After the highway was opened to traffic, the maintenance and repair has become an important means to ensure its quality and service life. Due to heavy traffic highways, high-speed driving, its conservation efforts in ensuring the construction quality of the premise, should be timely, fast, secure and can not interrupt traffic. At the same time, we should maximize the conservation of mechanization to strengthen the security of workers on the road, try to avoid frequent mobilization of machinery and equipment. Since too old highway from the opening of a wide variety of different degrees of disease occurred, we were in the Treatment of these diseases at the same time, trial and error, thus formed a relatively complete set of practices and experiences.
1、Pavement Classification of Diseases and Causes
After the highway, in traffic loads and natural factors, pavement cracks may occur, rutting, potholes, goes pro package, subsidence, jumping bridge culvert, bridge asphalt loss and other common diseases.
Pavement Cracks can be divided into a crack (crack Net), longitudinal cracks, transverse cracks.
⑴Pavement Structure and Materials Composition
The thickness of the bituminous material in the pavement structure bigger, the greater the amount of permanent deformation occurs in the deformation driving action. Therefore, the thickness of the pavement structure both have enough carrying capacity, but also has good resistance to rutting. Rigid or semi-rigid, can greatly reduce the base layer and subgrade deformation, thereby reducing the overall rutted pavement. Asphalt mixture has a certain creep and stress relaxation phenomenon in traffic loads, when the force of asphalt beyond its elastic limit and yield point, it is possible to produce plastic deformation, accumulation rut. Rut also have a certain relationship with the mix of options.
⑵Design and Construction
Asphalt Mixture ratio Mix base material and subgrade soil composition, such as design, are likely to affect the generation of rutting. Whether the degree of compaction during the construction of roadbed, drainage, primary compaction, pavement thermal stability to specifications will also affect the generation of rutting.
⑶Road traffic conditions
A large number of heavy or overloaded vehicles on the road due to its uniaxial load increase, and thus more prone to rutting. At the same reason wheels continue to wear the road, especially in the main lane vehicle traveling more, also produced in the ruts.
Pits asphalt concrete pavement is a common disease, its causes have construction mix temperature is too high, so that the aging of asphalt, reducing the bond strength, fragility, driving under load is easy to form pits; mixture temperature is too low, not enough to even make the paving, compaction is not sufficient, leading to compaction It is not enough, but also easy to form pits.pavement layer below elevation control is lax, resulting in insufficient thickness of asphalt upper layer structure, thereby driving under load, this part of the mixture is easily "take away", the formation of pits.After the pavement cracks, water infiltration into the grassroots level, at the traffic load, the base layer may occur loose, subsidence, resulting in the surface layer further cracking. This cycle repeated asphalt surface subsidence will occur off to form a pit.
Road subsidence occurred can be divided into two categories: local settlement and a large area of subsidence.Local small area subsidence is normally provided by the local forming grassroots inadequate, insufficient strength in traffic load, road surface crack occurs when the water penetrated the damaged further soften the grassroots, so that the surface layer subsidence.A large area of subsidence are generally made roadbed uneven settlement or partial slippage caused.
The coarse asphalt concrete sealing water poor performance, when poor drainage deck easily between the asphalt surface and the deck water in winter prone to frost damage in traffic load, pavement prone turtle crack or even fall off. Especially in the winter snow or ice is performed after sprinkle salt melt due to saline corrosive effect on concrete, so when salt water to penetrate into the deck, the deck will produce different degrees of corrosion, the formation of mortar, from the cracks in reverse osmosis to the pavement under traffic load, pavement cracks quickly, falling, pit.