Among the construction techniques of currently completed and planned highways, more than 95% are semi-rigid base asphalt pavements. This road pavement structure has advantages in terms of construction cost and load-bearing, but it is prone to cracks, loosening, slurry, and voiding. , subsidence, insufficient subgrade strength, subgrade slippage and other deep-seated diseases. It is not easy to treat deep-seated road diseases. The traditional maintenance plan is generally: do not treat the deep-seated diseases in the early stage and let them develop; when the deep-seated diseases develop to a certain extent, cover them or add pavement; and when the deep-seated diseases are serious enough to affect traffic, Then carry out excavation treatment, that is, traditional large and medium-sized maintenance construction, and the disadvantages it brings are also very obvious, such as high cost, serious waste, impact on traffic, impact on the environment, etc. In such an environment, extending the service life of roads, reducing the cost and waste caused by road maintenance, and improving the overall quality of roads have become a new round of topics.

[1].Hot asphalt mixture is composed of aggregate, powder and asphalt. The management of raw materials mainly involves how to ensure the quality and safe production of raw materials in all aspects of storage, transportation, loading and unloading, and inspection.
1.1 Management and sampling of asphalt materials
1.1.1 Quality management of asphalt materials
(1) Asphalt materials should be accompanied by the original factory’s quality certificate and factory inspection form when entering the asphalt mixing plant.
(2) The laboratory shall take samples of each batch of asphalt arriving at the site to check whether it meets the requirements of the specification.
(3) After the laboratory sampling and inspection pass, the materials department should issue an acceptance form, recording the asphalt source, label, quantity, arrival date, invoice number, storage location, inspection quality, and the location where the asphalt is used, etc.
(4) After each batch of asphalt is inspected, no less than 4kg of material sample should be retained for reference.

As a novice who has just entered the road maintenance industry, today we will learn about the differences between emulsified asphalt and modified asphalt that we commonly use in road maintenance construction.
First of all, the obvious difference between emulsified asphalt and modified asphalt is that emulsified asphalt contains water, while modified asphalt does not.

[1] Common diseases of asphalt pavement
There are nine types of early damage to asphalt pavement: ruts, cracks, and potholes. These diseases are most common and serious, and are one of the common quality problems of highway projects.
1.1 Rut
Ruts refer to the longitudinal belt-shaped grooves produced along the wheel tracks on the road surface, with a depth of more than 1.5cm. Rutting is a band-shaped groove formed by the accumulation of permanent deformation in the road surface under repeated driving loads. Rutting reduces the smoothness of the road surface. When the ruts reach a certain depth, due to water accumulation in the ruts, cars are most likely to slide and cause traffic accidents. Rutting is mainly caused by unreasonable design and serious overloading of vehicles.

The emulsified asphalt equipment is an "internally heated local rapid asphalt storage heater device". The series is currently the most advanced asphalt equipment in China that integrates fast heating, energy saving and environmental protection. Among the products, it is a direct heating portable equipment. The product not only has a fast heating speed , save fuel, and do not pollute the environment. It is easy to operate. The automatic preheating system eliminates the trouble of baking or cleaning asphalt and pipelines. The automatic cycle program allows the asphalt to automatically enter the heater, dust collector, induced draft fan, asphalt pump, and asphalt as needed. It consists of temperature display, water level display, steam generator, pipeline and asphalt pump preheating system, pressure relief system, steam combustion system, tank cleaning system, oil unloading and tank device, etc., all of which are installed on (inside) the tank to form a Compact one-piece structure.

When using a thermal oil bitumen tank, it should be noted that the longer the bitumen is stored in the thermal oil bitumen tank, the more sediment will be produced by oxidation, and the more serious the impact will be on the quality of the bitumen. Therefore, when using a thermal oil asphalt tank, you must check the bottom of the tank once a year to determine whether the thermal oil asphalt tank needs cleaning. After half a year of use, you can test it. Once it is found that the antioxidants are reduced or there are impurities in the oil, you must add anti-oxidants in time, add liquid nitrogen to the expansion tank, or perform fine filtration of the thermal oil heating equipment. Hope that the majority of construction users Even if you know how to use it, you also need to know how to maintain the thermal oil bitumen tanks.