cee 3400A_LAB5

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School

Georgia State University *

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Course

4600

Subject

Civil Engineering

Date

Apr 3, 2024

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pdf

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Uploaded by Fkhairy

Georgia Institute of Technology School of Civil and Environmental Engineering Soil Mechanics Laboratory MEMORANDUM To: Ryann Khalil Date: 3/04/2024 From: Fukhraj Khairy Lab Partners: Jordan P.G Benjamin G.M Darien R Subject : Compaction Sample Description Name: Piedmont Soil Source: North Georgia Condition: N/A Visual Classification and Unified Symbol: ML Remarks: N/A Test Procedure The following ASTM standards and procedures were used to determine the maximum dry unit weight of compaction of soils that can be used for the specification of field compaction. Table 1 : ASTM Standards Used In this laboratory, both variants of the Proctor Compaction Test were carried out. The procedures for these tests are essentially the same, but there are a few crucial distinctions. To begin with, secure a sample of Piedmont Soil that has been sieved through Sieve #4. Add water to the soil sample to reach a water content that is approximately 6% below the optimum level, which is around 12% for this type of soil. Make sure the soil is mixed well. To calculate the amount of water needed to achieve the desired water content, use the formula: Mw = ω * Ms, where ω is the water content and Ms is the mass of the soil. Next, measure the combined weight of the Proctor mold and its base plate. Once you have recorded the weight, attach the collar to the mold’s top. start adding the moist soil into the mold.

Take into account that the soil will be compacted, so the amount you need to add depends on the test method: 1. For the Standard Proctor Test, fill the mold to slightly more than half of its height. 2. For the Modified Proctor Test, fill the mold to slightly more than one-third of its height. After the soil is added, gently position the hammer inside the mold and initiate the hammer drops. After loading the soil, cautiously situate the hammer in the mold and start executing the 25 drops. Rotate the mold a little with each hit to guarantee even compaction throughout the sample. Post compaction, redo the steps for reloading the mold, and then compact 25 more times. For the standard method, carry out these steps five times until the mold is filled; for the modified test, also repeat five times. Once compacting concludes, the soil should slightly surpass the mold's rim. Detach the collar and employ a straight edge to scrape off surplus soil. Ascertain the mass of mold, base plate, and compacted soil. Remove the base plate, then employ a jack to eject the compacted soil cylinder. Get a moisture container, find out its mass. Extract a sample from the center of the compacted soil and put it in the container. Jot down the mass of moisture container with the wet soil sample. Add extra water to the primary soil sample aiming to boost the water content by 4%. Redo all the preceding steps. Elevate the water content by an additional 4% twice and reiterate all steps. After completing all experiments (four in total), position the moisture containers in the oven to dry until weight stabilizes. The subsequent day, evaluate the mass of the moisture containers coupled with the dry soil samples. Test Results The equations used to calculate the Actual Water Content and the Dry Unit Weight are shown below. An example calculation is performed for Table A1, Test 1 of the Modified Proctor Test. Mass of Water = (mass of container + wet soil) − (mass of container + dry soil) = 235g – 195.96g = 39.04g Mass of Dry Soil = (mass of container + dry soil) − (mass of container) = 195.96g – 8.5g = 187.46g Water content (%) ?𝑎??? ??????? = ?𝑎?? ?? ?𝑎??? ?𝑎?? ?? ??𝑦 ??𝑖? × 100 = 39.04 187.46 ∗ 100 = 20.83 Sample calcs for Dry unit weight. 𝑉???? = 943.69 ?? ^3 ? ???? = 4343.4 ?? ? ?????? ???? = 5899 ?? ? ??𝑖? = ? ?????? ???? − ? ???? = 5899 − 4343.4 = 1555.6?? ∗ 1??/1000?? = 1.5556??

?? ??𝑖? = ? ??𝑖? ∗ 9.81 ? ? 2 = 1.5556 ∗ 9.81 = 15.26 ? 𝑦 ?𝑢?? = ?? ??𝑖? 𝑉 ???? = 15.26 943.69 = 0.01617 ∗ 1000 = 16.17 𝐾? ? 3 ?𝐶 = 0.2083 𝑦 ? = 𝑦 ?𝑢?? 1 + ?𝐶 = 16.17 1 + 0.2083 = 13.38 ?? ? 3 Dry Unit Weight of Zero Air-Voids Line 𝑦 ??𝑦= 𝑦 𝑚 𝜔+ 1 𝐺 𝑠 = 9.81𝑘𝑁/𝑚^3 0.2083+( 1 2.65 ) =16.75 ?𝑁/?^3 Table 2 : Summarized Test Results STANDARD Mass of Water (g) 39.04 21.32 35.83 73.16 Mass of dry soil (g) 187.46 77.38 113.77 203.94 Water content (%) 20.83 27.55 31.49 35.87 Bulk Unit Weight(kN/m^3) 16.17 18.45 17.86 17.34 Dry unit weight(kN/M^3) 13.38 14.46 13.58 12.76 Zero Air Voids kN/m^3 16.75 15.03 14.17 13.33 MODIFIED Mass of Water (g) 5.29 11.02 17.89 15.66 Mass of dry soil (g) 32.49 44.92 67.88 49.39 Water content (%) 16.28 24.53 26.36 31.71 Bulk Unit Weight(kN/m^3) 20.41 19.41 20 18.32 Dry unit weight(kN/M^3) 17.55 15.59 15.83 13.91 Zero Air Voids kN/m^3 18.16 15.76 15.31 14.13

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