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Compaction

Asphalt, Roads, Trench Restoration

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Goal of CompactionPlace loose soil in the field and compact it to make soil strong as possible

Maximum shear strengthVery little settlement

Find soil lowest emin ……highest dry unit weight

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Field Compaction Equipment

Vibratory Smooth Wheel Rollers

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Field Compaction Equipment

Pneumatic rubber-tired roller

Field Compaction Equipment

Vibratory sheepsfoot roller

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Soil Compaction Equipment

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Field Compaction EquipmentVibroflotation unitVibrate loose sand deposits

Field Compaction EquipmentDrop weight 10 to 20 feet at close centresMakes cratersLoss fill and sand

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Field Compaction Equipment

Proctor Test

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Standard Proctor Test

Modified Proctor Test

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Impact of No. Blows

Impact of No. Blows

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Impact of Proctor MethodIncrease energyincrease dry unit weightDecrease optimum moisture content

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Influence of compaction on soil hydraulic conductivity

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Soil Compaction Measurement

Soil Compaction MeasurementUse dry sand with known dry density and specific gravityUse dry sand to get volume of holeQuick and reliable method

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Soil Compaction MeasurementUse radioactive material to get moisture content and soil densityQuick methodReliable if calibratedRadioactive device therefore special transportation and rules must be followed

Compaction Specification

Standard Proctor Specification95 to 100 percent of MDUW

Modified Proctor Specification92 to 98 percent of MDUW

100 (Proctor)t unit weighdry Max.

tunit weighdry Insitu (%) level Compaction x=

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Compaction SpecificationMake sure compacted soil same as Proctor material (grain size distribution analysis)Add water to soil if too dry

95% Field Specification