Lesson 6/Learning Event 1
Learning Event 1
PLANT SITE SELECTION
The site selection for a hot mix plant is an important part of your duties. To prevent delays in the
road or airfield construction, the plant must be located so that it is close to the project and to the
materials needed for that project. Travel time to and from the plant must be held to a minimum.
A central plant should be located between the source of aggregate and asphalt and the site of the
project. Ton-mileage for hauling the mix components and the mix itself are computed and
optimized. The minimum laying temperature of the mix will limit the distance it can be
transported, depending on the speed of the hauling equipment, the rapidity of bitumen cooling,
the maximum allowable mixer temperature, and weather conditions. Normally, mixes can be
moved up to 50 miles in a temperate climate. The plant location should also have a good
A central plant should be sited in a well-drained area with stable soil. The site must provide
room to maneuver equipment and stockpiled materials, and space to store drummed asphalt.
Asphalt should be stored at a safe distance from the plant in order to reduce the fire hazard.
A side hill location will improve drainage, and also will reduce the explosion hazard associated
with loading trucks in a pit. However, the plant must be on a level foundation to insure
maximum stability, facilitate alignment, and prevent wear of the plant components. Should it be
necessary to locate the plant on a level site, the loading pit should be as large as possible to allow
for maximum ventilation. Also, prevailing winds should be identified to prevent dust from
contaminating populated areas.
Figure 19 illustrates a typical location of an asphalt plant with respect to the job site.