GB/T 21296.3-2020Automatic instruments for weighing road vehicles in motion—Part 3: Weighing axle loads (English PDF)

3.1 Axle Load Weigher

Axle load weigher refers to a weighing instrument that can measure the axle load (which can be directly measured, or can be obtained by accumulating the separately measured wheel loads) and the axle-group load in one weighing.

NOTE 1: axle load weigher may adopt a single load receptor or multiple load receptors.

NOTE 2: axle load weigher that can measure the axle-group load in one weighing is also called axle-group load weigher. [GB/T 21296.1-2020, Definition 3.7.2]

3.2 Axle Load Weigher WIM

Axle load weigher WIM refers to a WIM weighing instrument which adopts the axle load weigher and its combination, which are embedded in the pavement, and with the upper surface of the load receptor on the same plane as the pavement, to measure the axle load and axle-group load (if applicable) of the vehicle, so as to obtain the gross vehicle mass. [GB/T 21296.1-2020, Definition 3.7.3]

6.3 Requirements for Load Receptor

6.3.4.2 Position limiting system

For the low-speed axle load weigher WIM, an appropriate position limiting system shall be designed and adjusted to allow the load receptor to have a certain movement clearance, without colliding the surrounding roadbed or other surrounding objects that are not expected by the design. The position limiting system shall have the function of preventing loosening and retreating, and shall be convenient for repair, maintenance and adjustment. The various components of the position limiting system shall receive the anti-corrosion treatment.

6.3.4.3 Embedment fastening

For the medium-speed and high-speed axle load weigher WIMs, the load receptors shall be embedded in the pavement and fastened together with the pavement, so as to prevent the load receptors from loosening or jumping out of the pavement, which may affect the weighing or cause potential safety hazards.

6.3.4.4 Limit of control instrument

Weighing instruments with no clearance between the load receptor and the pavement must not be used as control instruments.

6.3.5 Anti-skid requirements for the surface of load receptor

In accordance with different environmental conditions of service and product types, appropriate anti-skid measures (such as: using anti-skid pattern steel plate, welding anti-skid patterns on the steel plate, welding anti-skid studs on the steel plate, spraying anti-skid paint on the steel plate, and using steel-mixed structure weighing platform, etc.) shall be taken on the surface of the load receptor of the axle load weigher WIM, so as to prevent the slippage of wheels, which may affect product application or cause safety accidents.

6.3.6 Requirements for processing and surface coating

6.3.6.1 Requirements for weldments

The various weldments on the load receptor of the axle load weigher WIM shall be firmly and reliably welded. The welding seams shall be uniform, smooth, and free of cracks and welding slag; there shall be no welding defects, and shall comply with the requirements of QB/T 1588.1.

6.3.6.2 Requirements for castings

The surface of the castings on the load receptor of the axle load weigher WIM shall be smooth, and free of defects, such as: shrinkage porosity, cold insulation, pores and slag inclusions, etc.

6.3.6.3 Requirements for machining

The relevant mechanically cut work pieces of the axle load weigher WIM shall comply with the requirements of QB/T 1588.2.

6.3.6.4 Requirements for forgings

The forgings on the load receptor of the axle load weigher WIM shall be free of defects, such as: cracks, interlayers and slag inclusions, etc.

6.3.6.5 Requirements for plating pieces

The surface of the relevant plating pieces of the axle load weigher WIM shall have uniform colors, and shall not manifest defects, such as: spots and rust, etc.

6.3.6.6 Deformation treatment

During the production of the load receptor and its components of the axle load weigher WIM, measures shall be taken to prevent warpage or deformation, and if necessary, appropriate modes shall be taken to carry out aging treatment and correct the deformation caused by stress release.

Before installation, the flatness of the upper surface of the load receptor of the axle load weigher WIM shall be inspected, and if necessary, remedial measures shall be taken. The flatness error of any point on the upper surface of the load receptor must not be lower than the corresponding requirements of the pavement (the inspection may be conducted in accordance with the road surface flatness and detection method provided in 8.2.3 of GB/T 21296.1-2020).

During transportation, necessary protective measures shall also be taken to prevent deformation of large-sized components of the axle load weigher WIM.

6.3.6.7 Anti-corrosion requirements

6.3.6.7.1 Basic requirements

The various steel structure components on the load receptor of the axle load weigher WIM shall receive the anti-corrosion treatment. The anti-corrosion treatment shall not be lower than the general requirements of atmospheric corrosion environment specified in GB/T 28699.

6.3.6.7.2 Quality of surface painting

The surface paint layer of the various components of the axle load weigher WIM shall be flat, uniform in color, smooth and firm; the paint layer shall not have defects, such as: brush lines, sagging, wrinkling, bubbles, peeling and falling off, etc. After painting, the surface shall be complete and free of paint leakage, and shall comply with the requirements of QB/T 1588.4.

6.3.6.8 Warning signs

For the equipment parts that affect the driving safety of the vehicle, paints or signs with warning colors shall be used.

6.4 Requirements for Foundation Pit

6.4.1 Requirements for the installation of sensors in the foundation pit

When the pavement near the foundation pit exceeds the road conditions allowed by the equipment, appropriate slope adjustment shall be performed to ensure that the installation requirements of the axle load weigher WIM are satisfied. […]

6.5 Requirements for Electrical Cabinets

6.5.1 Requirements for ventilation

The design of the electrical cabinets shall ensure smooth ventilation, and provide effective protective measures for the dissipation of humid air, as well as the heat dissipation of electrical heating components and the sun, etc.

6.5.2 Waterproof requirements

The design of the electrical cabinets shall ensure to be waterproof, and provide effective protective measures for rainwater, driving splash water and snow melting water, etc.

6.6 Grounding Requirements

The axle load weigher WIM and its accessory parts shall be provided with appropriate grounding devices, so as to ensure that the load receptor, electrical cabinet, sensor enclosure and electrical equipment enclosure are firmly grounded, with the ground resistance <= 4 ohm.

7.1 General Requirements

In addition to the stipulations of Chapter 6 in GB/T 21296.1-2020, the axle load weigher WIM shall also comply with the requirements of 7.2 ~ 7.6.

7.2 Width of Load Receptor

The load receptor shall have a sufficient width in the vertical direction of the driving direction, so as to satisfy the width requirements of the vehicle's driving lane.

7.3 Axle Identifier

If necessary, an appropriate axle identifier shall be equipped to identify whether there is a tyre running over, as well as single and double tyre information (or tyre width) and coupling information, etc. The type of the axle identifier can be strain sensing type, digital charging type, switch type and laser type, etc. The design of the axle identifier installed on the lane and with physical contact with the tyres shall satisfy the requirement of half the width of the specified driving lane. The typical value of ordinary lanes is 1.5 m; the typical value of ultra-wide lanes is 2.0 m.

NOTE: the axle identifiers installed on the lane and with physical contact with the tyres can be installed on the load receptor to form an integrated structure, or they can be separately installed in front of or behind the driving direction of the load receptor.

7.4 Vehicle Identifier

When the axle load weigher WIM enters the continuous automatic operating mode, if necessary, vehicle identifiers may be equipped, such as: infrared light screen, coil detector and laser vehicle divider, etc. The device shall be able to detect whether the vehicle enters or leaves the controlled weighing area.

In accordance with the operating conditions, the axle load weigher WIM may adopt the load receptor, in combination with the relevant software, to automatically identify the vehicle and simulate the functions of the above-mentioned vehicle identifier.

7.5 Load Cell

The load cell of the axle load weigher WIM shall comply with the requirements of GB/T 7551.

In accordance with different areas and environment conditions of service, load cells with humidity classification marked as SH, CH or unsigned shall be selected.

7.6 Electronic Weighing Meter

The electronic weighing meter of the axle load weigher WIM shall comply with the requirements of GB/T 7724.

8.1 General Requirements

The installation and maintenance of the axle load weigher WIM shall rigorously comply with the installation guidelines and maintenance guidelines provided by the equipment manufacturer.

The user shall maintain the controlled weighing area clean, regularly inspect the equipment operation and road conditions, and if necessary, repair and adjust them.

8.2 Installation of Auxiliary Facilities

8.2.1 Installation of deceleration ridges

When the user installs the deceleration ridges for the low-speed axle load weigher WIM, the deceleration ridges shall be installed in front of the load receptor and at a distance of over 18 m away from the front edge of the load receptor. The prerequisites for the installation of the deceleration ridges shall be determined in accordance with the traffic conditions and the road conditions of the equipment installation site.

The installation of the deceleration ridges for the medium-speed axle load weigher WIM and the high-speed axle load weigher WIM is prohibited.

8.2.2 Installation of speed limit warning signs

For the low-speed axle load weigher WIM, the user shall install and maintain the speed limit warning signs at an appropriate location, with the speed limit 5 km/h.

For the medium-speed axle load weigher WIM, the user shall install and maintain the speed limit warning signs at an appropriate location, with the speed limit 30 km/h.

For the high-speed axle load weigher WIM, the user shall install and maintain the speed limit warning signs at an appropriate location, with the speed limit 90 km/h.

8.2.3 Installation of other auxiliary facilities

The installation of other auxiliary facilities that are conducive to vehicle passing shall be carried out by the user in accordance with the demands, such as: weighing lanes, weighing detection kilometer signs and constant-speed driving, etc.

8.3 Equipment and Pavement Inspection

8.3.1 Inspection of water drainage devices

For equipment with a water drainage device on the load receptor, the user shall inspect, dredge and clean the water drainage device inside the foundation pit of the load receptor in accordance with the relevant regulations on equipment maintenance and management, so as to prevent the drainage pipes from being blocked by debris and silt, and ensure smooth water drainage.

8.3.2 Rodent bite inspection

The user shall inspect the various underground cables in accordance with the relevant regulations on equipment maintenance and management, so as to ensure that the cable inlet and outlet ports are tightly blocked to prevent rodent bite.

8.3.3 Pavement inspection

The user shall inspect the pavement 30 days after the completion of equipment installation and every six months thereafter. When it exceeds the stipulations of Chapter 8 in GB/T 21296.1-2020, the pavement shall be repaired in time.

9.1 General Rules

The test shall be carried out on the site where the axle load weigher WIM is used. […]

9.2 Preparation before Test

9.2.1 Requirements for test environment