Ashoke KarmokarInnovation Division
Bridgestone Corp., Japan
ATRC 2107 ChennaiJune 16-17, 2017
A broader outlook on Recycle vis-a-visCircular Economy in the tire industry
2/26Copyright © 2017 Bridgestone Corporation | June 16-17, 2017
Circular Economy: The concept
A step change in business strategy which includes;
- opting for reusable materials in design
- ending of wasteful manufacturing process
- embracing renewable material in the products
- developing markets for repurposed products
Circular Economy is a new element for future industrial models toward replacing take-make-dispose approach with more restoration by taking back valuable resource in the regenerating loop;
- circular approach instead of linear one
Ref.:1. Ellen MacArthur Foundation (2015), ‘Growth Within: A Circular Economy Vision for a Competitive Europe.’ 2. Accenture (2014), ‘Circular Advantage: Innovative Business Models and Technologies to Create Value in a Worlds
without Limits to Growth.’
3/26Copyright © 2017 Bridgestone Corporation | June 16-17, 2017
Ref.: http://www.etrma.org/uploads/Modules/Newsroom/2015-09-29_etrma-position-paper-on-circular-economy_vf.pdf
… and is now taking the next step towards improved performance essential in line with the Circular Economy.
Circular Economy: Tire Industry
ETRMA Vision:… tire industry has already
brushed up many of the stated principles of Circular Economy,
End-of-life stage: collection and the subsequent recover/ recycle rate of scraped tires show commendable result as compared to other wastes.
4/26Copyright © 2017 Bridgestone Corporation | June 16-17, 2017
Scrap Tire Managements: USA & EU
Total Scrap(2015):
USA: 4.04 mil. tons(treatment: 87.9%)
Europe:3.87 mil. tons(treatment: 92.2%)
1. RMA, 2015 U.S. Scrap Tire ManagementSummary (updated May 2017)2. ETRMA, End-of-Life Tyre REPORT 2015
Europe2
USA1Recovering/recycling rates of scraped tires in the USA and Europe show the higher levels of around 90%
5/26Copyright © 2017 Bridgestone Corporation | June 16-17, 2017
Last 5 years Trends
Scrap Tire Management: Japan
Graph based on JATMA Statisticshttp://www.jatma.or.jp/environment/report01.html
(accessed on May31, 2017
No. of scrap tires in 2016: 94 million (treatment : 90.5%)
new market for scraped tire derived materials
6/26Copyright © 2017 Bridgestone Corporation | June 17, 2017
Bulk Properties of TDR Materials Lightweight (1/3 ~1/2 of soil)
Durable (> 50years)
Resilient (low hysteresis loss)
High repose angle (stiff slope)
Thermal insulation (1/8-1/5 of soil)
Permeable (about 10 times of sand)
Commonly recognized as beneficial for use as geomaterials in civil/geotechnical engineering application
Scrap Tire Derived Aggregates
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Drainage layer Thermal insulation Clay rubber
Applications:
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DrainageLayers
Conventionally used Gravel
Drainage Under High Embankment: Outlines
Tire Shreds
Permeability of tire shreds under compressed conditions
Embankment in Mountainous area
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Results of Consolidation Tests
0
10
20
30
40
0 90 180 270 360 450Vertical Pressure(kPa)
Com
pres
sive
Stra
in (%
)
Initial Density(5.7kN/m³)
Initial Density(6.5kN/m³)
0
0.3
0.6
0.9
1.20.1 1 10 100 1000
Vertical Pressure (kPa)
Void
Rat
io
Initial Density(5.7kN/m³)
Initial Density(6.5kN/m³)
Very high levels of compressive strain of tire shreds
High level of void ratio exists even after imparting quite heavy compaction
26 ‒ 33% compression of tire shreds for a load equivalent to 20m high embankment
10/26Copyright © 2017 Bridgestone Corporation | June 17, 2017
1.E-07
1.E-06
1.E-05
1.E-04
1.E-03
1.E-02
1.E-01
1.E+00
1.E+01
0 5 10 15 20 25
圧縮率 (%)
透水係数(cm/s)
SG(Com)
SG(Ret)
Grvl(H)
SCJV(BS)
SCJV(JH1)
SCJV(JH2)
1.801.80SCJV(J2)SCJV(J2)
1.711.71SCJV(J1)SCJV(J1)
1.721.72SCJV(B1)SCJV(B1)
1.771.77GGrvlrvl
0.650.65~~0.850.85
SGSG
密度密度
gg//cccc
テストテスト
1.801.80SCJV(J2)SCJV(J2)
1.711.71SCJV(J1)SCJV(J1)
1.721.72SCJV(B1)SCJV(B1)
1.771.77GGrvlrvl
0.650.65~~0.850.85
SGSG
密度Density
gg//cccc
テストMaterials
Compression (%)
Coefficient of
Permeability
(cm/s)
Applied Permeability Tests
11/26Copyright © 2017 Bridgestone Corporation | June 17, 2017
Construction Details Construction area:
40m x 10m / layer Tire shreds:
200m3 (120ton) / layer Layer thickness:
400mm (500mm laying)
Cross Section of Embankment
Hobetsu Tunnel EastHighway Construction Area
Hokkaido, Japan
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Laying Dressing
Finishing
Major Steps of Construction
Completed Embankment (after 1 year)
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Drainage layer Thermal insulation Clay rubber
Applications:
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ConstructionSite
Frost-Heave Mitigation: Outlines
Investigate the in-situ performance of Tire Shreds
Site: Hokkaido, Japan (Highway water drainage system)
Problem: Frost-heaving causes severe damage to the civil engineering structures
Measures: Replace frost-susceptible soil by material that does not contain water, and pores be large enough for free draining of water
SiphoningEffect
Thermal ConductionEffect
Frost-susceptible
soil
CrackingEffect
FrostedArea
Pre-castConcreteTrench
LateralPressure
Up
SiphoningEffect
Thermal ConductionEffect
Frost-susceptible
soil
CrackingEffect
FrostedArea
Pre-castConcreteTrench
LateralPressure
Up
Image of frost-penetration phenomenon
Tilt/Crack effects
15/26Copyright © 2017 Bridgestone Corporation | June 17, 2017
Laboratory Study: Thermal Conductivity
0
20
40
60
80
100
0.01 0.1 1Grain Size (mm)
Cumulative Percentage (%)
Rubber Grains
Toyoura SandSohma Sand (#6)
Materials: Rubber powder ・ Toyoura sand ・ Soma sand
Apparatus: Thermal Conductivity Meter (for sheet/blanket form materials with thickness <10mm)
Results:
Thermal conductivity of sand is 3-4 times higher than tire rubber powder
Thermal Conductivity Meter
Specimens
Scrap tire shreds may be beneficial for mitigating frost-penetration phenomenon
Grain size distribution of materials
16/26Copyright © 2017 Bridgestone Corporation | June 17, 2017
Field Constructions
Conventionally used material : Gravel
ScrapTire Shreds
Field construction using scrap tire shreds
Laying Compaction Soil Capping
Site in Winter Spell (Snow deposition 130cm)
Site view
ShredsGravel
New material Cross-sectional Image
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Temperature Distributions
Elapsed Time(Months)
Elapsed Time(Months)
Effective insulation behavior of tire shreds over gravel backfill
12C higher Temp. of ground soil behind tire shreds than gravel side
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Drainage layer Thermal insulation Clay rubber
Applications:
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Cement Treated Clay Rubber: Concept
Concept of CTCR
Addition of rubber grain is thought to offer an effective means of improving ductility, and thus enabling the use in geotechnical structures where deformation is anticipated
20/26Copyright © 2017 Bridgestone Corporation | June 17, 2017
Cement Treated Clay Rubber Preparation
Preparation of CTCR
Common lab. set-up was used for preparing CTCR sample
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せん断応力 (kN/m2)
水平変位 (mm)
ゴム混入(0g/L)ゴム混入(200g/L)ゴム混入(400g/L)ゴム混入(600g/L)
0 2.5 5 7.5 10 12.5 15 17.5 20 22.5 25
20
40
60
80
100
120
140
160
Shear
Stress
Horizontal Displacement (mm)
Rubber (0g/L)Rubber (200g/L)Rubber (400g/L)Rubber (600g/L)
High Toughness
Shear Behavior of CTCR
Toughness improves with the inclusion of rubber grains, and such improvement varies with the amount of rubber grains
22/26Copyright © 2017 Bridgestone Corporation | June 17, 2017
Permeability Behavior of CTCR
Fine cracks in CTCR allow only less water bleeding channels to be formed and thus maintains lower coefficient of permeability
23/26Copyright © 2017 Bridgestone Corporation | June 17, 2017
Field Application: Offshore Waste Disposal Site
Disposal Sites at Tokyo Bay Area
CTCR
Sea
Use of CTCR near the foundation for basement sealing was adopted as the potential method of wall construction
Cross Sectional Image(Double Layered Steel Pipe Wall)
24/26Copyright © 2017 Bridgestone Corporation | June 17, 2017
ShipPosition
Preparatory ShipS
N G-Block
Field Construction
Construction continued for 3 days with on-site collection of dredged clay and mixing/laying of CTCR on-board of a ship
25/26Copyright © 2017 Bridgestone Corporation | June 17, 2017
Field Construction: Packs of Rubber Grains
About 80 tons of scrap tires derived rubber grains were used in this advanced and highly sensitive field application
Sack:550kg144 sacks
26/26Copyright © 2017 Bridgestone Corporation | June 16-17, 2017
Summary
Scrap tire derived materials in the forms of shreds/grains have shown essential properties, e.g., permeable, insulating, resilient, etc., and those properties may be recognized as beneficial to many other engineering field applications.
Case studies on the use of scrap tire derived materials in diversified civil/geotechnical engineering applications are highlighted as potential technology portfolio for tire recycling.
Such initiatives in a greater way would increase the recycling of scrap tires which in turn is believed to be helpful in realizing the interests of Circular Economy.