What technical specifications and implementation requirements must be followed during the installation and lifting of asphalt mixing plants?
As a professional enterprise specializing in the integration and service of core equipment for road engineering, Asian Construction Equipment Group Co., Ltd. (abbreviated as ACE Group) has been deeply involved in the full lifecycle service of asphalt mixing plants for many years. We understand that the installation and lifting process is a crucial prerequisite for ensuring optimal equipment performance and extending its service life. Asphalt mixing plants have complex structures and numerous heavy components; the quality of their installation and lifting directly determines subsequent production efficiency, product quality, and operational safety. Based on this, and drawing upon ACE Group’s extensive project experience, this guide has been compiled to systematically explain the core processes, technical points, and management requirements for the installation and lifting of asphalt mixing plants, providing professional reference for industry colleagues and project implementation.
I. Preliminary preparations: Laying a solid foundation for construction.
(一) Site survey and foundation acceptance
Before commencing installation and lifting operations, a comprehensive and detailed site survey must be conducted. Key survey aspects include: site topography and ground leveling, geological bearing capacity testing (which must meet the equipment foundation design load requirements, generally not less than 200 kPa), surrounding environment (such as safety distances to nearby buildings, high-voltage lines, and major roads), and a detailed survey of underground utilities (water supply and drainage, gas, and communication cables). The survey results must be compiled into a dedicated report, which will serve as the basis for optimizing the equipment layout and lifting plan, ensuring that the site’s spatial dimensions, bearing capacity, and access conditions meet the operational requirements of the mixing plant main structure, auxiliary equipment, and lifting equipment.
Simultaneously, the concrete mixing plant foundation was strictly inspected according to the design drawings and the “Code for Acceptance of Construction Quality of Concrete Structures” (GB 50204-2015). Key aspects checked included: foundation geometric dimension deviations (allowable deviation ±5mm), top surface elevation (allowable deviation ±3mm), surface flatness (allowable deviation 2mm/m), and concrete strength (required to reach 100% of the design strength). The foundation surface must be free of structural defects such as cracks, honeycomb, pitting, and exposed reinforcement. The positional deviation of the anchor bolt pre-reserved holes must be controlled within ±2mm. Only after the inspection is passed and the acceptance documents are signed can the subsequent installation process begin, providing a solid foundation for stable equipment installation.
(二) Review of construction drawings and technical briefing
Led by the technical lead, the construction team, supervision unit, equipment suppliers, and relevant personnel from the client side will conduct a review of the construction drawings. The core focus of the review will be on: the rationality of the overall layout of the mixing plant, the accuracy of the installation coordinates of each component, the feasibility of the connection node structures, the safety of the lifting process, and compatibility with surrounding facilities. Any design conflicts, dimensional deviations, or technical ambiguities in the drawings will be identified and resolved promptly. For critical aspects such as the lifting path of large modular components and high-altitude docking accuracy, the drawing plans will be optimized based on the results of on-site surveys.
After the drawings are reviewed and approved, the technical supervisor conducts a specialized technical briefing for the construction team, clarifying the technical parameters, quality control standards, safety operating procedures, progress milestones, and emergency response measures for each construction stage. The briefing content is detailed down to critical details such as the lifting angles of specific components, tightening torque, and precision tolerance ranges. This is done through a combination of written briefing records and on-site practical demonstrations to ensure that every construction worker clearly understands the work requirements, laying a solid foundation for the smooth progress of the construction project.
(三) Preparation of construction equipment and tools
Based on the production capacity of the asphalt mixing plant (e.g., 2000 type, 4000 type), the weight of core components (e.g., the weight of the mixing unit can reach 50-150 tons), and the installation process requirements, construction equipment and tools are precisely configured. Lifting equipment selection must meet a safety factor of 1.2 times the maximum lifting weight. Commonly used equipment includes: truck cranes (50-200 tons), crawler cranes (for ultra-heavy components or complex sites), flatbed trailers (for component transportation), and forklifts (for handling small components). All lifting equipment must be certified by a third party, be within its validity period, and be equipped with safety devices such as torque limiters and height limiters.
At the same time, prepare specialized installation tools and consumables, including: high-precision torque wrenches (torque accuracy ±3%), spirit levels (accuracy 0.5 mm/km), theodolites (angular accuracy 2″), jacks, winches, specialized lifting equipment (steel wire ropes, shackles, balance beams), and sealing materials (high-temperature resistant sealant, rubber gaskets), etc. All tools must be pre-calibrated, and consumables must meet the design material requirements to ensure the continuity and reliability of the construction process.
II、Core Lifting and Installation Process: Precise and Efficient Positioning
(一) Lifting and installation sequence planning
Following the core principles of “prioritizing main components over secondary ones, larger components over smaller ones, lower components over upper ones, and internal components over external ones,” the lifting sequence is scientifically planned to avoid interference from overlapping operations and the risk of rework. The specific sequence is as follows:
1. Mixing plant base (the core load-bearing foundation, prioritized for precise positioning);
2. Aggregate batching system (hoppers, supports, and other large components);
3. Powder supply system (powder tanks, screw conveyor main body);
4. Asphalt supply system (asphalt tanks, heating devices);
5. Mixing plant main body and cover;
6. Dust removal system (large dust collector main body);
7. Control room, electrical cabinets, and other small, high-precision components;
8. Various conveying pipelines, connectors, and accessories.
(二) Specialized Lifting Methods and Key Technical Points
1. Lifting of heavy components (mixer base, main body, large powder silos): The preferred method is dual-crane lifting or single-crane multi-point balanced lifting. For dual-crane lifting, cranes of the same model and performance should be selected, and a synchronous control system must be used to ensure synchronized lifting and movement. Lifting points should be symmetrically arranged, and the load distribution should be even (each crane’s load should not exceed 80% of its rated capacity). For single-crane multi-point lifting, the lifting point positions should be determined through finite element analysis, and a balance beam should be used to distribute the load and prevent local deformation of the component.During the lifting process, guide ropes were used to control the component’s position and prevent collisions. The lifting speed was controlled to within 0.5 m/min, and a 10-20 cm adjustment space was reserved during positioning, allowing for precise alignment using a traction device.
2. Lifting of long structural components (aggregate belt conveyors, long-distance screw conveyors): Depending on the length and rigidity of the components, either integral or segmented lifting methods are selected. Integral lifting requires precise calculation of the center of gravity and the installation of temporary reinforcement supports (such as I-beam reinforcement) to prevent bending deformation during lifting; segmented lifting requires pre-assembly and trial fitting on the ground, marking precise alignment lines, and then lifting each segment into place sequentially. Flange or welded connections are used during segmented connection to ensure that the coaxiality deviation is controlled within 0.5 mm/m.
3. Lifting of small, precision components (sensors, electrical components, instruments): A lifting method involving manual assistance and small lifting equipment (electric hoists, winches) should be used. Flexible slings should be used as lifting gear to avoid damaging the component surfaces. Personnel must wear anti-static gloves, and direct dragging of components is strictly prohibited. Components should be secured immediately after positioning to prevent falling or collision damage.
III. Meticulous Installation Process: Ensuring Optimal Performance
(一) Installation of the mixing unit
1. After the base is in place, use shims to adjust the levelness. Both longitudinal and transverse levelness deviations should be controlled within 0.2 mm/m. When tightening the anchor bolts, use a diagonal and even tightening method, ensuring the torque value meets the design requirements (generally 800-1000 N·m for M30 bolts). After tightening, recheck the levelness.
2. After the main unit is hoisted into place, it should be precisely aligned with the base, adjusting the coaxiality deviation to ≤0.3mm, and then the connecting bolts should be tightened. When installing the transmission device and reducer, ensure that the coaxiality deviation of the motor, reducer, and main unit input shaft is ≤0.2mm, and the coupling gap is controlled between 2-4mm. Add the specified type of lubricating oil (generally industrial gear oil GL-5) according to the equipment manual, filling it to the oil level mark. There should be no abnormal vibration or noise during trial operation.
3. The mixing blades must be installed strictly according to the angle markings (the typical design angle is 30°-45°), and the gap between the blades and the liner should be controlled at 5-10mm to ensure uniform mixing; when installing the discharge gate, adjust the flatness of the sealing surface to ≤0.5mm, install high-temperature resistant sealing strips, and conduct a leakage test during trial operation to ensure there is no leakage of asphalt or aggregate.
(二) Installation of the aggregate batching system
1. During the installation of the aggregate bins, ensure that the verticality deviation of the bin body is ≤1 mm/m, the bin partitions are tightly sealed, and there are no gaps between adjacent bins to prevent aggregate mixing; the inclination angle of the bin body should be determined according to the type of aggregate (generally 60°-65° for crushed stone and 65°-70° for sand) to ensure smooth and unobstructed flow of aggregates without any retention.
2. During the installation of the belt conveyor, the longitudinal horizontal deviation of the frame shall be ≤1mm/m, and the transverse vertical deviation shall be ≤2mm/m. The tension of the conveyor belt is controlled by adjusting the position of the rollers. During no-load test operation, the belt deviation shall be ≤5mm/10m; the weighing device must be installed to ensure that the weighing hopper is level, the sensors are subjected to uniform force, and the wiring connections are secure. After calibration, the weighing error shall be controlled within ±0.5%, meeting the requirements of “Weighing Display Controller” (GB/T 7724-2017).
3. The aggregate hopper and discharge gate must be installed with a secure and sealed connection. The discharge gate should open and close smoothly, the electric actuator’s response time should be ≤0.5s, and the limit switches must be accurately positioned to prevent over-opening or over-closing.
(三) Installation of the powder supply system
1. When installing the powder storage tank, the foundation must be leveled and compacted. A level instrument should be used to calibrate the verticality of the tank body, with a deviation of ≤1mm/m. The tank body should be secured using a combination of anchor bolts and wind-resistant guy wires (the strength of the guy wires needs to be reinforced in areas with wind speeds ≥6 on the Beaufort scale). The tank body must be equipped with a dedicated grounding device, with a grounding resistance of ≤4Ω, to prevent the risk of dust explosion caused by static electricity accumulation.
2. During the installation of the screw conveyor, ensure that the longitudinal levelness deviation of the casing is ≤0.5 mm/m, and that the gap between the screw blades and the casing is uniform (2-3 mm) to prevent material jamming. A high-precision tension sensor should be used for the weighing device, and the weighing error should be controlled within ±0.3%. After installation, perform three full-scale load calibrations to ensure accurate measurement.
3. The conveying pipelines are connected using flanges, with wear-resistant rubber gaskets used for sealing. The bolts are tightened evenly in a diagonal pattern. The pipeline layout is designed to minimize the path length and reduce the number of elbows (elbow radius of curvature ≥ 3 times the pipe diameter) to lower the resistance to powder conveying; pneumatic ball valves are used, with a switching accuracy of ≤ 0.1s, ensuring precise control of the powder conveying volume.
(四) Installation of the asphalt supply system
1. The asphalt tank installation must ensure a tank body levelness deviation of ≤1 mm/m. The foundation should be equipped with a moisture-proof layer and an insulation layer. The outside of the tank body should be wrapped with rock wool insulation material with a thickness of ≥50 mm. The internal heating device (heat transfer oil heating pipes) must be securely installed and evenly distributed. Temperature sensors should be installed in the middle and bottom of the tank, with a measurement accuracy of ±1℃, to ensure that the asphalt temperature is stably controlled within the production range of 130-160℃.
2. The asphalt conveying pipelines are made of stainless steel (304 or 316L), with a heating device and insulation layer on the outside. The connections use a double sealing method of welding and flanges, and the welded joints undergo penetrant testing (PT) to ensure there are no defects such as pores or cracks. The pumping system uses a dedicated asphalt gear pump, with flow rate and head matching the asphalt plant’s capacity. During trial operation, the pump body shows no leakage, and the pressure remains stable (fluctuation range ≤ 0.2 MPa).
3. The asphalt spray nozzle is installed directly opposite the aggregate discharge point of the mixing plant, and the nozzle angle is adjusted to 45°-60° to ensure even spraying of asphalt onto the aggregate surface. An electromagnetic flow meter is used for metering, with a metering error controlled within ±0.5%, and it is linked to the control system to achieve precise closed-loop control of asphalt usage.
IV. Key Points for Quality Control Throughout the Entire Process
(一) Quality inspection of incoming components
All incoming components must be accompanied by factory certificates of conformity, material certificates, and performance test reports. ACE Group, in conjunction with the supervising unit, will conduct special inspections:
1. Visual inspection: verifying that components are free from defects such as deformation, corrosion, and cracks, and that the surface coating is intact;
2. Dimensional inspection: ensuring that critical dimensions (such as connection flange thickness and bolt hole spacing) are within a tolerance of ±2mm.
3. Performance Testing: The mixing drum body undergoes ultrasonic testing (UT), with a 100% weld qualification rate; the gearbox undergoes no-load test run, operating smoothly and quietly with a temperature rise of ≤40℃; the sensors are calibrated for accuracy, and the error meets design requirements.
Any parts that fail inspection are strictly prohibited from being used on site and must be returned to the supplier for replacement.
(二) Dynamic Control of Installation Accuracy
During the installation process, a closed-loop control model of “real-time monitoring – adjustment – verification” was adopted, with key precision indicators tracked throughout:
1. Foundation elevation and levelness: Verified after each process step; deviations exceeding limits were corrected using shims or secondary grouting;
2. Component verticality and coaxiality: Monitored in real time using a theodolite and laser alignment instrument, and re-verified after adjustment;
3. Connection gap and sealing accuracy: Checked using feeler gauges, with a sealing surface gap of ≤0.1mm to ensure no leakage.
All precision data must be recorded and archived to form quality traceability documents.
(三) Quality control of connecting parts
Bolt connections must be tightened strictly according to the design torque, using a torque wrench in three stages (initial tightening, re-tightening, and final tightening). Thread locking compound must be applied to bolts in critical areas (main machine base, tank fixing bolts) to prevent loosening; welded connections must be performed by certified welders, with beveling treatment before welding and slag removal after welding, followed by non-destructive testing (UT/PT) to ensure weld quality; sealed connections require the selection of sealing materials compatible with the medium, even application of sealant during installation, and pressure testing after tightening (asphalt pipelines are tested at 1.5 times the working pressure, with no leakage for 30 minutes).
V. Comprehensive Security Management Measures
(一) Personnel Safety Management
Before construction began, ACE Group organized specialized safety training for all personnel. The training covered topics such as lifting and hoisting safety procedures, working at height regulations, electrical safety procedures, fire and explosion prevention requirements, and emergency response procedures. A test was administered after the training, and only those who passed were allowed to work. Workers were required to wear appropriate personal protective equipment (safety helmets, safety harnesses, non-slip shoes, and protective gloves). Personnel working at height were required to obtain a work-at-height permit, and safety harnesses were to be secured using the “high-point attachment, low-point use” method. Working without a permit or engaging in unsafe practices was strictly prohibited.
(二) Safety precautions at the construction site
The construction site is enclosed with a fence, dividing it into work areas, office areas, and material storage areas. Safety warning signs are displayed (including warnings for lifting operations, working at heights, and fire hazards). Working platforms at height are equipped with guardrails (height ≥ 1.2m) and safety nets, and safety protection sheds are installed below the working areas. Unauthorized personnel are strictly prohibited from entering the work areas. The construction site is equipped with sufficient fire-fighting equipment (dry powder fire extinguishers, fire sand, fire hoses) and first-aid supplies, and emergency exits are provided to ensure smooth emergency response.
(三) Equipment Safety Management
Before using lifting equipment, a comprehensive inspection is required: the wire ropes must be free of broken strands and excessive wear (wear less than or equal to 3%), the brakes must be sensitive and reliable, and the limit switches must be effective; electrical equipment must be protected against rain, moisture, and electrical leakage, the distribution box must be equipped with a leakage protection device (leakage action current ≤ 30mA), and the wires must be protected by conduits; a dedicated person must monitor the equipment during operation, and if any abnormality is found, the equipment must be stopped immediately for inspection; regular maintenance and servicing should be performed, and worn parts should be replaced to ensure the safe and reliable operation of the equipment.
(四) Safety Management and Control for Specialized Operations
High-altitude work must avoid overlapping operations; if overlapping is unavoidable, isolation and protective layers must be installed. Lifting operations require a dedicated person to direct the work, and the command signals must be standardized (using both hand gestures and walkie-talkies). Open-air lifting operations are strictly prohibited in winds of force 6 or higher, or during rain or snow. Electrical work requires power to be switched off, and a “Do Not Energize” sign must be displayed. Before starting work, a voltage test must be performed to ensure that there is no electricity before proceeding. During asphalt system installation, open flames are strictly prohibited near the work area, and a combustible gas detection device must be installed at the construction site to prevent asphalt leaks from causing fires.
VI. Description of Usage Scenarios
This guide is applicable to the installation and lifting operations of new construction, expansion, and renovation projects for various types of asphalt mixing plants (fixed, mobile, batch, and continuous) manufactured by ACE Group and other companies in the industry. It covers the construction scenarios of asphalt mixing plants supporting various road engineering projects, including municipal roads, highways, airport runways, and port terminals. It can serve as a core basis for construction units to prepare construction plans, for technical personnel to provide technical guidance, and for operators to perform operations. It can also be used by project owners as a reference for supervising and managing project quality and safety.
VII. Frequently Asked Questions and Answers for Customers
Q1: How long does it typically take to install and assemble asphalt mixing plants of different capacities?
A1: The installation and hoisting period mainly depends on the production capacity of the concrete mixing plant and the on-site construction conditions. The typical project timelines for ACE Group are as follows: for small mixing plants (2000 type and below), the period is approximately 15-20 days; for medium-sized mixing plants (3000-4000 type), the period is approximately 25-35 days; for large mixing plants (5000 type and above), the period is approximately 40-60 days. If the site is restricted, requires night work, or encounters adverse weather conditions, the period may be extended accordingly. We will develop a precise schedule based on the actual site conditions during the early stages of the project to ensure timely completion.
Q2: During the installation process, how can we ensure the installation accuracy of the concrete mixing plant to avoid problems such as excessive vibration and high noise during subsequent operation?
A2: ACE Group controls installation accuracy through a “three-tiered guarantee”: first, it uses high-precision measuring equipment (laser alignment instruments, electronic levels) for real-time monitoring to ensure that key indicators remain within the design specifications; second, it implements a “process handover inspection” system, where each accuracy-related process must be reviewed and approved by the technical supervisor before proceeding to the next step;third, after the equipment is installed, conduct no-load and load test runs. Use vibration sensors and noise detectors to monitor the equipment’s operating status. If abnormal vibration or noise occurs, troubleshoot and adjust the equipment promptly (such as adjusting the main unit’s levelness and optimizing the coaxiality of the transmission system) to ensure stable operation.
Q3: How should we deal with the risk of deformation of large components (such as the mixing unit) during the lifting process?
A3: We will take comprehensive preventive measures before lifting: firstly, we will determine the optimal lifting points through finite element analysis and use a special balancing beam to distribute the load and avoid local stress concentration; secondly, we will adopt temporary reinforcement measures for heavy components (such as welding reinforcing bars) to improve the rigidity of the components; and thirdly, we will select lifting equipment with matching performance, control the lifting speed and posture, and avoid impact loads. If any signs of deformation are detected during the lifting process, we will immediately stop lifting and address the issue by adjusting the lifting points, adding reinforcement measures, or changing the lifting plan to ensure the safety of the components before continuing the operation.
Q4: What after-sales support services will your company provide after the installation is complete?
A4: ACE Group provides comprehensive after-sales support services:
1. After installation, a professional team will conduct equipment commissioning (including no-load and load testing) to ensure that all equipment performance meets the standards; 2. We provide specialized training for the owner’s operators, covering equipment operation, daily maintenance, and troubleshooting;
3. We provide a one-year free warranty service, with dedicated personnel conducting regular inspections during the warranty period to promptly resolve any equipment operating issues;
4. We establish a long-term service mechanism, providing lifelong technical support and spare parts supply services to ensure the long-term stable operation of the equipment.
Q5: The construction site is located near a residential area. How can we control construction noise and dust pollution?
A5: For construction sites near residential areas, we will implement specific environmental protection measures:
1. Noise control: We will use low-noise construction equipment, set up noise barriers, and schedule work times appropriately (avoiding 10:00 PM to 6:00 AM and lunch breaks). We will also minimize horn use during lifting operations to reduce noise impact;
2. Dust control: The construction site ground will be hardened, material transport vehicles will be covered with tarpaulins, and mist cannons and sprinkler systems will be used to suppress dust. Enclosed measures will be taken during the handling of powdery materials to prevent dust dispersion and ensure compliance with local environmental emission standards.
VIII. Conclusion
The installation and lifting of asphalt mixing plants is a technically intensive and complex engineering project, and its quality and safety directly determine the equipment’s operational efficiency and the overall project benefits.Drawing on years of industry experience, Asian Construction Equipment Group Co., Ltd. has built an integrated implementation system encompassing “precise planning in the early stages, refined process control, and comprehensive service support throughout the entire lifecycle.” By strictly adhering to the technical specifications and management requirements outlined in this guide, we can effectively guarantee the safety, standardization, and efficiency of installation and lifting operations. In the future, Asian Construction Equipment Group Co., Ltd. will continue to focus on technological innovation, constantly optimizing installation and lifting processes to provide customers with more professional and reliable asphalt mixing plant integration services, contributing to the high-quality development of road engineering.
Note: The content of this guide is based on the practical experience of Asian Construction Equipment Group Co., Ltd. projects and current national and industry standards. It is intended for reference only by relevant organizations when carrying out asphalt mixing plant installation and lifting work. Specific implementation requires targeted adjustments based on actual project conditions, equipment technical parameters, and site conditions.
