A Brief Discussion on the Construction of Mechanized Teams for Highway Pavement Maintenance

With the rapid economic development, the continuous increase in transportation traffic volume and the continuous extension of black roads, especially the promulgation and implementation of the "Road Traffic Safety Law", society has put forward new requirements and challenges of "safety, comfort and speed" for road conditions and rapid maintenance. The Sanshui District Highway Bureau of Foshan City has taken the lead in the blackening of road maintenance and the rapid repair of asphalt pavement among all highway bureaus in Foshan City. In the face of the rapid maintenance of asphalt pavement under heavy traffic, it has increased investment in maintenance machinery and personnel allocation, and improved the skills and professional and mechanical levels of mechanical maintenance workers to meet the needs of the rapid development of the highway maintenance industry.

The current development status of highway maintenance in Sanshui District, Foshan City

With Foshan building itself into the third largest city in Guangdong Province, the development of infrastructure, especially road transportation, has become a hot trend. Sanshui District, as a pioneering area for the blackening of road surfaces by the Foshan Municipal Highway Bureau, is responsible for the maintenance and management of 154.6 kilometers of roads in the district. Among them, after nearly three years of road surface renovation, about 60% of the road mileage has been transformed into comfortable asphalt roads for driving. The blackening of the road surface has been gradually achieved.

At the same time, to ensure smooth road traffic and road safety, toll stations were abolished in Foshan. All sections under the management and maintenance of the Sanshui Highway Bureau have no toll stations at the entrance and exit. The traffic volume on National Road 321, provincial roads and urban roads has increased significantly, and various diseases such as rutting, displacement and damage on the road surface have gradually emerged. After the completion and renovation of highways, how to establish a mechanized maintenance construction team for rapid maintenance is placed before us. If the highway department does not have a mechanized maintenance team for rapid maintenance and efficient repair, it will to a considerable extent affect the level and ability of the highway maintenance department to serve the society. Therefore, it is of great significance to establish mechanized maintenance teams, achieve the matching of construction techniques and machinery, quickly repair the road surface, reduce maintenance cycles, and ensure the safe passage of highways.

The construction of mechanized teams for highway pavement maintenance

In order to change the backward situation of highway pavement maintenance construction methods, starting from 1994, the Sanshui District Highway Bureau merged the original ten small road teams and established one maintenance center and two maintenance work areas to be responsible for the maintenance tasks of 146 kilometers. In the past three years, in the face of the rapid development of the highway network, in light of the current situation of blackening of the road surface in our bureau and the development trend of the large-scale transportation network in Foshan, we have proactively intervened in the development plan of mechanized maintenance and rapid road surface repair. We have established mechanized operation teams as the basic units to achieve cross-work area and cross-regional mechanical dispatching and leasing construction operations throughout the bureau. Vigorously develop the matching of maintenance machinery and maintenance personnel to enhance the capacity for rapid emergency repair and maintenance.

2.1 Matching of maintenance machinery

In the face of road surface diseases and rapid road maintenance construction under heavy traffic, without the corresponding maintenance machinery, the duties of the highway maintenance department cannot be fulfilled, and thus it is impossible to do a good job in highway maintenance, let alone talk about the quality of maintenance. Over the past two years, the Sanshui Highway Bureau has purchased a large number of mechanical equipment and strengthened the cooperation and training of human resources. The level of mechanized maintenance has been greatly improved, and the maintenance quality has been recognized and highly praised by the society.

2.1.1 Road surface joint sealing unit

As the years of road operation increase, various crack diseases often occur on the road surface. Common diseases of asphalt road surface include longitudinal cracks, transverse cracks, fatigue cracks, block-shaped cracks, reflective cracks, etc. Diseases of cement concrete road surface include longitudinal cracks, transverse/diagonal cracks, corner damage, corner spalling, joint seal layer damage, etc. If the joint sealing treatment is not carried out in time, Rainwater flowing into the lower surface pavement structure and subgrade along the cracks in the road surface will accelerate the enlargement of the cracks and form potholes. Pavement joint sealing treatment can prevent the occurrence of potholes to the greatest extent, stop the further spread of cracks, and thus extend the service life and maintenance cycle of the pavement.

In response to the cracking of asphalt pavement and the daily maintenance of cement pavement, our bureau has imported a German-made Baling brand crack sealer to carry out preventive maintenance on the pavement. This machine is easy to move and is equipped with a hot machine function for seam cleaning (heating) assembly and seam filling. The joint cleaning device uses high-pressure and high-temperature combustion gas to effectively remove (or heat and melt) the original old joint filling materials and debris. The joint filling adopts a three-legged guiding method and can manually control the oil pump speed and opening size to control the oil output, ensuring high joint filling quality. Moreover, a 1.5-ton asphalt melting furnace was jointly developed with Huizhou Highway Machinery Factory. It uses heat transfer oil to heat asphalt, featuring fast heating speed, simple and practical operation, and excellent heat preservation effect. At present, this machine can fill up to 4 kilometers of cement road joints on a single line in a day.

Personnel configuration: As this crack filling machine has no power of its own and is towed by a maintenance vehicle, the personnel coordination consists of one maintenance vehicle driver, one person for forward crack cleaning, one person for rear crack filling, one person for command, and one person for sign maintenance. This can effectively form a rapid crack filling team with high efficiency and stable quality, featuring forward crack cleaning and rear crack filling.

2.1.2 Asphalt Pavement Rapid Repair Group

To meet the requirements of mechanized maintenance and rapid traffic opening, our bureau has invested over 3 million yuan to purchase advanced W50 imported small road milling machines, F5C small asphalt pavers, BW120 small vibratory rollers, 600-700kg hand-guided rollers and dump maintenance vehicles, forming a key joint maintenance team for G321. The capacity for rapid road surface repair has been unprecedentedly enhanced.

The W50 small road milling machine is an original import from Wittgen, Germany. As the first step in the rapid road repair process, this machine has a power of 69kW, a milling width of 50cm, and a maximum depth of 16cm. The depth is controllable, the transmission is smooth, it can move quickly, and the conveyor belt is detachable. It is suitable for rapid milling operations on roads in urban areas and heavy traffic regions.

The F5C small paver is a small asphalt paver from Dynapac in Germany. It is driven by hydrostatic pressure and has an output power of 29kW. The standard (basic) width of the screed is 1200mm and can be extended to 2400mm. The minimum paving width can be reduced to 600mm by installing a partition. The maximum spreading width can reach 3100mm by mechanically installing a screed. The maximum spreading thickness is 200mm, the spreading speed is 0 to 25m/min, and the walking speed is 0 to 3km/h. The heating of the ironing plate adopts gas heating and electronic ignition. The arch of the ironing plate can be adjusted within the range of -2% to 4%. It features balance, flatness and ease of operation. This paver is specifically designed for construction on narrow roads and major highways such as G321 where traffic volume is increasing day by day. It can also be used in bicycle lanes, pedestrian paths, shoulders, parking lots and sports venues.

The BW120 roller is a German BMW double steel wheel vibratory roller with a power of 22kW and a compaction width of 1.2m. It is hydraulically driven and easy and convenient to operate.

Personnel allocation To meet the construction requirements that milling must be completed and traffic opened on the same day, the workload for each shift of milling is approximately 200 square meters. The minimum personnel combination is as follows: 3 waste material loading and unloading vehicles, 3 drivers, 1 milling machine operator, 1 commander, 3 paver operators, 2 asphalt loading and unloading vehicle drivers, 1 commander and 3 to 4 auxiliary personnel, and 1 to 2 roller operators. One person is needed for sign maintenance.

2.1.3 Overhaul Mobile Team

To meet the development requirements of later major overhauls and construction and maintenance projects of highways, our bureau has formed a mechanical major overhaul mobile team consisting of over 40 people, including senior engineers, engineers, assistant engineers, technicians and mechanical operators. This team is equipped with two large ABG asphalt pavers, a W1900 large milling machine, three imported asphalt rollers ranging from 10 to 13 tons, two asphalt mixers (with a combined hourly production capacity of 250 tons), a stabilized soil mixer with an hourly production capacity of 800 tons, a single steel wheel roller of 19 to 25 tons, and a variety of construction machinery with excellent control precision. The daily construction capacity reaches 3,000 tons of asphalt mixture, and the annual construction capacity reaches 80 million tons. Over the past three years, the major repair mobile team has completed approximately 200 million yuan worth of asphalt pavement projects. It has been hailed by the outside world as the vanguard of Sanshui's road traffic. It can quickly and effectively complete the major repair of main roads in a very short time, especially the major repair of ruts at urban traffic lights and the road network renovation project of our bureau, making early preparations for the mechanization, marketization and scientification of maintenance.

2.1.4 Road Surface Cleaning Team

Equipped with 3 large ZLJ5150TSL road sweepers and 5 water trucks with a capacity of 5 to 8 tons, they are responsible for road sweeping, washing, cooling of newly paved roads, clearing obstacles, and daily maintenance of the road surface, ensuring rapid traffic opening and safeguarding the safety of construction workers.

2.2 Personnel Training and improvement

People are the masters of all activities. If the quality and level of people are not improved, even the best mechanical configuration will just be for show and will be difficult to exert its due efficiency. For personnel training, our bureau adopts a three-level training system jointly conducted by the manufacturer, the municipal bureau and the mechanical management department of our own unit, forming a "reverse slope" training theory that involves training by the manufacturer, on-site tracking by technical personnel and joint summary.

The use, operation and maintenance of mechanical equipment, as well as the proficient and mechanized coordination of construction techniques, are like a ball placed on a slope. Without sufficient crawling force, it will not move forward and will either retreat as time goes by. This is the human slope theory, which means that if a person stands on a slope and does not receive training, exercise and improvement of their abilities, they will slowly slide down the slope like a ball. To comprehensively enhance the level of mechanical maintenance and strengthen the job skills of mechanical personnel, it is necessary to conduct "anti-slope" training, urging and guiding mechanical personnel to keep learning hard and be familiar with their jobs. Improve and perfect one's operational and management skills through practice, achieve the best combination and optimization of personnel and machines, and adapt to the requirements of market competition in highway maintenance.

2.2.1 Strengthen practice and guidance to enhance the overall management level of machinery throughout the process

In response to the low quality of maintenance machinery workers, the mechanical administrative department has specially assigned a mechanical engineer who has been responsible for the mechanized construction and on-site management of large-scale construction machinery for many years to be in charge of the entire process management of maintenance machinery and the technical training of workers. During the practical production of construction, they urge road maintenance workers to improve their road maintenance skills and mechanized maintenance levels, achieving a balance between "man and machine". Standardize internal management work and achieve comprehensive management.

In order to ensure the safe and effective normal operation of mechanical equipment, reduce the frequency of faults and improve work efficiency, the Sanshui Highway Bureau, based on the current status of mechanical equipment, translated foreign language materials and instructions, enabling management personnel to fully familiarize themselves with advanced mechanical technologies and products, and formulated the "Safety Operating Procedures for Mechanical Equipment" and the "Technical Maintenance Procedures for Mechanical Equipment". It ensures the normal operation of various mechanical equipment and realizes the safe production of equipment and the joint management of personnel.

In terms of maintenance management, our bureau has significantly strengthened the tracking, inspection and maintenance of machinery. We have established a maintenance approach that combines self-inspection during daily use, mutual inspection, and regular checks by professional personnel. We also send the equipment to repair shops for random and synchronous on-site maintenance by operators and managers. We keep detailed records of equipment failures and maintenance.

2.2.2 Organize civilized locomotive competitions to enhance the comprehensive quality of mechanical maintenance personnel

The construction of mechanized teams requires the common development of mechanical hardware levels and human resource software. People are the creators of wealth. To enable mechanized teams to play a full, efficient and rapid role, it is necessary to give full play to people's subjective initiative.

First of all, it is necessary to strengthen ideological education for maintenance workers, change their backward view that the technical content of highway maintenance operations is not high, the operation content can be handled by manual means, and that China has an abundant labor force and low workers' wages, and manual maintenance can save costs. Let them realize the importance of mechanized maintenance from the ideological level Mechanization is an important condition for ensuring the quality of maintenance and a guarantee for the rapid and smooth operation of highways.

Second, enhance training to improve mechanical operation skills, familiarize oneself with new processes and materials, shift from being afraid of machinery to enjoying it, and become the masters of mechanical maintenance. The operators are proficient in the ten-character operation guideline of "cleaning, tightening, adjusting, lubricating and anti-corrosion" for equipment maintenance, strictly control the quality of external fuel and water, do a good job in the cleaning of the "three filters", and vigorously strengthen the guidance of mechanical management personnel on the safe operation and technical maintenance of large, medium and small-sized machinery, with dedicated personnel and dedicated machines for maintenance.

Third, strengthen mechanical management and carry out civilized locomotive competition activities. Our bureau requires that every mechanical operator must be proficient in the operation, use and maintenance of at least two types of machinery. We strengthen the management of mechanical usage, operate the machinery correctly in accordance with the operating procedures, and give certain rewards to mechanical operators who perform well in mechanical operation and use, which has better mobilized the enthusiasm of workers.

In today's increasingly fierce market competition and with the rapid advancement of science and technology, only by implementing the "anti-slope" theory, strengthening the training, education and guidance of mechanical personnel, improving their comprehensive quality, and optimizing the construction of mechanical human-machine teams, can our management personnel and mechanical operators adapt to the requirements of large-scale highway production. Only in this way can the work goal of "maintaining good roads and serving the society" be better achieved.

The effects and prospects of mechanized implementation of road surface maintenance

The development of maintenance mechanization is a modern construction method to enhance production efficiency and achieve rapid road restoration, which can reduce the chance of construction workers being injured by passing vehicles while working on the road surface. At the same time, through the construction of mechanized maintenance teams, we have strengthened internal management, improved the technical quality and maintenance quality of maintenance workers, extended the maintenance and repair cycle of the road surface, and reduced maintenance costs. As a result, we have created relatively good social value and received high praise from the provincial highway departments, enabling our bureau's mechanized maintenance to take the lead in the province. The construction and practice of the road maintenance mechanization team have enabled our bureau's highway maintenance to embark on a professional, mechanized and scientific path of safe production, ensuring high standards and quality of highway maintenance, and maximizing the safety and smoothness of highways, especially national and provincial roads passing through. This is an important manifestation of safety guarantee projects and also lays a solid foundation for adapting to the competition in the maintenance market.

Problems and areas for improvement in the mechanization of maintenance

(1) Properly handle the relationship between the utilization rate and the integrity rate of mechanical equipment. There is an essential difference between highway maintenance departments and transportation production enterprises. The higher the equipment utilization rate of transportation production enterprises, the better their benefits. The higher the utilization rate of highway maintenance machinery and equipment is, the greater the cost expenditure will be, and the greater the financial pressure on the maintenance unit will be. The economic benefits reflected by the maintenance department lie in society rather than the maintenance department, which may lead to the maintenance department's reluctance to use or own mechanical equipment.

(2) Gradually form a market-oriented leasing pattern for maintenance machinery, implement cross-work area joint operations and cross-regional rapid repair operations. However, due to the current system, our maintenance departments (highway bureaus, highway sections, etc.) do not have maintenance qualifications, which leads to certain problems in the operation of leasing business for mechanized maintenance teams, contract disputes, and invoice issuance. This needs to be considered and improved under the condition of sorting out multiple relationships.