A1.Summary The base course of asphalt pavement is composed of rigid and semi-rigid，The surface is paved with different materials accord to the base course,to enhance the bonding effect and improve the quality of the highway.In addition, the asphalt surface will ooze water,after seepage, a lot of moisture will be concentrated in the base and surface layer,Causes of asphalt pavement potholes, loosening, fracture.As a result, the surface stability and strength can be improved to a maximum extent by performing seal coat on semi-rigid or rigid base surface,Improve waterproof performance. 2.The principle and characteristics of macadam synchronous seal technology The main difference between common stone seal and stone synchronous seal is that,The stone synchronous seal can substantially shorten the time interval between the binder spray and the stone，To make the binder better to allow the stone to be immersed.The principle of the stone synchronous seal technology is to use professional equipment,Material such as crushed stones or asphalt that is sticky on the pavement,Then use the rolling method,The road surface is crushed into asphalt macadam,Thus, the stability of the pavement and the stability of the structure are guaranteed.The technology of synchronous sealing of macadam can improve the anti cracking, water resistance and crack resistance of the pavement,The life of the road can be greatly prolonged by the use of the technology. 3.The role of synchronous seal technology 3.1 load transfer The asphalt surface is closely related to the rigid and semi-rigid base structures, and plays a supporting and switching role in these structures.Asphalt surface layer can play the role of anti-skid, waterproof and anti noise,It also plays a role in resisting shear, sliding, cracking and so on, so that the load can be transferred to the base.If the transmission load is reached, the continuous bonding between the surface layer and the base layer shall be maintained, and the continuity shall be treated by the sealing layer. 3.2 Increased pavement strength After the completion of the grassroots seal processing base will increase a friction resistance and adhesive force, the rigid bond between transition, provide support to ensure that the surface layer of soil, grass, cushion, can together to resist the load, so that the overall strength of the road increases. 3.3 Waterproof penetration In addition to increasing the strength, the quality of asphalt concrete in construction, stone strength, impact factors, size is also an important proportion, mixing, paving, rolling temperature, time will affect the quality of asphalt. Especially the precipitation area pavement often appear serious water seepage, thus adding gravel under seal is very necessary. 3.4 Low cost, long life From the kind of aggregate, the stone synchronous seal layer does not have too many special requirements, so it can reduce construction cost.In the application of slurry seal technology, it will be applied to the multi grade aggregate, and the aggregate will have relatively strict requirements. In general, the aggregate is transported to the construction site in the field, resulting in increased cost of the project. 4 Introduction of construction technology of macadam synchronous seal There are three main steps in the construction of the stone synchronous seal:The first step is heating during transportation; the second step is laying by spraying; the third step is full rolling. 4.1 Heating transportation In this project, the traffic of the construction section should be controlled first, and the surface of the highway on the construction site should be deeply cleaned,The heating temperature and dosage of asphalt binder should be strictly controlled，To ensure that it can deliver the materials to the construction site at the appointed time. 4.2 pray laying When the construction of the crushed stone seal is carried out on the site,Seal truck need dump truck and running truck to spray the crushed stones. 4.3 fully compacted When the stone synchronous seal coating is complete,The next process is to compact the road surface,Thus, the solidification time of the pavement can be shortened effectively,And attention should be paid to compaction,See if there is any prominent place,Until the protrusion is rolled flat.