GB/T 23827-2021Road traffic sign plate and support (English PDF)

3.1 Sign plate

An assembly that consists of a sign base plate, a sign plate surface, chutes, rivets, etc.

3.2 Support

A member that supports and connects the fastening sign plate.

NOTE: Supports include posts, beams, flanges, hoops and fasteners, etc.

5.1 Structural size

5.1.1 Road traffic signs are composed of sign plates and supports; and their shape and size shall meet the requirements of GB 5768.2 or design requirements.

5.1.2 The maximum allowable deviation of the external size of the sign plate is ±5mm; if the external size is greater than 1.2m, the allowable deviation is ±0.5% of the external size.

5.1.3 The reflective film pasted on the retroreflective sign plate shall meet the requirements of GB/T 18833. The black film with the durability matching the reflective film is pasted on the reflective film as a mask; and the plate surface information can also be formed by printing ink or digital printing on the reflective film. When necessary, active light-emitting units can be added or sign illuminating facilities can be installed to the sign plate surface according to the terrain and sunshine conditions. When the illuminating type or light-emitting type is adopted, its performance shall comply with the provisions of GB 5768.2 and GB/T 31446.

5.1.5 The sign base plate can be reinforced with a chute; and the reinforcing method and the size of the chute shall meet the design requirements. The reinforcement connection between the sign bottom plate and the chute can adopt riveting, welding or other technological methods, and shall meet the following requirements.

a) When using the aluminium alloy plate to make the sign base plate, the countersunk rivets shall be used for connection. The riveting spacing shall be uniform, generally 150mm±50mm; and the riveting shall be strengthened at the end of the chute to disperse the stress. The shape of the rivet shall meet the requirements of GB/T 869; the diameter should be no less than 4mm, and it shall match the sign base plate and the chute.

b) The quality of the welding process shall be stable and reliable; there shall be no leakage welding, virtual welding and other phenomena; and the welding strength shall be uniform. The strength of welding or other process connection methods shall be no lower than the strength requirements of the same type of materials when connected by rivets.

5.1.6 The sign post can be made of H-section steel, steel pipe, aluminium alloy profile, wood, synthetic material and reinforced concrete pipe, etc., or steel truss. The shape and size of the sign post shall meet the design requirements; the outer diameter, thickness and curvature of the seamless steel pipe shall meet the requirements of

GB/T 8162; and the outer diameter, thickness and ovality of the straight seam electric welded steel pipe shall meet the requirements of GB/T 13793.

5.1.7 When the sign post is a steel member, the top shall be covered with a post cap.

The structure size of the post cap shall meet the design requirements.

5.1.8 The connection between the sign plate and the post can be in the form of hoop clamping or steel strap bundling; and its structural dimensions shall meet the material and design requirements.

5.2 Appearance quality

5.2.1 The characters and graphics of the sign plate shall comply with the provisions of

GB 5768.2. On the same sign plate, the various materials used for the sign base plate and the sign plate surface shall be compatible; and the sign plate shall not be rusted or damaged due to electrochemical action, different thermal expansion coefficients or other chemical reactions.

5.2.2 The sign plate shall not have the following defects:

a) cracks, wrinkles, edge peeling;

b) obvious air bubbles, scratches or other damage;

c) uneven colour;

d) inhomogeneous retroreflective performance.

5.2.3 The sign plate should be flat, without obvious dents or deformation on the surface; and the unevenness of the plate surface shall be no greater than 7mm/m.

5.2.4 When the surface of the sign plate is reflective film, the splicing shall meet the following requirements.

a) The mask should be spliced as little as possible; when the length or width and diameter of the sign plate are smaller than the maximum width of the mask product, there shall be no splicing seam.

b) When the seam cannot be avoided by pasting the mask, it shall be spliced in the same direction as the reference marking of the mask. Splicing is divided into lap splicing and flat splicing. When taking lap splicing, it should be horizontal splicing seam; and it shall be lap-spliced from the upper to the lower part; the overlapping part of the glass bead type reflective film shall be no less than 5mm; and the overlapping part of the microprism type reflective film shall be no less than 30mm.

When taking flat splicing, it should be vertical splicing seam; the clearance between splicing seams shall not exceed 1mm.

c) Within 5cm from the edge of the sign plate, there shall be no splicing seam.

5.2.5 The supports shall have a smooth surface and uniform colour; and shall not be damaged, deformed, corroded, leaked plating or other appearance quality defects.

5.3 Quality of anti-corrosion layer of steel members

The quality of the anti-corrosion layer of the sign base plate and supports made of steel members shall meet the requirements of GB/T 18226.

5.4 Mechanical properties of materials

5.4.1 Sign base plate and chute

The material used to make the sing base plate shall meet the following requirements in terms of mechanical properties:

a) The mechanical properties of the aluminium alloy plate used to make the sign base plate shall meet the requirements of GB/T 3880.2; when it is used for high-grade roads, the aluminium alloy plate with designations of 5A02-O, 5052-O or other designations with similar properties should be used. For large sign plates such as gantry type and cantilever type, or sign plates used in coastal and windy areas, aluminium alloy plates with designations of 3004-O, 3104-O or other designations with similar properties should be used;

b) The extruded aluminium alloy profiles used to make the sign base plate and the

a) The sign plate shall not appear damages such as cracks, nicks, depressions, bubbles, erosion, peeling, chalking or deformation; and the shrinkage on any side shall be no greater than 0.8mm;

b) The reflective film shall not warp or detach from the edge of the sign base plate;

c) When the material of the sign base plate is a synthetic resin sheet, the weather resistance of the sign base plate shall comply with the provisions of GB/T 24721.5;

d) The chromaticity coordinates and luminance factor of the sign plate shall meet the requirements of Table 1 or meet the requirements of GB/T 18833;

e) When the surface of the sign plate is reflective file or made by other processes such as ink printing or digital printing, under the conditions of an observation angle of 0.2° and an incident angle of -4°, its retroreflection coefficient value shall meet the requirements of GB/T 18833.

6.1 Test preparation

6.1.1 Specimen preparation

Sample preparation includes the following methods:

a) Randomly select the sign plate and support made by the sign manufacturer or take the corresponding size from them as a specimen;

b) Randomly select the raw materials used by the manufacturer, paste the reflective film and black film on the sign base plate; and make a sign plate specimen. The size of the specimen shall meet the requirements of GB/T 18833.

6.1.2 Test environment

Before the test, the specimen shall stand in an environment with a temperature of 23°C ± 2°C and a relative humidity of 50% ± 10% for 24h, and then the test is carried out.

The test shall be carried out in an environment with a temperature of 23°C ±2 °C and a relative humidity of 50% ± 10%.

6.2 Structural dimensions

6.2.1 Visually inspect the structural composition. Dimensions, riveting spacing, plate thickness, outer diameter, wall thickness, etc. shall be measured by measuring tools such as ruler, tape, vernier calliper, plate thickness micro-meter, and wall thickness micro-meter.

6.2.2 The connection strength when welding the sign base plate and the chute shall be tested in accordance with the methods specified in GB/T 228.1, GB/T 2651 and GB/T 3250.

6.3 Appearance quality

6.3.1 Sign plate characters and graphics

Use visual inspection to check whether the characters and graphics of the sign plate meet the requirements of GB 5768.2 for characters and graphics.

6.3.2 Defect inspection

In a dark and open environment at night, at a distance of 10m from the sign plate, use the high beam of the car headlight as the light source to illuminate the sign plate vertically. Visually observe the retroreflective performance of the same material, the same colour, and different areas on the surface of the sign plate. If obvious differences can be identified, the retroreflective performance is not uniform.

The remaining defects shall be visually inspected or inspected with a four-fold magnifying glass under the condition that the ambient illuminance is greater than 150lx during the day.

6.3.3 Unevenness of the plate surface

The sign plate is placed freely on a platform with its face up, and a steel ruler and a feeler gauge are used to measure the maximum gap between the plate and the ruler at any point.

6.3.4 Panel splicing

Under the condition that the ambient illuminance is greater than 150lx during the day, visually check the splicing direction of the mask and measure with a ruler to check the lap-splicing width or flat-splicing gap.

6.10 High and low temperature resistance of sign plate

The high and low temperature resistance performance test of the sign plate is carried out according to the following steps:

a) Put the 150mm×150mm specimen into the test box; start the equipment; gradually reduce the temperature in the box to -40°C ± 3°C; and turn off the power after keeping this temperature for 72h;

b) Wait for the test box to rise to room temperature naturally; then raise the temperature of the test box to 70°C ± 3°C after about 12h; and keep the temperature at this temperature for 24h and then turn off the power;

c) Take out the specimen after waiting for the test box to cool down to room temperature naturally. Stand for 2h at a temperature of 23°C ± 2°C and a relative humidity of 50%±10%; and check the surface changes according to the requirements of 5.9.

6.11 Weather resistance of sign plate

6.11.1 Natural exposure test

According to GB/T 3681, place the 150mm×250mm specimen facing due south; and expose it to the sun at the local latitude angle or 45°±1° to the horizontal plane.

After the specimen began to be exposed to the sun, the surface inspection shall be performed once a month. After half a year, the surface inspection shall be performed every three months. When the reflective film reaches the exposure period specified in

GB/T 18833, after two years of exposure to the sun, the sign base plate of the synthetic resin board shall be inspected and tested in accordance with the methods specified in GB/T 24721.1.

6.11.2 Artificial accelerated aging test

According to GB/T 16422.2, the size of the specimen is 65mm×142mm. If the reflective film reaches the test time specified in GB/T 18833, rinse it thoroughly with clean water and dry it with a soft cloth; and then conduct inspection and performance test according to the method specified in GB/T 18833. After the synthetic resin board has been tested for 1200h, the inspection and performance test shall be carried out in accordance with the methods specified in GB/T 24721.1.

6.12 Adhesion performance of sign board and sign base plate

Cut out the reflective film and black film of 200mm×25mm; and paste the reflective film and black film on the sign base plate to make the adhesion performance specimen.

The size of the sign base plate is 200mm × 50mm, and the test is carried out according to the method of GB/T 18833.

e) When specified in the contract;

f) When the state-authorized quality supervision department proposes type inspection.

7.2 Sampling and Judgment Methods

7.2.1 Conduct random sampling for each batch of products or conduct sampling testing according to JT/T 495; at least three samples shall be taken.

7.2.2 Each test shall be tested for at least three times (should be carried out on different specimens), and the average value shall be taken as the test result. The results shall meet the following requirements:

a) If the test data all meet the standard requirements, this batch of products is judged to be qualified;

b) If there is one item in the test data that does not meet the standard requirements, double number of products shall be selected to re-inspect this indicator. If the re-inspection is qualified, this batch of products is determined to be qualified; if the re-inspection is unqualified, this batch of products is determined to be unqualified.