March 2016 No.71
Japanese Infrastructure Newsletter

IDI QUARTERLYInfrastructureDevelopment

Institute—JAPANC O N T E N T S
The 17th Infrastructure Technology Development Award 2015

1

High Durable Concrete with Seawater

2

Countermeasure against Liquefaction and Mitigation of Global Warming by Log Piling

4

Infrastructure Development Institute – Japan (IDI)
Suido-cho Bldg, 3-1, Suido-cho, Shinjuku-ku, Tokyo, 162-0811, JAPAN
Tel: +81-3-5227-4107 Fax: +81-3-5227-4109 E-Mail: idi17@idi.or.jp Website: http://www.idi.or.jp/english/00index.htm

Infrastructure Development Institute - JapanThe 17th Infrastructure Technology Development Award 2015
The Japan Institute of Country-ology and(Environment-Friendly Concrete with Seawater,Engineering (JICE) was established as a public

Byproducts, and Special Additives）”.

interest corporation to promote constructionengineering in Japan by conducting cutting-edge

The three excellence prizes were awarded toresearch and development activities.

“Tunnel Enlargement Method for Shield
Tunneling with Segments (WJ Segment Method)”,

To provide more incentives for construction“Hybrid tsunami protection wall to enable ‘ultra’technology researchers and research institutes torapid construction (Minimization of site worksenhance the level of construction engineeringand nearby producing materials due to divide

more effectively, JICE commenced Infrastructure

wall into pre-casted blocks)”, andTechnology Development Award with the Coastal“Countermeasure against liquefaction andDevelopment Institute of Technology (CDIT)

mitigation of global warming by log piling (Logunder the auspices of the Ministry of Land,

Piling method for Liquefaction mitigation andInfrastructure, Transport and Tourism (MLIT).

Carbon stock (LP-LiC))”.

Twenty-five technologies competed for the 17th

One of the grand prizes and two of the excellence

Infrastructure Technology Development Award.

prizes were introduced in the previous issue ofIn principle, the technologies had to have been

IDI Quarterly (No. 70).

developed within the past five years and applied

The other two technologies are introduced in thisto the real construction sites in the last threeissue.

years.
For any inquiries/ comments regarding theThis year, two grand prizes were awarded for theprizes please contact JICE:

following technologies as a result of examination:

Website: http://www.jice.or.jp/“Fluidized Bed Incinerator with Turbocharger(Japanese version only)(Energy-saving and low environmental load

E-Mail: webmaster@jice.or.jp

incinerator for sewage sludge)” and “HighDurable Concrete with Seawater

March 2016 No.71

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High Durable Concrete with Seawater（Environment-Friendly Concrete with Seawater, Byproducts, and Special Additives）
1. Background of Technology Development
Breakwaters, sea walls, wave dissipating

It is generally accepted that concrete mixed

concrete blocks, and pavements located at ports,

with sea water has following material properties:

coastal structures, and factories are often exposed

Firstly, the early strength is higher but long termfor a long period to severe natural environment

strength gain is slower than ordinary mixture;such as impact or friction due to abrasion of wave,Secondly, workability is not good enough to castwater flow or traffic load. In such cases, highly

the concrete due to shorter period of flowability;

durable concrete with high density and strength

Thirdly, the sea water causes steel reinforcement

is required to stand such natural circumstances.

to become corroded in a short term.

Besides, on isolated islands, at offshore or coastal
areas, and for restoration works from disasters, toHigh durable concrete with seawater wasdeveloped so as to solve these problems.

obtain fresh water for mixing concrete becomes a
critical issue.

2. Detailed Description of the Technology
For this newly developed concrete, sea water,

possible to use concrete debris and steel slag asthat is enormous natural resource, and industrial

For the reinforced concrete structure,byproducts such as blast-furnace slag, fly ash, silica
fume, and special additives are utilized. It is also

aggregate.
anticorrosive reinforcement is required to maintainhigh durability.

３．Advantages of the Technology[Lengthen Infrastructure Life Time]The long term strength of concrete mixed withseawater, blast-furnace slag, fly ash, and special
additives is increased as shown in Figure 1.
Water tightness is also enhanced as shown in
Figure 2. The durability of concrete against
impact or friction due to abrasion of wave, waterflow or traffic load are also expected to beimproved. The durability of reinforced concrete isensured for long term if anticorrosive
reinforcement is used as shown in Photo 1.
Figure 1 Compressive Strength of ConcreteMarch 2016 No.712Infrastructure Development Institute - Japan

Permeability coeffient（m/sec）

3.5E-123.0E-12Water
PenetrationDepth

2.5E-122.0E-12

Epoxy coated rebar（ａ）エポキシ樹脂塗装

1.5E-12

Carbon fiber rod（ｂ）炭素繊維ロッド

1.0E-125.0E-13
0.0E+00
真水
Fresh
water

海水
Sea
water

海水＋AN 海水+AN+SF

Sea
Sea
water
water
+special +special
additive additive+silica
fume+silicafume

Figure 2 Water tightness Test
（Pressured at 1.0MPa for 48 hours）

Ordinalsteelbarbar
Ordinarysteel（ｃ）普通鉄筋

Photo 1 Corrosion of reinforcement after accelerated test(Equivalent to 100 years’ service life）[Improved Workability]
This concrete can be placed in the same manner as
ordinary concrete.

[Reduced Construction Period]
The concrete formwork can be removed earlier thanordinary concrete, and the curing time can beshortened due to early strength developing property.

[Reduced Construction Cost]
Concrete’s cost can be reduced if fresh water is not

Photo 2 Wave dissipating concrete block using
sea water

easily available.

[Less Impact for the Environment]
CO2 emission can be reduced due to the use of
seawater and byproducts.

[Reduced Waste Material]
Byproducts, such as concrete debris and steel slag,
can be reused as shown in Photo 2, 3 and 4.

Photo 3 Wave dissipating concrete block using sea
water and debris

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４．Applicability
 Breakwaters, sea walls, wave dissipating concrete
blocks, pavements etc. located at ports, coastal
structures, and factories.
 This technology is adoptable for reinforced
concrete, provided that its anticorrosion property
and characteristic are ensured.

Photo 4 Pavement using sea water and steel slag

５．Installation Record
Restoration work from the Great East Japan
Earthquake at Soma port in Fukushima
Prefecture, Oct. 2012-Oct. 2013.
Technology developer: Obayashi Corporation

Masumi Muto

Joint developers: Port and Airport Research Institute, Tokyo

Obayashi Corporation

Institute of Technology, Tohoku University, JFE Steel

E-Mail: muto.masumi@obayashi.co.jp

Corporation

TEL: +81-3-5769-1062

Contact:

FAX: +81-3-5769-1984

Countermeasure against Liquefaction and Mitigation of Global Warming by Log Piling（Log Piling Method for Liquefaction Mitigation and Carbon Stock (LP-LiC)）
1. Background of Technology Development
The background for the development of thisAs the IPCC 5th Assessment Report (2013)

technology is as follows:

shows, global warming has become increasinglyGlobal warming is a serious problem

serious, and reduction of greenhouse gases is arequiring mitigation.

crucial issue. Another urgent issue is advancing

A huge earthquake is predicted to hit Japannational resilience measures againstin the near future, and we must prepare

earthquakes expected to hit the Tokyo

countermeasures against liquefaction,

metropolitan area and the Nankai Trough.

which can cause extensive damage even inLiquefaction due to earthquakes is particularly

areas far from the epicenter.

dangerous, as it occurs over a wide area and soForests in Japan are now extremely

can cause serious damage even far from thebountiful. We are now at the stage to utilize

epicenter. Low-environmental-impact, low-cost,them and a technology that can spursustainable measures are therefore necessary.

demand for wood is desired.

On the other hand, forests in Japan are now
extremely bountiful, which allows for theMarch 2016 No.71
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Infrastructure Development Institute - Japan

extensive use of wood resources. The Japanese

civil engineering, the same as in other sectors

government recently put into place thesuch as construction and furniture.

requirements for the expanded use of wood in

2. Detailed Description of the Technology
The log piling method for liquefaction

semi-permanently stocked in the ground. The

mitigation and carbon stock (LP-LiC) is amethod therefore mitigates global warming

method that densifies ground and increases

by construction work, a particularliquefaction resistance by piling logs into thecharacteristic not seen in other methods (Fig.

ground (Figs. 1 and 2). The method uses6). While log heads are generally set below

non-processed, non-cut green logs. LP-LiC is a

the groundwater level, to ensure prevention of

low-vibration and low-noise method (Fig. 3),

biodeterioration, we partially process log

and it can be performed with smallheads in consideration of possible

construction machinery (Photo 1) and doesgroundwater fluctuations. By combining

not extensively displace ground around themodern and traditional techniques for using

construction site (Fig. 4). Construction islogs as stated above, we have established atherefore possible in urban areas, narrowmodern and reliable design and construction

sites, and detached houses, wheremethod. Through creating below-groundconstruction in close proximity is required.

forests using this method, we are

As logs do not biodeteriorate below

simultaneously stocking carbon, mitigating

groundwater level (Fig. 5), the carbon

earthquake disaster due to liquefaction, andabsorbed during growth can be

mitigating global warming for the first time.

Grounddensification bypiling logs into
sandy ground0

Safety factor of liquefaction FL
1
2
BFs1FcFiller (crushed stone)
Covering soil

Depth D (m)Log0Fs25As

10Loose sandAc1 M=9,amax =200 Gal
Mihama, Urayasu-shi

Dense sand215Original ground (SPT)
Af ter log piling (SPT)
Recommendations f or Designof Building Foundations

Figure1 Principle of LP-LiC liquefaction
countermeasures

Figure2 Effects of LP-LiC

Photo1 Installation by small construction
machinery at a narrow site

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Infrastructure Development Institute - Japan110

100Japanese standard：75 dB100

8070Noise level LA5 ( dB )Vibration level LV10 ( ｄB )906050SAVE Composer:
50 - 65 dB

4030Log piling by diesel hammer

20Heavy tamping

SCt or S5Japanese sPandard：8D dB

80
70

SAVE Composer：
70 - 8D dB

60Log piling by diesel hammer

Vibroflotation

SCP or SD

50

Lt-LiC

1090

Heavy tamping
Vibroflotationaeasured value

LP-LiC400
1

1100
105istance from vibration source D ( m )10100

Distance from sound source D ( m )(a)Vibration level(b) Noise level
Figure 3. Vibration/noise level by LP-LiCLow Possibility of biodeterioration Highk≈1x10-9 m/s

Measurement coordinates (E-W direction) ( m )-303Horizontal-6

N1N26Distance 0.4 m
Distance 1.4 m

North sideN3N4N5

Outwardlevel

N6 N70.4m
1.4m

inwardW1W2

Level ofbiodeterioration

Capillary No
height biodeteriorati
Saturatedon
at all times

Lowest groundwater
level

Figure 5. Possibility of wood biodeteriorationin the ground

W4W6-4W8

InwardOutward

W7W9
Distance 0.4 m
Distance 1.4 m

0.4m
1.4m

Figure 4. Displacement in surrounding construction site byLP-LiC-76.0-50050← Emission Stock →W5

CO2 balance of carbon stock and CO2 emission
per 1 m3 of improvement volume ( kg-CO2/m3 ）

-100

0-8

Possibility ofbiodeterioration is far
less than highest
groundwater level

Groundwaterlevel fluctuation

W34Log head

Depth

Measurement coordinates (N-S direction) ( m )West side

Horizontal
displacement ( mm )30 20 10 0 -10-20-30830
20100-10-20-30

Crack,
Backfilling,under structure,sand
surface soil,
Inorganic,
gravel etc
undisturbed
Highest groundwater
Clay

Unsaturated
at all times

Effect of carbon
stock8.5
Effect of material
substitution

58.5Liquefaction measure
A= 500 m2，D= 8 m
100

Densification method Deep mixing method(sand)(cement)

LP-LiC(wood)

Figure 6. Comparison between improvement methods forCO2 balance of carbon stock and CO2 emission

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Infrastructure Development Institute - Japan

3. Advantages of the Technology[Liquefaction mitigation]
This method is based on a highly reliableprinciple of ground densification and cancertainly improve liquefaction resistance.
[Carbon stock]
Increased use of LP-LiC as a liquefaction
countermeasure results in increased carbonstock.
[Effects on the surrounding area]

This method can be used in narrow areas
because of its low vibration, low noise, andlow displacement characteristics.
[Indirect effects]
This method extensively uses domestic wood
resources that are now going unused,
contributing to forest regeneration. It canrecharge water resources and prevent
landslides in mountainous areas in addition
to liquefaction prevention in coastal areas.

4. Applicability
Target: Liquefaction prevention measures for

Log tree species: Basically any tree species

surrounding buildings, detached houses,can be used (cedar, cypress, larch, etc.).

embankments (for roads, railways, residential

Log specifications: Log top diameter: 0.13 ≤ Dt

land, and river and coastal conservation),< 0.18 m; log length: ≤ 6 m; number of joints: ≤parking lots, parks, sporting grounds, etc.

2

Applicable ground: SPT N value ≤ 20, sandy
soil, fine fraction content ≤ 50%, maximum
improvement depth ≤ 12 m

5. Installation Record
One-story public hall in Urayasu City
(Sept–Nov 2013) and 10 other cases.
Technology developer: Tobishima CorporationContact
Masayuki Tsutsui, Tobishima Corporation
E-Mail: masayuki_tsutsui@tobishima.co.jp
TEL: +81-4-7198-1101
FAX: +81-4-7198-7586

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About IDI and IDI-quarterly
Infrastructure Development Institute (IDI)-Japan is a general incorporated
association operating under the guidance of Ministry of Land, Infrastructure,
Transport and Tourism of Japanese Government.
IDI provides consulting services for mobilizing International Assistance todeveloping countries, promoting international exchange of information and humanresources, and supporting globalization of project implementation systems targeting
both developed and developing countries in the field of infrastructure.
IDI has been publishing the free quarterly journal “IDI Quarterly” since1996 for thepurpose of introducing information relating to public works and construction
technologies developed in Japan to foreign countries. We have distributed thejournal to administration officials in more than 90 countries around the world bye-mail.
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