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State-of-the-art Recycling Technologies for Building Materials in Japan Part 1 Cement & Concrete

State-of-the-art Recycling Technologies for Building Materials in Japan Part 1 Cement & Concrete. Takafumi NOGUCHI. CONTENTS. Resource Recycling Model of Concrete Environmental Aspect of Cement Production Environmental Aspect of Aggregate Production

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State-of-the-art Recycling Technologies for Building Materials in Japan Part 1 Cement & Concrete

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  1. State-of-the-art Recycling Technologies for Building Materials in JapanPart 1 Cement & Concrete Takafumi NOGUCHI

  2. CONTENTS • Resource Recycling Model of Concrete • Environmental Aspect of Cement Production • Environmental Aspect of Aggregate Production • Environmental Aspect of Concrete Production • Concrete Recycling

  3. 1. RESOURCE RECYCLING MODEL OF CONCRETE

  4. RESOURCE RECYCLING MODEL 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

  5. RESOURCE RECYCLING MODEL OF CONCRETE (2) • Final disposal sites for industrial waste

  6. Raw material acquisition • mining of aggregates • mining of stones for cement production • energy sources and energy production • water supply • Realization • production of concrete and concrete elements • design • construction • Utilization • use • maintenance • repair • renovation • Life end • demolition • reuse • recycling • disposal • landfill RESOURCE RECYCLING MODEL OF CONCRETE (3) • Typical Life Phases of Concrete Product / Concrete Structure Life phases of concrete product

  7. Use Maintenance Repair Demolition Recycling Construction Detailed Design Technology Concept Potential to influence Ei Conceptual Design Waste disposal, landfill The Chance to Influence Degree of Environmental Impact / Environmental Efficiency Demol/ Recycl Utilization Design Construction Life Cycle Phases of Concrete Structure RESOURCE RECYCLING MODEL OF CONCRETE (4) • Potential Chance to Influence Degree of Environmental impact

  8. RESOURCE RECYCLING MODEL OF CONCRETE (5) • Life Cycle of Concrete Structure • Material and energy flows and consequent environmental impacts

  9. Slag 12,331 Fly Ash 4,551 Others 8,702 CO2 44,725 Buildings Civil Structures Limestone 84,267 Cement 82,181 (Import: 1,228, Export: 7,564） Others 28,617 Concrete 475,842 (including Cement-based Products) New Stocks Gravel, Sand 301,000 Aggregate for Concrete 405,404 Crushed Stone 412,000 Existing Stocks Road Subbase Materials and Others 320,955 Recycle on Site Others 16,000 Waste Disposal 1,780 Aggregate for Asphalt Concrete 53,821 Recycled Crushed Stone 51,180 Asphalt Concrete 71,400 Asphalt 3,379 Asphalt Concrete Lumps 14,200 Concrete Lumps 35,040 Asphalt Concrete 16,140 Unit：1,000t RESOURCE RECYCLING MODEL OF CONCRETE (6) • Material Flows of Concrete Discharge of Concrete < 10% of Input Enormous Amounts of Concrete Stocks

  10. ENVIRONMENTAL ASPECT OF CEMENT PRODUCTION

  11. ENVIRONMENTAL ASPECT OF CEMENT PRODUCTION (1) • Raw Materials and Energy for 1 ton of Normal Portland Cement Highest level of energy efficiency thanks to the energy conservation measures taken during the period between 1970 and 1990

  12. ENVIRONMENTAL ASPECT OF CEMENT PRODUCTION (2) • Fuel for Cement • Coal : 85% • from China, Australia, Russia, and Indonesia • Petroleum coke : 10% • Industrial waste : 3% • Heavy oil : 1%

  13. Local Construction Nonferrous Municipality Waste plastics metals Sewage sludge, Printing Sludge generated by Molding sand, Water purification, Sludge, Slag, Steel Incineration ash, Paper&Pulp Municipal waste, Gypsum Waste plastics Incineration ash Sludge, Slag, EP ash Incineration Chemicals ash Fishery Sludge, Building Waste plastics, Seashells, Gypsum Food product Cement material Wastes Waste diatomaceous Waste board, Earth, Automobile Sludge Waste plastics, Molding sand, Distillery residue, Petroleum Paints residue, Sludge Agriculture Used tires Electric Waste clay, Sludge, Waste plastics Waste oils, power Used catalysts, Electric & Pachinko DOC, FOC Coal ash, Electronic appliances EP dust(ash), Used Sludge, Gypsum Pachinko Textile Waste plastics, machines Used toner Sludge, Cartridges, Waste plastics CFCs ENVIRONMENTAL ASPECT OF CEMENT PRODUCTION (3) • Recycling Ecosystem of Cement Production

  14. ENVIRONMENTAL ASPECT OF CEMENT PRODUCTION (3) • Waste and Byproducts Utilized by Cement Industry

  15. ENVIRONMENTAL ASPECT OF CEMENT PRODUCTION (4) • Waste and Byproducts Utilized by Cement Industry • Recently • Sewage sludge, Incineration ash from municipal solid waste

  16. ENVIRONMENTAL ASPECT OF 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

  17. Foundation Iimprovement Others Civil Structures Cement Civil Structures Buildings Others Concrete Aggregate Landfill Road Cement Export ENVIRONMENTAL ASPECT OF CEMENT PRODUCTION (6) • Utilization of Blast Furnace Slag and Fly Ash Blast Furnace Slag (24,518,000t) Fly Ash (6,919,000t)

  18. Fly Ash Cement Slag Cement Portland Cement Production (x10,000 t) Fiscal Year ENVIRONMENTAL ASPECT OF CEMENT PRODUCTION (7) • Changes in cement production by type 99,270,000 tons in 1996 ratio of blended cement production has been gradually increasing

  19. ENVIRONMENTAL ASPECT OF 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

  20. ENVIRONMENTAL ASPECT OF CEMENT PRODUCTION (9) • “Ecocement” recently developed in Japan • made using incineration ash from municipal solid waste and sewage sludge • Dioxins completely decomposed at a high temperature without being resynthesized • rapidly cooled to below 200C in a cooling tower • captured in a bag filter and an active coke-packed tower • Heavy metals contained in incinerated ash • recovered/concentrated • delivered to nonferrous metal factories for recycling

  21. (%) CaO SiO2 Al2O3 Fe2O3 SO3 Cement 62 - 65 20 - 25 3 - 5 3 - 4 2 - 3 12 - 31 23 - 46 13 - 29 4 - 7 1 - 4 Incin. Ash Limestone 47 - 55 Clay 45 - 78 10 - 26 3 - 9 Silica sand 77 - 96 Iron source 40 - 90 Gypsum 26 - 41 37 - 59 ENVIRONMENTAL ASPECT OF CEMENT PRODUCTION (10) • Chemical compositions of portland cement and incineration ash

  22. ENVIRONMENTAL ASPECT OF CEMENT PRODUCTION (11) • Raw materials combination • Ecocement replaces limestone and clay with incineration ash Sewage sludge 9% Silica sand 4% Others2% Others 1% Incineration Ash 38% Clay 16% Limestone 78% Limestone 52% Normal Portland Cement Ecocement

  23. Ig. Loss SiO2 Al2O3 Fe2O3 CaO SO3 R2O Cl Normal Type EC 1.1 17.0 8.0 4.4 61.0 3.7 0.26 0.04 Rapid Hardening Type EC 0.8 15.3 10.0 2.5 57.3 9.2 0.50 0.90 NPC 1.5 21.2 5.2 2.8 64.2 2.0 0.63 0.01 ENVIRONMENTAL ASPECT OF CEMENT PRODUCTION (12) • Chemical Composition of Ecocement (%)

  24. ENVIRONMENTAL ASPECT OF CEMENT PRODUCTION (13) • Physical Properties and Quality of Ecocement W/C=0.50, S/C=3.0

  25. Incinerated Ash Raw Sludge Limestone, etc. Bug Filter Denitration Air Smelter Drainage Crusher Heavy Metal Recovery Rotary Kiln Tank for Homogenization Tank Clinker Cooler Bug Filter Gypsum Clinker Ecocement Raw Materials Gas Water Mill ENVIRONMENTAL ASPECT OF CEMENT PRODUCTION (14) • “Ecocement” recently developed in Japan

  26. Panoramic view of Ichihara Ecocement plant Heavy metal refining process Rotary kiln Bag filter Flue gas cooling tower Gas treatment Administrative office & bottom ash storage facilities Homogenizing tank 34m Fly ash tank Raw mat. mill Rotary dryer 80m 366m 58m Lot area; 16,700m2 Ecocement tank

  27. ENVIRONMENTAL ASPECT OF CEMENT PRODUCTION (17) • Ichihara Ecocement Corporation (Rotary kiln)

  28. Application for construction Application for construction Application for construction Concrete block Concrete roof External wall Application for civil works Application for civil works Application for civil works Inter rocking block Concrete block Marine product ENVIRONMENTAL ASPECT OF CEMENT PRODUCTION (18) • Applications of Ecocement to various concrete products

  29. ENVIRONMENTAL ASPECT OF AGGREGATE PRODUCTION

  30. Crushed Stone River Gravel Pit Gravel Hill Gravel Sea Gravel Others 1963 1965 1967 1969 1971 1973 1975 1977 1979 1981 1983 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 Production (million t) ENVIRONMENTAL ASPECT OF AGGREGATE PRODUCTION (1) • Changes in aggregate production 949 million tons in 1990 Crushed stone and Crushed/pit sand have become major Good quality river sand and river gravel have become depleted • Causing • exposure of bedrock on the bottom of the sea • erosion of embankments • endangering sand spits and fishing grounds

  31. ENVIRONMENTAL ASPECT OF 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

  32. ENVIRONMENTAL ASPECT OF AGGREGATE PRODUCTION (3) • Aggregate, 70% by volume of concrete, anticipated as a recipient of waste and byproducts from other industries

  33. 600 500 400 300 200 100 0 Concrete Production Concrete Waste Production and Waste (million t) Concrete Waste from Buildings Concrete Waste from Civil Structures 1950 2000 2050 Year ENVIRONMENTAL ASPECT OF CONCRETE PRODUCTION (1) • Changes in concrete production 600 million tons in 1990 decrease due to reductions in investment in new construction of buildings and civil structures

  34. Recovered Water Supernatant Water Sludge Water Returned Concrete Mixer Agitator Truck Returned Concrete Mixer Agitator Truck Washing Water Waste Sludge Cake Sludge Solid Final Disposal Coarse Aggregate Fine Aggregate Road Subbase Mixing Water ENVIRONMENTAL ASPECT OF 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

  35. CONCRETE RECYCLING

  36. Reuse Disposal 1990 1995 2000 0 10 20 30 40 Emission of Concrete Lumps (million t) CONCRETE RECYCLING (1) • Recycle ratio of demolished concrete • Effort by the Ministry of Construction • Recycling Plan 21 • Construction Recycling Promotion Plan ’97 • For road bottoming materials • For mechanical stabilization materials

  37. 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

  38. Demolished Building Sound-proof Wall Gravity Retaining Wall Backfilling Concrete Pavement Road Subbase Basement Foundation Improvement Crusher Powder Packing Sieve Packing 40-0mm Recycle Plant 60-20mm CONCRETE RECYCLING (3) • Recycle in Apartment Complex

  39. 600 500 400 300 200 100 0 Concrete Production Concrete Waste Production and Waste (million t) Concrete Waste from Buildings Concrete Waste from Civil Structures 1950 2000 2050 Year CONCRETE RECYCLING (4) • Changes in concrete production 600 million tons in 1990 • Premature deterioration • Ends of their service lives • Demolished decrease due to reductions in investment in new construction of buildings and civil structures

  40. 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”

  41. Demolished Concrete Lumps Jaw Crusher Vibratory Sieves Heating Tower Impact Crusher Cone Crusher Coarse Aggregate Scrubber Vibratory Sieves Road Subbase, Backfill Vibratory Sieves Fine Aggregate Scrubber Low Quality Recycled Coarse Aggregate Low Quality Recycled Fine Aggregate Vibratory Sieves High Quality Recycled Coarse Aggregate High Quality Recycled Fine Aggregate Powder (c) High Quality Recycled Aggregate (b) Low Quality Recycled Aggregate (a) Road Subbase CONCRETE RECYCLING (6) • Recycling process of demolished concrete lumps

  42. 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

  43. CONCRETE RECYCLING (8) • Today’s conventional concrete recycling • Roadbed material • Aggregate for concrete excluding structural use

  44. 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

  45. Water Absorption (%) Recovery Percentage (%) Size of Supplied Concrete Lumps Recycled Fine Aggregate 5-10mm not less than 10mm Gravel Recycled Coarse Aggregate Sand Cement Paste Powder No 1st 2nd 3rd Number of Crushing Treatment No 1st 2nd 3rd Original Concrete Crushing Treatment CONCRETE RECYCLING (10) • Quality and recovery percentage of recycled aggregate

  46. Heating Device Filled with Concrete Lumps Recovery of Fine Aggregate Recovery of Coarse Aggregate Bug Filter Sieve Tube Mill Tube Mill Fine Aggregate Coarse Aggregate Fine Powder CONCRETE RECYCLING (11) • Efficient equipment for producing high quality recycled aggregate (1) • Heated scrubbing

  47. Heating at 300C Rubbing process Concrete rubble Removal of powdered cement hydrate Weakening of hardened cement paste CONCRETE RECYCLING (12) • Heated scrubbing

  48. Heated scrubbing Powder Storage Tank Dart Collector Classifier Coarse Aggregate Mill Recycled Coarse Aggregate Recycled Fine Aggregate Heating Tower Fine Aggregate Mill Input Hopper

  49. CONCRETE RECYCLING (14) • Recycled structural aggregates& by-product powder

  50. 14 12 Recycled Fine/ Former systems 10 8 Absorption (%) 6 Recycled Coarse/ Former systems Coarse & fine/ CLC system 4 2 Virgin aggregate 0 2.0 2.2 2.4 2.6 Oven-dry density (g/cm3) CONCRETE RECYCLING (15) • Quality of Recycled Aggregates

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