Lesson 4/Learning Event 1
Learning Event 1
DURATION OF HOT PLANT MIX PAVING JOBS
When constructing a road or airfield pavement, it is necessary for you to be able to estimate the
duration of the hot plant mix paving operation. In this lesson, you will learn how to make these
estimates and determine the capabilities of laydown and maintenance equipment.
This production estimating technique is useful when paving roads in the Theater of Operations.
Normally, estimating the production or duration of such a hot plant mix paving job is simply a
matter of calculating the number of tons of mix per 1" of lift per paver that the plant can produce
and then looking up the paving width and paving speed on the paving chart. Then, it is necessary
to determine how many passes you will have to make and multiply the number of passes by the
paving distance. The number of hours necessary to complete the job is determined by dividing
the answer obtained (number of passes x paving distance) by the paving speed times sixty (60).
NOTE: Pavers traveling at the same time = One Pass.
The result is the duration of paving operations, assuming no breakdowns or stopping due to
weather. However, a problem occurs when the number of trucks committed to haul the mix is
restricted-as often is the case in the Theater of Operations. When paving close to the plant there
is very little travel time between plant and paver and few trucks are required. When paving
further from the plant more trucks are required. Otherwise, the plant and paving operations must
be slowed to keep pace with the haul capability of a fixed number of trucks.
Before trying to calculate the duration of such a project, some assumptions must be defined.
First, we will assume that the paving begins dose to the plant and moves away. Second, we will
assume that there are a fixed number of trucks available to support the project. If somewhere
along our paving project, the combined haul capability of these trucks falls below the output of
the plant (the paver can always keep up with the TOE Army plant), the operation must slow to
match the haul capacity of the trucks. Third, we will assume that it takes approximately the
same amount of time to load a truck at the plant as it will take to off-load the truck at the paver.
This is reason-