Basic Provisions and Paving Methods for Asphalt Pavements

General provisions

1. Asphalt pavement is a pavement structure formed with stone as aggregate and asphalt as binding material. The main types of asphalt pavement are surface treatment, through and through, asphalt crushed stone, asphalt soil and so on.

2. Asphalt pavement project must consider the road surface, roadbed drainage and asphalt pavement pavement after the water temperature stability of the grassroots.

3. Asphalt pavement grass-roots level must have enough strength and then degree, have good stability, and with the surface layer can be good combination.

4. Asphalt pavement and gravel road cross, gravel road should be done not less than 20m long asphalt pavement; and dirt road cross, dirt road should be done not less than 20m long gravel road.

5. Asphalt pavement and tractor road intersection, there should be a special tractor crossing.

6. Before the construction of asphalt pavement, pavement design, construction methods, construction organization, quality standards and safety operations, etc., to the construction staff detailed briefing.

Asphalt and emulsified asphalt

1. Road asphalt mainly use petroleum asphalt, petroleum asphalt technical standards and petroleum asphalt types of surface layer used in asphalt standard according to relevant requirements and regulations.

2. Asphalt pavement selection of petroleum asphalt grade, should be selected according to regional climatic conditions, construction temperature, surface type, construction methods and mineral materials.

3. When the asphalt grade and technical indicators do not meet the technical requirements, other grades of asphalt or diluent mixing. High viscosity petroleum asphalt available residual oil as a diluent.

4. The heating temperature of petroleum asphalt materials should not exceed the relevant requirements and regulations, my mouth boiling to the construction temperature after the insulation time, petroleum asphalt shall not exceed 6h, the day of boiling asphalt should be used up on the day. If the heating temperature is too high or the holding time is too long, it should be tested and then used.

5. Cationic emulsified asphalt is a mixture of asphalt and water plus an appropriate amount of cationic emulsifier emulsion, it is a new type of road construction materials, than the asphalt material to save energy, save asphalt, construction is simple, and has the superiority of the construction of the wet and low-temperature conditions.

6. Emulsified asphalt produced by the factory. Road emulsified asphalt technical standards should be consistent with the relevant requirements and regulations.

7. Emulsified asphalt can be used for asphalt surface treatment, penetration, asphalt gravel, asphalt concrete and other various asphalt pavement structure.

8. Asphalt material construction should be done needle penetration, ductility, softening point, viscosity, asphalt mixing and adhesion test, asphalt concrete pavement should also be done Marshall stability test.

Emulsified asphalt construction should be carried out on the sieve residue, mixing stability, viscosity, evaporation residues and other tests.

 

Mineral materials for asphalt pavement

1. Asphalt pavement mineral materials used mainly crushed stone, gravel, stone chips, sand and furnace dust.

2. Crushed stone to limestone rolled products for the best. Stone should meet the specifications, the strength of three or more.

Stone and asphalt material bonding, water boiling method should not be less than 3 levels.

Stone in the needle flake particle content should be no more than 15%.

Stone should be clean, dry, no weathering, no impurities, soil content should be less than 1%.

3. Gravel do asphalt pavement mineral material, should be screened, generally only applies to low traffic asphalt surface structure. Lack of gravel or rolling gravel difficulties, do large traffic volume asphalt road aggregate, should be mixed with not less than 50% of the gravel.

4. Asphalt pavement sand is generally river sand, sea sand or mountain sand. Its mud content should be less than 5%. Powdered sand, fine sand, especially fine sand should not be used.

5. Stone chips are mechanically rolled rocks into a variety of fine grained material. Stone chips require specifications team design standards, no weathering, no impurities.

6. Asphalt pavement with mineral powder should be limestone powder, less than 0.074mm powder not less than 80%, water content of not more than 1%, can also be used as cement or ground lime instead of mineral powder.

7. Asphalt pavement with mineral materials should be sieved, stone abrasion, stone crushing, needle flake content and other tests.

Asphalt surface treatment of pavement construction

1. Asphalt surface treatment pavement is asphalt and mineral material according to layer paving method or mixing method to repair the thickness of not more than 3㎝ of the thin layer of pavement.

2. Layer paving method of surface treatment with asphalt and stone paved in layers, according to pouring asphalt and spreading the number of stone can be divided into single-layer type, double-layer type and three-layer type.

3. Various types of asphalt surface treatment pavement material specifications and dosage according to the relevant requirements and regulations selected.

4. Asphalt surface treatment before construction should be grass-roots level or the thickness of the old pavement, compaction, smoothness, arch, bending value, etc. to check. The quality of grass-roots level should meet the relevant requirements and regulations.

5. Asphalt surface treatment construction should be checked before the machine, so as to avoid failure, affecting the construction. The main inspection content:

①. Asphalt sprinkler: check the oil pump system, sprinkle oil pipeline, oil gauge, insulation equipment and other faults.

Formal oil sprinkling should be carried out before the road side of the test sprinkler, check the nozzle is not blocked. Every day after the car, should be a small amount of diesel fuel to clean the oil pump system and nozzles;

②. Stone spreading machine: check the transmission system and hydraulic adjustment system, and test sprinkle, to determine each specification stone spreading when walking speed and outlet control clearance;

③. The roller: check the mechanical properties and the drum surface is intact, the surface of the drum with depression or pits and grooves shall not be used;

④. Wheelbarrow: whether the tire leakage, axle, groove is well.

6. Asphalt material in the back of the mix, before paving and sprinkling should be marked and temperature checks.

7. Sprinkle oil should be checked before the number of various types of stone materials required for the project is sufficient, whether the specifications are in line with the requirements, whether or not pollution, wet.

8. Asphalt surface treatment construction should comply with the following procedures and requirements:

①. Put the pavement edge: according to the paving width nail stakes, pull lines or use white ash to draw the pavement edge;

②. Sweep the grass-roots surface of floating soil, horse manure, weeds, wood chips and so on;

③. Sprinkle the permeable layer of asphalt (old asphalt pavement can not be sprinkled);

④. In the permeable layer of asphalt dry condensation, sprinkle the first asphalt.

If you find that the number of sprinkling is not enough, leakage, lack of edge or accumulation and other phenomena, should be immediately made up with artificial sprinkling or scraping. In order to avoid the overlap of oil sprinkling, can be in each section of the joints paved 1-1.5m wide linoleum paper or other coverings.

When the road surface is wide and needs to be sprinkled in two widths, it should be lapped along the center line of the road surface, and the width of the lap is 5-15㎝;

⑤. Spreading the first mineral material: Spreading the first mineral material immediately after sprinkling asphalt. When using stone spreading machine to spread the material, the spreading machine should follow the asphalt spreading machine closely; when spreading the material by hand, the stone material should be sprinkled according to the dosage quota at one time. Partial lack of material or too much, with artificial appropriate to make up, will be excess stone sweep out.

Whether mechanical or manual spreading, should be bamboo broom to find uniform, asphalt is not exposed;

⑥. Rolling: after spreading a section of stone, immediately with 6-8t roller. The roller should start from the edge of the road surface to the center of the road rolling, arrive at the center line, and then start from the other side to the center of the road rolling, each time the overlap of the wheel track is about 30㎝. Rolling 3-4 times;

Seven, double, three layers of surface treatment, then repeat the fourth, fifth and sixth procedures.

9. The initial maintenance of surface treatment pavement is one of the main links in construction. The end of rolling can be opened to traffic. But should be sent to direct traffic or set up roadblocks to control the speed of traffic, the speed should not exceed 20km/h.

Open to traffic at the beginning, there is a flood of oil, should be spread with the upper layer of specifications of the mineral material, and carefully swept evenly. If the surface layer has damage, it should be repaired in time.

10. The use of cationic emulsified asphalt repair surface treatment, construction procedures and asphalt surface treatment is basically the same.

Emulsified asphalt can be spread in the stone wet conditions.

Emulsified asphalt storage, shall not be subject to sunlight and freezing. General storage temperature is not less than 5 ℃. Emulsion lumps should be filtered out, when the lumps are too much, can be heated to about 30 ℃ by micro-fire, stirring after use.

Emulsified asphalt sprinkled should be blackened on the surface of the mineral material (emulsion cracking) before rolling. Generally in 1, 2d before opening to traffic.

Asphalt emulsion surface treatment with material specifications and quantity according to relevant requirements and regulations.

11. Asphalt surface treatment pavement construction must be closely linked, not disconnected. The length of each section should be arranged according to the number of rollers and oil sprinkling equipment capacity, the construction of the day section should be completed on the day. In order to avoid asphalt cooling can not cover the stone or dust pollution caused by adverse consequences.

Construction in the rain was forced to interrupt should be closed to traffic, to be dry after the stone to continue construction.

12. Asphalt surface treatment construction temperature should not be less than 15 ℃, the maximum daily temperature in winter is less than 15 ℃ before half a penny should end the construction to ensure that the pavement molding.

Emulsified asphalt construction, the temperature should not be less than 5 ℃, and half a pon before the end of the construction of freezing.