Bitumen Requirements

There are many Bitumen Requirements in the construction of pavements. A bitumen mix use in the construction of flexible pavement. It serves the following needs.

• Strength
• Drainage and
• Friction

Bitumen Requirments

The main Bitumen Requirements are,

1. Strength

It is one of the important Requirements for construction of flexible pavements. The bitumen layer composes of three main courses. They are,

• Surface course
• Binder and
• Base course

Purpose of bitumen mix is to give Strength to pavements. And load dispersion throughout the layers of the pavement. The loads are dynamic or static loads. It transfers to the base subgrade through the aggregate course. A granular base with a bituminous surface course provides for roads of low traffic. It is sufficient and economical.

There is a higher amount of bitumen content in the wearing course. This makes the layer more flexible. This helps in increasing the durability.

2. Drainage

It is draining of water collects on the ground. The water is from excess rainfall, over irrigation, seepage from areas at higher levels. The water standing on roads causes damages to pavements. And increase maintenance cost.

Subsurface drainage facilitates using granular sub base in the construction of flexible pavement. Permeable asphalt treated base uses to provide positive surface drainage on major highways. This behaves as a separate course for facilitating subsurface drainage.

3. Friction

It is one of the important Requirements for construction of pavements. At vehicle passage in wet conditions, it needs the layer to provide slip resistance and friction. This makes the safety of the passengers.

The large and small size of asphalt mix gives the friction. On mixing the large and small mixture it forms a waterproof layer. The large surface mix uses to squeeze the water out from the bottom of a vehicle wheel.