7/23/2019 2 - Aggregate Gradation and Sampling
1/31
Aggregate Gradation
7/23/2019 2 - Aggregate Gradation and Sampling
2/31
CIVL 3137 38
Gradation Analysis
percent coarser
or
percent retained
percent finer
or
percent pas sing
Percentages
are calculatedby mass
7/23/2019 2 - Aggregate Gradation and Sampling
3/31
CIVL 3137 39
Gradation Chart
0
20
40
60
80
100
PercentPassing
Opening Size (mm)
Total mass percent passing each sieve
7/23/2019 2 - Aggregate Gradation and Sampling
4/31
CIVL 3137 40
Gradation Chart
0
20
40
60
80
100
Percent
Passing
Opening Size (mm)
Total mass percent passing each sieve
7/23/2019 2 - Aggregate Gradation and Sampling
5/31
Sieves
CIVL 3137 41
7/23/2019 2 - Aggregate Gradation and Sampling
6/31
Shakers
Gilson Shaker Mary Ann Shaker
CIVL 3137 42
7/23/2019 2 - Aggregate Gradation and Sampling
7/31
CIVL 3137 43
Sieve Sizes
7/23/2019 2 - Aggregate Gradation and Sampling
8/31
CIVL 3137 47
Gradation Chart
0
20
40
60
80
100
0.010.1110100
Pe
rcentPassing(%)
Opening Size (mm)
1" " 3/8" 4 8 16 30 50 100 200
7/23/2019 2 - Aggregate Gradation and Sampling
9/31
Gradation Example 1
7/23/2019 2 - Aggregate Gradation and Sampling
10/31
Gradation Example 2
7/23/2019 2 - Aggregate Gradation and Sampling
11/31
CIVL 3137 50
Uniformly Graded Aggregate
0
20
40
60
80
100
0.010.1110100
Percent
Passing
Opening Size (mm)
1" " 3/8" 4 8 16 30 50 100 200
Uniformly
graded
gravel
Uniformly
graded
sand
7/23/2019 2 - Aggregate Gradation and Sampling
12/31
CIVL 3137 51
Uniformly Graded Aggregate
Narrow range of sizes
Grain-to-grain contact
High void content
High permeabilityLow stability
Difficult to compact
7/23/2019 2 - Aggregate Gradation and Sampling
13/31
CIVL 3137 52
Open-Graded Aggregate
0
20
40
60
80
100
0.010.1110100
Percent
Passing
Opening Size (mm)
1" " 3/8" 4 8 16 30 50 100 200
Open
graded
gravel
Open
graded
sand
7/23/2019 2 - Aggregate Gradation and Sampling
14/31
CIVL 3137 53
Open-Graded Aggregate
Few fine particles
Grain-to-grain contact
High void content
High permeabilityHigh stability
Difficult to compact
7/23/2019 2 - Aggregate Gradation and Sampling
15/31
CIVL 3137 54
screenings
7/23/2019 2 - Aggregate Gradation and Sampling
16/31
CIVL 3137 55
Gap-Graded Aggregate
0
20
40
60
80
100
0.010.1110100
Percent
Passing
Opening Size (mm)
1" " 3/8" 4 8 16 30 50 100 200
Open
graded
gravel
Open
graded
sand
Gap
graded
blend
7/23/2019 2 - Aggregate Gradation and Sampling
17/31
CIVL 3137 56
Gap-Graded Aggregate
Missing middle sizes
No grain-to-grain contact
Moderate void content
Moderate permeabilityLow stability
Easy to compact
7/23/2019 2 - Aggregate Gradation and Sampling
18/31
CIVL 3137 57
Dense-Graded Aggregate
0
20
40
60
80
100
0.010.1110100
Percent
Passing
Opening Size (mm)
1" " 3/8" 4 8 16 30 50 100 200
Dense
graded
gravel
7/23/2019 2 - Aggregate Gradation and Sampling
19/31
CIVL 3137 58
Dense-Graded Aggregate
Wide range of sizes
Grain-to-grain contact
Low void content
Low permeabilityHigh stability
Difficult to compact
7/23/2019 2 - Aggregate Gradation and Sampling
20/31
CIVL 3137 59
Fullers Curve
Fuller, W.B. and Thompson, S.E. The laws ofproportioning concrete," Transactions of the
ASCE, v. 159, 1907.
0.50
ii
dp
D
pi = percent passing ith sieve
di = opening size of ith sieve
D = maximum particle size
7/23/2019 2 - Aggregate Gradation and Sampling
21/31
CIVL 3137 60
7/23/2019 2 - Aggregate Gradation and Sampling
22/31
CIVL 3137 61
Maximum Density Curve
In 1962 FHWA published a modified version ofFullers equation with a different exponent.
0.450.50
ii
dp
D
pi = percent passing ith sieve
di = opening size of ith sieve
D = maximum particle size
7/23/2019 2 - Aggregate Gradation and Sampling
23/31
CIVL 3137 62
7/23/2019 2 - Aggregate Gradation and Sampling
24/31
CIVL 3137 65
Dense-Graded Aggregate
0
20
40
60
80
100
0.010.1110100
PercentPassing
Opening Size (mm)
1" " 3/8" 4 8 16 30 50 100 200
TDOT 411-D
Maximum
Density
Curve for
" NMAS
7/23/2019 2 - Aggregate Gradation and Sampling
25/31
CIVL 3137 66
Dense-Graded Aggregate
0
20
40
60
80
100
0 1 2 3 4 5
Percent
Passing
Opening Size (mm) Raised to the 0.45 Power
"3/8"4830200
TDOT 411-D
1/2" 5/8"
Maximum
DensityCurve for
NMAS
7/23/2019 2 - Aggregate Gradation and Sampling
26/31
Aggregate Sampling
CIVL 3137 67
7/23/2019 2 - Aggregate Gradation and Sampling
27/31
Aggregate Sampling
CIVL 3137 68
7/23/2019 2 - Aggregate Gradation and Sampling
28/31
Aggregate Sampling
CIVL 3137 69
7/23/2019 2 - Aggregate Gradation and Sampling
29/31
Minimum Sample Size
CIVL 3137 70
7/23/2019 2 - Aggregate Gradation and Sampling
30/31
Sample Quartering
CIVL 3137 71
7/23/2019 2 - Aggregate Gradation and Sampling
31/31
Sample Splitting
CIVL 3137 72