News

Road markings are the “silent conductors” of urban traffic order, undertaking the important mission of guiding traffic flow, regulating traffic, and ensuring safety. However, with the continuous growth of traffic volume, erosion by the natural environment, and the upgrading of road maintenance needs, old road markings will gradually wear, fade, and become blurred, and even overlapping old and new markings may occur. This not only affects the visual recognition of traffic participants but also may pose potential traffic safety hazards. At this time, an efficient, environmentally friendly, and safe marking removal technology becomes the key to road maintenance work. High-pressure water cleaning technology for road markings emerges as the times require, and with its unique advantages, it has gradually replaced traditional removal methods, becoming the mainstream solution in the industry and injecting green new vitality into urban road maintenance.​

The core of high-pressure water cleaning for road markings is to use a high-pressure water pump to pressurize water to an extremely high pressure (usually 150-220MPa, which can be increased to 300MPa in special scenarios), convert the high-pressure water into high-speed water flow through a special fan-shaped nozzle, and accurately break the bonding surface between the marking coating and the road surface by virtue of the impact force and shear force of the water flow, so that the marking coating is completely peeled off to achieve non-destructive removal. As a physical cleaning technology, compared with traditional methods such as chemical solvent removal, mechanical milling, and sandblasting, it fundamentally avoids many drawbacks of traditional processes, demonstrates significant technical advantages, and has been recognized and supported by the relevant technical specifications of the National Technical Committee for Standardization of Jet Equipment .​

Environmental protection is the most prominent highlight of high-pressure water cleaning technology. Traditional chemical removal methods require the use of a large number of chemical agents containing heavy metals and organic solvents, which not only pollute soil, water, and air but also may corrode road materials and shorten the service life of the road surface; mechanical milling and sandblasting methods will generate a lot of dust, endanger the health of construction personnel, and pollute the surrounding environment at the same time. In contrast, high-pressure water cleaning only uses clean water as the medium, without adding any chemical reagents. No dust is generated during the cleaning process, and no harmful pollutants are discharged. The cleaned wastewater and marking residues can be recycled and treated by professional equipment to avoid secondary pollution, which fully conforms to the modern green and environmental protection concept of road maintenance and meets the environmental protection control requirements of various regions. Districts such as Changning and Chongming in Shanghai, and Xuzhou in Jiangsu Province have taken the lead in applying this technology, achieving good application results in urban areas with dense population and high environmental protection standards, and winning wide recognition from surrounding residents.​

High efficiency, speed, and no damage to the road surface are another core advantages. The impact force of high-pressure water flow can accurately act on the marking coating without damaging the base course of asphalt, cement, and other road surfaces, which can maximize the retention of the original flatness and structural integrity of the road surface, avoid road damage caused by marking removal, and reduce the subsequent road repair costs. In terms of construction efficiency, the high-pressure water cleaning equipment is easy to operate and can be operated by a single person. The removal speed can reach hundreds of meters per hour, which is ten times that of the traditional chemical removal method and several times that of the mechanical milling method, which can greatly shorten the construction period and reduce the impact on traffic. It is especially suitable for busy traffic areas such as urban main roads, highways, and parking lots. Night construction (22:00 – 6:00 the next day) can be used to further reduce traffic interference, realizing “construction without blocking roads and maintenance without disturbing residents”. In a main road marking renewal project in Changning District, Shanghai, the construction team completed the removal of thousands of meters of old markings in only two days, with no dust and no noise throughout the process, fully reflecting its high efficiency advantage.​

The wide application range and prominent economy have continuously expanded the application scenarios of high-pressure water cleaning technology. High-pressure water cleaning can efficiently remove all types of markings, including solvent-based, hot-melt sprayed, water-based coatings, and reflective glass bead-containing markings. It is suitable for different types of road surfaces such as asphalt and cement, and can be widely used in the renewal and maintenance of markings in various scenarios such as urban roads, highways, airport runways, industrial parks, and parking lots. It can even meet the needs of removing difficult special markings such as colored hot-melt markings[8]. In the long run, although the initial investment of high-pressure water cleaning equipment is slightly higher, there is no need to continuously purchase chemical solvents. The equipment is simple to maintain and has a low failure rate. Moreover, it can completely remove the markings, provide a flat and clean foundation for re-marking, extend the service life of new markings, and greatly reduce the overall maintenance cost, which has both economic and social benefits. This is highly consistent with the conclusion of the cost-benefit analysis of advanced road maintenance technologies.​

A standardized construction process is the key to ensuring the effect of high-pressure water cleaning. The complete construction process is usually divided into four stages: In the pre-preparation stage, the construction team needs to conduct on-site investigation, clarify the type of markings, road conditions and surrounding traffic conditions, formulate a detailed construction plan, prepare equipment such as high-pressure water marking removers, warning signs, and residue removal vehicles, and complete the traffic control approval and communication with the surrounding area; In the on-site control stage, strictly implement the principle of “first closing the road, then setting up control”, set up warning signs and enclosures, conduct safety protection inspections on construction personnel, and ensure construction safety; In the core removal stage, first clean up the debris in the construction area and locate the boundary of the markings, then adjust the appropriate water pressure, nozzle angle (15-30°) and moving speed (0.5-1 meter per minute) to accurately clean the markings. For stubborn markings, repeated operations or auxiliary slight milling can be performed, and attention should be paid to protecting the road joints to avoid damage; In the final acceptance stage, timely clean up the residues and recover the waste water, check the road surface removal effect (residue ≤ 5%), repair minor road scratches, remove the enclosures and restore traffic, and complete the acceptance closed loop to ensure that the construction quality meets the relevant standards.​

With the continuous improvement of China’s road construction and the continuous improvement of environmental protection requirements, high-pressure water cleaning technology for road markings, with its core advantages of high efficiency, environmental protection, safety and economy, has been widely used in the maintenance of municipal roads and highways in many parts of the country, becoming an important support for road marking renewal and traffic environment optimization. In the future, with the continuous upgrading of technology, high-pressure water cleaning equipment will become more intelligent and miniaturized, with more convenient operation and further expanded application scenarios. It will inject new motivation into urban traffic safety and green road maintenance, help create a more orderly, safer and more environmentally friendly road traffic environment, and provide strong support for green urban construction.