The following stockpiles are available (% passing shown):
Sieve Stockpile A Stockpile B Stockpile C Stockpile D Specification
18 mm 100.0 100 100 100 100
16 mm 92.0 100 100 95.0 95-100
12.5 mm 59.8 100 95.7 80.0 70-85
5.0 mm 5.9 95.8 95.2 45.0 40-50
2.0 mm 2.5 59.5 94.9 35.0 30-38
900 ?m 2.3 42.0 94.6 35.0 27-33
400 ?m 2.2 31.2 84.1 35.0 22-28
160 ?m 1.7 19.3 14.7 20.0 6-10
71 ?m 1.2 11.5 4.4 15.0 3-6
Cost at the
Plant Site
($/ton) 7.00 10.82 9.51 8.88
a. Combine two or more of the stock gradations to obtain the specified gradation.
b. What is an estimate of the cost per ton for the blended aggregate? (materials only)