1. There should be no less than 5 transport trucks in front of the paver before starting to pave the mixture, to avoid stopping and waiting for the material, and to maintain continuous paving.
When there is a high-power paver, a single machine full section paving can be used, and the single machine or dual machine scheme can be determined through comparison of experimental sections. Regardless of the paving scheme used, a paving machine that can automatically retract and adjust the width should be equipped.
When using a 3-layer asphalt structure layer, the lower layer should be constructed using the hanging line method regardless of whether it is constructed in layers. The middle and upper layers should be constructed using non-contact balanced beams or floating reference beam devices, but the hanging line method should still be used for construction in the middle layer of the bridge head transition section.
When using a dual machine joint paving of a 3-layer asphalt mixture structural layer, the overlapping positions of the lower and middle layers should avoid the lane wheel track. The tracks of the front and rear pavers should overlap by 30-60mm, and the overlapping positions of the middle and upper layers should be staggered by more than 200mm. The distance between the front and rear of the two pavers is generally 10-20m to ensure that the mixture does not segregate, and the longitudinal joint is a hot joint. The longitudinal joints of the surface layer should be located at the markings, and the remaining layers should be adjacent to both sides of the road markings. After each layer is paved, manual cooperation and edge tapping should be carried out to make the edges neat and dense.
5. Before starting the paver, the preheating of the ironing plate should be 0.5 to 1 hour in advance, and the temperature should not be lower than 120 ℃. During the paving process, the vibrating or ramming device of the screed should be selected with appropriate vibration frequency and amplitude to improve the initial compaction of the road surface. The widening connection of the ironing plate should be carefully adjusted until there are no obvious signs of segregation in the paved mixture.
6. The spiral distributor of the paver should be adjusted to maintain a stable and balanced rotation speed corresponding to the paving speed, and the mixture should be kept at a height of no less than 2/3 of the feeder on both sides to reduce the segregation of the mixture during the paving process.
7. The low paving temperature of hot mix asphalt mixture shall be in accordance with Article 5.2.2 of the Technical Specification for Construction of Highway Asphalt Pavements (JTGF40-2004) based on the thickness of the paving layer, temperature, wind speed, and surface temperature of the underlying layer, and shall not be lower than the requirements of the specification table.
8. The paving speed of asphalt mixture should be controlled between 2-6m/min, and the paving speed of the upper layer should not exceed 5m/min. The amount of material used for paving should be suitable for the output of the mixer.
9. The mobile ridge method is generally implemented on the upper layer, and the specific construction methods are as follows:
(1) The length and cross slope of the road section constructed using the mobile ridge method should strictly follow the design implementation.
(2) According to the length of the construction section using the moving ridge method, diagonal lines are taken on both sides of the starting end of the section, and construction is divided into two sections, as shown in the figure below:
(3) Selection and process of construction machinery
A paver with automatic width adjustment and manual coordination should be used for paving and trimming. During the construction of the first section, the paver uses multiple pavers of different widths based on the width of the road surface. Each paver uses the hanging line method to control the elevation. When each paver is laid to the diagonal according to the divided paving width, the paving width automatically decreases until the small paving width of the paver is completed. Then, another paver is started until the first section is completed. Then, manually remove any unexpected areas outside the diagonal and ensure that the diagonal is straight. The second section also adopts multiple paving methods, and the insufficient parts of the paver are manually supplemented.
10. In areas where pavers cannot be used, such as narrow road surfaces, ramps with small flat curve radii, widened areas, and oblique bridge heads, manual paving of the mixture can be used. Manual paving should strictly control the operation time, loose paving thickness, flatness, etc.
11. Strictly follow the design to connect the pavement structure layer and bridge tunnel transition plate (as shown in the figure below), and prepare the working surface at least one day in advance to handle issues such as undercompaction, looseness, and unevenness, and remove loose materials and all debris. The supervising engineer shall inspect and accept this.