Questions and Answers
The apparatus includes: A stiff metal straightedge of any convenient length but not less than _____ in.
10 in
When using this test method for soils containing hydrated halloysite, or in which past experience indicates that results will be altered by air-drying, use the _____ preparation method.
moist
The data sheet(s)/form(s) shall contain: Compaction curve plot showing compaction points used to establish compaction curve, ____ 100 % saturation curve, value or point of maximum dry unit weight and optimum water content.
AND
What apparatus should be standardized before initial use or after repairs?
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In operating the manual rammer, hold the guide sleeve steady and within _____ of vertical.
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For Dry Preparation Method: Do not use mechanical splitting to obtain subspecimens.
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In the equation $\rho_m = K x (M_t - M_{md}) / v$, what does $M_t$ represent?
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The extension collar assembly shall have a height extending above the top of the mold of at least _____ in.
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For Linear Measurement Method: Measure the inside diameter of the mold ____ times at the top of the mold and ____ times at the bottom of the mold.
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What additional items are included for determining the volume of a compaction mold?
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The minimum test specimen (test fraction) mass for Method C is about ____ kg of dry soil.
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For Moist Preparation Method: Select molding water contents for the rest of the subspecimens to provide at least ____ subspecimens wet and ____ subspecimens dry of optimum.
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For Comparison of Results and Standardized Volume of Mold: The difference between the two methods should not exceed ____ % of the nominal volume of the mold.
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What equation determines the test (finer) fraction percentage?
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The rammer shall fall freely through a distance of ____ ± 0.05 in from the surface of the specimen.
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The minimum test specimen (test fraction) mass for methods A and B is about __ kg of dry soil.
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The shape of the compaction curve on the ___ side of optimum may be relatively flat or up and down when testing some soils.
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For each point on the compaction curve, calculate, record, and plot dry unit weight to the nearest __.
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How do you determine the test (finer) fraction percentage?
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What is maximum dry unit weight?
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What is optimum water content?
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For each point on the compaction curve, calculate, record, and plot dry unit weight to the nearest 0.1 lbf/ft3 (0.02 kN/m3) and molding water content to the nearest ___%.
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From the compaction curve, determine the compaction results: optimum water content, to nearest ___% and maximum dry unit weight, to the nearest ___ lbf/ft3 (0.02 kN/m3).
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The equation $K x (M_t - M_{md}) / V$ is used to calculate?
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Specific gravity should be determined to the nearest __ value.
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Study Notes
Apparatus and Preparation
- Apparatus includes a stiff metal straightedge of at least 10 inches in length.
- For soils with hydrated halloysite or affected by air-drying, the moist preparation method is recommended.
- The extension collar assembly must extend at least 2 inches above the mold.
Data and Measurements
- Data sheets must include a compaction curve, maximum dry unit weight, and optimum water content.
- For the Linear Measurement Method, measure the inside diameter of the mold six times at both the top and bottom.
- For each compaction curve point, record dry unit weight to the nearest 0.1 lbf/ft³ and molding water content to the nearest 0.1%.
Standardization and Testing
- Standardization of balance, molds, and rammer (mechanical or manual) is necessary before initial use and at intervals not exceeding 1000 test specimens or annually.
- The minimum test specimen mass for Method C is approximately 29 kg of dry soil, while for Methods A and B, it is about 16 kg.
Compaction and Density Calculations
- The rammer should fall freely from a height of 18 inches ± 0.05 inches to the specimen surface.
- Moist density is calculated using the equation ρm = K x (Mt - Mmd) / V, where Mt is the mass of moist soil in mold and mold.
- Specific gravity determination should be to the nearest 0.01.
Compaction Curve Insights
- The shape of the compaction curve on the dry side of optimum may vary from flat to fluctuating for well-draining soils.
- The optimum water content represents the water level for maximum dry unit weight in compaction testing.
- Maximum dry unit weight is the highest density obtainable as determined by the compaction curve.
Summary of Compaction Parameters
- For results comparison, the difference in methods should not exceed 0.5% of the nominal volume of the mold.
- The test fraction percentage is calculated with the equation PF = 100 - PC.
- At least two subspecimens should be prepared, wet and dry of optimum, varying by approximately 2%.
Results Analysis
- From the compaction curve, determine optimum water content and maximum dry unit weight with precision of 0.1% and 0.1 lbf/ft³ respectively.
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Description
Test your knowledge on ASTM D1557 Standard Test Methods for Laboratory Compaction of Soil with these flashcards. Each card covers key terms and procedures related to soil compaction, including apparatus specifications and preparation methods. Perfect for students or professionals looking to reinforce their understanding of soil testing standards.
