1. Analysis of hot melt road coating formula
The formula of hot melt road coating is a complex system. The selection and ratio of each component directly affect the final performance of the coating. Synthetic resin is the main film-forming substance, usually petroleum resin or rosin modified resin, and its content is generally between 15%-25%, which provides basic bonding performance and durability for the coating. Plasticizers such as phthalate compounds, with a content of about 5%-10%, can improve the flexibility and low temperature performance of the coating.
The filler system is usually composed of calcium carbonate, quartz sand, etc., accounting for up to 50%-70%, which not only reduces costs, but also improves the mechanical strength and wear resistance of the coating. Pigments are mainly titanium dioxide and yellow iron oxide, with a content of 5%-15%, ensuring the bright color and long-term color retention of the marking. Additives include antioxidants, ultraviolet absorbers, etc. Although the total amount is less than 5%, it is crucial to improve the aging performance and construction characteristics of the coating.
2. Performance characteristics of hot melt road coating
Hot melt road coating has many excellent properties. Its fluidity is the key to construction, and the melt viscosity is usually controlled at 1500-3000cP (180℃) to ensure smooth spraying and neat marking edges. Bonding strength is the guarantee of durability. The bonding force with asphalt pavement should not be less than 0.8MPa, and with cement pavement should not be less than 1.0MPa.
Wear resistance directly determines the service life. The mass loss after wheel rolling test (JT/T280 standard) should be less than 50mg. Reflective performance is an important indicator of night safety. The initial retroreflective coefficient must reach 350mcd·lx-1·m-2 or above. In addition, the coating must have good environmental adaptability, maintain stable performance in the temperature range of -20℃ to 70℃, and be able to resist erosion by environmental factors such as ultraviolet rays and rain.
3. Hot melt road coating detection method
The detection of hot melt road coating includes physical properties, chemical composition and environmental adaptability. The physical performance tests mainly include melt viscosity determination (rotational viscometer), softening point test (ring and ball method), density determination (specific gravity bottle method), etc. Chemical composition analysis can use infrared spectroscopy (FTIR) to identify the resin type, and X-ray fluorescence spectroscopy (XRF) to determine the content of inorganic components.
Environmental adaptability assessment includes artificial accelerated aging test (xenon lamp aging box), water resistance test (performance change after immersion in water) and low temperature bending test (no cracking at -20°C). Construction performance testing focuses on heating stability (performance change after 180°C for 4 hours) and glass bead distribution uniformity (microscope observation). All tests should comply with the provisions of national standard GB/T16311 and industry standard JT/T280.