There is a technique called overlay construction method for the construction of asphalt. In driveway paving, the method of finishing the floor cobblestone using design concrete is also called overlay, but this time I will introduce the construction method to be done by Driveway paving contractors.
Since asphalt is a paving material that needs periodic maintenance after being laid once, those with parking lots may need overlay paving in the future. This information is useful for you if you want to do pavement yourself or even if you want to call an Asphalt paving company for your work as you know the complete process yourself and take care very well.
If you have a concrete paving site such as a parking lot, you will know how to lose it, so let's take a look at each one.
#Crack of asphalt is repaired by an overlay construction method
Once the asphalt has weakened or damaged, it will be repaired using the overlay method.
The overlay construction method is a way to restore road pavement by painting new asphalt over the surface of damaged asphalt. Let's take a closer look at what kind of place will be constructed for what reason.
#What is the overlay construction method?
The overlay construction method is a construction method where the pavement is piled only on the surface when concrete already paved is damaged or deteriorated.
Asphalt is a very convenient paving material, but it has low friction resistance and has the disadvantage of getting dented or worn out as soon as a continuous load is applied. Before the harm happens, repair is necessary with a span of 5 to 10 years depending on the usage situation. At that time it will be an overlay pavement that renews only the surface. There is no such thing as creating an empty space between the two because it spreads something like an emulsion between the old asphalt and the new asphalt.
#Place where overlay construction method is performed
Overlay construction is done in places where subsidence of the ground and deterioration of the road surface are occurring. It is also used when unevenness occurs continuously on the surface of the road and it is not flat. If you cannot overlay anymore by repeating construction many times, scrape with a cutting machine and then re-pave.
There are times when overlapping is done by the method of crushed stone mastics asphalt pavement in the place where you want to keep the life as long as possible, especially in the subway, etc. as much as possible.
# It is also possible to pave asphalt with concrete
Overlay paving usually has the same asphalt mixture on top, but sometimes concrete is overlaid on top. Because it puts white concrete on black asphalt, it is called "white topping". It was invented as a fundamental repair method to a place where ruffles occur as soon as asphalt pavement.
It is a test pavement that appeared in the United States in the early 1990s. Concrete should be thicker than 5 ~ 10 cm thick. After cutting the existing asphalt, clean the cutting surface by surface treatment, etc., and put the concrete
# Overlay method flow
What exactly is the construction flow of overlay pavement?
When new asphalt is laid on the original asphalt, it looks like a simple work at first glance, but there are various points to be noted. I will introduce notes unique to heavy machinery used and road painting.
1. Check existing pavement version
If the existing paving plate is thick and exceeds 15 cm, crush the pavement plate using a concrete crusher or a large breaker. Both the concrete crusher and the large breaker are attached to the tip of a hydraulic excavator and used. The crusher is a scissors type, it is relatively lightweight and small, making it easy to use in a narrow range.
In the construction of parking lots and the like, if you want to set up a drain outlet etc, make a groove at this stage. When there is a drain dugout box, raise it with sealant.
2. Spread floor and roadbed
You have to need to do the leveling of the road floor and the roadbed which becomes the base of the asphalt. The ground is divided from the lowest layer to "road body", "roadbed", "underlying roadbed", "upper layer roadbed", "underlying stratum", "surface layer", and usually the automobile, etc. is running on the surface layer. The roadbed exists far deeper and is a very important part of the foundation of the road. Bulldozers and motor graders are often used for smooth the surface of the driveway of the parking lot being constructed.
It is mainly sand used for road floor. In laying down, we will use the macadam and the tire roller mainly for rolling the surface.
3. Laying and rolling operation
Next, load the asphalt mixture. You will do the leveling with the construction machine that refers to the asphalt finisher that can be flowed while loading the asphalt mixture as it travels. A step will perform the initial rolling that treads and stabilizes while the asphalt is hot with a road roller.
By pressure action, it is possible to stabilize the arrangement of the rough aggregate in the mixture and make a durable asphalt.
Overlay method that varies depending on the purpose
Even if it says a bite overlay construction method, there are several kinds. "Cutting overlay" and "Thin layer asphalt pavement". Both are countermeasures against the fact that the asphalt on the surface was damaged, but what is the difference between the construction methods?
Paving can be done with cutting overlay with no difference in height
The difference from the overlay construction method is that you can cut only the necessary minimum thickness when you do not want to change the height of the road surface. It is used when there is a possibility of cutting from the relation with the building on the roadside when the foundation is rough. Since it is possible to finish the road cutting and paving on the same day, it is a method of living the quick-drying of asphalt which is hard to influence the traffic.
Thin layer asphalt pavement can prevent road cracks
Thin layer asphalt pavement is a method of paving asphalt mixture thin layer of 2 ~ 3 cm thick on the pavement already made. It is a construction method that is often done as prevention before asphalt cannot be used completely.
There are also asphalt mixtures with functionality such as flexibility, water tightness, drainage and so on. It is a low-cost construction method that can be done without cutting and because there are few materials to use.
The points of the overlay construction method are as follows.
- How to pile new asphalt over asphalt which deteriorated and cracked etc.
- Use for road subsidence, deterioration of road surface, continuous roughness
- There is also a technique called "white topping" in which concrete is layered on existing asphalt
- Confirm existing pavement plate → Road floor · Roadbed as laying → Construction in order of leveling and rolling
- The cutting overlay is effective when you do not want to change the height of the road surface
- Inexpensive construction to stop the degradation of asphalt, thin asphalt pavement
The asphalt itself has low construction costs, quietness and water repellency, and it can run in a short time after construction, so it has very useful characteristics. However, there is a disadvantage that such a useful asphalt is prone to denting and rubbing, and regular maintenance is necessary.