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State-of-the-art Recycling State-of-the-art Recycling Technologies for Building Technologies for Building
Materials in JapanMaterials in Japan
Part 1 Cement & ConcretePart 1 Cement & Concrete
Takafumi NOGUCHI
CONTENTSCONTENTS
1. Resource Recycling Model of Concrete
2. Environmental Aspect of Cement Production
3. Environmental Aspect of Aggregate Production
4. Environmental Aspect of Concrete Production
5. Concrete Recycling
1. RESOURCE RECYCLING 1. RESOURCE RECYCLING MODEL OF CONCRETEMODEL OF CONCRETE
RESOURCE RECYCLING MODEL RESOURCE RECYCLING MODEL OF CONCRETE (1)OF CONCRETE (1)
Total material input 2,000,000,000 t/year– Buildings and civil structures 1,000,000,000 t/year
• Concrete production 500,000,000 t/year• Steel production 32,530,000 t/year• Wood 17,000 t/year
Total waste 458,360,000 t/year– General waste 52,360,000 t/year– Industrial waste 406,000,000 t/year– Concrete lumps 35,000,000 t/year
RESOURCE RECYCLING MODEL RESOURCE RECYCLING MODEL OF CONCRETE (2)OF CONCRETE (2)
Final disposal sites for industrial waste
120
140
160
180
200
220
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
Pos
sib
le w
aste
infi
nal
dis
pos
al a
rea
(mill
ion
ton
)
GeneralIndustrial
RESOURCE RECYCLING MODEL RESOURCE RECYCLING MODEL OF CONCRETE (3)OF CONCRETE (3)
Typical Life Phases of Concrete Product / Concrete Structure
Raw material acquisition
mining of aggregatesmining of stones for cement productionenergy sources and energy productionwater supply
Realizationproduction of concrete and concrete elementsdesign construction
Life enddemolitionreuserecyclingdisposallandfill
Utilization use maintenancerepairrenovation
Life phases of concrete product
RESOURCE RECYCLING MODEL RESOURCE RECYCLING MODEL OF CONCRETE (4)OF CONCRETE (4)
Potential Chance to Influence Degree of Environmental impact
Life Cycle Phases of Concrete Structure
Design Construction UtilizationDemol/Recycl
Conceptual DesignTechnology Concept Detailed Design
Construction Demolition RecyclingUse
MaintenanceRepair
The Chance to Influence Degree of Environmental Impact / Environmental Efficiency
Potential to influence Ei
Waste disposal, landfill
RESOURCE RECYCLING MODEL RESOURCE RECYCLING MODEL OF CONCRETE (5)OF CONCRETE (5)
Life Cycle of Concrete Structure– Material and energy flows and consequent environmental impacts
RESOURCE RECYCLING MODEL RESOURCE RECYCLING MODEL OF CONCRETE (6)OF CONCRETE (6)
Material Flows of Concrete
LimestoneLimestone 84,267 CementCement 82,181
(Import: 1,228, Export: 7,564 )
Others 28,617Gravel, SandGravel, Sand301,000
Crushed StoneCrushed Stone412,000
Others 16,000
Asphalt 3,379
Recycled CrushedRecycled CrushedStoneStone51,180
Slag 12,331Fly Ash 4,551Others 8,702
COCO22
44,725
Aggregate for ConcreteAggregate for Concrete405,404
Road Subbase Materials and OthersRoad Subbase Materials and Others320,955
Aggregate for Asphalt Concrete53,821
ConcreteConcrete475,842(including Cement-based Products)
Asphalt Concrete71,400
BuildingsCivil Structures
New Stocks
Recycle on Site
ExistingStocks
Waste DisposalWaste Disposal1,780
Concrete LumpsConcrete Lumps 35,040Asphalt Concrete 16,140
Asphalt Concrete Lumps14,200
Unit :1,000t
Enormous Amounts of Concrete Stocks
Discharge of Concrete < 10% of Input
ENVIRONMENTAL ASPECT ENVIRONMENTAL ASPECT OF CEMENT PRODUCTIONOF CEMENT PRODUCTION
ENVIRONMENTAL ASPECT OF ENVIRONMENTAL ASPECT OF CEMENT PRODUCTION (1)CEMENT PRODUCTION (1)
Raw Materials and Energy for 1 ton of Normal Portland Cement
Raw Materials (kg) Energy
Limestone 1,093Fuel (kg)[Coal Equivalent (6,200 kcal/kg)]
105Clay 203
Silica Stone 76
Iron Ore 30Electric Power (kwh)[including co-generation]
99Gypsum 34
Total 1,436
Highest level of energy efficiencythanks to the energy conservation measurestaken during the period between 1970 and 1990
ENVIRONMENTAL ASPECT OF ENVIRONMENTAL ASPECT OF CEMENT PRODUCTION (2)CEMENT PRODUCTION (2)
Fuel for Cement– Coal : 85%
• from China, Australia, Russia, and Indonesia
– Petroleum coke : 10%– Industrial waste : 3%– Heavy oil : 1%
ENVIRONMENTAL ASPECT OF ENVIRONMENTAL ASPECT OF CEMENT PRODUCTION (3)CEMENT PRODUCTION (3)
Recycling Ecosystem of Cement Production
PrintingIncineration ash,Waste plastics
Electric &Electronic appliances
Sludge,Waste plastics,
Used tonerCartridges,
CFCs
TextileSludge,
Waste plastics
Electricpower
Coal ash,EP dust(ash),
Gypsum
AgricultureWaste plastics
FisherySeashells,Wastes
Nonferrousmetals
Molding sand,Sludge, Slag,
Gypsum
LocalMunicipality
Sewage sludge,Sludge generated byWater purification,Municipal waste,Incineration ash
Buildingmaterial
Waste board,Sludge
Paper&PulpSludge,
Incinerationash
ConstructionWaste plastics
Food productWaste diatomaceous
Earth,Waste plastics,
Distillery residue,Sludge Petroleum
Waste clay, Sludge,Waste oils,
Used catalysts,DOC, FOC
ChemicalsSludge,
Waste plastics,Gypsum
SteelSlag, EP ash
CementAutomobile
Molding sand,Paints residue,
Used tires
PachinkoUsed
Pachinkomachines
ENVIRONMENTAL ASPECT OF ENVIRONMENTAL ASPECT OF CEMENT PRODUCTION (3)CEMENT PRODUCTION (3)
Waste and Byproducts Utilized by Cement Industry
Type Uses Amount (t)Blast Furnace Slag Raw Material, Additive 12,162,000Fly Ash Raw Material, Additive 5,145,000Byproduct Gypsum Additive 2,643,000Sludge Raw Material 1,906,000Nonferrous Slag Raw Material 1,500,000Steelmaking Slag Raw Material 795,000Ash Dust Raw Material, Fuel 734,000Coal Waste Raw Material, Fuel 675,000Casting Sand Raw Material 477,000
ENVIRONMENTAL ASPECT OF ENVIRONMENTAL ASPECT OF CEMENT PRODUCTION (4)CEMENT PRODUCTION (4)
Waste and Byproducts Utilized by Cement Industry
Type Uses Amount (t)Scrap Tire Fuel 323,000Reclaimed Oil Fuel 239,000Oil Waste Fuel 120,000White Clay Waste Raw Material, Fuel 106,000Plastic Waste Fuel 102,000Others - 433,000Total - 27,359,000
RecentlySewage sludge, Incineration ash from municipal solid waste
ENVIRONMENTAL ASPECT OF ENVIRONMENTAL ASPECT OF CEMENT PRODUCTION (5)CEMENT PRODUCTION (5)
Use of sewage sludge and incineration ash from municipal solid waste– the high temperature safely decomposes
hazardous materials including dioxins– no new waste is generated– requires no additional incineration
facilities– extends the service lives of final disposal
sites
ENVIRONMENTAL ASPECT OF ENVIRONMENTAL ASPECT OF CEMENT PRODUCTION (6)CEMENT PRODUCTION (6)
Utilization of Blast Furnace Slag and Fly Ash
CementLandfill
Civil StructuresBuildings Others
Foundation IimprovementOthers
Cement
Export
Road
ConcreteAggregate
Civil Structures
Blast Furnace Slag (24,518,000t) Fly Ash (6,919,000t)
ENVIRONMENTAL ASPECT OF ENVIRONMENTAL ASPECT OF CEMENT PRODUCTION (7)CEMENT PRODUCTION (7)
Changes in cement production by type
0
2000
4000
6000
8000
10000
12000
1975 1980 1985 1990 1995 2000
年度
t生産量(万)
フライアッシュセメント高炉セメントポルトランドセメント
Fiscal Year
Fly Ash CementSlag CementPortland Cement
Production (x10,000 t)99,270,000 tons
in 1996
ratio of blended cement production has been gradually increasing
ENVIRONMENTAL ASPECT OF ENVIRONMENTAL ASPECT OF CEMENT PRODUCTION (8)CEMENT PRODUCTION (8)
The increasing trend of blended cement production because of– Expected increase in the number of thermal
power plants producing coal ash– Expected increase of crude steel production
affected by the construction rush in economically buoyant China
– Law on Promoting Green Purchasing in 2001 in which blast-furnace slag cement and fly ash cement were designated as green procurement products
ENVIRONMENTAL ASPECT OF ENVIRONMENTAL ASPECT OF CEMENT PRODUCTION (9)CEMENT PRODUCTION (9)
“Ecocement” recently developed in Japan– made using incineration ash from municipal soli
d waste and sewage sludge– Dioxins completely decomposed at a high temp
erature without being resynthesized• rapidly cooled to below 200C in a cooling tower• captured in a bag filter and an active coke-packed towe
r
– Heavy metals contained in incinerated ash• recovered/concentrated• delivered to nonferrous metal factories for recycling
ENVIRONMENTAL ASPECT OF ENVIRONMENTAL ASPECT OF CEMENT PRODUCTION (10)CEMENT PRODUCTION (10)
Chemical compositions of portland cement and incineration ash
Limestone 47 - 55Clay 45 - 78 10 - 26 3 - 9
Silica sand 77 - 96Iron source 40 - 90
Gypsum 26 - 41 37 - 59
12 - 31 23 - 46 13 - 29 4 - 7 1 - 4
CaO SiO2 Al2O3 Fe2O3 SO3
62 - 65 20 - 25 3 - 5 3 - 4 2 - 3CementIncin. Ash
(%)
ENVIRONMENTAL ASPECT OF ENVIRONMENTAL ASPECT OF CEMENT PRODUCTION (11)CEMENT PRODUCTION (11)
Raw materials combination– Ecocement replaces limestone and clay with incineration ash
Silica sand4%
Normal Portland Cement
Limestone78%
Clay16%
Others2%
Ecocement
Limestone52%
Sewage sludge9%
Others1%
IncinerationAsh 38%
ENVIRONMENTAL ASPECT OF ENVIRONMENTAL ASPECT OF CEMENT PRODUCTION (12)CEMENT PRODUCTION (12)
Chemical Composition of Ecocement
0.010.632.064.22.85.221.21.5NPC
0.900.509.257.32.510.015.30.8Rapid
Hardening Type EC
0.040.263.761.04.48.017.01.1Normal
Type EC
ClR2OSO3CaOFe2O3Al2O3SiO2Ig.
Loss
(%)
ENVIRONMENTAL ASPECT OF ENVIRONMENTAL ASPECT OF CEMENT PRODUCTION (13)CEMENT PRODUCTION (13)
Physical Properties and Quality of Ecocement
Densityg/cm3
Spec. Surf.cm2/g
Initial Seth-min
FinalSeth-min
Comp. Str., N/mm2
3h 1d 3d 7d 28d
N-EC 3.17 4250 2-35 4-25 - 10 30 41 53
RH-EC 3.13 5300 0-30 0-50 10 25 38 53 58
NPC 3.16 3350 2-22 3-10 - 15 29 44 61W/C=0.50, S/C=3.0
ENVIRONMENTAL ASPECT OF ENVIRONMENTAL ASPECT OF CEMENT PRODUCTION (14)CEMENT PRODUCTION (14)
“Ecocement” recently developed in Japan
Ecocement
Bug Filter
Mill
Gypsum
Clinker
Clinker Cooler
Rotary KilnTank for
HomogenizationTank
Bug Filter DenitrationAir
Smelter
DrainageHeavy Metal RecoveryCrusher
Incinerated AshRaw Sludge
Limestone, etc.
Raw MaterialsGasWater
Administrative office & bottom ash storage facilities
Rotary dryer
Raw mat. mill
Homogenizing tank
Flue gas cooling tower
Bag filterRotary kiln
Heavy metal refining process
Fly ash tank
Lot area; 16,700m2
366m
34m
80m
58m
Gas treatment
Ecocement tank
Panoramic view of Ichihara Ecocement plantPanoramic view of Ichihara Ecocement plant
ENVIRONMENTAL ASPECT OF ENVIRONMENTAL ASPECT OF CEMENT PRODUCTION (17)CEMENT PRODUCTION (17)
Ichihara Ecocement Corporation (Rotary kiln)
ENVIRONMENTAL ASPECT OF ENVIRONMENTAL ASPECT OF CEMENT PRODUCTION (18)CEMENT PRODUCTION (18)
Application for construction Application for construction Application for construction
Application for civil works Application for civil works Application for civil works
External wall Concrete block Concrete roof
Inter rocking block Concrete block Marine product
Applications of Ecocement to various concrete products
ENVIRONMENTAL ASPECT ENVIRONMENTAL ASPECT OF AGGREGATE OF AGGREGATE
PRODUCTIONPRODUCTION
ENVIRONMENTAL ASPECT OF ENVIRONMENTAL ASPECT OF AGGREGATE PRODUCTION (1)AGGREGATE PRODUCTION (1)
Changes in aggregate productionCrushed StoneRiver GravelPit GravelHill GravelSea GravelOthers
Production (million t)
19631965196719691971197319751977197919811983198519861987198819891990199119921993199419951996199719981999200020012002
949 million tons in 1990
Crushed stone and Crushed/pit sand
have become major
Good quality river sand and river gravel have become depleted
Causingexposure of bedrock on the bottom of the sea erosion of embankmentsendangering sand spits and fishing grounds
ENVIRONMENTAL ASPECT OF ENVIRONMENTAL ASPECT OF AGGREGATE PRODUCTION (2)AGGREGATE PRODUCTION (2)
Changes in aggregate production– Absolute ban on collection of sea gravel and sea
sand being implemented – Regulations on crushed stone collection being
tightened from the aspect of natural landscape protection
– Ready-mixed concrete plants in Tokyo receiving not only crushed limestone from western Japan but also river sand from China
• Wide-area transfer of aggregate over regions and borders
ENVIRONMENTAL ASPECT OF ENVIRONMENTAL ASPECT OF AGGREGATE PRODUCTION (3)AGGREGATE PRODUCTION (3)
Aggregate, 70% by volume of concrete, anticipated as a recipient of waste and byproducts from other industries
Type Standard
Blast Furnace Slag Aggregate JIS A 5011-1
Ferronickel Slag Aggregate JIS A 5011-2
Copper Slag Aggregate JIS A 5011-3
Electric Arc Furnace Oxidizing Slag Aggregate JIS A 5011-4
Molten Slag Aggregate JIS A 5031
Fly Ash Calcined Lightweight Aggregate
ENVIRONMENTAL ASPECT OF ENVIRONMENTAL ASPECT OF CONCRETE PRODUCTION (1)CONCRETE PRODUCTION (1)
Changes in concrete production
Concrete Production
Concrete Waste
Concrete Wastefrom Buildings
Concrete Wastefrom
Civil Structures
Production and Waste (million t)
600
500
400
300
200
100
0
1950 2000 2050 Year
600 million tons in 1990
decrease due to reductions in investment in new construction of buildings and civil structures
ENVIRONMENTAL ASPECT OF ENVIRONMENTAL ASPECT OF CONCRETE PRODUCTION (2)CONCRETE PRODUCTION (2)
Waste and byproducts generated from RMC plants– Returned concrete from 1m3 of RMC : 0.009
m3
– Sludge cake resulting from 1m3 of RMC : 5.88 kg
Returned ConcreteMixerAgitator Truck
Returned ConcreteMixerAgitator Truck
WashingWater Waste
Returned ConcreteMixerAgitator Truck
Returned ConcreteMixerAgitator Truck
Supernatant WaterSludge WaterSupernatant WaterSludge Water
Recovered WaterRecovered Water
Sludge SolidSludge Solid Sludge CakeSludge Cake
Mixing WaterCoarse Aggregate
Fine AggregateRoad Subbase
Final Disposal
CONCRETE RECYCLINGCONCRETE RECYCLING
CONCRETE RECYCLING (1)CONCRETE RECYCLING (1)
Recycle ratio of demolished concrete
0 1000 2000 3000 4000
1990年度
1995年度
2000年度
tコンクリート塊排出量(万 )
再利用処分ReuseDisposal
1990
1995
2000
Emission of Concrete Lumps (million t)
0 10 20 30 40
Effort by the Ministry of ConstructionRecycling Plan 21 Construction Recycling Promotion Plan ’97
For road bottoming materialsFor mechanical stabilization materials
CONCRETE RECYCLING (2)CONCRETE RECYCLING (2)
Discrepancy between– the amount of concrete lumps generated
and
– the amount of concrete lumps removed from construction sites
– Reason• In-situ recycling as road bottoming and backfill
materials• Inclusion in dirt and soil to be disposed of at
landfill sites
CONCRETE RECYCLING (3)CONCRETE RECYCLING (3)
Recycle in Apartment Complex
Recycle Plant
SieveCrusher
Demolished Building
Sound-proof Wall
60-20mm
Powder
40-0mm
Backfilling Gravity Retaining Wall Concrete Pavement
Packing
BasementFoundationImprovement
Packing
Road Subbase
CONCRETE RECYCLING (4)CONCRETE RECYCLING (4)
Changes in concrete production
Concrete Production
Concrete Waste
Concrete Wastefrom Buildings
Concrete Wastefrom
Civil Structures
Production and Waste (million t)
600
500
400
300
200
100
0
1950 2000 2050 Year
600 million tons in 1990
decrease due to reductions in investment in new construction of buildings and civil structures
Premature deteriorationEnds of their service livesDemolished
CONCRETE RECYCLING (5)CONCRETE RECYCLING (5)
Reuse of concrete lumps as aggregate for concrete– Enormous amount of concrete lumps
generated– Demand for concrete lumps for roads
decreasing• New road construction gradually decreasing• Method of repairing existing roads shifting
from repavement to “mill and overlay”
CONCRETE RECYCLING (6)CONCRETE RECYCLING (6)
Recycling process of demolished concrete lumps
Demolished Concrete Lumps
Jaw Crusher
Impact Crusher
Vibratory Sieves
Road Subbase, Backfill
Cone Crusher
Vibratory Sieves
Vibratory Sieves
Low Quality Recycled Coarse
Aggregate
Heating Tower
Coarse Aggregate Scrubber
Fine Aggregate Scrubber
Low Quality Recycled Fine
Aggregate
High Quality Recycled Coarse
Aggregate
High Quality Recycled Fine
Aggregate
Powder
Vibratory Sieves
(a) Road Subbase (b) Low Quality Recycled Aggregate (c) High Quality Recycled Aggregate
CONCRETE RECYCLING (7)CONCRETE RECYCLING (7)
Uses for concrete lumps determined by– the qualities of the recycled material
• Density• Water absorption
– depending on» percentage of cement paste contained within» adhering to the surfaces of original aggregate
– depending on production method
CONCRETE RECYCLING (8)CONCRETE RECYCLING (8)
Today’s conventional concrete recycling– Roadbed material– Aggregate for concrete excluding structural
use
CONCRETE RECYCLING (9)CONCRETE RECYCLING (9)
High quality recycled aggregate– Repeating crushing
• Recovery percentage decreasing• Fines generation increasing
– Carrying out high level treatment such as heating and grinding in order to minimize the adhering cement paste
CONCRETE RECYCLING (10)CONCRETE RECYCLING (10)
Quality and recovery percentage of recycled aggregate
5-10mmnot less than10mm
No 1st 2nd 3rd
Number of Crushing Treatment
Water Absorption (%)
Recovery Percentage (%)
Recycled Fine Aggregate
Recycled CoarseAggregate
Powder
Size of SuppliedConcrete Lumps
Sand
Gravel
Cement Paste
No 1st 2nd 3rd Original ConcreteCrushing Treatment
CONCRETE RECYCLING (11)CONCRETE RECYCLING (11)
Efficient equipment for producing high quality recycled aggregate (1)– Heated scrubbing
Recovery ofFine Aggregate
Recovery ofCoarse Aggregate
Sieve
Tube MillTube Mill
Fine PowderFineAggregate
CoarseAggregate
Bug FilterHeating DeviceFilled withConcrete Lumps
CONCRETE RECYCLING (12)CONCRETE RECYCLING (12)
• Heated scrubbing
Heating at
300CRubbing process
Concrete rubbleWeakening of
hardened cement paste
Removal of powdered
cement hydrate
Input Hopper
Heating Tower
Fine Aggregate Mill
Classifier
Dart Collector
Powder Storage Tank
Recycled Coarse Aggregate
Recycled Fine Aggregate
Coarse Aggregate Mill
Heated scrubbingHeated scrubbing
CONCRETE RECYCLING (14)CONCRETE RECYCLING (14)
Recycled structural aggregates& by-product powder
CONCRETE RECYCLING (15)CONCRETE RECYCLING (15)
Quality of Recycled AggregatesA
bs
orp
tio
n
(%)
Oven-dry density (g/cm3)
0
2
4
6
8
10
12
14
2.0 2.2 2.4 2.6
Virginaggregate
Recycled Coarse/ Former systems
Recycled Fine/Former systems
Coarse & fine/CLC system
CONCRETE RECYCLING (16)CONCRETE RECYCLING (16)
An Example of Application
Acoustic Laboratory ・ Construction period:11/2000-9/2001 ・ Place:Koto-ku, Tokyo ・ Structure:Reinforced concrete structure, three levels above the ground ・ Building area:363.41m2
・ Total floor area:667.75m2
Structure B : ・ Place:Kitakyushu city・ Year of completion: 1988
Structure A : ・ Place:Chofu city, Tokyo・ Year of completion: 1960
CONCRETE RECYCLING (17)CONCRETE RECYCLING (17)
An Example of Application
CONCRETE RECYCLING (18)CONCRETE RECYCLING (18)
Concrete plant
Recycled aggregate plant
An Example of Application
CONCRETE RECYCLING (19)CONCRETE RECYCLING (19)
Efficient equipment for producing high quality recycled aggregate (2)– Mechanical scrubbing-1 (eccentric tubular
type) Concrete Lumps
EccentricTubular Mill
Motor
ExternalCylinder
Scrubbing
Transmission GearRecovery
Mechanical scrubbing-1 Mechanical scrubbing-1 (eccentric tubular type)(eccentric tubular type)
Mechanical scrubbing-1 Mechanical scrubbing-1 (eccentric tubular type)(eccentric tubular type)
Eccentricrotor device
2nd sieve1st sieve
Product
After the rotor device
CrushedConcrete lump
Mechanical scrubbing-1 Mechanical scrubbing-1 (eccentric tubular type)(eccentric tubular type)
Old apartment Houses12 x 4-storiedConcrete lump: 11,500 t
New apartment Houses7 x 9-19-storiedRecycled coarse aggregate: 3,000 tRecycled concrete volume: 3,000 m3
( Total concrete volume:40,000 m3 )
CONCRETE RECYCLING (23)CONCRETE RECYCLING (23)
Efficient equipment for producing high quality recycled aggregate (3)– Mechanical scrubbing-2 (screw type)
Cylinder HollowInput
Middle Cone Ejection Cone
OutletRotary Blade
CONCRETE RECYCLING (24)CONCRETE RECYCLING (24)
Efficient equipment for producing high quality recycled aggregate (3)– Mechanical scrubbing-2 (screw type)
CONCRETE RECYCLING (25)CONCRETE RECYCLING (25)
Efficient equipment for producing high quality recycled aggregate (4)– Wet scrubbing and gravity classification
Drum
RodsSupply Exit
Concrete Lumps
Water Level Range in Air
Chamber
Recycled Aggregate with Low Density
Recycled Aggregate with High Density
Water LevelLow Density Zone
High Density Zone
CONCRETE RECYCLING (26)CONCRETE RECYCLING (26)
Efficient equipment for producing high quality recycled aggregate (4)– Wet scrubbing and gravity classification
Political Aspects Political Aspects
Prime Minister, Junichiro Koizumi
The Manifesto of the Democratic Party of Japan (opposition party)– “From Concrete to People, People, People”
Why concrete is not recycled into concrete?
Government official
“It is because there is no industrial standard.”
suffered a crushing defeat in the general election
CONCRETE RECYCLING (27)CONCRETE RECYCLING (27)
CONCRETE RECYCLING (28)CONCRETE RECYCLING (28)
JIS A 5021, March 2005– Recycled aggregate for concrete - class H
(RA-H)• High qualityHigh quality recycled aggregate and used as
aggregate for JIS A 5308 (Ready-mixed concrete)• The amount of deleterious substancesdeleterious substances tested through
comparisoncomparison with several confirmatory samples including each deleterious substance
CONCRETE RECYCLING (29)CONCRETE RECYCLING (29)
JIS A 5021, March 2005– Recycled aggregate for concrete - class H
(RA-H)• The minimum rate of testingminimum rate of testing and the criteria of alkali-criteria of alkali-
silica reactivitysilica reactivity dependent on the identification of the identification of the attribute of original aggregatesattribute of original aggregates
• Unless identified, tested at frequent intervals and treated as an aggregate of potential alkali-silica reactivity
• Must be produced in a plant assessed, surveyed and assessed, surveyed and certifiedcertified by an approved body
CONCRETE RECYCLING (30)CONCRETE RECYCLING (30)
• Physical Properties Requirements for RA-H
Coarse aggregate Fine aggregate
Oven-dry density (g/cm3) not less than 2.5 not less than 2.5
Water Absorption (%) not more than 3.0 not more than 3.5
Abrasion*1 (%) not more than 35 NA
Material passing 75 m sieve (%) not more than 1.0 not more than 7.0
Percentage of solid volume for evaluation of particle shape (%)
not less than 55 not less than 53
Chloride ion content (%) not more than 0.04
*1 : for pavement
CONCRETE RECYCLING (31)CONCRETE RECYCLING (31)
• Limits of Amount of Deleterious Substances for RA-H
Category Deleterious substances Limits (mass%)
A Tile, Brick, Ceramics, Asphalt concrete 2.0
B Glass 0.5
C Plaster 0.1
DInorganic substances other than
plaster 0.5
E Plastics 0.5
F Wood, Paper, Asphalt 0.1
Total 3.0
CONCRETE RECYCLING (32)CONCRETE RECYCLING (32) Large amount of by-product fines
– Resulting from production of high quality recycled aggregate
– Possible uses • Addition to road bottoming• Cement material• Concrete addition• Asphalt filler• Ground improving material• Inorganic board material
– Demands• Quality stabilization• Reduction of quality control cost
CONCRETE RECYCLING (33)CONCRETE RECYCLING (33)
Ground improvement
Raw material of cement
CONCRETE RECYCLING (34)CONCRETE RECYCLING (34)
Recyclable concrete like steel and aluminum
Production process of concrete – Conventional downstream approach
• focusing on– Cost reduction– Efficiency in production
– New production systemNew production system• incorporating upstream (inverse) processes in
consideration of recyclability
CONCRETE RECYCLING (35)CONCRETE RECYCLING (35) Conventional Material Flow of Concrete Recycling
heating
rubblingcrush
impactcrush
frictioncrush
Loop3
demolition
use and managenment
Production of Structural ConcreteLoop 1 (Target : Structural Concrete)Loop 2 (Target : Non-structural Concrete)Loop 3 (Target : Sub-base Materials)
environmentaldisruption
structuralaggregate
Subbase Materials
sieving
non-structuralaggregate
subbasematerials
Inspection
environmentaldisruption
demolition
demolition
compressivecrush Loop1
Non-structural Concrete
sieving
sieving
compressivecrush
impactcrush
compressivecrush
Loop2
Structural Concrete
waste em
issions
(concrete rubble,asphalt concrete rubble,mixed rubble)
CONCRETE RECYCLING (36)CONCRETE RECYCLING (36)
Completely recyclable concrete (CRC)– Cement recovery type CRC
Concrete whose materials are entirely usable after hardening as materials of cement or recycled aggregate, since all the binders, additions, and aggregate are made of cement or materials for cement.
CONCRETE RECYCLING (37)CONCRETE RECYCLING (37)
Completely recyclable concrete (CRC)– Cement recovery type CRC
Precast ConcreteFoundationsMade from CRCin Kita-kyusyu
CONCRETE RECYCLING (38)CONCRETE RECYCLING (38)
Completely recyclable concrete (CRC)– Cement recovery type CRC
Perfect Recycle Housein Kita-kyusyu
CONCRETE RECYCLING (39)CONCRETE RECYCLING (39)
Completely recyclable concrete (CRC)– Aggregate recovery type CRC
Concrete in which the aggregate surfaces are modified without excessively reducing the mechanical properties of the concrete, in order to reduce the bond between aggregate and the matrix, thereby permitting easy recovery of original aggregate.
CONCRETE RECYCLING (40)CONCRETE RECYCLING (40)
Completely recyclable concrete (CRC)– Aggregate recovery type CRC
Chemical treatment
Physical treatment
The principal ingredient of the coating agent is mineral oil. The agent hydrolyzes in alkali conditions of fresh concrete, forming acidic matter and indissoluble amalgam on the surface of the aggregate. The surface coating results in decreased amounts of cement hydrate, and leads to decreased adhesive strength between aggregate and paste matrix, allowing easy recovery of the original aggregate.
The coating agent is a water-soluble synthetic resin emulsion, which is applied in process of abrasion, and which is chemically stable in fresh concrete. The uneven surfaces of virgin aggregate become smoother, the shape of the aggregate being roughly maintained. This has the effect of decreasing adhesive strength between aggregate and paste matrix.
CONCRETE RECYCLING (41)CONCRETE RECYCLING (41)
Material flow should be further optimized in cooperation with other industriesin cooperation with other industries as part of the resource recycling of society as a whole, reflecting back on the abundant resource consumption of abundant resource consumption of concreteconcrete and the long service liveslong service lives of buildings and civil structures.
CONCRETE RECYCLING (42)CONCRETE RECYCLING (42)
Research and development involving Research and development involving “recycling” as a keyword should clarify “recycling” as a keyword should clarify what what recycling design ought to berecycling design ought to be and and how it how it ought to be carried outought to be carried out and examine if it is and examine if it is essentially effective in establishing a essentially effective in establishing a sustainable global environment for the sustainable global environment for the present and future. Otherwise, present and future. Otherwise, environmental technology intended to environmental technology intended to improve the issue of the global environment improve the issue of the global environment could be chained to another vicious circle.could be chained to another vicious circle.
CONCRETE RECYCLING (43)CONCRETE RECYCLING (43)
Toward the future, in addition to Toward the future, in addition to technologies for treating existing stock, technologies for treating existing stock, it is vital to established production it is vital to established production systems whereby systems whereby new stock serves as new stock serves as resources by actively introducing resources by actively introducing lifecycle design involving recycling lifecycle design involving recycling designdesign, which incorporates, which incorporates
inverse processes of productioninverse processes of production..
AssignmentAssignment
Select one building material in one country except concrete in Japan.
Investigate the annual amount of production, recycle and final disposal of the selected material in the country.
Investigate the recycling technologies of the selected material and the uses of the recycled material.
You can download the today’s presentation file atYou can download the today’s presentation file at
http://bme.arch.t.u-tokyo.ac.jp/class_info/index.htmlhttp://bme.arch.t.u-tokyo.ac.jp/class_info/index.html