Road marking is the most basic and effective component of traffic management facilities, and is one of the effective ways to guide vehicles to drive in a standardized manner. Road marking paint is a paint that is applied on the road surface to indicate traffic.
1. Characteristics of road marking paint
The paint should have good adhesion to asphalt or cement pavement and should not peel off easily during use;
Road marking paint should have good weather resistance and wear resistance, with little color change during use, clear markings, not easy to crack or wear; it should maintain good reflectivity, and the reflective effect will not decrease significantly over a long period of time;
Road marking paint should have good construction performance, fast drying, smooth surface, strong adhesion to glass beads, easy control of marking thickness during construction, and uniformity of marking thickness.
2. Types of road marking paint
Usually, road marking paint can be divided into two categories: solvent-based and hot-melt. Solvent-based road marking paint is the most commonly used, but this type of paint releases a large amount of solvent during use, which seriously pollutes the environment. It is stipulated that the content of organic solvents (especially solvents that are prone to produce photochemical smog) in solvent-based paints must be less than 17% (volume). This regulation undoubtedly greatly restricts the use of solvent-based road marking paints. Since then, other advanced industrial countries have followed suit and successively issued environmental protection regulations to stipulate the limits of volatile organic compounds (VOCs). The development of solvent-based road marking paints has since gone downhill. Nowadays, with the improvement of living standards, people have higher and higher requirements for living environment, and solvent-based road marking paints can no longer meet the needs of contemporary society.
Vibration-type hot-melt road marking paint is modified on the basis of hot-melt road marking paint. It is mainly to improve the fluid properties of the original marking paint so that the paint has excellent thixotropic properties in the molten state. By shortening its drying time and improving the compressive strength and softening point, and using special construction tools to regularly draw various protruding pattern markings such as dots, strips, and blocks on the marking surface, the completed marking has a vibration function after the car presses the line. On rainy nights, the coating of ordinary hot-melt road markings is flat, which is easily covered by rain in rainy night environments, and the road markings lose their retro-reflection of incident light, making it difficult for drivers to distinguish road markings. The concave parts between the protrusions of the vibration-type road reflective markings divert rainwater, and the protrusions remain above the water surface, and can continue to reflect light from the part above the water surface.
Vibration markings are also called raised markings, noise markings, and rainy night markings. From the shape of the product, they can be roughly classified into: dot-type vibration markings, square-type vibration markings, and rib-type vibration markings.
Because this type of marking is expensive and the construction is more complicated than ordinary hot-melt markings, it is mainly used in accident-prone areas and places that require high recognition of road contours. Such as the sidelines, turns, diversions, entrance and exit markings, bridges, tunnels, steep slopes and other sections of high-grade highways; parking lines, lane demarcations, special lane demarcations, etc. at intersections of urban roads; other places where markings with prompt functions are required.
3. Application and existing problems of road marking paint
Road traffic marking is mainly used on the road surface, which is exposed to the sun, rain, wind, snow, ice and vehicles, so there are strict requirements for its performance. First, it requires a short drying time and simple operation to reduce traffic interference; second, it requires strong reflective ability, bright colors, and strong reflectivity to ensure good visibility during the day and night; third, it should have anti-skid and wear resistance to ensure driving safety and service life. With the diversification of road marking paint types and construction methods, it is necessary to select the paint variety that meets the necessary conditions for traffic marking according to the use effect of the paint.
From the development trend, the quality of hot-melt road reflective marking paint is constantly improving. However, due to construction quality reasons, there are still unsatisfactory aspects. The main problems are:
- First, the paint variety is single, it cannot be reasonably selected, and it is easy to cause waste;
- Second, the improper use of reflective glass beads makes the reflective effect of the marking poor;
- Third, the construction temperature is difficult to control;
- Fourth, the anti-skid performance of the marking is not taken seriously, making the marking a hidden danger of accidents such as vehicle skidding and side sliding.
