6. Road Marking Procedure – As per MoRTH & IRC 35

6.1 Surface Preparation

Clean the pavement surface thoroughly to remove dust, loose aggregate, grease, oil, moisture and any foreign matter before marking. Use mechanical brooms, air compressors, or dry air jets to ensure a dry, clean and sound surface suitable for thermoplastic adhesion. Concrete surfaces may require a primer as specified.

6.2 Pre‑Marking & Layout

Mark the reference centrelines and alignment with chalk, rope or laser guides to ensure accurate positioning of longitudinal, transverse and symbol markings. All layouts shall conform to IRC 35 dimensions and spacing for lane lines, edge lines, stop lines, arrows, zebra crossings and other symbols.

6.3 Melting & Heating of Thermoplastic

Heat the thermoplastic material in a pre‑melter with mechanical stirring. Maintain the heating temperature within the manufacturer’s recommended range (typically 170–200 °C, often cited as 180 °C ±10 °C) and avoid overheating above safe maximum. Do not keep the material molten for more than 4 hours to prevent degradation.

6.4 Application of Thermoplastic

• Transfer the molten material to the applicator and maintain the application temperature throughout the process.
• Apply markings using a screed box or automatic profile machine capable of producing uniform lines with controlled width and thickness.
• Maintain a finished thickness of at least 2.5 mm exclusive of surface‑applied glass beads for longitudinal and transverse markings.
• Apply continuous or intermittent lines as required; use appropriate stencils for arrows, letters and symbols. Hand spraying may be used for small areas if specified.

6.5 Drop‑On Glass Beads

Dispense Type‑2 reflectorising glass beads uniformly using a forced‑feed bead dispenser while the thermoplastic is still hot so that beads embed into the surface before cooling. Typical application rate is ≈250 g/m² for high retro‑reflectivity.

6.6 Weather & Surface Conditions

Markings must be applied only on dry surfaces with pavement temperature above 10 °C and ambient conditions that will not trap moisture under the film. Avoid application in rainy, foggy, or excessively humid conditions. Concrete should be fully cured and free of laitance.

6.7 Finished Road Marking Properties

After application and cooling, thermoplastic road markings shall meet the following performance requirements in accordance with MoRTH Clause 803 and IRC:35‑2015:

• Skid Resistance: Markings shall not be slippery when wet, ensuring safe braking and traction for all types of vehicles.
• Adhesion & Durability: Markings must remain firmly bonded to the pavement without lifting, cracking, chipping, or deforming under traffic and temperature variations up to 60 °C.
• Chemical Resistance: Markings shall resist oil, grease, sodium chloride, and other chemical contaminants typically encountered on roads, without noticeable discoloration or deterioration.
• Retro-reflectivity & Visibility: Markings shall retain original dimensions, alignment, color, and retro-reflective performance throughout their design life, ensuring optimal visibility during day and night.
• Weather Resistance: Markings should withstand UV exposure, rainfall, and seasonal temperature fluctuations without loss of integrity or adhesion.

6.8 Quality & Testing

All materials and workmanship shall comply with the IRC 35 Code of Practice and MoRTH Specification Clause 803. Test certificates and manufacturer declarations shall be provided for raw materials (thermoplastic compound and glass beads). Thickness, retro‑reflectivity, adhesion and colour shall be verified during execution.

8. Notes & References

All work shall follow the relevant provisions of MoRTH Clause 803, including Table 800-9 and Table 800-10, and IRC:35‑2015 for test methods, sampling, and quality control. Contractors must submit Material Test Certificates (MTCs) and manufacturer specifications for all road marking materials prior to application.