In road traffic marking construction, whether it is applied to brand-new concrete pavement or weathered old asphalt pavement, professional marking primer is an indispensable part. Especially when covering old lines or thermoplastic marking construction, the quality of the primer is directly related to whether the marking can be firmly attached to avoid falling off, so its role should not be ignored.
New asphalt pavement road marking primer application
For the newly paved asphalt pavement, its surface is rich in asphalt organic matter, these organic matter and road marking paint in the binder – petroleum resin has good compatibility. During the construction process, when the construction temperature reaches 180-220°C, which is much higher than the melting point of asphalt (usually between 120-150°C), the petroleum resin and asphalt can fully melt and fuse with each other. This fusion not only eliminates the clear interface between the road surface and the marking, but also greatly enhances the interaction force between them, thus ensuring a solid adhesion of the marking.
Technical indicators:
Construction temperature: 180-220°C
Melting point of asphalt: 120-150°C
Petroleum resin content: ≥30%
Adhesion test: ≥0.5MPa (according to ASTM D4541 standard)
Road marking machine use method:
Preheating: preheat the road marking paint machine to 180-220°C to ensure the paint can be fully melted.
Uniform Spraying: Use high pressure airless spraying technology to ensure the road marking primer evenly covers the asphalt pavement.
Temperature monitoring: real-time monitoring of the construction temperature to ensure that the application is carried out within the optimum temperature range.
Application of road marking primers on concrete pavements
In contrast, concrete pavements exhibit very different characteristics. As a hydrophilic substance, cement pavement is oleophobic, which means that it has relatively little adhesion to petroleum resins. In addition, the rigid structure of concrete pavements gives them a limited ability to deform, whereas road marking paints are inherently thermoplastic and harden in cold weather. Therefore, in order to tightly bond these two materials with very different properties, a primer with good toughness is needed to act as a bridge. At the same time, the road marking paint should also have excellent impact resistance, taking into account the fact that the road marking paint is subjected to impacts from all directions during use.
Technical indicators:
Adhesion test: ≥0.4MPa (according to ASTM D4541 standard)
Impact resistance: ≥50cm (according to GB/T 1732 standard)
Toughness test: ≥5mm (according to GB/T 1731 standard)
Road marking machine use method:
Surface treatment: Use high-pressure water gun or mechanical grinder for surface treatment of cement pavement to increase the roughness.
Undercoater Spraying: Use low pressure aerated spraying technology to ensure the road marking primer evenly covers the cement road surface.
Drying Time: Ensure that the marking primer dries sufficiently (usually takes 15-30 minutes) before proceeding with the marking.
Application of road marking primer on old asphalt pavements
For old asphalt pavements, especially those with low asphalt content and where the stone has protruded from the road surface, the nature of the pavement has gradually approached that of a concrete pavement. Therefore, when marking on such pavements, it is often necessary to use marking primers or special matching primers similar to those used on concrete pavements. These primers can effectively enhance the adhesion between the paint and the road surface to ensure the stability and durability of the road marking paint.
Technical index:
Adhesion test: ≥0.45MPa (according to ASTM D4541 standard)
Anti-aging performance: ≥1000 hours (according to GB/T 1865 standard)
Weathering resistance test: ≥500 hours (according to GB/T 9276 standard)
Road marking machine use method:
Surface cleaning: use sweeper or high-pressure water gun to clean the old asphalt pavement to ensure no dust and debris.
Special undercoat spraying: use high pressure airless spraying technology to ensure that the special marking primer evenly covers the old asphalt pavement.
Temperature control: Control the construction temperature between 160-200°C to ensure that the marking primer is fully combined with the pavement.
Through scientific and reasonable selection and application of marking primer, the adhesion and durability of marking can be significantly improved, providing a strong guarantee for the safety and smoothness of road traffic. Combined with the latest technical indicators and the use of road marking machine, it can ensure the construction quality and prolong the service life of marking.