Lesson 2/Learning Event 1
Example: The specifications and other data for a road-mix project are:
L = 1.1 miles(1.1 x 5,280 = 5,808 feet)
W = 24 feet
FCT = 2 inches
Rate of bitumen application 0.5 gal/sq yd/inch of final compacted thickness.
LF = 10 percent (or) 1.10 for aggregate
LF = 5 percent (or) 1.05 for binder
Find the drums of bitumen and loose cubic yards of aggregate needed for this job (53 gallons = 1
drum)
SOLUTION:
TRAVEL PLANT MIX
Travel-plants are used only for road mixes, when you have more than 2 miles to do. The travel-
plant mixing allows close control of the mixing operation. The proportion of the bituminous
material and the aggregate, and the uniformity with which the two are mixed are of the greatest
importance. In order to achieve a uniform product, several precautions must be taken:
establish a uniform windrow of prepared material
check carefully the uniformity of the gradation of the material in the windrow
determine the proper amount of binder for mixing with the aggregate
check that the road-mixing machine is in satisfactory operating condition.
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