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ECE 302 Fall 2017
HOMEWORK #1 SOLUTION
Aggregate (Total 59 points)
Due September 22, 2017
HW1A. (4 pts)
While the round and smooth aggregate particle in PCC can improve the workability of fresh
concrete during the mixing, the angular and rough aggregate particles in asphalt concrete can
increase the stability of materials and reduce the rutting due to the increased aggregate
interlocking properties.
HW1B. (4 pts)
The bulk dry specific gravity considers the total particle volume, whereas the dry-rodded unit
weight considers the volume of the container.
Percent volume of particles = 72.5
2.639×62.4 =44.0%
Percent voids = 100 – 44.0 = 56.0%
HW1C. (12 pts)
a.
b. The maximum size is 2 in.
c. The nominal maximum size is 1-1/2 in.
d. Semi-log gradation chart
e. 0.45 power gradation chart
