov e , a nunderstanding of nondestructive
testing and evaluation is fast
becoming very important forpracticing civil engineers. The work
involves a knowledge of thedeterioration mechanism operating
i n c o n c r e t e u n d e r d i ff e r e n t
conditions, awareness of the varioust e s t s ava i l a bl e , a n d a c l e a r
understanding of the limitations
associated with different tests. Witha view to impart the required
professionalism and promoteawareness among the engineers, in2001 the Japan Concrete Instituteintroduced an examination to‘qualify or license’ engineers in the

ICUS/INCEDE Newsletter Vol. 1, No. 4

area. This exermination has beencalled the ‘concrete shindan shi test’.
Interstingly the japanese (kanji)
character used for shindan are thesame as used in the term ‘kenko(health) shindan (chek up)!!’In other words, the effort isdirected to creating awarenesstowards the fact that,(a) much like our health, concrete
structures should be subject to aregular check up, so that any
symptoms of deterioration, can becaught early and appropriately
rectified, and,(b) such examination and decisions
for further action should be
carried out by appropriately
qualified personnel.
Concluding remarks
Repair and rehabilitation of
concrete structures has become amulti-billion dollar industry in theworld, and all out effort is required toensure that not only new structures aredesigned and constructed withadequate care, even the existing
structures are appropriately modified
to be safe. Some of the steps taken in
Japan in this direction have beenbriefly discussed here. However it isclear that closer cooperation between
researchers and designers in the world
would go a long way in a more
effective utilization of the limited
resources.

Editor’s note: Readers may also
refer to an extended version of thisarticle at our website (http://icusincede.iis.u-tokyo.ac.jp).

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2nd ICUS/INCEDE Open Lecture
The second ICUS/INCEDE
Open Lecture was held on January
24, 2002 at the Institute of Industrial Science of the University ofTokyo with major focus on issues
to be considered in urban safety. It
was attended about 100 participants from Tokyo and its neighboring cities.
There were four speakers in thelecture. Two of them were renowned Japanese technocrats; Dr.
Tsuneo Katayama, the Director
General of National Institute ofEarth Science and Disaster Prevention and Prof. Shunji Murai of
Keio University, both of them arealso Professor Emeritus of the
University of Tokyo. Other two
speakers were Profs. T. Takahashi

and M. Setojima, both are the visiting professors at ICUS/INCEDE.
Dr. Katayama presented a lecture on the purpose of earthquake
disaster prevention research in Japan in which he elaborated the history of earthquake disaster prevention research in Japan and its expected future development.
In his talk, Prof. Murai presented
a proposal to wealthy urban planning the role of space information
technology. He covered various
aspects of this proposal during thetalked and emphasized that role ofspace information technology was
important to estimate and realize
the proposal.
Dr. M. Setojima spoke on evalu-

ation of urban environment using
remote sensing technology inwhich the importance of evaluation of landscape was emphasized
and remote sensing technology
was expected as a powerful tool
for such evaluation.
Prof. T. Takahashi presented on
administration for earthquake
disaster prevention of Japan. He
talked in detail the various counterm e a s u r e t a ke n by J a p a n e s eGovernment towards disasterprevention.
The following two articles
s u m m a r i z e t h e t a l k s o f D r.
Katayama and Prof. Murai in thislecture.
(R. Ooka)

Dr. T. Katayama (left) and Prof. S. Murai during their talks in the 2nd ICUS Open Lecture

Smallness Can Be a Culture
by Dr. Tsuneo Katayama
ICUS/INCEDE is small, and I
know that the INCEDE part of it iseven smaller. Encountered withsuch a difficult problem as disastermitigation in developing nations,one often feels that it is almost impossible to single-handedly do anything significant.
Although almost six years havepassed since I left INCEDE, I
strongly remembered those days inwhich we worked so hard to internationally establish INCEDE. It istrue that the work was hard because
the organization was small. But
don’t be discouraged.

We saw very recently that a single
individual can change the future ofa nation. Aung San Suu Kyi, leaderof the pro-democracy movement of
Myanmar, has been released after ayear and seven months under housearrest. It has already been 12 years
since Suu Kyis National League for
Democracy won the general election
by a landslide in 1990, but the generals refused to cede power. Now
neighboring countries clearly suggest that the only way for Myanmar
to develop of its situation is to adopt
democracy.

Smallness is undoubtedly one of
the important attributes of the Japanese culture and I do believe that it
is also one of the vital characteristics of ICUS/INCEDE.
You can do whatever you believe
is right, because ICUS is small, andyou can strongly show your identity,
because you work in a small organization. Shortcomings can be madeinto strong points. Best wishes forthe bright future of ICUS/INCEDE.

ICUS/INCEDE Newsletter Vol. 1, No. 4

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Safety vs. Disasterby Prof. Shunji Murai
As a former professor of Intituteof Industrial Science, theUniversity of Tokyo, first of all, I
congratulate ICUS/INCEDE for agood start with the well organizedteam works.
I would like to propose myviewpoints with respect to safety
vs. disaster for the consideration of
future direction. As different fromthe existing definition, I think thatdisaster will be a negative effectincurred before and after a natural
phenomenon or a human activity.
In other words, disaster is anegative change. Therefore in myview, if an urban planning anddesign was not done properly that
resulted in traffic jam, ugly city

landscape, dirty streets, etc., it is adisaster.
On the other hand, safety in mydefinition will be a positive effectto be guaranteed for future.
Regardless of safety or danger in thecurrent condition, it could become
safety if one can guarantee thefuture. In spite of my view, safety is
considered by many people to be in
the condition of no danger. My
thought is that it should be a positive
promise. Therefore a safe city willb e e nv i r o n m e n t a l ly h e a l t hy,
beautifully scenic, making people
happy and comfortable, free fromfear, etc.
As I deliver this lecture at ICUS

workshop in January this year,
most of the Japanese cities are adisaster with spider nets of electricpoles and not a safety to me. The
reclaimed coast, which replaced abeautiful beach, is a disaster andnot a safety to me. I hope that thereaders may understand my view
points.
I wish all the best for ICUS
and I am sure that ICUS is not adisaster but a safety to all. Lastly, I
myself should be careful that I do
not become a disaster but a safety.
The photographs presented below
are kindly provied by the GreenBench Research Group-Chairman:
Prof. Shunji Murai

February 1995: The construction
with steep slopes was a disaster

April 1998: The slope was not yet safein spite of the plantation of trees instead of grasses

September 1998: The slope was much improved
with trees growing

August 1999: Green Bench Method certified how tochange from disaster to safety condition

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International Symposium on

NEW TECHNOLOGIES FOR URBAN SAFETY OF MEGA CITIES IN ASIA
This one-day symposium is beingorganized by the Center (ICUS) at
the Grand Pacific Hotel, Bangkok, incollaboration with the Asian Instituteof Technology (AIT), Thailand, on
October 28, 2002. The objective is tocreate awareness towards issues
related to urban safety engineeringand disseminate information about useof latest techniques such as Remote
Sensing, GIS, GPS and othercomputational tools, in creating

databases and inventories of urban
i n f ra s t r u c t u re . A d d i t i o n a linformation about the schedule, andother details will be available at thecenter website (http://icusincede.iis.u-tokyo.ac.jp).

Tenth International Conference on Structural Faults and Repair
An International Conference on
Structual Faults and Repair will beheld in Commonwealth InstituteKensington, London, UK during July
1 - 3, 2003. It is organized by
University of Edinburgh.
The main theme of this conferenceis extending the life of bridges,
concrete, composites, buildings andcivil structures. The deadline of theabstract (within 200 words) is August
31, 2002.
The adress for futher information
is as follows. Prof. M. C. Forde, Schoolof Civil and Environmental
Engineering, University of
Edinburgh, The King's Buildings,
Edinburgh EH9 3JN, Scotland, UK
FAX +44-131-452-8596, E-mail :m.c.forde@ed.ac.uk.

The Fifth International Conference on Urban Climate (ICUC-5)
The Fifth International Conference
on Urban Climate (ICUC-5) is going
to be held in Lodz, Poland during
September 1 - 5, 2003. It is organizedby the International Association for
Urban Climate (IAUC) and the
University of Lodz in co-operation with
the World Meteorological Organization.
ICUC-5 is the continuation of aseries of similar conferences starting in
Kyoto, Japan in 1989, followed by thosein Dakha, Bangladesh in 1993, Essen,
Germany in 1996, and Sydney,Australia

in 1999. The success of this series helped
to create a cohesive international
community of urban climatologists that
led to the formation of the IAUC ( http://www.geography.ohio-state.edu/
UrbanClimate/ ) in 2000. ICUC-5 is thefirst conference to be organised by the
new Association.
The aims of the conference remain
as before, to provide an international
forum where the world's urban
climatologists can meet to showcase anddiscuss modern developments inresearch, and the application ofclimatic knowledge to the design ofbetter cities. ICUC-5 wishes to caterto the interests of a diverse communityof meteorologists, climatologists,hydrologists, ecologists, engineers,architects and planners and others
interested in these topics.
The futher details of this conference
information are available in web site
http://www.geo.uni.lodz.pl/~icuc5.

The United Nations World Disaster Reduction Campaign
Disaster Reduction for Sustainable Mountain Development
As every year since the earlynineties, the United Nations isorganizing a World Disaster
Reduction Campaign, which
culminates on International DisasterR e d u c t i o n D ay, t h e s e c o n dWednesday of October,9 Octorber
this year. The World Disaster
Reduction Campaigns are organizedby the Secretariat of the International
Strategy for Disaster Reduction,
located in Geneva, Switzerland.
The first aim of the 2002 World
Disaster Reduction Campaign istherefore to increase globale
awareness of successful disaster
reduction efforts in mountain areas sothat vulnerable mountainpopulations can benef it fromalready existing experiences. The
second aim of the 2002 Campain is
to raise awareness more generally on
disaster reduction, so that past andnew solutions in vulnerability andrisk reduction can be explained andshared.

Visitors to ICUS
Some of the visitors to ICUS/
INCEDE during Jan. - Mar. 2002;* Prof. D. K. Paul, Department
of Civil Engineering, Indian
Institute of Technology (Feb. 19).
* Dr. Pennung Warnitchai,

School of Civil Engineering, Asian
Institute of Technology, Thailand(Mar. 21-22)* Dr. Somnuk Tangtermsirikul,
Sirindhorn International Institute ofTechnology, Thammasat University,

Thailand (Mar. 21-22)* Dr. Marek Rebow, Institue of
H e a t E n g i n e e r i n g, Wa r s a w
University of Technology, Poland(Mar. 26)

ACTIVITY RECORDS

Prof. Yasuoka visited AIT toparticipate in a research meeting.
(Mar. 21-23)
Prof. Meguro visited New York to
study the on-going rehabiliation
activities aftermath of the WTC
disaster. (Feb. 24-Mar. 3)

Dr. Dutta visited Switzerland toattend the international
conference on Flood Estimation
in Bern. (Mar. 4-9)
Dr. Dutta also visited Thailand toparticipate in a field survey forflood modeling. (Mar. 13-17)

During the period of JanuaryMarch, 2002, ICUS staff haveparticipanted in various international
research activities including filed
surveys, conferences and project
meetings. Some of those are listed:

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Editor's Note
As a research center, ICUS/
INCEDE is involved in various
research activities towards urban
safety. The word safety has a broad
meaning. There is no doubt that it
is most important to protect ahuman life from natural disasters,such as earthquakes, floods, etc.,
wh i c h i s d e a l t w i t h i n t h econventional disaster-preventionengineering field. However, that is
not enough to secure safety for as o c i e t y. T h e r e a r e e q u a l ly
important other issues to be dealt
with to attain that. For example, inrecent years the global

environmental problem has becomea very serious issue. This problem
has occurred because the humanactivities exceed the environmental
capacity of the earth. This hascaused many adversed effects, suchas climate change on an earth scale,broader-scale air pollution, sea
pollution, a change of ecosystem,
exhaustion of natural resources andenergy, etc. These phenomena arethreatening the safety of humanbeings after all. The similar thing has
occurred also in urban scale. In order
to secure urban safety, we must pay
attention not only to natural disasters
but also to environmental and social
problems widely.

ICUS/INCEDE has beendeveloped and reorganized fromINCEDE with the aim of carryingout intense research for tackling
various issues towards urban safety
covering such broad aspects.
As ICUS/INCEDE is a small
research organization, it is
impossible for it to tackle all these
problems alone. However, We wantto aim at such a large target.
Moreover, in order to tackle suchlarge research domains,
cooperation of many people relatedwith these problems is expected.

ICUS/INCEDE, Institute of Industrial Science, The University of Tokyo
4-6-1 Komaba, Meguro-ku, Tokyo 153-8505, Japan
Tel: (+81-3)-5452-6472, Fax: (+81-3)-5452-6476, http://icus-incede.iis.u-tokyo.ac.jp/

International Center for Urban Safety Engineering, ICUS/INCEDE
Institute of Industrial Science, The University of Tokyo
4-6-1 Komaba, Meguro-ku, Tokyo 153-8505, Japan

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International Center for
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ICUS/INCEDE Newsletter Vol. 1, No. 4(R. Ooka)