What happened to the potholes in the newly paved asphalt concrete pavement

First, the quality of the roadbed.

1.The compaction of the subgrade is insufficient, and the moisture content is not applied.

Larger subgrade soil is replaced or quicklime is used.

treatment, or compacting the subgrade in rainy days, resulting in insufficient bearing capacity of the subgrade, under long-term overload, the uneven settlement of the subgrade forms cracks, which are reflected to the road surface, and cause despawning and dislocation over time.

2.The roadbed drainage facilities are not perfect.

The water in the roadbed cannot be drained, resulting in the instability of the roadbed.

3.For the roadbed in wet areas and areas with abundant groundwater, no filter layer is set.

and sealing layer, so that groundwater seeps into the subgrade and destroys the subgrade structure.

Second, the quality of the pavement problem.

1.There is no permeable oil or layer oil between the roadbed and the pavement, especially for the subgrade and pavement of different materials, which will lead to the poor overall combination of the subgrade and the pavement, and seriously affect the structural performance.

2.The asphalt material did not pay attention to heat preservation and rain protection during transportation, and the minimum allowable temperature value could not be reached when the material was blanked and paved, and it was not treated as a waste material, and it was directly paved. Or the asphalt meets the quality standard of the paving material, but the construction is not strictly in accordance with the requirements in the paving process, such as the selection of rolling machinery is not suitable, the number of rolling times is insufficient, and the wet construction is used to sprinkle too much water.

These people will inevitably have omissions, negligence, and cheating when operating. Xi'an Enchi digital construction visualizes the construction process data and monitors the paving and rolling of the road surface in real time.

3.The road drainage facilities are unreasonable or no drainage facilities are provided.

Third, improper maintenance of pavement after forming.

1.Asphalt pavement is not maintained using the correct health care method.

2.The maintenance intensity is not up to the permissible open traffic intensity, and the traffic is opened.

We're having the same issue as well? Could it be a problem with asphalt?

Potholes are generally a grassroots problem.

1. Asphalt pavement concrete layer permeability:Part of the construction unit did not follow the design and construction requirements, in order to save costs in the asphalt pavement concrete layer filled with coarse material, resulting in more coarse material and less fine material, and the void ratio is far greater than the national requirements. After being put into use, especially in the rainy season, water permeability will occur, which is one of the causes of potholes on the pavement.

Second, the strength of the base layer is insufficientIn the process of asphalt pavement construction, due to mechanical failure or improper operation method of workers, the base mixture is segregated, and the local base strength can not meet the requirements of design and construction. If in the general road section, the gravel base will appear segregation, resulting in the local coarse aggregate is too concentrated, and the water tightness is too poor.

Third, there is a local interference layer between the asphalt concrete layer and the base layerBecause the local floating soil, floating slurry cleaning of the base is not clean, in the construction process, the local isolation layer is generated, if the asphalt concrete layer of the corresponding position leaks, the mud bag will be formed, the shear ability and compressive strength of the road surface can not meet the design requirements, and the mud gushes out will be caused by the repeated action of vehicle pressure.

The thickness of the surface layer is not enough, the adhesion of the asphalt mixture is not good, the heating temperature of the asphalt is too high, the rolling is not compact, and under the action of rain and driving, the performance of the surface layer material is deteriorating day by day, loose, cracking, and gradually forming a pit.

Asphalt pavement refers to various types of pavement paved with asphalt materials mixed with mineral materials. Asphalt binder improves the ability of paving pellets to resist road damage to the road surface caused by driving and natural factors, making the road surface smooth and dusty, impermeable and durable. Therefore, asphalt pavement is one of the most widely used high-grade pavements in road construction.

The asphalt structure layer of asphalt pavement itself belongs to the category of flexible pavement, but its base layer can also use rigid cement concrete or semi-rigid hydraulic material in addition to flexible materials.

Analysis of the cause of the pit:

The thickness of the surface layer is not enough, the adhesion of the asphalt mixture is not good, the heating temperature of the asphalt is too high, the rolling is not compact, and under the action of rain and driving, the performance of the surface layer material is deteriorating day by day, loose, cracking, and gradually forming a pit.

When paving, the plaster and garbage on the surface of the lower layer are not completely removed, so that the upper and lower layers can not be effectively bonded;

In front of the pavement cover, the original potholes, loose and other diseases have not been completely repaired;

If the maintenance is not timely, when the road surface is loose, peeling, network cracking and other diseases, or damaged by mechanical scrapers, it is timely maintenance and repair.

1. For individual potholes, the holes should be chiseled into rectangular straight groove walls, and then the groove and concrete fragments and dust should be cleaned and filled with cement mortar and other materials to achieve smoothness and compactness.

2. For more potholes and connected together, they should be repaired by covering the surface.

When there are many potholes on the pavement, the repair steps are as follows:

1) Draw a rectangle parallel or perpendicular to the road centerline.

2) Cut a groove 5 7 cm deep along the edge of the patch area with a cutting machine, and chisel the smooth surface of the cut.

3) Use compressed air to blow off the concrete debris and dust in the tank.

4) Concrete should be designed and prepared according to the original concrete ratio, and it should be mixed with early strengthening agent.

5) Fill the mixed concrete into the tank, pave and vibrate compact, and keep it flush with the original concrete panel.

6) Spray curing agent. After the concrete reaches the strength of the traffic, it will be opened to traffic.

3. For potholes with a large area and a depth of less than 3cm, asphalt concrete can be used to repair them.

1) Draw a rectangular treatment area parallel or perpendicular to the center of the pavement, and chisel with a pickaxe to a depth of 2 3cm.

2) Remove concrete debris and dust.

3) spray the bottom surface of the chiseled groove and the wall surface of the groove with a clay layer asphalt, and its dosage is 0 4 o 6kg m2.

4) Pave asphalt concrete in the trough, and roll it densely and flat, and after the asphalt concrete is cooled, open to traffic.

Repair with Jianket cement concrete repair material.

This construction process.

Tool preparation, identification, cutting, chiseling, cleaning, wetting, stirring, repairing, curing, cutting, opening traffic.

1) Tool preparation: generator, cutting machine, hair dryer, high-pressure water gun, air pick, sponge or mop, vertical mixer (if you don't have the conditions, you can replace it with a hand-held mixer), channel steel (scraper), iron wipe, shovel, water storage bucket, clean water.

2) Identification: According to the principle of "round hole square supplement", draw a good identification line around the pothole.

3) Cutting: Cutting along the drawn identification line, the depth is not less than 5cm, and the depth is determined according to the depth of the pothole.

4) Chisel removal: use a pickaxe to chisel the concrete within the range of the cutting joint, and avoid the phenomenon of gnawing edges when chiseling.

5) Cleaning: clean up the chiseled concrete, and clean the cut façade with a brush or iron trowel, and there shall be no floating ash.

6) Wetting: fully moisten the surface of the cleaned pit with clean water, there shall be no open water before repairing, if there is open water, clean up the water with a sponge or mop.

7) Stirring: according to the water-cement ratio (if the weather temperature is high, you can add a little more water, but the range of water should be controlled within 13%), add the pothole cement pavement repair material and clean water to the mixer, stir for 3-5 minutes until it is uniform, and then add 10% 50% clean gravel, continue to stir until it is uniform. (Note:.)

The proportion of aggregate incorporation is determined according to the depth of the pit, the shallower the pit, the less aggregate proportion is added, and the diameter is less than 30 continuous gradation, preferably washed with water).

8) Repair: pour the evenly stirred repair material into the clean repair area, immediately use a scraper to catch up and then use a trowel to collect the light to achieve a forming, the operation time is controlled within 30 minutes, and the surface shall not be calendered twice after the initial setting (if possible, it can be supplemented by vibration to make the repair material more dense, but not over-shocking).

9) Maintenance: After the final setting is completed, immediately sprinkle water to cover the plastic film for curing.

10) Cutting seams: 1 hour of final setting, cut out no less than 6 seams at the position of the original panel cutting joints or construction joints, and lay sealants.

11) Open traffic: 4 hours after the completion of the repair, the isolation will be lifted and the traffic will be opened. (If conditions permit, the maintenance time can be appropriately extended.) ）