8.4. Recycling Technologies and Processes: Case Study
8.4.1. Recycling Project of C&D Waste in Shangrao City
Recycling project of the C&D waste in Shangrao city is a comprehensive project started in 2014. The annual treatment planning in the first stage is 300,000 t of C&D waste and 50,000, 80,000, 120,000, and 60,000 t of recycled aggregate, renewable powder, recycled fine sand, and recycled construction materials, respectively. The whole process is able to reduce the spread of dust, while also using source separation process which aimed at separating solids and reusing for the production of raw materials. The waste water being removed of solid substances after precipitation is reused as wash water. Meanwhile, the heavy metal–contaminated construction waste is sorted, separated, and eluted of harmful substances in the relevant sections, to achieve zero emissions in the whole process, as demonstrated in Fig. 8.29. The process is divided into six sections: pretreatment and stacking section, clean waste crushing and sorting section, heavy metal pollution control section, classified storage section, deep processing combined with grinding section, and manufacturing section of products.
8.4.1.1. Pretreatment and Stacking Section
Primary crushing, manual sorting, and stacking of raw material are performed in this section.
After being transported from off-site to the disposal site into the working area, the C&D waste is sent into the jaw crusher. In this period, large blocks of waste are primarily crushed to facilitate the crushing and separation of reinforced concrete blocks in subsequent sections. The approaching working area is to provide space for the transport of vehicles, also being capable of storing a small amount of waste.
The crushed waste is then sent to the manual sorting platform for the separation of larger iron blocks, cloth, plastic, fabric, etc. Due to the complex components of C&D waste, manual sorting is able to ensure the successful separation of large blocks while making the subsequent process more efficient.
The materials are transported into automatic enclosed stacking system through a manual sorting platform. The stacker is able to store 18,000 m3 waste, which could meet the demand for the storage amount of a week, and is a transition and buffer between the storage and disposal of C&D waste. This section is necessary due to the discontinuous collection of C&D waste.
8.4.1.2. Crushing and Sorting Section of C&D Waste
This section is the major process in which C&D waste is produced into aggregates, and is aimed at finely crushing and separating the impurities. This section is equipped with impact crusher, powerful iron drawer, mud remover, wind-conveyor sorting machines, and circular sieve.
The materials are first transported into the impact crusher, of which the outlet particle size is less than 40 mm. Then they are sent to the three-layer mud sieve by belt conveyor. The slim reinforced bars, steel nails, and other metals (not including heavy metal pollutants) are also removed in this section.
The linear mud sieve is aimed at removing the materials of particle size less than 1 mm. Most of these wastes contain mud, which is hard to be recycled. The materials above the sieve are sent back to the crusher, whereas those in the middle are transported to the next sorter.
Wind-conveyor sorting machines are used to sort the light waste like wood. Then they are screened in the circular sieve and are classified into four different classes based on the particle size. Dust removers are also equipped in this section.
8.4.1.3. Treatment Section of Heavy Metal–Contaminated C&D Waste
Surface Stripping
About 3–6 mm of the surface of C&D waste contaminated by high concentrations of heavy metals is stripped off and immersed in commercial caustic soda solution of industrial 2–8 M grade. Electrolysis treatment is performed upon the leaching solution to recycle the heavy metals.
Crushing
Washing and Solid–liquid Separation
The crushed C&D waste is washed with water (liquid:solid = 5:1) and is solid–liquid separated. The wash water is treated by adding nano-iron powder (20 nm). The washed C&D waste is eluted with glyphosate according to procedure d.
Eluting With Glyphosate and Solid–liquid Separation
Glyphosate is added into the washed C&D waste (liquid:solid = 2:1) and eluted one to three times. Most heavy metal ions would be combined with glyphosate and transformed into the nonleachable and stable phase. Solid–liquid separation is performed after the pH has been adjusted to neutral. The waste water is treated while the eluted C&D waste is sent for further washing.
Eluted C&D Waste
Eluted C&D waste is washed with water (liquid:solid = 5:1) before solid–liquid separation is performed. C&D waste is dried and sent for heavy metals detection.
8.4.1.4. Classified Storage Section
The materials in this section are semifinished products, which are divided into four classes: 0–5, 5–15, 15–22, and 22–31.5 mm. The storage capacity of each room of the warehouse is 350 m3, the functions of which are continuous feeding for the combined grinding and loading for sale of semifinished products.
8.4.1.5. Deep Processing and Combined Grinding Section
A detailed process of this section is demonstrated in Fig. 8.30. The materials has already been sorted and removed of mud, impurities, and iron and are high in quality and the mud content is less than 1% before being set into the combined grinding system. They are first transported into the roll press and grinded to particles less than 5 mm. These small particles are then sent to thermal whirlcone conical grinder with dryers. The high-speed rotating grinding parts are able to crush by stirring, rolling, and vibrating. The front of this grinder is crushed by mainly hitting and the back by mainly squeezing. The low-intensity waste like sintered bricks and cement stones are ground to powder, which are high-activity metakaolin, whereas the high-intensity waste like natural rocks or river sand are ground to fine sand.
The ground materials are classified into three classes: 0–0.08, 0.08–0.16, and 0.16–2.36 mm and are collected in the tanks, respectively.
8.4.1.6. Manufacturing Section of Products
Detailed process of manufacturing section of products is demonstrated in Fig. 8.31. Recycled aggregates in the crushing and sorting section are used as raw materials, those of 0–5 and 5–15 mm are generally selected. Main products include recycled blocks, recycled bricks, road bricks, permeable bricks, and wall materials.
The overall layout distribution and the land coverage of each section are listed in Table 8.23.
The main pollutants in the manufacturing process are the inorganic mineral dust generated in the transportation of materials. In this project, sealed storage warehouse is adopted while dust caps are equipped on the belt conveyors. The inlet and outlet sections of materials are equipped with steel covers along with bag filters for dust catching. All crushing facilities are equipped with fully enclosed soundproofed rooms in which negative pressure is generated. Meanwhile, the rotation speed and gap between transfer stations are minimized to strengthen the airtight thus controlling the spread of dust.
Table 8.23
General Layout and Land Coverage of This Project for Annual Treatment Scale of 300,000 t of Construction and Demolition Waste
| No. | Item | Land Coverage (m2) | Building Construction Area (m2) | Structure Construction Area (m2) |
| 1 | Stack area of demolition waste | 403 | 403 | |
| 2 | Pretreatment stack area | 4943 | 9886 | |
| 3 | Crushing, sorting, and classified storage workshop | 2889 | 5778 | |
| 4 | Deep processing workshop | 1099 | 2198 | |
| 5 | Metal pollutants disposing workshop | 550 | 1100 | |
| 6 | Storage warehouse of recycled micropowder | 320 | 900 | |
| 7 | Repair shop, warehouse | 763 | 763 | |
| 8 | Controlling center | 479 | 479 | |
| 9 | Test building | 1008 | 3024 | |
| 10 | Multifunctional building | 1008 | 3024 | |
| 11 | Product storage yard | 5000 | ||
| 12 | Guard room | 40 | 46 |
Sand and gravel separation facilities are adopted in the wastewater treatment system. The solid materials separated from this section can be used as producing raw materials while the wastewater deprived of solid substances is also reused.
8.4.1.7. Labor Organization
Labor organization information of this project is introduced below.
Annual working days: 252–300 days;
Main manufacturing posts: two shifts;
Auxiliary manufacturing posts: one shift;
Working time per shift: 8 h.
Information of labor force involved is listed in Table 8.28.
8.4.2. Centralized Disposal and Recycling Project of C&D Waste in Nantong City
8.4.2.1. General Introduction of This Project and Its Processes
The annual treatment planning in the first stage is 1,000,000 t of C&D waste and 100,000 m3 of recycled concrete aggregate, 200,000 t of premixed mortar, 200,000 t of cementing materials, and 400,000 t of recycled aggregate (sand, gravel). A comparison of the disposal process and recycled products is listed in Table 8.29.
Table 8.24
Facilities in Pretreatment Section for Annual Treatment Scale of 300,000 t of Construction and Demolition Waste
Table 8.25
Facilities in Crushing and Sorting Section for Annual Treatment Scale of 300,000 t of Construction and Demolition Waste
Table 8.26
Facilities in Deep Processing Section for Annual Treatment Scale of 300,000 t of Construction and Demolition Waste
Table 8.27
Facilities in Product Manufacturing Section for Annual Treatment Scale of 300,000 t of Construction and Demolition Waste
| No. | Item | Model & Specification | QTY | |
| 1 | Ingredient storage bin 3 × 4 m3 (body fabric) | Aggregate storage bin | 4 m3 | 3 |
| Measuring bin | 1200 kg ± 2% | 1 | ||
| Sensor | CST-2000 | 4 | ||
| Cylinder | SC80 × 300-S-CB-Y | 3 | ||
| Vibrator | B-0.5 | 3 | ||
| Motor | 7.5 kW | 1 | ||
| Belt | B500 × 17.1 m | 1 | ||
| Frame | Steel structure | 1 | ||
| 2 | Blender (body fabric) | Blending barrel | JS750 | 1 |
| Motor reducer | 30 kW | 1 | ||
| Lifting motor | 7.5 kW | 1 | ||
| Lubrication system | 1 | |||
| Cylinder | SC160 × 300-S-TC-M-Y | 1 | ||
| 3 | Cement measuring system (body fabric) | Cement weighing hopper | 350 kg ± 1% | 1 |
| Sensor | CSB-250 | 3 | ||
| Butterfly valve | DN250 | 1 | ||
| Vibrator | B-0.25 | 1 | ||
| 4 | Water measuring system (body fabric) | Water measuring cylinder | 200 kg ± 1% | 1 |
| Transmission pump | 2.2 kW | 1 | ||
| Pipeline | 2″ | 1 | ||
| Sensor | CST-500 | 1 | ||
| Butterfly valve | DN80 | 1 | ||
| Filling valve | DN25 | 1 | ||
| 5 | Belt conveyor (body fabric) | Flat belt | B600 × 8 m (center distance) | 1 |
| Planet-cycloid retarder | 4 kW | 1 | ||
| Table Continued | ||||
| No. | Item | Model & Specification | QTY | |
| Frame | Steel structure | 1 | ||
| Tightener | 1 | |||
| Receiving hopper | 1 | |||
| 6 | Grading station 1 × 4 m3 (plus material) | Aggregate storage bin | 4 m3 | 1 |
| Measuring bin | 800 kg ± 2% | 1 | ||
| Sensor | CST-1000 | 4 | ||
| Cylinder | SC80 × 300-S-CB-Y | 1 | ||
| Vibrator | B-0.5 | 1 | ||
| Motor | 2.2 kW | 1 | ||
| Belt | B500 × 5 m | 1 | ||
| Frame | Steel structure | 1 | ||
| 7 | Vertical blender (plus material) | Blending barrel | JN350 | 1 |
| Motor reducer | 7.5 kW | 1 | ||
| Lifting motor | 4 kW | 1 | ||
| Cylinder | SC80 × 250-S-TC-Y | 1 | ||
| 8 | Cement measuring system (plus material) | Cement weighing hopper | 150 kg ± 1% | 1 |
| Sensor | CSB-250 | 3 | ||
| Butterfly valve | DN250 | 1 | ||
| Vibrator | B-0.25 | 1 | ||
| 9 | Water measuring system (plus material) | Water measuring cylinder | 80 kg ± 1% | 1 |
| Transmission pump | 1.1 kW | 1 | ||
| Pipeline | 1 1/4″ | 1 | ||
| Sensor | CST-250 | 1 | ||
| Butterfly valve | DN80 | 1 | ||
| Filling valve | DN25 | 1 | ||
| Table Continued | ||||
| No. | Item | Model & Specification | QTY | |
| 10 | Belt conveyor (plus material) | Flat belt | B500 × 7 m (center distance) | 1 |
| Planet-cycloid retarder | 2.2 kW | 1 | ||
| Frame | Steel structure | 1 | ||
| Tightener | 1 | |||
| Receiving hopper | 1 | |||
| 11 | Block molder | Host machine | QT10-15 | 1 |
| Vibrating motor (with frequency conversion, without independent fans) | 11 kW | 2 | ||
| Distributing motor | 4 kW | 1 | ||
| Pallet conveyor | 1 | |||
| Hydraulic system | 22 kW | 1 | ||
| Random mold | 1 | |||
| 12 | Plus material device | 1 | ||
| 13 | Heat insulating board conveying device | 1 | ||
| 14 | Wet product conveyor line | Sweeping motor | 0.18 kW | 1 |
| Frame | 1 | |||
| Spacing device | 1 | |||
| 15 | Elevator 10F | Frame | SBJ10 | 1 |
| Motor power | 7.5 kW | 1 | ||
| Lifting device | 1 | |||
| Table Continued | ||||
| No. | Item | Model & Specification | QTY | |
| 16 | Lowerator 10F | Frame | SBJ10 | 1 |
| Motor power | 7.5 kW | 1 | ||
| Lifting device | 1 | |||
| 17 | Composite vehicle | Conveyor (carrier) | 1 | |
| Actuating device for conveyor | 3 kW | 1 | ||
| Subequipped vehicle (10 floor) | 1 | |||
| Actuating device for subequipped vehicle | 3 kW | 1 | ||
| Speed control device | 1 | |||
| Positioning device | 1.5 kW | 1 | ||
| 18 | Dry product conveyor line | Frame | 1 | |
| Sweeping machine | 0.18 kW | 1 | ||
| Spacing device | 1 | |||
| 19 | Plate recycling line | Plate turnover machine | SF10 | 1 |
| Gear motor | 0.75 kW | 1 | ||
| Overpass | 1 | |||
| 20 | Stacking machine | Walking device | 1.1 kW | 1 |
| Clamp device | 1 | |||
| Lifting device | 1 | |||
| Rotation device | 0.55 kW | 1 | ||
| Prestack device | 1 | |||
| Hydraulic system | 15 kW | 1 | ||
| 21 | Pitch conveyor | Tank chain | 7.5 kW | 1 |
| 22 | Wood tray separator | Wood tray | 2.2 kW | 1 |
| Table Continued | ||||
| No. | Item | Model & Specification | QTY | |
| 23 | Processing line hydraulic system | Triphase asynchronism motor | Y180L-4 22 kW | 1 |
| 24 | Electronic controlling system | Electric cabinet | 3 | |
| Control console | 4 | |||
| Industrial computer | 19″ LED display | 2 | ||
| PLC | 4 | |||
| Touch screen | TP-177A (Siemens) | 3 | ||
| Transmission instrument | GM8802F | 6 | ||
| Connecting cable | 1 | |||
| 25 | Control room | 6000 × 2250 × 2500 | 1 | |
| 26 | Packaging system | Horizontal packing machine | 1 | |
| Packaging machine | 1 | |||
| Winding machine | 1 | |||
| Transporting line | 2.5 m | 4 | ||
| Packaging control console | 1 | |||
| 27 | Pneumatic system | Air compressor | 5.5 kW | 1 |
| Pipe | 1 | |||
| FR, FRL | 1 | |||
| 28 | Spiral conveyor | XL219 | φ219 × 6 m | 1 |
| XL165 | φ165 × 5.5 m | 1 | ||
Table 8.28
| Department | Number of Staff | |||||
| Day Shift | Morning Shift | Swing Shift | Night Shift | Non Shift | Total | |
| Construction & demolition waste pretreatment | 3 | 3 | 1 | 7 | ||
| Crushing and sorting | 4 | 4 | 1 | 9 | ||
| Deep grinding process | 3 | 3 | 1 | 7 | ||
| Storage and loading | 2 | 2 | ||||
| Product manufacturing | 5 | 5 | 1 | 11 | ||
| Mechanical maintenance | 2 | 2 | ||||
| Technical production (experiment) | 2 | 1 | 1 | 4 | ||
| Guard | 1 | 1 | 1 | 3 | ||
| Logistics, administration | 3 | 1 | 4 | |||
| Financing | 3 | 3 | ||||
| Management | 5 | 5 | ||||
| Total | 23 | 11 | 17 | 1 | 5 | 57 |
Table 8.29
Comparison of Handling Process and Recycled Products in Nantong City Project
| No. | Item | Plan 1 | Plan 2 | Plan 3 |
| 1 | Resource products | Concrete products, mortar, concrete aggregate and cementing materials | Concrete products, mortar | Road material (cushion) |
| 2 | Pretreatment | Multistage crushing, screening | Multistage crushing, screening | Single-stage crushing |
| 3 | Separation of bricks, gravel, concrete | Relatively complete | Relatively complete | Mixed |
| 4 | Usage of recycled aggregate | |||
| 4.1 | Stone | Various classes (5–25 mm), able to be produced into concrete products and aggregate | Various classes (5–25 mm), able to produce into concrete products and aggregate | Those particle size larger than 25 mm account for more than 60%, can only be produced into road construction materials |
| 4.2 | Grit | 0–5 mm, able to be produced into concrete products and premixed mortar | 0–5 mm, able to be produced into concrete products and premixed mortar | |
| 4.3 | Powder | ≤0.16 mm, specific surface area of about 3000 cm2/g, can be used as cementing (blending) material | ||
| 5 | Variety of recycled products | Diversified | Small | Single (very small) |
| 6 | Sales of recycled products | |||
| Table Continued | ||||
| No. | Item | Plan 1 | Plan 2 | Plan 3 |
| 6.1 | Annual treatment capacity of 300,000 t | Smooth, low market share | Risk existing, large amount which will hit the market | Risk existing |
| 6.2 | Annual treatment capacity of 500,000 t | Smooth, low market share | Large risk, cannot be accommodated in market | Large risk |
| 6.3 | Annual treatment capacity of 800,000–1,000,000 t | Small risk, diversified market | Huge risk | Huge risk |
| 7 | Environmental pollution | Little | Little | Much |
| 8 | Installed capacity | Very large | Large | Small |
| 9 | Land occupation | Large | Large | Small |
| 10 | Investment | Very large | Large | Small |
| 11 | Technical sophistication | Very high | High | Low |
| 12 | Reliability | High | High | High |
| 13 | Value of recycled products | Very high | High | Low |
| 14 | Sustainability | Good | Normal | Bad |
Table 8.30
Components of Projects and Their Functions and Construction Area for Annual Treatment Scale of 1,000,000 t of Construction and Demolition Waste in Nantong City Project
| No. | Section | Function | Construction Area (m2) |
| 1 | No. 1 combined workshop | Production of recycled powder and sand | 12,606 |
| 2 | Product manufacturing and steam curing workshop | Products manufacturing | 1730 |
| 3 | Comprehensive building | Office work | 2700 |
| 4 | Technical center | Research work | 2700 |
| 5 | Office | Dork business | 228 |
| 6 | Maintenance workshop | Maintenance of facilities | 48 |
| 7 | Entrance | Inspection | 48 |
| 8 | Canteen | Dinner | 1238 |
| 9 | No. 2 combined workshop | Manufacturing of recycled aggregates | 3230 |
| Total | 24,528 | ||
Table 8.31
Material Balance of Annual Production of 100,000 m3 Recycled Concrete Products in Nantong City Project
| Material | Unit Consumption, t/m3 | Hourly Consumption, t | Daily Consumption, t | Annual Consumption, t |
| Cement | 0.30 | 6.67 | 100 | 30,000 |
| Sand | 0.15 | 3.33 | 50 | 15,000 |
| Recycled fine aggregate | 0.85 | 18.9 | 283.3 | 85,000 |
| Recycled coarse aggregate | 0.45 | 10 | 150 | 45,000 |
| Additive | 0.003 | 0.067 | 1 | 300 |
| Water | 0.18 | 4 | 60 | 18,000 |
The general construction area of each section is listed in Table 8.30.
8.4.2.2. Material Balance
The material balance of the annual production of 100,000 m3 recycled concrete products is listed in Table 8.31.
The material balance of the annual production of 100,000 m3 recycled concrete is listed in Table 8.32.
Table 8.32
Material Balance of Annual Production of 100,000 m3 Recycled Concrete in Nantong City Project
| Material | Unit Consumption, t/m3 | Hourly Consumption, t | Daily Consumption, t | Annual Consumption, t |
| Cement | 0.28 | 11.2 | 112 | 28,000 |
| Stone | 0.625 | 25 | 250 | 62,500 |
| Sand | 0.35 | 7.78 | 116.7 | 35,000 |
| Recycled fine aggregate | 0.35 | 7.78 | 116.7 | 35,000 |
| Recycled coarse aggregate | 1.25 | 25 | 250 | 62,500 |
| Fly ash | 0.065 | 2.6 | 26 | 6500 |
| Mineral powder | 0.084 | 3.36 | 33.6 | 8400 |
| Additive | 0.0059 | 0.235 | 2.36 | 590 |
| Water | 0.22 | 8.8 | 88 | 22,000 |
The material balance of the annual production of 200,000 t of premixed mortar is listed in Table 8.33.
8.4.2.3. Main Facilities
Main facilities involved in this project are listed in Table 8.34. The facilities are classified into six groups according to the different producing sections.
8.4.2.4. Layout and Structures
Engineering Project
The engineering design elevation is ±0.000, the interior height difference of manufacturing workshop is 150 mm, and the interior height difference of nonmanufacturing workshop is 450 mm.
Table 8.34
Main Facilities Involved in This Project for Annual Treatment Scale of 1,000,000 t of Construction and Demolition (C&D) Waste in Nantong City Project
| No. | Facility | Style & Specification | Disposing (Producing) Capacity | Quantity | Note |
| 1 | C&D waste pretreatment section | ||||
| 1) | Feeder | SEFTG-490 | 140 t/h | 2 | |
| 2) | Primary crusher | SEFPE-750 | 100–150 t/h | 2 | |
| 3) | Secondary crusher | SEFPF-1315 | 100–150 t/h | 2 | |
| 4) | Tertiary crusher | SEFPY-1300 | 100 t/h | 2 | |
| 5) | Metal separator | SEFF1000 | 6 | ||
| 6) | Screening device | SEF3YK2460 | 200 t/h | 6 | |
| 7) | Fine material grading device | SEFYK1854 | 16 t/h | 2 | |
| 8) | Plenum pulse dust collector | XLPM6A | 12,000 m3/h | 6 | |
| 9) | Plenum pulse dust collector | XLPM2A | 3000 m3/h | 6 | |
| 10) | Belt conveyor | B650-1000 | 50–60 t/h | 26 | |
| 11) | Loader | ZL50 | 3 | ||
| 2 | Storage and transportation section for recycled aggregate | ||||
| 1) | Belt conveyor | B650-1000 | 50–00 t/h | 10 | |
| 2) | Batching system | 6 | |||
| 3) | Plenum pulse dust collector | XLPM2A | 3000 m3/h | 8 | |
| 3 | Recycled products manufacturing section | ||||
| 1) | Measuring and batching system | 2 | |||
| 2) | Blender | 2 m3 | 30 m3/h | 2 | |
| 3) | Fabric material blender | 350 L | 2 | ||
| 4) | Blender | 0.5 m3 | 1 | ||
| Table Continued | |||||
| No. | Facility | Style & Specification | Disposing (Producing) Capacity | Quantity | Note |
| 5) | Plenum pulse dust collector | XLPM2A | 3000 m3/h | 2 | |
| 6) | Building block molder | QT10-15 | 2 | ||
| 7) | Elevator | 2 | |||
| 8) | Lowerator | 1 | |||
| 9) | Palletizer | 1 | |||
| 10) | Multifunctional large extruding machine | SEF90-120 × 1200 | 40,000 m3/a | 2 | |
| 11) | Curing device | 1 | |||
| 12) | Packaging machine | JHDKB | 1 | ||
| 13) | Forklift | 2 t | 3 | ||
| 4 | Concrete production section | ||||
| 1) | Blender | 2 m3 | 120 m3/h | 1 | Theoretical capacity |
| 2) | Sand separating and recycling system | 1 | |||
| 5 | Premixed mortar | ||||
| 1) | Sand drying machine | Φ2.5 × 5.4 m | 35 t/h | 1 | 5% water |
| 2) | Vibrating screen | 1 | |||
| 3) | Blender | 6 m3 | 30 t/h | 2 | |
| 4) | Packaging machine | 2 | |||
| 5) | Bag filter | 6000 m3/h | 1 | ||
| 6 | Cementing material production section | ||||
| 1) | Rolling machine | GM800 | Throughput: 48 t/h | 1 | |
| 2) | Powder concentrator | O-X500 | 20–40 t/h | 1 | |
| 3) | Bag filter | 36,000 m3/h | 1 | ||
| 4) | Bag filter | 4500 m3/h | 1 | ||
General Layout
1. General layout should possibly take advantage of terrain conditions and surrounding facilities, and should have a clear functional partition. The material storage area, production areas, and administrative welfare facilities must be separated, whereas the latter should be located at the upwind of the prevailing wind direction.
2. Make full use of terrain elevation, the direction of terrain height variation should be correlative to the process flow of the project to avoid useless work and to shorten the transportation distance, thus making the process more compactly and reasonably arranged.
3. Layout of the process should comply with the arrangement order from raw materials to finished products. The location of storage house of materials should be close to the users to shorten the transportation distance.
4. The arrangement of buildings and structures should be in line with the fire prevention interval and meet the fire requirements.
5. The site elevation and road elevation should be conducive to the discharging of rainwater and sewage. In the premise of meeting the requirements regulated in relative standards, integrated arrangement of each facility should be performed on basis of the whole process, fire, health, wind direction, transportation, and maintenance requirements.
6. The amount of site leveling work should be possibly minimized, balanced earthworks should be achieved.
Construction Materials and Structures
1. Construction for productive purposes
Wall: Reinforced concrete (or masonry brick, block) is used in the materials of the structures between fundamentals to the window, whereas those above the window are constructed by profiled steel sheets.
Door and window: PVC steel doors and windows and normal light steel doors are applied except those in substations or with dust and sound prevention.
Floor: Various floors are designed based on load of different floor like storage, workshop, yard, and other ground.
Roof: Unorganized free drainage and increased roof slope is applied to facilitate and promote drainage.
2. Construction for nonproductive purposes
Door and window: PVC steel doors and windows.
Floor: Fine concrete aggregate surface is generally applied, whereas special floors such as those in laboratories or toilets are made of antislip tile surface.
Roof: Organized drainage with UPVC pipes.
Features of Main Construction Buildings
1. C&D waste pretreatment workshop
The C&D waste pretreatment workshop is built on the basis of the initial height difference on the site and is constructed using fully enclosed structure. Crushing and grading of C&D waste are performed in this workshop.
2. Storage of recycled fine aggregate
Enclosed circular structure is applied in storage house of recycled fine aggregate. The upper part is composed of six steel plates of diameter 10 m, whereas the lower part are two layers of reinforced concrete frame structure. The first layer is used as power distribution room and the other is used as batching room.
3. Recycled aggregate storage house
Reinforced concrete retaining walls are applied around and below the house while light steel structure is used on the upper portion of the house.
4. Recycled aggregate processing workshop
Product processing and curing sections are the two main processes in this workshop, which are of concrete frame structure. Concrete roof with solar panel and hot water supply system is applied in product processing section while several curing rooms are separated in the curing section.
5. Laboratory
The laboratory, which is also the technical and production scheduling control center in this project, is constructed by two layers of reinforced concrete and infilled walls. The first floor is the detection station for raw materials and product quality with different manufacturing, curing, and detecting equipment, and the second floor is product researching laboratory.
6. Production control center
Production control center is constructed by two layers of reinforced concrete and infilled walls. The first floor is used as canteen and bath room and the second floor is for production scheduling and office.
7. The buildings of production control center and laboratory are of energy conservation design.
Structure
1. Seismic fortification
The seismic fortification intensity is set as 6 degree for the region, and the basic earthquake acceleration value designed is 0.05 g.
2. Design load adopted
Basic wind pressure: 0.45 kN/m2.
Load of productive structures is provided by the engineering process.
Load of nonproduction workshops are adopted according to Load code for the design of building structures (GB 50009-2012).
3. Structure selection and application
a. The C&D waste pretreatment workshop is applied with the reinforced concrete column frame-bent structure with light steel roofs.
b. The recycled aggregate storage house is applied with the reinforced concrete column frame-bent structure with light steel roofs and retaining wall around it.
c. The storage house of recycled fine aggregate is applied with steel plate silo structure, which is sustained by two layers of cast-in-site reinforced concrete framework.
d. The mortar and concrete workshop is applied with the reinforced concrete column frame-bent structure with light steel roofs.
e. The recycled aggregate production workshop is applied with the reinforced concrete column frame-bent structure with light steel roofs.
f. The cementing material production workshop is applied with the reinforced concrete column frame-bent structure with light steel roofs.
g. The control center is applied with three layers of cast-in-site reinforced concrete framework.
h. The laboratory is applied with two layers of cast-in-site reinforced concrete framework.
i. The mechanic maintenance workshop, warehouse, substation, and guard are applied with one layer of cast-in-site reinforced concrete framework.
j. The car washing and water treatment buildings are applied with cast-in-site reinforced concrete framework structure.
k. The C&D waste storage yard is applied with the reinforced concrete column frame-bent structure with light steel roofs.
There are two entrances (primary and secondary entrance) in the project to shunt the traffic flow and people. The main entrance is located in the southwest of the plant, the width of entrance is not less than 14 m and is connected with the planned roads. The road in the plant is the circular road around the main producing workshop. The main roads are 14–10 m wide and the turning radius is not less than 9 m. The other roads are 7–4 m wide and the turning radius is not less than 6 m. The roads are all city roads with road traffic stones and gullies for drainage. The cross slope of the road is 1% and the longitudinal slope is not less than 0.3%.
Table 8.35
Main Index of General Layout of This Project for Annual Treatment Scale of 1,000,000 t of Construction and Demolition Waste in Nantong City Project
| No. | Item | Unit | Quantity | Note |
| 1 | Land occupation of this project | m2 | 107,060 | |
| 2 | Land occupation of buildings and structures | m2 | 34,653 | Not including the area of storage yards |
| 3 | Construction area of buildings and structures | m2 | 41,790 | Not including the area of storage yards |
| 1) | Administrative auxiliary facilities | m2 | 3,069 | |
| 2) | Industrial buildings | m2 | 38,721 | |
| 4 | Area of storage yards | m2 | 15,826 | |
| 5 | Building density | % | 32 | |
| 6 | Floor area ratio | 0.39 | ||
| 7 | Building coverage | % | 47 | Including the area of storage yards |
| 8 | Road area | m2 | 20,880 | |
| 9 | Landscaping area | m2 | 21,410 | |
| 10 | Landscaping ratio | % | 20 | |
| 11 | Parking space | 12 | Small | |
| 12 | Length of bounding walls | m | 1,250 | |
| 13 | Earthwork volume | m3 | ||
| 1) | Amount of excavation | m3 | ||
| 2) | Amount of filling | m3 | 43,000 |
Cement concrete is the main material of the roads. The structure is 22 cm of C30 concrete layer, 30 cm of gravel fundamental layer, and 5 cm of sand-gravel cushion.
The main index of general layout of this project is listed in Table 8.35.
Main Buildings and Construction Structure in Nantong City Project
Main buildings and construction structure in this project for annual treatment scale of 1,000,000 t of C&D waste are listed in detail in Tables 8.36–8.38.
Table 8.36
Main Buildings and Construction Structure in Nantong City Project (1–5)
| Item | C&D Waste Storage Yard | C&D Waste Pretreatment Workshop | Recycled Aggregate Storage House | Recycled Fine Aggregate Storage House | Concrete Workshop | |
| No. | 1 | 2 | 3 | 4 | 5 | |
| aConstruction grade | V | V | V | V | V | |
| aFireproof endurance rating | II | II | II | II | II | |
| bSeismic precautionary intensity | 6 degree | 6 degree | 6 degree | 6 degree | 6 degree | |
| Main structure | Reinforced concrete column frame-bent structure | Reinforced concrete column frame-bent structure | Reinforced concrete column frame-bent structure | Reinforced concrete column frame-bent structure | Reinforced concrete column frame-bent structure | |
| Storey, total height | One, 9.6 m | One, 14 m | One, 14 m | Three, 27 m | Four, 24 m | |
| Base area (m2) | 6768 | 3564 | 3060 | 1260 | 300 | |
| Total construction area (m2) | 6768 | 3564 | 3060 | 3840 | 309 | |
| Structure and decoration | Wall | Color steel plate, concrete retaining wall | Color steel sandwich panel | Color steel plate, concrete retaining wall | Concrete | Concrete |
| Ground | Concrete | Concrete | Concrete | Concrete | Concrete | |
| Floor | Concrete | Concrete | ||||
| Roof | Color steel sandwich panel | Color steel sandwich panel | Color steel sandwich panel | Color steel sandwich panel | Color steel sandwich panel | |
| Door | Steel | Steel | Steel | Steel | Steel | |
| Window | PVC steel | PVC steel | ||||
Table 8.37
Main Buildings and Construction Structure in Nantong City Project (6–10)
| Item | Mortar Workshop | Cementing Material Workshop | Cementing Material Warehouse | Recycled Aggregate Production Workshop | Car Washing and Water Treatment | |
| No. | 6 | 7 | 8 | 9 | 10 | |
| aConstruction grade | V | V | V | V | V | |
| aFireproof endurance rating | II | II | II | II | II | |
| bSeismic precautionary intensity | 6 degree | 6 degree | 6 degree | 6 degree | 6 degree | |
| Main structure | Reinforced concrete column frame-bent structure | Reinforced concrete column frame-bent structure | Reinforced concrete column frame-bent structure | Reinforced concrete column frame-bent structure | Reinforced concrete structure | |
| Storey, total height | Four, 24 m | Four, 24 m | Three, 27 m | One, 8.4 m | ||
| Base area (m2) | 3748 | 1440 | 850 | 9775 | 528 | |
| Total construction area (m2) | 4460 | 1780 | 2600 | 8641 | ||
| Structure and decoration | Wall | Concrete | Color steel plate | Upper: Steel | Color steel sandwich panel | Reinforced concrete |
| Lower: Porous concrete block concrete | ||||||
| Ground | Concrete | Concrete | Concrete | Concrete | Reinforced concrete | |
| Floor | Concrete | Concrete | Reinforced concrete | |||
| Roof | Color steel sandwich panel | Color steel sandwich panel | Concrete | Concrete, color steel sandwich panel | ||
| Door | Steel | Steel | Steel | Steel | ||
| Window | PVC steel | PVC steel | PVC steel | PVC steel | ||
Table 8.38
Main Buildings and Construction Structure in Nantong City Project (11–16)
| Item | Mechanic Maintenance | Substation | Laboratory | Production Control Center | Guard (I) | Guard (II) | |
| No. | 11 | 12 | 13 | 14 | 15 | 16 | |
| aConstruction grade | V | V | V | ||||
| aFireproof endurance rating | II | II | II | II | II | II | |
| bSeismic precautionary intensity | 6 degree | 6 degree | 6 degree | 6 degree | 6 degree | 6 degree | |
| Main structure | Frame structure | Frame structure | Frame structure | Frame structure | Frame structure | Frame structure | |
| Storey, total height | One, 8 m | One, 5.5 m | Two, 8 m | Three, 11.6 m | One, 3.6 m | One, 3.6 m | |
| Base area (m2) | 840 | 315 | 1008 | 1008 | 20 | 25 | |
| Total construction area (m2) | 840 | 315 | 2016 | 3024 | 20 | 25 | |
| Structure and decoration | Wall | Reinforced concrete | Reinforced concrete | Porous concrete block | Porous concrete block | Porous concrete block | Porous concrete block |
| Ground | Reinforced concrete | Reinforced concrete | Concrete, ground tile | Concrete | Concrete | Concrete | |
| Floor | Reinforced concrete | Reinforced concrete | Reinforced concrete | Reinforced concrete | Reinforced concrete | Reinforced concrete | |
| Roof | Reinforced concrete, ground tile | Reinforced concrete, ground tile | |||||
| Door | Steel | Steel | PVC steel | PVC steel | PVC steel | PVC steel | |
| Window | PVC steel | PVC steel | PVC steel | PVC steel | PVC steel | PVC steel | |
| Inner wall | Inner wall coatings | Inner wall coatings | Inner wall coatings | Inner wall coatings | Inner wall coatings | Inner wall coatings | |
| Outer wall | Outer wall coatings | Outer wall coatings | Outer wall coatings | Outer wall coatings | Outer wall coatings | Outer wall coatings | |
The process of construction waste disposal, production of recycled aggregate and premixed mortar is demonstrated in Figs. 8.32 and 8.33, respectively.
An overview of the engineering project is demonstrated in Fig. 8.34.
8.4.2.5. Design of Electronic Control System
General Proposal of Electronic Control System
The core control unit of the electronic control system is PLC control of Siemens S7-300 series. The whole system includes PLC network operating system, touch screen and intelligent host monitoring systems, industrial TV monitoring systems, centralized control, and decentralized stand-alone control system (divided into three module control system, shown in Figs. 8.36–8.38). The general structure of the system is shown in Fig. 8.35. The control functions include “Environmental protection control without secondary dust generation,” “intelligent production line process control,” “intelligent diagnostic control of key devices,” and “industrial system control.”
PLC network operating system is applied with the structure of one main station and multiple substations. The main station is settled in the central control room, and the substations are located in different sections of the combined production line (for instance, the pretreatment section, fine crushing and sorting section, and recycled powder material production section). The data exchange between the main station and substations is achieved using the network communication.
Control and monitoring of the whole production line can be operated in the main station, where countercurrent sequence start control and downstream parking control can also be performed. In substations, the control and monitoring of different modules and sections can be achieved. Operation boxes are equipped for debugging and maintenance of each module.
Control of each device and its data collection can be obtained by PLC control through sensors. Physical and mathematical models can be established according to process requirements to achieve the best control effect.
PLC control system is capable of remote diagnostic via the observation and analysis of each input port, output port, and intermediate parameters among the electronic control system. Completely intelligent surveillance monitoring can be achieved in this system.
Each substation is equipped with touch screens, whereas host machine is set in the main station. Dynamic display of the equipment operating status and parameters in each station is reflected on the touch screen (voltage, current, bearing temperature, humidity, vacuum, etc.). Dynamic display of the operating status and parameters of equipment in all production lines equipment can be reflected on the PC screen in the master station.
Table 8.39
Main Products Manufactured in Nantong City Project
| Product | Recycled Powder Material | Recycled Fine Sand | Recycled Product |
| Annual production capacity (t) | 150,000 | 250,000 | 100,000 |
Table 8.40
Main Features and Index of Recycled Building Materials
| Product | Size (mm) | Performance Index | Standard Consulted |
| Recycled micropowder material | 0–0.075 | Fineness (45 μm square mesh residue) <20% | GB/T 1596-2005 |
| Water content <1.0% | |||
| Water requirement ratio <105% | |||
| Loss on ignition <8.0% | Fly ash used for cement and concrete | ||
| 7 d activity >60% | |||
| 28 d activity >70% | |||
| Recycled fine sand | 0.16–2.36 | Micropowder content <3% | GB/T 25176-2010 |
| Clay lump content <0.5% | |||
| Light material content <0.5% | |||
| Firmness <8% | Recycled fine aggregate for concrete and mortar | ||
| Crushing index <25% | |||
| Apparent density >2450 kg/m3 | |||
| Fineness module 1.90–2.60 | |||
| Recycled fine aggregate | 0–5 | Micropowder content <7% | GB/T 25176-2010 |
| Clay lump content <1% | |||
| Light material content <1% | |||
| Firmness <10% | Recycled fine aggregate for concrete and mortar | ||
| Crushing index <25% | |||
| Apparent density >2350 kg/m3 | |||
| Fineness module 2.30–3.00 | |||
| Recycled aggregate | 5–15 | Micropowder content <1% | GB/T 25177-2010 |
| Clay lump content <0.5% | |||
| Recycled aggregate | 15–22 | Water absorption <5% | |
| Impurities <1% | Recycled coarse aggregate for concrete | ||
| Recycled aggregate | 22–31.5 | Firmness <10% | |
| Crushing index <12% | |||
| Apparent density >2350 kg/m3 |
Terminal of the industrial TV monitoring system is located in the central control room. The complete set of equipment includes display screen, image segmentation, camera, optical terminal, and cable. Either centralized control in central control room and centralized control or independent, decentralized local control is applicable.
8.4.2.6. Products
The main products manufactured in this project include recycled aggregate, recycled powder materials, recycled sand, and gravel. Recycled aggregate is the primary intermediate product and can be used as raw materials for the production of recycled powder materials and other products. Meanwhile, it can also be sold directly as finished products based on the real market condition. Main products manufactured in this project are listed in Table 8.39.
Main products are recycled micropowder material and recycled fine sand. All the products should meet the regulation that is listed in detail in Table 8.40.
Recycled micropowder is the recycled material produced after the grinding of waste clay and waste cement debris in C&D waste, the particle size of which is less than 0.075 mm. Recycled micropowder is of hydration activity and can be used as supplementary cementitious material. The activity index reaches 70% and the surface area exceeds 410 m2/kg, meaning it can partially replace the cement or fly ash in concrete. It is also suitable as a kind of cement admixture, which can effectively reduce the energy consumption and save the cost of cement.
Dry sand is the main raw material in dry mortar production. River sand and manufactured sand should generally be dried in the process. The less than 1% water content of recycled fine sand avoids the drying procedure and thus save the project investment. Meanwhile, the circular particle size of recycled fine sand is suitable as the raw material of mortar production.
8.4.2.7. Water Engineering
Water Supply
Production water (except that outside the mixing station) and domestic water is directly supplied from the municipal water supply network (an inlet pipe DN150, water pressure ≥0.25 MPa). To ensure the reliability of production water, a 150-t homogenize tank is set near the product manufacturing workshop. The production water in this plant is delivered by the pump next to the tank.
Table 8.41
Detailed Amount of Water Used in Nantong City Project
| No. | Water Used | Amount of water (m3) | Pressure (MPa) | Note | ||
| Day & Night | Average (h) | Maximum (h) | ||||
| 1 | Production water | |||||
| 1.1 | Concrete workshop | 88 | 8.8 | 8.8 | 0.25 | 2 shift production |
| 1.2 | Washing | 6.4 | 0.64 | 0.64 | 10% water supply | |
| 1.2.1 | Washing of mixing station | 16 | 1.6 | 1.6 | 0.2 | Recycled use |
| 1.2.2 | Washing of mixing vehicle | 48 | 4.8 | 4.8 | 0.4–0.5 | Recycled use |
| 1.3 | Product manufacturing workshop | 60 | 4 | 4 | 2 shift production | |
| 1.4 | Hot water for product curing (85°C) | 53 | 2.2 | 2.2 | 3 shift production | |
| 1.5 | Curing water (sprinkling) | 13 | 1.63 | 1.63 | 1 shift production | |
| 1.6 | Laboratory | 13 | 0.82 | 2.04 | 2 shift production | |
| Subtotal | 233.4 | 18.1 | 19.4 | |||
| 1.7 | Unforeseen demand: 10% | 23.4 | 1.81 | 1.94 | ||
| Total | 256.8 | 20.0 | 21.4 | |||
| 2 | Domestic water | |||||
| 2.1 | 42 | 1.75 | 4.38 | 300 people/day | ||
| 2.2 | Subtotal | 42 | 1.75 | 4.38 | ||
| 2.3 | Unforeseen demand: 10% | 4.2 | 0.18 | 0.44 | ||
| Total | 46.2 | 1.93 | 4.82 | |||
| 3 | Firewater | |||||
| 3.1 | Outdoor | 144 | 72 | 72 | Once, 2 h | |
| 3.2 | Indoor | 108 | 54 | 54 | Once, 2 h | |
| Total | 252 | 126 | 126 | |||
The automatic water softener is equipped for the disposal of hot water in product curing section to reduce the hardness of water.
Hot Water
The main methods of preparation of hot water for product curing are: the solar heat collector + air-source heat pumps + hot water tank set on the roof of recycled aggregate production workshop, with heating tubes inside the tank for auxiliary heating.
The preparation of hot bathing water is similar to that of hot water for product curing, the main methods are: the solar heat collector + air-source heat pumps + hot water tank set on the roof of production control center.
The detailed amount of water used in listed in Table 8.41.
Drainage Engineering
1. The combined sewage and wastewater discharged from the domestic facilities after being treated through septic tanks, along with the kitchen water with oil after being treated through the oil separating tank, is discharged into the municipal sewage systems on the south of the plant with an emission flow rate of about 41 m3/d.
2. The car washing waste water is recycled for reuse after solid–liquid separation to save water.
3. The rainwater and washing water in the production field is collected through the drainage ditch and discharged into the riverway in the west side of the plant.
4. No production waste water is discharged during the whole production process.
5. The rainwater is calculated using the rainstorm intensity calculation formula in Nantong city: q = 2007.34 (1 + 0.752 lgp)/(t + 17.9)0.71.
P = 2.0 (years), t = 15 min, ψ = 0.60, the discharging amount is about 1323 L/S.
Other Materials and Facilities Involved in Water Engineering
1. Pipes
2. Facilities
a. Stable high-pressure water pump set for outdoor fire fighting
Main pump: XBD3/20-KDB (two pumps, one for backup)
Q = 20 L/S, H = 30 m, P = 11 kW.
Pressure-Stabilizing Pump: XBD3.2/5-KDB (two pumps, one for backup)
Q = 5 L/S, H = 32 m, P = 4 kW.
Scale of diaphragm air pressure tank: SQL%%C400 × 1400–1.6 V = 70L
b. Water pump set for indoor fire fighting
XBD5.4/15-DL (two pumps, one for backup)
Q = 15 L/S, H = 54 m, P = 15 kW.
c. Roof stainless steel firewater tank (12 t, 3 × 2.5 × 2 m) One
d. Hot water for product curing
Flat-plate solar collector: 300 m2
Air-source heat pump set:
MWV-L200T2/S One.
MWV-L1200T2/S One.
8.25-t stainless steel heating water tank (2 × 2.5 × 2 m) One.
33-t stainless steel heat preservation water tank (4 × 5 × 2 m) One.
Power: 105 kW, 380 V/3N-50 Hz.
e. Hot bathing water preparation
Flat-plate solar collector: 150 m2
Air-source heat pump set: FM-20Q (R) One.
15-t stainless steel heat preservation water tank (3 × 2.5 × 2.5 m) One.
Power: 46.3 kW, 380 V/3N-50 Hz.
f. Automatic water softener: JDRF-S180T-600/J942T-600 One
Q = 4–6 t/h Resin loading: 375 kg.
8.4.2.8. Dust Prevention and Removal
The main dust pollutant in the production line of material manufacturing process is the inorganic mineral dust produced in the transportation section. To control its emissions, series of measures are taken, including closed material storage reservoir, pneumatic conveying of powder in pipes strictly sealed, application of pipe screw conveyors, and belt conveyor (with cover) used for bulk material transportation while minimizing the gap between the speed and transfer points.
Table 8.42
Dust Controlling Devices Involved in Nantong City Project
| Dust Collecting Point | Dust Catcher | QTY | Air Volume (m3/h) | Emission Concentration (mg/m3) | Emission Amount | Note | |
| kg/h | kg/d | ||||||
| Pretreatment | Bag filter | 6 | 12,000 | ≤30 | 2.16 | 30.24 | |
| Pretreatment | Bag filter | 6 | 3000 | ≤30 | 1.35 | 18.9 | |
| Recycled fine aggregate warehouse | Bag filter | 8 | 3000 | ≤30 | 0.45 | 6.3 | 2 for regular use |
| Mortar, concrete | Bag filter | 2 | 3000 | ≤30 | 0.18 | 2.52 | |
| Recycled aggregate production | Bag filter | 2 | 3000 | ≤30 | 0.18 | 2.52 | |
| Cementing material | Bag filter | 1 | 60,600 | ≤30 | 1.818 | 43.63 | |
| Cementing material | Bag filter | 1 | 12,000 | ≤30 | 0.36 | 8.64 | |
| Cementing material | Bag filter | 6 | 3000 | ≤30 | 0.45 | 10.8 | 5 for regular use |
| Total | 32 | 6.95 | 123.55 | ||||
1. Wet construction work should be applied while prevention caps are equipped to prevent the diffusion of dusts.
2. Dust catchers are set in the pretreatment and screening sections.
3. Pneumatic conveying equipment are used for the unloading of bulk powder materials, sealed pipes are used throughout the whole process.
4. Bag filters are equipped on top of the powder material warehouse.
5. Spiral pipe conveyors are used for the powder materials transportation.
6. Bag filters are equipped in the blending device of recycled product manufacturing section.
7. Dust prevention caps are covered on the belt conveyors.
8. Enclosed structures are applied in the pretreatment workshops and recycled aggregate warehouses.
9. Bag filters are equipped on top of the recycled aggregate warehouse.
10. The material drop distance should be minimized.
Thirty-two dust catchers (for 32 dust production points) are set throughout the plant and the dust collecting efficiency can be up to 99.5% and the dust emission is less than 30 mg/Nm3. The dust controlling devices involved in this project are listed in Table 8.42.
8.4.2.9. Labor Organization
The shift arrangement in this project is listed below:
252–300 annual working days;
The main production posts: two shifts, three shifts;
The auxiliary production posts: one-shift;
Eight working hours per shift.
Information of labor force involved in this project is listed in detail in Table 8.43.
8.4.3. Utilization Center of Recycled Resources Produced by C&D Waste in Suzhou City
8.4.3.1. General Introduction
Annual generation amount of C&D waste in Suzhou city is about 5 million tons. The annual handling capacity of this project is 1,000,000 t while the generation of recycled products is about 900,000 t.
8.4.3.2. Main Structures and Processes
Main structures including office buildings and manufacturing workshops are listed in Table 8.44.
Table 8.43
Information of Labor Force Involved in Nantong City Project
| Department | Labor | |||||
| Day Shift | Morning Shift | Swing Shift | Night Shift | Nonshift | Total | |
| C&D waste storage | 1 | 1 | 1 | 1 | 1 | 5 |
| C&D waste pretreatment | 11 | 11 | 6 | 28 | ||
| Recycled aggregate warehouse | 1 | 1 | 1 | 3 | ||
| Recycled fine aggregate warehouse | 1 | 1 | 1 | 3 | ||
| Recycled aggregate production | 8 | 8 | 6 | 22 | ||
| Product curing | 2 | 2 | 2 | 2 | 8 | |
| Mortar | 8 | 8 | 6 | 22 | ||
| Concrete | 4 | 4 | 4 | 12 | ||
| Cementing material | 5 | 5 | 5 | 5 | 20 | |
| Cementing material storage house | 3 | 3 | 3 | 3 | 12 | |
| Mechanic, auto maintenance | 5 | 2 | 2 | 2 | 2 | 13 |
| Storage yard for finished products | 2 | 2 | 2 | 1 | 1 | 8 |
| Technical (including experiments) | 6 | 1 | 1 | 1 | 9 | |
| Guard | 1 | 2 | 2 | 2 | 2 | 9 |
| Car washing and water pool | 1 | 1 | 1 | 3 | ||
| Driver (forklift) | 2 | 7 | 7 | 2 | 6 | 24 |
| Driver (mortar and concrete vehicle) | 5 | 5 | 5 | 5 | 20 | |
| Logistics | 2 | 4 | 2 | 1 | 1 | 10 |
| Financing | 3 | 3 | ||||
| Administration | 4 | 2 | 2 | 8 | ||
| Management | 3 | 3 | ||||
| Total | 35 | 70 | 68 | 19 | 53 | 245 |
Table 8.44
Main Structures Including Office Buildings and Manufacturing Workshops for Annual Handling Capacity of 1,000,000 t Construction and Demolition Waste in Suzhou City Project
| No. | Item | Land Occupation (m2) | Construction Area (m2) | Note |
| 1 | Comprehensive office building | 400 | 1200 | 3 floors |
| 2 | Mechanical repair workshop | 210 | 210 | 1 floor |
| 3 | Distribution room | 120 | 120 | 1 floor |
| 4 | Fire-fighting pool and pump house | 92 | 12 (pump houses) | Pool area 480 m3 |
| 5 | Guard room | 24 | 24 | 1 floor |
| Metering room | 24 | 24 | 1 floor | |
| 6 | Exhibition area for recycled building materials | 1566 | ||
| 7 | Exhibition area for finished building materials | 11,926 | ||
| 8 | Storage area for raw materials | 12,950 | ||
| 9 | Pretreatment and brick production workshop | 5400 | 5400 | Partially exposed basement, 12 m height |
| 10 | Recycled mortar production workshop | 4500 | 4500 | Partially exposed basement, 12 m height |
Comprehensive disposal of C&D waste in this project includes unloading, pretreatment (crushing, magnetic and air sorting, screening, etc.), manufacturing of and curing of recycled blocks and bricks, production of recycled cement mortar, and building materials. C&D waste is sent into the storage area for unloading and stacking. Feeders and enclosed belt conveyors are equipped in this section, whereas excavators are used for loading of raw materials into feeders and transporters, in which C&D waste is conveyed to the pretreatment section. The first process is crushing; materials coming out of the outlet are classified into different sizes so that they can meet the demands for the subsequent recycled products. The crushed materials are removed of iron and metal substances and then sent for air sorting, where light materials like plastics and wood are separated. Materials are classified into five different groups based on their size through the vibrating screener (≤4.75, 4.75–9.5, 9.5–20, 20–31.5, and ≥31.5 mm). These aggregates are sent to isolated storage pits through belt conveyors. The whole process is demonstrated in Fig. 8.39.
Materials of size below 4.75 mm are fine aggregates and can be used as raw materials for recycled cement mortar, blocks, and bricks production. Materials of size between 4.75 and 9.5 mm are coarse aggregates and can be used as raw materials for recycled blocks. Materials of size between 9.5 and 20 mm, 20 and 31.5 mm, and above 31.5 mm can be used as road materials like stable layer of water below the pavement.
Process of manufacturing of recycled blocks and bricks is introduced below and demonstrated in Fig. 8.40.
The crushed C&D waste is used as raw materials and is mixed with certain ratio of water, cement, and paint. Then it is sent through an automatic process line including proportioning, mixing, molding, curing, splitting, and stacking. Main manufacturing equipment are proportioning and mixing process line, concrete product molders, conveyors, curing plates, and molders for recycled products.
8.4.3.3. Material Balance
The material balance of the whole utilization center of recycled resources produced by C&D waste in Suzhou city is demonstrated in Fig. 8.41.
8.4.3.4. Layouts and Land Coverage
Land coverage of unloading and storage area is 12,950 m2 in which the hopper and enclosed belt conveyors are equipped. Excavators are used as loading machines for waste and materials. Land coverage of pretreatment and brick manufacturing workshop is 90.00 × 60.00 m, which is separated into pretreatment area, classified storage area of aggregate, brick manufacturing facilities area, and steam curing area. The pretreatment area is about 40.00 × 30.00 m in size with crushers, magnitude and airblow separators, vibrating screens, and belt conveyors.
The temporary storage area consisted of five separated storage pits and its coverage area is about 45.00 × 15.00 m. (1) Storage pit for aggregate of size less than 4.75 mm, land coverage 5.00 × 15.00 m, storage volume 200 m3, (2) Storage pit for aggregate of size 4.75–9.5 mm, land coverage 7.50 × 15.00 m, storage volume 300 m3, (3) Storage pit for aggregate of size 9.75–20.00 mm, land coverage 10.00 × 15.00 m, storage volume 400 m3, (4) Storage pit for aggregate of size 20.00–31.50 mm, land coverage 12.50 × 15.00 m, storage volume 500 m3, (5) Storage pit for aggregate of size larger than 31.50 mm, land coverage 10.00 × 15.00 m, storage volume 400 m3.
Land coverage of brick manufacturing workshop is 45.00 × 30 m, in which additive storage house, mixing system, twin-shaft mixer, brick producer, stacker, and composite carts are equipped. Land coverage of steam curing workshop is also 45.00 × 30 m, in which steam curing kiln and boilers are installed. Oil-fired boilers are used of which the steam volume is 2 t/h and the steam pressure is 0.20–0.25 MPa.
Table 8.45
Comparison of Two Dust Removal Methods
| Bag Filter | Micron Dry Fog Spraying | |
| Energy cost | High | Low, less water consumption |
| Operation | Complex | Easy |
| Land coverage | Large | Small |
| Installation | Heavy machines, large size of wind tubes, complex installation | Easy |
| Investment | Large | Small |
| Removal effect | Low for small particles | High for comprehensive treatment, especially PM 2.5 |
Table 8.46
Main Dust Removal Facilities Involved
| No. | Item | Style | QTY | Note |
| 1 | Centrifugal fan | Gas flow 2000 m3/h, air pressure 400–600 Pa, rotation speed 1400 r/min, N = 2.2 kW | 3 | |
| 2 | Pulse bag filter | N = 5 kW | 1 | |
| 3 | Flue pipe | 320 × 120 mm | 320 | PVC |
| 160 × 120 mm | 480 | PVC | ||
| φ400 mm | 120 | Galvanized steel | ||
| 4 | Cover | 1000 × 1000 mm | 12 | Stainless steel |
| 5 | Micron dry fog dust removal system | Sauter mean diameter SMD: 1–10 μm, with host device, gas tank, electric controlling system, spray tank, heating and insulation systems | 2 | |
| 6 | Remote fog spraying system | Approximately 50–100 μm | 2 |
Waste, materials, and aggregate are transferred to recycled mortar workshop from pretreatment section through belt conveyor, the land coverage of this workshop is 90.00 × 50.00 m, in which ingredients storage house, dryers, and mixers are equipped. All the transportation facilities are fully enclosed. Meanwhile, coverage of storage house of products and demonstration area of recycled products is 11,926 and 1566 m2.
8.4.3.5. Dust Controlling System
Dust controlling system is also an important section in this project. The main process is “micron dry fog spraying at initial + bag filter at terminal,” the comparison of the two methods is listed in Table 8.45. The equipment used includes centrifugal blower (CF-11, 2000 m3/h, pressure 400–600 Pa, rotation speed 1400 rpm, N = 2.2 kW), pulse-jet bag series dust filter (N = 5 kW), micro dry fog spraying system (Sauter mean diameter SMD: 1–10 μm), and remote spray system (50–100 μm).
Main dust removal facilities involved are listed in Table 8.46, including three centrifugal fans, a pulse bag filter, flue pipes, covers, micron dry fog dust removal systems, and remote fog spraying systems.
Table 8.47A
Main Facilities Throughout the Utilization Project for Annual Handling Capacity of 1,000,000 t Construction and Demolition Waste in Suzhou City Project
| No. | Item | Style | Power (kW) | Unit | QTY |
| Feeding Section | |||||
| 1 | Excavator | Volume 1.5 m3 | 10 | Set | 2 |
| 2 | Hopper | 2800 × 2800 | Set | 3 | |
| 3 | Belt conveyors | Suit | 1 | ||
| Pretreatment Section | |||||
| 1 | Crusher | CPSJ-40 | 355 | Set | 3 |
| 2 | Electromagnetic separators | RCDD-12 | Set | 3 | |
| 3 | Winnowing | Set | 2 | ||
| 4 | Vibration sieve | 4.75 mm/9.5 mm/20 mm/31.5 mm | Set | 3 | |
| 5 | Belt conveyors | Suit | 1 | ||
| Temporary Storage Section for Aggregates | |||||
| 1 | Double flap grabbers (2 t) | DS2 (1.0) 1.2–00 | 15 | Set | 2 |
| 2 | Fabric machine (with belt) | 500 × 1000 | Set | 2 | |
| Brick Production Section | |||||
| 1 | Host computer | MT130-70S | 200 | Suit | 2 |
| 2 | Fully automatic brick molding machine | MT130-70S | Suit | 2 | |
| 3 | Lifting and transportation section | MT130-70S Matic | Suit | 2 | |
| 4 | Palletizing section | MT-CUBER-ST | Suit | 2 | |
| 5 | Ingredients mixing section | MP1500/1000 MP500/300 | Suit | 2 | |
| 6 | Automatic cart pits | MT130/70S LSC | Suit | 1 | |
| 7 | Steel pallets | 2592 pallets | Suit | 2 | |
| 8 | Wood pallets | 10,000 pallets | Suit | 2 | |
| 9 | Conservation kiln | Suit | 2 | ||
| 10 | Excavator | 2 | |||
| 11 | Forklift | 2 | |||
| 12 | Scraper | 4 | |||
| 13 | Steam boiler | 2 t/h | Suit | 1 | |
| Manufacturing Section for Recycled Mortar | |||||
| A | Raw material storage section | 170 | |||
| 1 | Aggregate warehouse | 3 m3 | 8 | ||
| 2 | Accessories warehouse | 2.5 m3 | 5 | ||
| 3 | Feeding belt | Variable frequency, B = 600 mm | Set | 3 | |
| Table Continued | |||||
| No. | Item | Style | Power (kW) | Unit | QTY |
| B | Drying section | Tumble dryer, D = 1.5 m | Set | 1 | |
| C | Screening and lifting system for thermal materials | ||||
| 1 | Screw conveyor | Set | 1 | ||
| 2 | Vibratory screening machine | D = 2.5 mm | Set | 1 | |
| 3 | Central chain bucket elevator | Set | 1 | ||
| D | Classified sieving machine | 0.3 mm/0.6 mm/1.2 mm | Set | 1 | |
| E | Intensive mixer | Evenness 1:100,000 | Set | 1 | |
| F | Pneumatic system | Suit | 1 | ||
| G | Electronic controlling system | Suit | 1 | ||
| H | Dust removal section | Suit | 1 | ||
| Corollary Facilities | |||||
| 1 | Crane | 8 t | 13 | Set | 1 |
| 2 | Loader | Volume 5 m3 | 2 | ||
| 3 | Dump truck | 12 t | 4 | ||
| 4 | Mobile crushing facility | Disposal capacity 80 t/h, gas/electric | 80 | Set | 1 |
| 5 | Mobile screening facility | Disposal capacity 80 t/h, gas/electric | 50 | Set | 1 |
| Mechanic Repair Facilities | |||||
| 1 | Lathe | CD6140 A | Set | 1 | |
| 2 | Bench drill | Z520-2 ф12.7 | Set | 1 | |
| 3 | Grinder | S35L-250 | Set | 1 | |
| 4 | Welder | BX3-550 | Set | 1 | |
| 5 | Vise | Set | 2 | ||
| 6 | Gas welding system | Set | 1 | ||
| 7 | Charger | GCA804/0–160V | Set | 1 | |
| 8 | Planer | BD6063 | Set | 1 | |
Table 8.47B
Main Facilities Throughout the Utilization Project for Annual Handling Capacity of 1,000,000 t Construction and Demolition Waste in Suzhou City Project
| No. | Item | Style/Specification | Quantity | Note |
| 1 | Centrifugal air blower | CF-11, flow rate 2000 m3/h, air pressure 400–600 Pa, rotation speed 1400 r/min, N = 2.2 kW | 3 | 2 for use, 1 for backup |
| 2 | Pulse bag filter | N = 5 kW | 1 | |
| 3 | Flue pipe | 320 × 120 mm | 320 | PVC |
| 160 × 120 mm | 480 | PVC | ||
| φ400 mm | 120 | Galvanized steel | ||
| 4 | Collecting cover | 1000 × 1000 mm | 12 | Stainless steel |
| 5 | Micro dry atomized dust suppression system | Atomization particle size 1–10 μm, host machine, gas tank, electric control system, spray tank assembly, sprayer with universal joints, electric tracer, and heat preservation system | 2 | |
| 6 | Remote atomized spraying system | Particle size of about 50–100 μm | 2 |
Table 8.48
Features and Quality Requirements of the Recycled Cement Mortar
| Mortar | Strength Grade | Consistency (mm) | Water Retention Rate (%) | 14 d Tensile Bond Strength (MPa) | Frost Resistance | |
| Strength Loss Ratio (%) | Mass Loss Ratio (%) | |||||
| Masonry mortar | M2.5/M5/M7.5/M10/M15 | 50–90 | ≥82 | - | ≤25 | ≤5 |
| Plastering mortar | M5/M10/M15 | 70–100 | ≥82 | ≥0.15 | ≤25 | ≤5 |
| Ground mortar | M15 | 30–50 | ≥82 | - | ≤25 | ≤5 |
8.4.3.6. Main Facilities
The main facilities throughout the utilization project are listed in Table 8.47, which include all manufacturing sections like pretreatment, storage, sorting, and recycling processes. This table can be consulted to as a reference in other C&D waste recycling and utilization projects.
8.4.3.7. Products
The final products in this engineering project can be classified into four groups: Recycled cement mortar, recycled water permeable road bricks, recycled wall blocks, and recycled roadbed materials. The features and quality requirements of the four products are introduced below.
1. Recycled cement mortar. Recycled cement mortar using the recycled fine aggregate after presorting in this project can be produced into masonry mortar, plastering mortar and ground mortar (cannot be used as ground surface layers). The features and quality requirements of the recycled cement mortar are listed in Table 8.48.
2. Recycled water permeable road bricks. These are the road bricks with large water permeability produced using the C&D waste recycled aggregate and cement as raw materials along with proper amount of admixture; they are then molded and formed with mixture of water and naturally or steam curing is finally performed. The compression strength grades of the recycled water permeable road bricks are listed in Table 8.49.
Features and quality requirements of the water-permeable road brick produced by recycled aggregate are listed in Table 8.50.
3. Recycled wall blocks. The nominal diameter of aggregate used for recycled wall blocks should be less than 10 mm and the requirements are the same as those discussed earlier. The compression strength of recycled wall blocks is listed in Table 8.51.
Table 8.50
Features and Quality Requirements of the Water-Permeable Road Brick
| Item | Features and Requirements | |
| Maximum projection size of frontal adhesive skin and defect parts (mm) | ≤10 | |
| Maximum projection size of losing angle/corner (mm) | ≤15 | |
| Crack | Maximum projection size of the nonpenetrating cracks (mm) | ≤10 |
| Penetrating cracks | Not allowed | |
| Delamination | Not allowed | |
| Variegated color, color deviation | Not obvious | |
| Abrasion resistance | Pit length not large than 38 mm | |
| Water-retaining property | Not less than 0.6 g/cm2 | |
| Water permeation coefficient | Water permeation coefficient (15°C) ≥ 0.01 cm/s | |
| Frost resistance | Strength loss should be less than 20.0% after 25 freezing–thawing cycles | |
Table 8.52
Features and Quality Requirements of the Recycled Wall Blocks
| Item | Features and Requirements | |
| Minimum wall thickness (mm) | As load-bearing walls | ≥30 |
| Not as load-bearing walls | ≥16 | |
| Rib thickness (mm) | As load-bearing walls | ≥25 |
| Not as load-bearing walls | ≥15 | |
| Defected corner | Number | ≤2 |
| Minimum projection size in three directions (mm) | ≤20 | |
| Accumulative extended projection size of cracks (mm) | ≤20 | |
| Bend (mm) | ≤2 | |
| Frost resistance index (D25) | Mass loss ratio (%) | ≤5 |
| Strength loss ratio (%) | ≤25 | |
Features and quality requirements of the recycled wall blocks are listed in Table 8.52.
4. Roadbed materials. Those particles of size larger than 31.5 mm coarse aggregate can be used as the roadbed materials like the water stable layer under the sidewalk, or the lower cushion of the roadbed. The compression strength should meet the demand regulated in Technical guidelines for construction of highway road bases (JTJ034-2000).
8.4.4. Demonstration Project of C&D Waste Resource Reuse in Xi'an City
The annual disposal capacity of this project in Xi'an city is 1,000,000 t, whereas the generation of recycled aggregate, premixed mortar, cement admixture, building blocks, and wallboards products is about 500,000, 200,000, 40,000, 200,000, and 200,000 t, respectively.
Table 8.53
Main Materials Consumed in This Project for Annual Handling Capacity of 1,000,000 t Construction and Demolition (C&D) Waste in Xi'an City Project
| Product | Recycled Coarse Aggregate | Recycled Fine Aggregate | Cement Admixture | Premixed Mortar | Building Blocks | Wallboard | / |
| Annual yield | 334,000 t | 253,000 t | 40,000 t | 200,000 t | 100,000 m3 × 2 lines | 200,000 m2 | / |
| Total | |||||||
| Coarse aggregate | 33.4 | / | 4.0 | / | 12.3 | 1.3 | 50 |
| Fine aggregate | / | 25.3 | / | 13.4 | 9.1 | 0.9 | 48.7 |
| Powder materials | / | / | / | / | 1.2 | 0.1 | 1.3 |
| Cement | / | / | / | 5.5 | 3.1 | 0.3 | 8.9 |
| Other materials | / | / | / | 1.1 | 1.9 | 0.2 | 3.2 |
| Annual C&D waste consumed | 33.4 | 25.3 | 4.0 | 13.4 | 22.6 | 2.3 | 100 |
Enclosed workshops are applied in this project while multiple dust and noise prevention method are used. For instance, the crushing workshops are located underground, finished aggregated are stored in enclosed tanks, covers are equipped around the belt conveyors, PPDC pulse bag filters are set near the dust emission spots. Meanwhile, the double-layer walls and acoustic insulating material are also added to the structure of the workshop.
The main materials consumed are listed in Table 8.53.
8.4.4.1. Engineering Technical Process
The overall disposal process is demonstrated in Fig. 8.42. The whole demonstration project includes storage field of C&D waste, recycled aggregate production workshops, premixed mortar and concrete products manufacturing workshops, storehouse for finished products, test building, office building, and residual area.
Recycled aggregates that are able to replace natural sand and gravels are produced in this project through classified crushing and screening. Some of these aggregates can be applied as raw materials in deep processing process and are used to produce premixed mortar, cement admixture, and concrete. The rest are sold as commercial aggregates to concrete mixing stations, mortar plants, and backfilling of road base. The fine powder sorted is used in concrete production while the loess screened out is directly supplied to garden department as soil.
The recycled products should meet the demand required in relevant standards, including those of aggregates, gravel, concrete units, mortar, and wallboards. General process of aggregate production is demonstrated in Fig. 8.43.
Wood, paper, plastic, and iron blocks are separated manually after C&D waste is transferred into the mixing house. Then the waste is conveyed to aggregate production workshops for deep processing. The 5–31.5 mm coarse aggregate, 0–5 mm fine aggregate and powder materials are delivered separately.
Process of premixed mortar production is demonstrated in Fig. 8.44.
Process of concrete production in this project is demonstrated in Fig. 8.45.
Fine aggregate and powder material belts are operated on and used to transport them directly to the mortar production workshop. The water content can be reduced to below 0.5% using horizontal drying machines. Cement is added based on the target strength and application.
Process of wallboard production in this project is demonstrated in Fig. 8.46.
The main facilities used in this project are crushing, screening, transporting, gravel manufacturing, drying, mortar dry premixing, and wallboard and bulk components manufacturing sections, which are listed in detail in Table 8.54.
Annual disposal capacity of construction and demolition waste is 1 million tons in this project. A stockpile for raw materials of size 175 × 110 × 15 m is equipped to ensure the continuity and stability of production. The stockage volume is 182,000 m3 and holding capacity of C&D waste is 182,000 × 1.3 = 240,000 t based on 10 m of stack height, 40 degrees of natural repose angel of C&D waste, and 1.3 t/m3 of stacking density. The land coverage area is 175 × 110 = 19,250 m2, and the stockage area is divided into four districts, namely, waste brick warehouse, waste concrete warehouse, and two mixed warehouses. All these warehouses are enclosed steel framework structures with concrete walls to prevent the rain and dust.
The land coverage area of aggregate manufacturing workshop is 120 × 50 m = 6000 m2, and that of mortar and wallboard-component combined manufacturing workshops are 100 × 50 = 5000 m2, and 220 × 70 = 15,400 m2, respectively, with a sum of 26,400 m2.
Silo structures are used in aggregate warehouses to improve land utilization ratio. The volume of the 31.5-mm coarse aggregate warehouse, for instance, is Φ40 × 20 m = 25,000 m3 (storage capacity of about 3.5 million tons), which covers an area of 1256 m2. As for other warehouses, the volume, storage capacity, and land coverage area can be consulted to Table 8.53.
Silo structures are also used in premixed mortar warehouses, which include the decorative mortar warehouse (storage capacity of 1500 t, land coverage 114 m2), masonry mortar warehouse (storage capacity of 1800 t, land coverage 266 m2), and packed decorative and masonry mortar warehouses. The detailed features are listed in Table 8.55. All these warehouses are enclosed steel framework structures with concrete walls to prevent the rain and dust.
Table 8.54
Main Facilities Involved and Their Parameters for Annual Handling Capacity of 1,000,000 t Construction and Demolition Waste in Xi'an City Project
| No. | Item | Building Dimensions (m) | Storage Volume (t) | Land Coverage (m2) | Total (m2) | Architectural Style |
| 1 | Stockpile for raw materials | 175 × 110 | 240,000 | 19,250 | 19,250 | Frame-shear wall structure |
| 2 | Aggregate manufacturing workshop | 120 × 50 | / | 6000 | 6000 | Frame-shear wall structure |
| 3 | Mortar manufacturing workshop | 100 × 50 | / | 5000 | 5000 | Frame-shear wall structure |
| 4 | Concrete product manufacturing workshop | 220 × 70 | / | 26,400 | 26400 | Frame-shear wall structure |
| 5 | Aggregate warehouse | / | / | / | 6000 | / |
| 5.1 | 3.15-mm coarse aggregate warehouse | Φ40 × 20 | 35,000 | 1256 | / | Steel silo |
| 5.2 | 10-mm coarse aggregate warehouse | Φ31.4 × 20 | 20,000 | 744 | / | Steel silo |
| 5.3 | 5-mm coarse aggregate warehouse | Φ31.4 × 20 | 20,000 | 744 | / | Steel silo |
| 5.4 | 2.5-mm coarse aggregate warehouse | Φ16 × 20 | 5200 | 201 | / | Steel silo |
| 5.5 | Earth material warehouse | Φ16 × 20 | 5200 | 201 | / | Steel silo |
| 5.6 | Fine powder warehouse | Φ16 × 20 | 5200 | 201 | / | Steel silo |
| 6 | Mortar warehouse | / | / | / | 5000 | / |
| 6.1 | Decorative mortar warehouse | Φ12 × 20 | 1500 | 114 | / | Steel silo |
| 6.2 | Masonry mortar warehouse | Φ13 × 20 | 1800 | 266 | / | Steel silo |
| 6.3 | Masonry mortar warehouse | Φ13 × 20 | 1800 | 266 | / | Steel silo |
| Table Continued | ||||||
| No. | Item | Building Dimensions (m) | Storage Volume (t) | Land Coverage (m2) | Total (m2) | Architectural Style |
| 6.4 | Packed decorative mortar warehouse | 20 × 6 | 500 | 111 | / | Frame-shear wall structure |
| 6.5 | Packed masonry mortar warehouse | 20 × 12 | 1000 | 222 | / | Frame-shear wall structure |
| 7 | Curing room | / | / | / | 18,525 | Frame-shear wall structure |
| 8 | Office, residual, gardening area | 210 × 70 | / | / | 14,700 | Frame-shear wall structure |
| 9 | Road | / | / | / | 7150 | / |
| Total land coverage | 100,875 m2 | |||||
Table 8.55
Main Facilities Involved for Annual Handling Capacity of 1,000,000 t Construction and Demolition Waste in Xi'an City Project
| No. | Main Facilities | Style | Power (kW) | Unit Cost (Dollar) | Total (Dollar) | Note |
| Recycled Aggregate Workshop | ||||||
| 1 | Vibrating feeder | ZSW490 × 110 | 15 | 12,712 | 12,712 | |
| 2 | Jaw crusher | PE900 × 1200 | 110 | 103,188 | 103,188 | |
| 3 | Simmons cone crusher | CSB240 | 240 | 209,368 | 209,368 | |
| 4 | Centrifugal impact crusher | VS I 1140 | 400 | 86,738 | 86,738 | |
| 5 | Circular vibrating screen | 2YA2160 | 30 | 20,937 | 20,937 | |
| 6 | Circular vibrating screen | 3YA2160 | 74 | 22,432 | 44,865 | 2 screens |
| 7 | Vibrating feeder | GZD200 × 120 | 4.4 | 5234 | 5234 | |
| 873.4 | 483,041 | |||||
| Premixed Mortar Workshop | ||||||
| 1 | Dryer | Horizontal | 50 | / | ||
| 2 | Mortar processing line | SHEF-20SJ | 200 | 747,742 | 747,742 | |
| 250 | 747,742 | |||||
| Wallboard-Component Combined Workshop | ||||||
| 1 | 50 blending stations × 4 | 29,910 | 119,639 | |||
| 2 | Recycled aggregate board processing line | SHEF-20BC | 120 | 747,742 | 747,742 | |
| 3 | Recycled aggregate board processing line | SHEF-10 KC | 220 | 299,097 | 299,097 | |
| 340 | 1,166,477 | |||||
| Other | ||||||
| 1 | Belt conveyor | 650 mm | 5.5 | 1,944,129/m | 74,774 | |
| 2 | 5 loaders | Wheel XG951-III | 162 | 59,819 | 299,097 | |
| 167.5 | 373,871 | |||||
| Total | 1630.9 | 2,786,086 | ||||
Table 8.56
Typical Mix Proportion of C30 Concrete
| Material | Cement | Sand | Stone | Fly Ash |
| Amount, kg/m3 | 300 | 700 | 1100 | 100 |
The land coverage of wallboard-component combined workshop is 18,525 m2.
The residual and office area is divided into office building, laboratory building, restaurant, dormitories, staff area, gardening districts, etc. The total land coverage area is 210 × 70m = 14,700 m2.
The total land coverage area of the plant in this project is 100,875 m2.
8.4.4.2. Main Facilities Involved
The main facilities involved in this demonstration project are listed in detail in Table 8.55.
8.4.4.3. Economic Performance of C&D Waste Resource Reuse in This Project
Recycled Aggregate
Studies on the recycled aggregate reveal that those produced by C&D waste are mainly cracked concrete, mortar, and bricks. Production from recycled aggregate to concrete of high strength is unpractical due to its complex components and diversified material strength, but production of C30 and below C30 concrete is feasible. Take C30 as an example (Table 8.56).
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