2 - Aggregate Gradation

Aggregate Gradation

CIVL 3137 27

Gradation Analysis⎧⎪⎪⎪⎨⎪⎪⎪⎩

percent coarseror

percent retained

⎧⎪⎪⎪⎨⎪⎪⎪⎩

percent fineror

percent pas sing

Percentagesare calculatedby mass

Sieves

Shakers

Gilson Shaker Mary Ann Shaker

CIVL 3137 30

Gradation Chart

0

20

40

60

80

100

Opening Size (mm)

Perc

ent

Pass

ing

Total mass percent passing each sieve

Gradation Example

CIVL 3137 32

Coarse Aggregate SievesSieve

DesignationOpening

(in)Opening

(mm)3 in 3.00 75.02 in 2.00 50.0

1½ in 1.50 37.51 in 1.00 25.0

3/4 in 0.75 19.01/2 in 0.50 12.5

3/8 in 0.375 9.50

Bold = Full sieves

CIVL 3137 33

Fine Aggregate SievesSieve

Designation Opening

(in) Opening

(mm) No. 4 0.187 4.75 No. 8 0.0937 2.36

No. 16 0.0469 1.18 No. 30 0.0234 0.60 No. 50 0.0117 0.30 No. 100 0.0059 0.15 No. 200 0.0030 0.075

Bold = Full sieves

Aggregate Size

Gravel Sand Silt & Clay

4.75 2.36 1.18 0.60 0.30 0.15 0.075 mm

Coarse Fine

Coarse Fine Filler

Soil Mechanics

Concrete

Asphalt

No. 4 No. 8 No. 16 No. 30 No. 50 No. 100 No. 200

CIVL 3137 35

Range of Sieve SizesSieve

DesignationOpening

(in)Opening

(mm)3 in 3.00 75.0

. . .

. . .

. . .

No. 200 0.0030 0.075

CIVL 3137 36

Gradation Chart

0

20

40

60

80

100

0.010.1110100Opening Size (mm)

Perc

ent

Pass

ing

(%)

0

20

40

60

80

100

0.010.1110100Opening Size (mm)

1½" ¾" 3/8" 4 8 16 30 50 100 200

CIVL 3137 37

Open-Graded Aggregate

0

20

40

60

80

100

0.010.1110100Opening Size (mm)

Perc

ent

Pass

ing

1½" ¾" 3/8" 4 8 16 30 50 100 200

opengraded

CIVL 3137 38

Open-Graded Aggregate

Grain-to-grain contactHigh void contentLow but variable densityHigh stability if confinedLow stability unconfinedDifficult to compact

CIVL 3137 39

Dense-Graded Aggregate

0

20

40

60

80

100

0.010.1110100Opening Size (mm)

Perc

ent

Pass

ing

1½" ¾" 3/8" 4 8 16 30 50 100 200

opengraded

densegraded

CIVL 3137 40

Dense-Graded Aggregate

Grain-to-grain contactLow void contentHigh densityHigh stability if confinedHigh stability unconfinedDifficult to compact

CIVL 3137 41

Gap-Graded Aggregate

0

20

40

60

80

100

0.010.1110100Opening Size (mm)

Perc

ent

Pass

ing

1½" ¾" 3/8" 4 8 16 30 50 100 200

opengraded

densegraded

gapgraded

CIVL 3137 42

Gap-Graded Aggregate

No grain-to-grain contactHigher void contentLower densityLow stability if confinedLow stability unconfinedEasy to compact

CIVL 3137 43

Uniformly-Graded Aggregate

0

20

40

60

80

100

0.010.1110100Opening Size (mm)

Perc

ent

Pass

ing

1½" ¾" 3/8" 4 8 16 30 50 100 200

uniformlygraded

Aggregate for Concrete

Source: Design and Control of Concrete Mixtures (PCA, 2007)

Source: Design and Control of Concrete Mixtures (PCA, 2007)

Size Percent By Weight Passing Each Laboratory Sieve

Number 4" 3½" 3" 2½" 2" 1½" 1" ¾" ½" 3/8" No. 4 No. 8 No. 16 No. 50 No. 100

1 100 90–100 – 25–60 – 0–15 – 0–5

2 100 90–100 35–70 0–15 – 0–5

24 100 90–100 – 25–60 – 0–10 0–5

3 100 90–100 35–70 0–15 – 0–5

357 100 95–100 – 35–70 – 10–30 – 0–5

4 100 90–100 20–55 0–15 – 0–5 –

467 100 95–100 – 35–70 – 10–30 0–5

5 100 90–100 20–55 0–10 0–5 –

56 100 90–100 40–85 10–40 0–15 0–5

57 100 95–100 – 25–60 – 0–10 0–5

6 100 90–100 20–55 0–15 0–5 –

67 100 90–100 – 20–55 0–10 0–5

68 100 90–100 – 30–65 5–25 0–10 0–5

7 100 90–100 40–70 0–15 0–5 –

78 100 90–100 40–75 5–25 0–10 0–5

8 100 85–100 10–30 0–10 0–5

89 100 90–100 20–55 5–30 0–10 0–5

9 100 85–100 10–40 0–10 0–5

10 100 85–100 – – – 10–30

Standard Sizes of Processed Aggregate (ASTM C-33)

Size Midpoint Percent By Weight Passing Each Laboratory Sieve

Number 4" 3½" 3" 2½" 2" 1½" 1" ¾" ½" 3/8" No. 4 No. 8 No. 16 No. 50 No. 100

1 100 95 – 42.5 – 7.5 – 2.5

2 100 95 52.5 7.5 – 2.5

24 100 95 – 42.5 – 5 2.5

3 100 95 52.5 7.5 – 2.5

357 100 97.5 – 52.5 – 20 – 2.5

4 100 95 37.5 7.5 – 2.5 –

467 100 97.5 – 52.5 – 20 2.5

5 100 95 37.5 5 2.5 –

56 100 95 62.5 25 7.5 2.5

57 100 97.5 – 42.5 – 5 2.5

6 100 95 37.5 7.5 2.5 –

67 100 95 – 37.5 5 2.5

68 100 95 – 47.5 15 5 2.5

7 100 95 55 7.5 2.5 –

78 100 95 57.5 15 5 2.5

8 100 92.5 20 5 2.5

89 100 95 37.5 17.5 5 2.5

9 100 92.5 25 5 2.5

10 100 92.5 – – – 20

Standard Sizes of Processed Aggregate (ASTM C-33)

GRAIN SIZE DISTRIBUTION GRAPH

0

10

20

30

40

50

60

70

80

90

100

110100

GRAIN SIZE IN MILLIMETERS

PER

CEN

T PA

SSIN

1½" ¾" ⅜" 4 83" 16

2 3 4 5 6 7 8

Standard Sizes of Processed Aggregate (ASTM C-33)

Standard Sizes of Processed Aggregate (ASTM C-33)

GRAIN SIZE DISTRIBUTION GRAPH

0

10

20

30

40

50

60

70

80

90

100

110100

GRAIN SIZE IN MILLIMETERS

PER

CEN

T PA

SSIN

1½" ¾" ⅜" 4 83" 16

5 6 7

56 67

Standard Sizes of Processed Aggregate (ASTM C-33)

GRAIN SIZE DISTRIBUTION GRAPH

0

10

20

30

40

50

60

70

80

90

100

110100

GRAIN SIZE IN MILLIMETERS

PER

CEN

T PA

SSIN

1½" ¾" ⅜" 4 83" 16

5 7

57

Standard Sizes of Processed Aggregate (ASTM C-33)

GRAIN SIZE DISTRIBUTION GRAPH

0

10

20

30

40

50

60

70

80

90

100

110100

GRAIN SIZE IN MILLIMETERS

PER

CEN

T PA

SSIN

1½" ¾" ⅜" 4 83" 16

57

3

357

Standard Sizes of Processed Aggregate (ASTM C-33)

GRAIN SIZE DISTRIBUTION GRAPH

0

10

20

30

40

50

60

70

80

90

100

110100

GRAIN SIZE IN MILLIMETERS

PER

CEN

T PA

SSIN

1½" ¾" ⅜" 4 83" 16

67

4

467

CIVL 3137 54

Fineness Modulus

Fineness modulus (n.) an index of the coarseness or fineness of an aggregate; it is computed as the sum of the fraction retained on each full series sieve starting from the No. 100 sieve.

CIVL 3137 55

Fineness Modulus

0

20

40

60

80

100

0.010.1110100Opening Size (mm)

Perc

ent

Pass

ing

1½" ¾" 3/8" 4 8 16 30 50 100 200

+ + + + += =

94 80 58 32 10 0FM 2.74

100

CIVL 3137 56

Fineness Modulus

0

20

40

60

80

100

0.010.1110100Opening Size (mm)

Perc

ent

Pass

ing

1½" ¾" 3/8" 4 8 16 30 50 100 200

FM=FM 2.74

CIVL 3137 57

ASTM C-33 Sand

0

20

40

60

80

100

0.010.1110100Opening Size (mm)

Perc

ent

Pass

ing

1½" ¾" 3/8" 4 8 16 30 50 100 200

Coarse Sand

Fine Sand

CIVL 3137 58

ASTM C-33 Coarse Sand

0

20

40

60

80

100

0.010.1110100Opening Size (mm)

Perc

ent

Pass

ing

1½" ¾" 3/8" 4 8 16 30 50 100 200

=FM 3.45

Coarse Sand

CIVL 3137 59

ASTM C-33 Fine Sand

0

20

40

60

80

100

0.010.1110100Opening Size (mm)

Perc

ent

Pass

ing

1½" ¾" 3/8" 4 8 16 30 50 100 200

Fine Sand

=FM 2.15

Aggregate for Asphalt

CIVL 3137 61

Dense-Graded Aggregate

0

20

40

60

80

100

0.010.1110100Opening Size (mm)

Perc

ent

Pass

ing

1½" ¾" 3/8" 4 8 16 30 50 100 200

CIVL 3137 62

Fuller’s Curve

Fuller, W.B. and Thompson, S.E. “The laws of proportioning concrete," Transactions of the ASCE, v. 159, 1907.

⎛ ⎞= ⎜ ⎟⎝ ⎠

0.50i

id

pD

pi = percent passing ith sieve

di = opening size of ith sieve

D = maximum particle size

CIVL 3137 63

Fuller’s Curves

0

20

40

60

80

100

0.010.1110100Opening Size (mm)

Perc

ent

Pass

ing

1½" ¾" 3/8" 4 8 16 30 50 100 200

CIVL 3137 64

Fuller’s Curve

In 1962 FHWA published a modified version of Fuller’s 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

CIVL 3137 65

0.45 Power Chart

0

20

40

60

80

100

0 1 2 3 4 5Opening Size (mm) Raised to the 0.45 Power

Perc

ent

Pass

ing

¾"3/8"4830200

CIVL 3137 66

0.45 Power Chart

0

20

40

60

80

100

0 1 2 3 4 5Opening Size (mm) Raised to the 0.45 Power

Perc

ent

Pass

ing

¾"3/8"4830200

Aggregate Blending

Aggregate Blending Example