aggregate gradation - memphis handouts/2 - aggregate gradat… · civl 3137 59 fuller’s curve...

Aggregate Gradation

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Gradation Analysis

percent coarseror

percent retained

percent fineror

percent pas sing

Percentagesare calculatedby mass

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Gradation Chart

0

20

40

60

80

100

Perc

ent

Pass

ing

Opening Size (mm)

Total mass percent passing each sieve

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Gradation Chart

0

20

40

60

80

100

Perc

ent

Pass

ing

Opening Size (mm)

Total mass percent passing each sieve

Sieves

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Shakers

Gilson Shaker Mary Ann ShakerCIVL 3137 42

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Sieve Sizes

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Gradation Chart

0

20

40

60

80

100

0.010.1110100

Perc

ent

Pass

ing

(%)

Opening Size (mm)

1½" ¾" 3/8" 4 8 16 30 50 100 200

Gradation Example 1

Gradation Example 2

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Uniformly Graded Aggregate

0

20

40

60

80

100

0.010.1110100

Perc

ent

Pass

ing

Opening Size (mm)

1½" ¾" 3/8" 4 8 16 30 50 100 200

Uniformlygradedgravel

Uniformlygradedsand

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Uniformly Graded Aggregate

Narrow range of sizesGrain-to-grain contactHigh void contentHigh permeabilityLow stabilityDifficult to compact

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Open-Graded Aggregate

0

20

40

60

80

100

0.010.1110100

Perc

ent

Pass

ing

Opening Size (mm)

1½" ¾" 3/8" 4 8 16 30 50 100 200

Opengradedgravel

Opengradedsand

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Open-Graded Aggregate

Few fine particlesGrain-to-grain contactHigh void contentHigh permeabilityHigh stability Difficult to compact

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screenings

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Gap-Graded Aggregate

0

20

40

60

80

100

0.010.1110100

Perc

ent

Pass

ing

Opening Size (mm)

1½" ¾" 3/8" 4 8 16 30 50 100 200

Opengradedgravel

Opengradedsand

Gapgradedblend

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Gap-Graded Aggregate

Missing middle sizesNo grain-to-grain contactModerate void contentModerate permeabilityLow stability Easy to compact

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Dense-Graded Aggregate

0

20

40

60

80

100

0.010.1110100

Perc

ent

Pass

ing

Opening Size (mm)

1½" ¾" 3/8" 4 8 16 30 50 100 200

Densegradedgravel

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Dense-Graded Aggregate

Wide range of sizesGrain-to-grain contactLow void contentLow permeabilityHigh stabilityDifficult to compact

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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

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Maximum Density 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

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Dense-Graded Aggregate

0

20

40

60

80

100

0.010.1110100

Perc

ent

Pass

ing

Opening Size (mm)

1½" ¾" 3/8" 4 8 16 30 50 100 200

TDOT 411-D

MaximumDensityCurve for½" NMAS

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Dense-Graded Aggregate

0

20

40

60

80

100

0 1 2 3 4 5

Perc

ent

Pass

ing

Opening Size (mm) Raised to the 0.45 Power

¾"3/8"4830200

TDOT 411-D

1/2" 5/8"

MaximumDensity

Curve for½“ NMAS

Aggregate Sampling

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Aggregate Sampling

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Aggregate Sampling

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Minimum Sample Size

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Sample Quartering

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Sample Splitting

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