History of Asphalt and Road Construction
Before installing geotextile for road stabilization, it is better to get more familiar with road construction and the difference between concrete asphalt and bitumen asphalt and the structure of geotextile.
The path that connects the two places is called a road, and this type of road dates back to Mesopotamia (modern-day Iraq) around 2200 BC. The peak of modern road construction in Iran dates back to the time of Reza Shah, which means that most of the old roads are now about 100 years old and new technologies must be used to build new roads and repair old roads. Roads are designed and built based on the use and passing of heavy and light vehicles and environmental factors.
In the construction of roads, we should pay attention to the factors such as water infiltration, groundwater, canals and infrastructure under the road, ambient temperature, and the contraction and expansion of asphalt in different seasons, and so on.
Three Types of Asphalt for Road Stabilization
Asphalt or Asphalt concrete is a composite or combined material that is commonly used to pave roads, parking lots, airports, as well as the core of soil dams. The history of using this type of asphalt dates back to the early twentieth century, which is classified into three main categories:
- hot asphalt concrete
- protective asphalt concrete
- cold asphalt concrete
1. Hot Asphalt Concrete
Which is the most familiar type of asphalt, ie the same bitumen asphalt and hot stone materials that are spread hot during work. In this type, more than 90% of asphalt mixture is usually made of stone materials.
Hot asphalt is also classified as different types such as Topka surface asphalt, liner asphalt, asphalt sand, porous asphalt and bitumen asphalt with geotextile installation, which is more common in IRAN.
2. Protective Asphalt Concrete
Protective asphalt is a type of paving with a maximum thickness of 255 mm, which is used for the surface of sandy or asphalt roads. In protective asphalts, soluble bitumens, bitumens or pure bitumens with low humidity are used. Protective asphalts are used to make the road surface impermeable, prevent dust, increase the abrasion and slippery roads, as well as temporarily improve the existing asphalt and concrete procedures.
This type of procedure is very cost-effective compared to hot asphalt due to its speed and ease of implementation and the limited need for asphalt machinery and equipment. Types of protective asphalts include single-layer, multi-layer, cold-rolled protective asphalt, primer type, single coat type, silket type, Red Mix type protective mix, asphalt concrete advantages.
3. Cold Asphalt Concrete
Cold asphalt is obtained by mixing stone materials with soluble bitumen or emulsion at ambient temperature and is divided into two categories: factory cold asphalt and on-site cold mix asphalt. Cold asphalt is used by installing geotextiles in all pavement layers, provided that all design criteria or categories along with traffic restrictions of the route are observed.
Advantages and Disadvantages of Asphalt Concrete for Road Stabilization
Currently, two types of hot bitumen asphalt and cold concrete asphalt are used to build roads and paths, each of which has its advantages and disadvantages, for example:
Advantages of bitumen asphalt : life-Time with quality materials is up to 10 years
Disadvantages of bitumen asphalt : possibility of bitumen leakage, high water absorption,
Advantages of concrete asphalt: Life-Time with quality materials up to 30 years, suitable for sloping areas, suitable for heavy vehicle traffic, beauty and environmental protection, reducing maintenance and repair costs, low water absorption, cold and heat resistant Intense, high run speed, improved drainage, light reflection at night
Disadvantages of concrete asphalt : the need for advanced and expensive machines, the need for high accuracy in its production and execution, the production of high noise during work, the presence of expansion joints, more difficult repairs and operations in concrete pavement.
Of course, the usage of concrete asphalt on roads instead of bitumen asphalt has been common in various countries for many years, especially in developed countries, but in Iran people, contractors and construction officials are strangers to it and are the only few companies that use this type of asphalt in Iran. They use that the Isfahan-Shiraz freeway is of this category, and to improve the life of the road, the geotextile of Zarif Mosour Company has been used.
Learn more : Geotextile Installation Guide In Road Stabilization
Learn more : Geotextile of Zarif Mosavar industrial Group