Cold regenerator operation:
The cold regenerator has a crushing and mixing width of 2.4 meters. During the operation, a water tank truck should follow closely to ensure the mixing water. During the mixing process, the water content should be controlled by 1-2% higher than the optimal water content as specified in the test sheet (provided that it is known that the regenerator opens several water nozzles to convert the water content). Another water tank truck should be full of water and on standby at any time. Once the water tank working with the regenerator runs out of water, it should be immediately replenished. To ensure the continuous operation capability of cold regeneration. The traveling speed of the cold recycling machine shall be adjusted according to the pavement damage and recycling depth, which is generally 6m/min~12m/min, so that the grading fluctuation range of milled materials is small. The traveling speed of the regeneration unit shall be reduced and the speed of the milling rotor shall be increased in the section with serious mesh cracks. If the thickness of the structural layer of the old pavement layer is greater than 8cm, and it is difficult for the cold recycling machine to walk, the cold recycling machine shall first mill the old pavement layer, and then pave cement on the crushed materials for cold recycling mixing construction. In the process of cold regeneration, personnel shall follow to check the mixing depth and humidity at any time, generally subject to 20 meters. In case of any nonconformity, report it to the driver in time for solution. During each cold recycling construction, the vibratory roller shall follow 20m behind the cold recycling machine, and the mixed mixture shall be rolled with high amplitude and low frequency vibration in a timely manner at a speed equal to the driving speed of the cold recycling machine. Aim To seal the water in the mixture when the water content is good.
Two types of joints shall be considered during regeneration construction: longitudinal joints parallel to the road centerline and transverse joints perpendicular to the road centerline.
Longitudinal joint: the working width of the recycling machine is generally less than the width of the road or carriageway, so the cold recycling of the full width road requires multiple operations, resulting in the longitudinal joint between the adjacent working surfaces. A certain amount of overlap is required along the whole longitudinal joint to ensure the continuity of longitudinal joints between adjacent working faces. The overlap between adjacent working surfaces shall not be less than 10cm. The thicker the pavement, the greater the overlap; The coarser the particle size is, the greater the overlap is; When the interval between two adjacent operations is more than 12h, the overlap shall be increased. On the longitudinal joint, change the water injection amount according to the completion time of the built regeneration layer. The location of longitudinal joints shall avoid the wheel tracks of slow moving heavy vehicles as much as possible. During construction, guidance prompt shall be established by striking signs on the existing road surface or measuring the reference line to help the driver operate the recycling machine correctly and avoid the existence of unmixed sandwiches between adjacent working surfaces.
Transverse joint: the transverse joint formed due to the start or termination of each construction is discontinuous. Every shutdown, even if it only takes a few minutes to replace the tanker and cutter head, will also form a cross seam that seriously affects the uniformity of recycled materials. Therefore, the shutdown phenomenon shall be reduced as much as possible during the construction. If it is unavoidable, the transverse joints formed shall be overlapped carefully. Attention shall be paid to the water content when handling the transverse joints. Generally, the water content shall be halved as normal when the knife is lifted and dropped. At the beginning of regeneration construction, all the starting steps shall be carried out in strict sequence, especially the exhaust procedure of water pipes. All gases shall be discharged before the water reaches the spray bar. If the exhaust is improper, there may be no water in the mixture within the first few meters of the start of regeneration construction, which will lead to unstable sections in the pavement. When restarting after a temporary shutdown, the whole regeneration unit shall back off at least one rotor diameter distance of 1.5-2 meters to reach the regenerated material. This will ensure that all materials are disposed of after the start of construction. When the machine is shut down for more than the initial setting time of cement, the whole machine shall be backed up to 1.5m away from the regenerated road section and the cement shall be spread again. The problem of transverse joint will occur only when the construction stops. Therefore, the regeneration unit can only be shut down after the tank car is empty or under similar circumstances. The shutdown shall be minimized during construction, and the cutter head shall be replaced after each section of the road is completed, so as not to affect the subsequent process.
After the regeneration mixing is uniform, the color shall be consistent, there shall be no ash strips, ash lumps and flower surfaces, that is, there shall be no obvious segregation of coarse and fine materials, and the moisture shall be appropriate and uniform. At the end of the cold recycling construction every day, the knife head must be cleaned away from the road surface of the construction section on that day to prevent the knife washing water from flowing into the newly drilled pavement structure to create a soft foundation.