Application of synchronous sealing technology of asphalt gravel in road preventive maintenance
Abstract: Highway is an important part of modern transportation system, and its safety and reliability are directly related to smooth transportation and economic development. However, how to maintain the long-term durability and safety of roads has become a difficult problem for road maintenance departments and experts and scholars to solve. As the core concept of modern road maintenance work, preventive road maintenance technology has become one of the important development directions of road maintenance work. This article will focus on the application cases and advantages of the asphalt macadam synchronous seal layer to discuss the modern road maintenance work, aiming to provide reference and reference for the road maintenance work.
Keywords: highway maintenance; preventive maintenance; asphalt macadam synchronous sealing technology; application cases; advantages; existing problems and improvement ideas;
I. Introduction
The modern highway maintenance work with preventive highway maintenance technology as the core has gradually become a hot topic concerned by highway maintenance departments and scholars. The preventive road maintenance technology reduces the cost of repair and reconstruction in daily maintenance and improves the durability and reliability of the road through scientific maintenance and maintenance of the road. This article will discuss the modern highway maintenance work from the basic concepts, application cases and advantages of preventive highway maintenance technology.
2. The basic concept of asphalt macadam synchronous sealing layer maintenance technology
Asphalt macadam synchronous sealing technology is a relatively common highway foundation maintenance technology. The basic principle is to carry out initial maintenance treatment on the surface of the original pavement layer of the road, spray asphalt and gravel on the road surface at the same time, form a new pavement layer to protect the original pavement, so as to achieve the purpose of improving the quality of the pavement. This technology can effectively fill the cracks in the pavement, increase the hardness and skid resistance of the pavement, improve the durability and water resistance of the pavement, and has the advantages of low cost, long maintenance period, and simple construction. Specifically, the construction process of asphalt macadam synchronous sealing technology mainly includes the following steps: first, surface treatment is carried out on the original pavement, debris, water and soil are cleaned, and the pavement is corrected and hardened; Asphalt and gravel are sprayed to form a new pavement layer; then the road surface is compacted and shaped with a road roller to fully integrate the asphalt and gravel; finally, the road surface is accepted and evaluated for quality. In general, asphalt macadam synchronous sealing technology is a simple and practical preventive road maintenance technology, and has become one of the important technical means in modern road maintenance work.
3. Advantages of asphalt macadam synchronous sealing layer maintenance technology
Asphalt macadam synchronous seal maintenance technology has the following advantages: (1) Low cost: Compared with other pavement maintenance technologies, the cost of asphalt macadam synchronous seal layer technology is lower, because the materials, equipment and labor costs required are all Relatively small. (2) Long maintenance period: After the construction of asphalt macadam synchronous sealing layer technology, a solid waterproof layer can be formed, which can effectively prevent the roadbed from being eroded and infiltrated by water, and prolong the service life of the road surface. (3) High durability: Due to the treatment of the new coating of this maintenance technology, the road surface is more compact and has good adhesion, so the load on the roadbed is evenly distributed, ensuring the road’s bearing capacity and good durability. (4) Simple construction process: The construction process of asphalt macadam synchronous sealing layer maintenance technology is simple, the construction time is short, the number of users is small, and large machinery is not required, which can greatly reduce the construction cost. (5) Wide range of application: The asphalt macadam synchronous sealing technology is applicable to various forms of road preventive maintenance, no matter what the condition of the road surface, this technology can be used for maintenance treatment.
4. Application cases of asphalt macadam synchronous sealing layer maintenance technology
The designed subgrade width of the road section is 10.5m, located in the loess subsidence zone, the average temperature in summer is 26°C, the temperature in winter is -12°C, and the average annual precipitation is 522.6 mm. In recent years, under the combined action of the rapid growth of traffic volume (heavy traffic volume and increased proportion of heavy vehicles) and the continuous increase of traffic load, the road surface of this section has suffered from various degrees of disease, such as vertical and horizontal cracks, tortoise mesh cracks, and pockmarked surfaces. Diseases such as subsidence and roadbed subsidence are increasing, and the service life of the road surface is extended to improve the image of the road surface. In order to solve the above problems, our section implemented asphalt gravel synchronous sealing on this section in 2023, and later organized technical personnel to conduct regular follow-up observations on the appearance of the road surface, the depth of structures, and the water seepage coefficient. Technical condition is good.
In the maintenance project, the following measures are mainly adopted: (1) Send the asphalt and single-graded particle size gravel used in this project to the test and inspection room of the testing center for testing to ensure that all indicators meet the specification requirements.
(2) Repair road surface pits, ruts, subsidence, wrapping, cracks above 5mm and other diseases.
(3) For vertical and horizontal cracks less than 3mm, use SBS polymer sealing material to slot and fill the joints. Strictly follow the procedure of first slotting, then blower cleaning, and then preheating the joints. At the same time, other pollution or sundries on the road surface should be cleaned. Rinse and sweep.
(4) The preparatory work before synchronous sealing is in place. The pre-wrapped crushed stones are prepared in the courtyard of Jingchuan Maintenance Work Area, with an average transportation distance of 15 kilometers from the project road section, which is very beneficial to the construction. The cleaning of the pavement started 3 days before the planned sealing. The road sweeper and blower were spared, and manual cleaning was added to ensure the cleanliness of the pavement.
(5) Calibration and inspection of the synchronous sealing vehicle, the electronic system and control system of the vehicle are in good condition, and the measurement system and temperature control system of the synchronous sealing vehicle are calibrated before construction. In the research and analysis of the theoretical oil consumption (1.3kg/m2) and the actual estimated oil consumption (1.35kg/m2), there are two main points: 1. The driver is still in the stage of being familiar with the machine; 2. Vertical and horizontal Repeated sprinkling of seams is uneven.
(6) After analysis and calculation, according to the scope of the amount of crushed stone stipulated in the “Guiding Opinions on Synchronous Sealing of Asphalt Gravel” within the range of 9 to 11m3/1000m2, the appearance after the synchronous sealing layer is not too dense, with more exposed oil surface, and rubber wheels There are some sticky tires when the road roller is rolling. According to the past experience and the particularity of the construction section, our section adjusted it to 12m3/1000m2. During the maintenance period of more than one month, the floating sand was recovered to 1m3/1000m2, so the amount of crushed stone was actually obtained. 11m3/1000m2.
(7) Through the scientific determination and adjustment of the amount of asphalt and gravel, the effect of synchronous sealing and maintenance after one month is better. The asphalt can wrap 2/3 of the gravel, and the coarse aggregate particles are dense and stable without obvious loss. .
(8) Important management of quality. 1. The project actually started in March to carry out road surface potting and treatment of road surface diseases to ensure that the condition of the road surface meets the standards. 2. In July, when the weather is good and the surface temperature is high, the SX5255TBS asphalt macadam synchronous sealing vehicle is used for synchronous sealing, which ensures the quality of synchronous sealing of the road section of the project. 3. Use hand-held infrared thermometers and thermometers to monitor and control the asphalt loading temperature in parallel to ensure that the asphalt loading temperature is within the standard range.
(9) Rolling. At the same time as the spreading, the rubber-wheeled road roller was immediately used for rolling, and the rolling was maintained at a constant speed of 2km/h. According to the principle of first two sides, then the middle, first slow and then fast, the overlapping width of each wheel track was 30cm. The return position should not be on the same section, and the number of rolling times should be up to 6 times. After rolling, the aggregates are tightly embedded and squeezed, and the stones do not appear to be more crushed.
(10) Traffic control. Before the construction, according to the “Highway Maintenance Safety Operation Regulations” and “Gansu Provincial Provincial Highway Maintenance and Construction Operation Safety Management Regulations”, the traffic is closed in advance, and eye-catching safety signs and speed limit signs are set up on the job site. Traffic law enforcement officers are responsible Manage, command and divert traffic to ensure construction safety.
After rolling, the traffic will be opened. In the early stage of opening to traffic, a special person will be appointed to direct the traffic or set up construction signs to control the driving, so that the initial driving speed will be controlled within 30km/h.
(11) Supplementary sprinkling and initial maintenance. In order to implement refined maintenance and achieve a high-quality project, our section uses manual supplementary spraying treatment for some sections with uneven spraying and unsuitable edge alignment. During the initial maintenance, by placing the conical cylinders, the rolling edge of the passing vehicles is controlled in an orderly manner, and the early maintenance is realized by driving the rolling. the
(12) Draw marking lines with hot-melt paint. Sign a raw material supply contract with regular manufacturers, and each batch of raw materials is accompanied by a factory qualification certificate for this batch of materials.
According to the construction technical specifications of the hot-melt marking line, the length, width, thickness and longitudinal marking line spacing of the marking line segment shall be well controlled. Thoroughly clean the original road surface, apply primer to reduce peeling of marking lines. After follow-up and observation in the later stage, the application of asphalt macadam synchronous sealing technology in this road section has effectively improved the durability and reliability of the road surface, reduced the maintenance cost of the road, and improved the operation efficiency of the road, which has been well received by the general public.
5. Problems and improvement ideas in the construction process
(1) Problems in the construction of asphalt macadam synchronous seal layer: 1. Improper temperature control. The temperature control of asphalt is very important to the construction quality. If the temperature is too low, the asphalt may not completely wet the gravel, while if the temperature is too high, it will cause problems such as burning and sanding. 2. Problems with machinery and tools during construction. Improper use of implements can damage the asphalt surface, preventing gravel from adhering. 3 Construction site management is not strict. Lack of quality supervision of the construction process, inadequate inspection and management of materials and machinery. This can result in uneven thickness of the asphalt macadam layer, defects such as bubbling. (1) Improvement measures: 1. Carry out temperature testing and adjustment carefully before construction to ensure that the temperature of the asphalt is within an appropriate range. 2. Improve the technical quality of construction personnel, strengthen the training on the use of machinery and tools, and encourage professional and technical personnel to use maintenance machinery and tools skillfully and standardizedly. 3. Strengthen on-site management and establish a sound construction quality supervision mechanism. Strengthen the inspection of materials and equipment to ensure that they meet the requirements and ensure the construction quality. In the specific operation process, new technologies and materials can be considered. For example, fiber-reinforced asphalt can make the performance of asphalt more superior, thereby ensuring construction quality. Through the above improvement measures, the quality and efficiency of asphalt macadam synchronous sealing layer construction can be effectively improved.
6. Conclusion
The application of asphalt macadam synchronous sealing technology can effectively prolong the service life of the road and reduce the maintenance and reconstruction cost of the road.
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