30b. Aggregate

Question 1

Aggregate moisture

Answer 1

Absorbed water plus surface water

Question 2

Apparent S.G.

Answer 2

Gapp = WOD(air)/(WOD(air)-W(water))

Question 3

Dry S.G.

Answer 3

GOD = WOD(air)/(WSSD(air)-W(water))

Question 4

SSD S.G.

Answer 4

GSSD = WSSD(air)/(WSSD(air)-W(water))

Question 5

What sieve separates fine and coarse aggregates?

Answer 5

4.75 mm (No. 4)

Question 6

What sieve separates fine aggregates and material fillers?

Answer 6

0.075 mm (No. 200)

Question 7

Aggregate gradation

Answer 7

Distribution of particle sizes as a percent of total weight
Found through sieve analysis

Question 8

Maximum aggregate size

Answer 8

One size larger than nominal aggregate size

Question 9

Nominal maximum aggregate size

Answer 9

One size larger than first sieve to retain (cumulative) more than 10%

Question 10

Dense graded

Answer 10

Near the 0.45 power curve for max density
Low void content, high stability, difficult to compact

Question 11

What is the most common type of gradation?

Answer 11

Dense graded

Question 12

Open graded

Answer 12

Contains a small percentage of aggregate particles in the small size range

Question 13

Blending of aggregates

Answer 13

Obtain desirable gradation, economical, single material not enough