Case studies of Advanced Construction and Demolition waste(CDW)
Recycling initiatives and technologies In JAPANAffiliation
Location
Position:
Name/Surname

TOUZAKI Co.,Ltd
1-8-12 Shikahone Edogawa-ku, Tokyo 133-0031
CEOTADASHI TOUZAKI

e-mailtadashi@touzaki.co.jp

Title

Resource stock type Completely Recyclable Concrete(Concrete using limestone aggregate as the total amount ofaggregate)
Prevention
Re-useTheme
classification〇

Technology
development stage〇

RecycleReduce Co2
LegacyBusiness to overseas
Etc.
Practical use
Scheduled to be put into practical use by 2020
Scheduled to be put into practical use after 2020

Specific content- “Resource stock type Completely Recyclable Concrete” produced
using only high-quality limestone aggregate and limestone crushed
sand with chemical components confirmed, concrete itself becomes
high-quality calcareous resources.
-If you bake the concrete waste unprocessed raw as it is, it will betransformed into high-quality cement raw materials. That is, theconcrete waste will be used as a raw material for cement.
-Touzaki Co., Ltd. continues to make concrete that demonstrates itstrue value 100 years later in the form of high quality as well as"resource stock to the future"

Appeal point- As "closed loop recycling" of concrete waste,Concrete waste will be cement raw materials without processing.

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Resource stock type Completely Recyclable Concrete(Concrete using limestone aggregate as the total amount of aggregate)
1. O UTLINE"Resource stock type Com pletely Recyclable Concrete " embodies the concept andtechnology of "completely recyclable concrete" advocated by Professor Takafumi Noguchiof the University of Tokyo

Circulation diagram of resources
Resource stock typecompletely recyclableconcrete

JIS markConcrete
co mposedent ire ly o fl imest on e

Component indeterminate
concrete
Outs ideJ ISCon crete
co mpos ed
ent irely ofl imest on e

CFTHigh F low

Flya shHighStrengthUsecommonmat er ials

recy c lab lecon cret e

Content
Disp osa l

Reuse forcement
resour ces
and ot her sResour ces
Circulat ion

Reuse
as partaggregate

Reusing
the wholeamount as
lime
resour ces
Reuse asroadbedmaterial

High-value-added

Reduce environmental load

Environmental load

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Dispos al2. FEATURES(1) High d urabilit y①Alkali aggregate not reactive-Alkali silica reaction
Suppression of Alkali Aggregate Reaction (Civil Engineering , Building)
Implementation Procedure-Alkali carbonate reaction
Cement Association Concrete Special Committee Report F-47
②Less drying shrinkage⇒ According to the com pany's annual seasonal variation survey(average = less than 600 μ )(The examination is requested to the building materials testing center)③The linear expansion coefficient α of limestone is small (about 5 µ / ° C.)⇒ It can be expected to suppress temperature cracking(2) Less pumping loss
-It does not contain silt (viscosity) in the fine powder part↓-There is no excess adsorption of chemical admixture and moisture↓-Less slump loss due to pum p pum ping(3)Concrete waste is resource-After dismantling the structure, the concrete waste generated↓-Reusable as cement raw m aterial(Completely Recyclable Concrete = Resource Stock Type Completely Recyclable Concrete)(4) Fully compatible with ready m ixed concrete (JIS A 5308)(5) Acquired Ministerial Certification on High Strength Concrete-Acquired Ministerial Certification on High Strength Concrete alone at factory (2010.2)(Certification scope: moderate heat cement · design standard strength 80 N / mm 2)-By actual machine tests, it was confirmed that compression strength of 120 N / mm 2
could be achieved even with concrete using limestone for the total amount of aggregate-47-