Asphalt Drum Mix Plant

Written by: Finn Orfano • Edited by: Lamar Stonecypher
Published Nov 25, 2009

Asphalt is a useful ingredient that is used for road pavements. There are several processes for the production of asphalt and the Asphalt Drum Mix Plant is one of the main processes. The main feature of this plant is the controlled heating and mixing of the constituents.

What Is Asphalt?

Asphalt is the black or dark brown adhesive substance that contains bitumen as the primary constituent. Asphalts are extremely complex materials that contain saturated and unsaturated compounds. The composition differs depending on the crude oil characteristics. Asphalt normally includes 80% carbon, 10% hydrogen, 6% sulfur, and small quantities of nitrogen and oxygen. Bitumen is a general expression used for the manufactured or natural substances that exist as solids, semi-solids, or viscous material. Bitumen that occurs in nature is obtained during the processing of petroleum. The extensive usage of asphalt is due to its outstanding characteristics of resistance to water and binding capability. The hardness and strength of the road surfaces is influenced by the asphalt capability to bind the aggregate of sand and stone together.

Components Of Asphalt Drum Mix Plant

The major components of an Asphalt Drum Mix Plant are:

click to enlarge

Aggregate Feeder for regulating the flow of aggregate
Vibratory Screen removes the oversized and unnecessary materials from feeder
Conveyor to receive aggregate, and feed to dryer
Burner
Drying and Mixing Drum where mixing of asphalt and bitumen is arranged
Asphalt Tank that is insulated for heat control
Mineral Filler to feed mineral to the drum.
Control Panel to manage the production quantity and quality
Fuel Tank
Pollution Control Mechanism

Operation Of Asphalt Drum Mix Plant

The asphalt ingredients are fed constantly to the rotating drum that delivers a regular production of the hot mix. The major hot mix

click to enlarge

elements are the aggregates, asphalt, and the mineral fillers. The aggregates are transferred by the conveyor from the feeder bins to the rotary drum. The burner removes the moisture content from the aggregate, and then the aggregate is heated to attain the desired temperatures. The hot aggregate is mixed and coated with asphalt and the filler materials. The hot mix is transferred from the drum to vehicles by the load conveyor. The feeder bins, pumping unit with asphalt tank, and the mineral filler unit are coordinated to maintain proper proportion of the hot mix ingredients. The dust is accumulated by the dust collector, and moved through the pollution control unit, before it escapes to the environment.

Asphalt Characteristics

The highway design is influenced by the asphalt characteristics that are produced by the Asphalt Drum Mix Plant. The Asphalt Drum Mix Plant ensures that the asphalt produced should be of proper specifications and suitable for pavement. Asphalt has different functional properties that can affect the conditions on the road, like tire wear, brake efficiency, and road noise. The rolling friction also converts kinetic energy into sound waves. Therefore, the temperature, feed rate, and drum mixing have to be carefully monitored to produce asphalt of the correct specifications.