What are Asphalt Plants?
Asphalt plants are plants dedicated in the manufacturing of asphalt as well as macadam and other forms of coated road stone, at times communally known as blacktop.
The production of asphalt needs the mixture of a number of aggregates, sand and filler (such as stone dust), with the right mixtures, subjected to heating and then coated with a binder, frequently bitumen based or tar. The temperature of the completed product must be enough to be feasible after transporting to the last destination. A temperature in the range of 100 – 200 °C is usually adequate. More and more recycled asphalt pavement (RAP) is being used as component of the mix. Flammable binder is used and the heaters are mostly large liquid or gas fired burners. RAP is brought in after the heating procedure and must be accounted for in the whole mix temperature calculations.
The plants can be classified into three main classes: batch heater, continuous (or “drum mix”) and semi-continuous (or “asphalt plant”). The batch heater has the lowest throughput, while the continuous plant has the highest of about 500 Tons per hour.
The supply of asphalt for huge contracts is usually by tender with substantial pressure on price. A faulty batch of asphalt must be polished up and re-laid, often with added lane rental charges, at a cost which may be higher than the original price, so complicated control systems are needed.