Road construction is inseparably connected with the high consumption of bituminous materials. It is necessary to arrange special facilities and warehouses for their storage and preparation for future use. These may be completely independent units or parts of asphalt and emulsion plants.
In order to shorten a transport route of a binder to work location, such units are typically located in the middle of the processed area. When planning unit location, it is worth remembering that the economically justified distance of bitumen transportation by transit bitumen carriers is not more than 25-30 km.
Bitumen is transported from refineries in low-sided hopper cars or insulated oil containers. The second option is used exclusively for road maintenance. Such tanks are usually equipped with thermal insulation and heating system to maintain bitumen fluidity. If these conditions are fulfilled, it will be enough to only heat up the outlet nozzle in the place of unloading.
The main purpose of bitumen storage facilities is a short-term or a long-term storage of bitumen with its heating to a state of fluidity and dispensing into dehydration and heating units. Bitumen storage facilities should protect the binder against ingress of atmospheric and ground water.
Externally they are made as tanks with capacity from 100 to 3000 tons. If it is necessary to store different grades of bitumen, storage tanks with capacity exceeding 500 tons are divided into several sections, each of which may be used separately. To determine the capacity of bitumen storage facilities, in the first place it is necessary to take into account the frequency of bitumen supply and consumption.
Today, the most common classification criteria of bitumen storage facilities are the following: designation, capacity, location relative to the ground and the type of heat transfer agent.
According to tank position relative to the ground, isolated bitumen storage facilities are divided into pit-type storages, cut-and-fill storages, aboveground and underground bitumen storages.
The following can be used as a coolant in bitumen storage facilities:
- Saturated steam, which is passed through a system of pipes laid at the bottom of a storage facility;
- Gas obtained by burning any kind of fuel;
- Electric heating using a set special electrical packages or infrared sources. In practice, steam or electrical heating is used most commonly.
The capacity and designation of bitumen storage facility is taken into account when determining its structural design. Temporary and intermediate bitumen storages are coated with boards, bricks or other materials. Special tents are erected over bitumen storage facilities in order to protect them from atmospheric precipitation. Precast concrete elements are used for construction of capital and permanent bitumen storage facilities. In-situ concrete is a bit less common.
