Bitumen is used in the construction of roads due to the various properties and advantages it has over other construction materials for the pavement. Bitumen obtains certain unique properties that are incorporated into it during its manufacture. Bitumen as a raw material in the construction of flexible roads and bitumen as a mixture (which composes other materials, that is, aggregates / pozzolanas) has certain advantages, which encourage the use of bitumen widely in road construction.
Use of bitumen in flexible road construction
The reason behind the significant application of bitumen in flexible pavements is explained below:
1. The production of bitumen is economical
Bitumen is a by-product of the crude oil distillation process. Crude oil itself is a hydrocarbon composition. The main products that are available are gasoline, diesel, high octane fuels and gasoline. When these fuels are refined from crude oil, the bitumen is left behind. The subsequent treatment of the by-product, to make it free of impurities, provides pure bitumen.
As the demand for primary products is of paramount importance to society, bitumen as a by-product has survival for a long time. This by-product is used as a new construction material, without resorting to any other new resource.
2. The physical and rheological properties of bitumen provide versatility
The physical and chemical properties of bitumen are based on the load level, temperature and duration of the load. It is a thermoplastic and viscoelastic material. These dependencies make us really access traffic on the road so that the properties of the bitumen mixture can be varied depending on the calculated stress levels. This versatility of bitumen results in a great variety of bituminous mixtures, based on the application of roads.
3. The melting point of bitumen is low
It is very appreciable on the fact that bitumen has a favorable melting point, which helps both in surface coating and in wear resistance with ease.
The melting point of the bitumen should not be too high, as it can easily melt during laying of the pavement. At the same time, the bitumen has a melting point, which does not allow the already melted road to melt and deform at high temperatures. In areas of high temperatures, together with this quality of bitumen, the composition of the aggregate helps to cover the effect of elevated temperature.
4. Bitumen can be recycled
Since the melting point of bitumen is favorable, it can be melted back to its original state. This is called asphalt recycling process. The broken asphalt pieces are taken to the recycling plant, instead of being sent to landfills. This recycled mixture can be reused. If necessary, the old bitumen is mixed with new bitumen and new aggregates for the mixture to live again.
5. Gain of Adhesive Nature bitumen
As it is explained in the production of bitumen, it is free of hydrocarbons and, therefore, is not toxic. The by-product is refined to the maximum to get rid of organic materials and impurities. Bitumen has a very adhesive nature which keeps the materials in the road mix united under strong links. These become stronger when the mixture is configured, that is, ready for the movement of the vehicle.
6. The bitumen has a variety of colours
The traditional bitumen is black. This is because the dense organic material inside the bitumen is black. Now when certain pigments are added to the bitumen, the colour of our choice can be obtained. These are colored bitumen.