The highway is mainly asphalt concrete pavement. Compared with cement pavement, asphalt pavement has its obvious advantages: smooth surface, no joints, comfortable driving, abrasion resistance, low vibration, and easy maintenance. It is because of this that asphalt pavement can be easily maintained. It has made great progress.

Whether it is a maintenance project or an asphalt concrete pavement construction project, it is indispensable to "seal the layer" of the bottom layer. There are two kinds of sealing processes: the first method is to spray hot asphalt (or emulsified asphalt) on the surface of the bottom layer; the second method is to spread the emulsified asphalt on the surface of the bottom layer. The first method is relatively simple and economical, so it is widely used.

Asphalt spraying machine sprays liquid asphalt evenly on the gravel pavement to build asphalt pavement machinery. All self-propelled devices are installed on a car chassis, called asphalt spraying vehicles; all towed devices are installed on a trailer, mostly small.

The spray system consists of a circulation pipe, a small three-way valve and a spray pipe with nozzles. The circulation pipe is a relatively thick vertical and horizontal pipe, which is connected between the asphalt tank and the spray pipe. The spray pipe is located at the bottom and rear of the machine. After the bitumen pumps out the liquid bitumen from the bitumen tank, the bitumen can be returned to the bitumen tank for circulating heating according to the position of the three-way valve, or sent to the spray pipe for spraying.

Before spraying, the burner should be extinguished, and the width and height of the spraying pipe and the angle of each nozzle should be adjusted according to the construction requirements, and then spraying while driving. The spray system is equipped with a portable spray gun to repair pits or missing areas.

After the work is over, the asphalt tank and spray pipe should be drained of the remaining asphalt and rinsed with solvent. The main technical parameters of the asphalt sprayer are the capacity of the asphalt tank, the rated spraying volume and the spraying width.

The machine has the characteristics of simple structure, flexible maneuverability, easy starting, uniform spraying, convenient cleaning, economical and practical, and it is an economical asphalt sealing machine for engineering construction.