Procedures for using asphalt on outside construction

The external structure is a term other than the construction of the building that refers to the structure inside the buildings, the whole of the exterior. In addition, it seems that driveway paving contractors suggest asphalt, and also there are many people who want to pave their parking lots with asphalt material as well.

This discussion may help you if you want to pave your driveway or parking lot yourself or want to hair an asphalt paving company. Concrete and asphalt are generally used for the exterior pavement, but here I will explain the step by step construction when using asphalt.

In addition, I will introduce various knowledge useful for external construction, such as the merit and disadvantage of using asphalt for outside construction, how long it takes to actually use for construction area. For more info call or mail Phone: (844) – 266 – 7283

Email: kamal@standardpavinginc.com

Table of contents:

Ø  Basic knowledge of asphalt construction

Ø  Steps until completion of asphalt pavement

Ø  Summary

Basic knowledge of asphalt construction

I will introduce the basic properties of asphalt, the structure when laying on the ground, and the place where asphalt is used as a pavement material.

Basic properties of asphalt

When we so-called asphalt for paving is the official name "asphalt mixture" and is manufactured by blending asphalt and some other materials. The materials are roughly classified in descending order as follows.

Coarse aggregate

　It is relatively large gravel and crushed stone. This is about 85% of the large grain that remained through a 5 mm eye filter. Pavement materials mixed with coarse aggregate are rough on the surface, enhancing durability and anti-slip effect.

Tine aggregate

It falls on a 5 mm sieve and refers to relatively small gravel or crushed stone. The surface of the paved road which contains a lot of fine aggregates is finely fine and becomes strong against water and cracks.

Filler

It is a material called a mineral fine powder which crushed stone into powder and works to fill the gap between the above aggregate. It also increases the viscosity of the asphalt, making it easier to absorb impacts.

Asphalt

It is a tar-like substance purified from petroleum. It is a glue of the above materials and it performs the role of adhesive which completes as an asphalt mixture.

By the compounding ratio of these materials, the "particle size" of the asphalt mixture is determined. When the particle size is large, it is robust, it becomes strong against slipping, and when the particle size is small, it has water resistance and it becomes strong against cracking.

Asphalt pavement absorbs the impact on the road surface with moderate flexibility and drains quickly the rainy road surface due to good drainage.

This property helps automobiles and pedestrians safely pass through, and asphalt mixtures are widely used for road paving nationwide.

Structure of asphalt with seven layers

Looking at the asphalt pavement structure, it is divided into seven layers as follows.

1.      Surface layer

It is the the top layer that can be seen from the outside. By spreading asphalt, by distributing loads and impacts on the road surface and keeping the road flat, we ensure a state where cars and pedestrians can pass comfortably and safely.

2.       Substrate

It is a layer under the surface layer and plays the role of cushion between the roadbed and the surface layer further below. Asphalt is used only for the surface layer and base layer in the pavement, each kind of asphalt will change because each role is different.

3.       Upper Road

It is a layer that supports the base layer just above and has the role of further dispersing the load transmitted from the top.

4.      Underground Road

It is another roadbed that supports the upper roadbed. By making the roadbed into a two-layer structure, it is possible to increase the dispensability of the load.

5.      Building Road Floor

  It is the lower layer of the roadbed, and it is laid at a depth of about 12 inches from the surface layer, this layer might depend on the use of the driveway and load. Distribute the load transmitted from the top and let it flow downward.

6.      Original ground

It becomes the ground under the road floor. As we finally make a place to support the load, if it is weak it can be improved.

7.      Road

It is a part of the soil that further supports the ground. Pavement work will generally be repeated after digging down so far.

When looking at asphalt as paving material, flexibility is said to be particularly excellent. Compared to concrete as a similar pavement material, asphalt can be used without cracking in half of 5 cm, whereas concrete tends to crack unless it is applied with a thickness of about 10 cm. This advantage leads to cost savings by reducing material costs and man-hour.

Where asphalt is often used

Generally speaking, asphalt is often seen in roads such as general roads and highways. Asphalt is widely used for road pavement from its excellent road characteristics.

However, even outside the road, repairs are easy, construction costs are cheap, and functionalities such as drainage are high so it may be used for parking lots and housing exteriors. In addition, asphalt is also used as water-resistant the material on the roofs.

Steps until completion of asphalt pavement

There are five stages of roughly divided asphalt pavement work: "drilling", "roadbed adjustment / crush piling", "roadbed rolling", "asphalt blank piling" and "asphalt paving rolling pressure".

For each step, I will explain with notes.

Step 1 drilling the underground

In order to build the road floor and the bedrock which becomes the foundation of the road, we first dig in the construction area. Depending on the strength of the ground to be constructed, we will drill the roadbed as much as necessary, dig your driveway soil about 12 cm for a pedestrian and about 25 to 30 cm for the driveway or more according to the use of the driveway. We will reinforce the ground here if the ground is weak.

After excavation, tread the exposed soil with a roller etc. If you need a brick fence or a block fence at the scene at a parking lot or the like, it is installed at this stage.

Step 2 Roadbed adjustment/crush piling

Lay down crushed stones in the drill holes and form the roadbed. Large gravel is used for the lower roadbed, and small gravel stone is used for the upper roadbed.

Also, decide the height and slope of the roadbed so that rainwater accumulated on the surface of the asphalt flows smoothly to the side grooves. Depending on the shape of the parking lot (extended parking lot etc), it may be necessary to have many slopes.

Step 3 Make a rolling pressure on the road

To maintain the crushed stone density high, we will roll the roadbed. Put pressure on the crushed stone further with a road roller etc.

Tighten firmly until it reaches the specified density. If rolling pressure runs short, ground subsidence may occur, so it is a very important process.

Step 4 Layout the asphalt composite material

We will spread the asphalt mixture forming the surface layer and the base layer. The asphalt softens by heating and solidifies when it cools down, so it becomes a spreading operation while keeping warm if necessary.

Considering that it will settle after completion of the construction, carry out a work called "remaining bulk" to bulge the finished surface of asphalt beforehand.

After the overgrowth is complete, make it so that the road surface becomes flat.

Step 5 Rolling the asphalt pavement

Since asphalt just laid is mixed with air, it is soft and fluffy, so firmly pressurize it with a roller or vibrator to remove air and tread it.

Temperature management becomes very important also during rolling. To finish cleanly it is necessary that the high temperature is maintained, and if it cools down during work it will cause distortion and cracking.

After sufficiently treading down, wait for the asphalt to cool down and be completed.

Summary

I have introduced the basic knowledge that is convenient to know when using asphalt pavement for outside construction. The summary is summarized as follows.

a)      Asphalt for paving is a mixture of a plurality of materials, and types are different depending on the density of the material

b)      The asphalt pavement is divided into seven layers and laid by following five steps

Asphalt is an excellent paving material that has been used on roads throughout the country. Let's grasp the features and appropriate scenes and carry out the best external construction work.