FACULTY OF ENGINEERING AND BUILT ENVIRONMENTEXPERIMENT: COMPACTION TEST

MEHREEN ZEENAT HEERAHSCM-019211

MOHAMMAD ARSHAD HOSSANYSCM-020570

NIHAAD LAULLOOSCM-014963

GROUP NO.:GROUP 2

SUBJECT NAME:SOIL MECHANICS 2

COURSE CODE:ECG 4313

LECTURERS NAME:MISS JAMILAH BINTI JAADIL

DATE OF EXPERIMENT: 08. 07. 2014

DATE OF SUBMISSION: 16. 07. 2014

Table of ContentsPurpose3Introduction3Standard Reference3Significance3Equipment4Procedures4Calculations5Results and Calculations6Graph7Discussion7Conclusion8References9Appendix9

PurposeThis experiment was performed to determine the relationship between the moisture content and the dry density of a sample of soil for a specified compactive effort.IntroductionThis experiment is also known as the Proctor test. TheProctor compaction testis a laboratory method of experimentally determining the optimalmoisture contentat which a givensoiltype will become most dense and achieve its maximum drydensity. There are different ways to compact the soil on site. For example kneading compactors, tamping, vibration plates and static load compaction. But in this experiment we use the tamping or impact compaction. Compaction is a dense state which is achieved through the reduction of the air voids in the soil with little or no reduction in the water content. Compaction of the soil is very important before starting the construction as it decreases the risk of future settlement, it increases the shear strength of the soil and decrease the permeability also.Standard Reference ASTM D 698 Standard Test Methods for Laboratory CompactionCharacteristics of Soil Using Standard Effort (12, 400 ft-lbs/ft (600 KN-m/m) ASTM D 1557- Standard Test Methods for Laboratory Compaction Characteristics of Soil Using Modified Effort (56, 000 ft-lbs/ ft (2700 KN-m/m)SignificanceMechanical compaction is considered to be the most common and cheapest way of stabilizing the soil. One of the most important things for a geotechnical engineer is to check that performance and analysis of the compacted soil are meeting the performance of the design specifications. The required density and water content are usually stated in the design specifications. Usually, when increasing the soil density, the other engineering properties, like strength, stiffness, resistance to shrinkage and imperviousness of the soil will also improve. The optimum water is the water content that results in the greatest density for a specified compactive effort.Equipment1. Moulds2. Manual rammer3. Balance4. Drying oven5. Mixing pan6. Trowel7. Moisture cans8. Graduated cylinder9. Straight edge10. Ruler11. SieveProcedures1. The weight of the mould (mould + base + side screw) was measured by using the electronic balance.2. The internal diameter and height was measured by using a ruler.3. Afterwards grease was applied on the sides of the mould and on the collar.4. 5 mixing pans and 10 moisture cans were prepared (2 containers per sample).5. The weight of each moisture cans together with lid was measured with the help of electronic balance.6. The soil was sieved.7. 3kg of loose soil was then measured.8. The required amount of distilled water was measured according to the assumed water content.9. The soil was mixed thoroughly with the water by using both hands.10. After having mixed it completely, the soil was divided into 3 sections.11. The first section of the soil was put up to 2 of the mould.12. With the help of the rammer, the soil was compacted by 25 blows. 13. The second layer of soil is added and rammered 25 more times14. Then the collar was assembled and the screws were tightened.15. The last layer of soil was added and was rammered for 25 times again.16. Then the collar was removed and the soil was levered using a straight edge.17. The mould containing the compacted soil together with the base and side screws were weighed.18. Then a small portion of soil at the top was taken and placed in the moisture can.19. Afterwards the mould is turned upside down and a small portion of soil was taken at the bottom also and placed in another moisture can.20. Steps 5 to 19 were repeated for each assumed water content.21. The moisture cans were weighed.22. Then these moisture cans were placed in the oven to dry.23. After 24hr the moisture cans were removed from the oven and was allowed to cool for 10 minutes.24. Then the weight of the moisture cans was noted.Calculations

Results and CalculationsWater Content Determination:Water content9%12%15%18%21%

Compacted SoilTopBottomTopBottomTopBottomTopBottomTopBottom

MC = Mass of empty can+lid (g)33.032.933.333.033.232.032.632.432.633.0

MCMS = Mass of can, lid and moist soil (g)45.241.550.647.249.946.243.343.162.767.1

MCDS = Mass of can, lid and dry soil (g)44.340.848.745.847.844.441.841.557.261.2

MS = Mass of soil solids (g)11.37.915.412.814.612.49.29.123.628.2

MW = Mass of pure water (g)0.90.71.91.42.11.81.51.65.55.9

W = Water content (w%)7.968.8612.3410.9414.3814.5216.3017.3923.3120.92

Average water content (w%)8.4111.6414.4516.8522.12

Density Determination:Compacted Soil Sample no.12345

w = Assumed water content, w%912151821

Actual average water content, w%8.4111.6414.4516.8522.12

Mass of compacted soil and mold (g)58006850585059506200

Mass of mold (g)44005050445044004450

Wet mass of soil in mold (g)14001800140015501750

Diameter of mold (cm)10.210.410.110.210.1

Height of mold (cm)11.611.511.711.611.7

Volume of mold (cm3)947.9976.9937.4947.9937.4

Wet density, 1.4771.8431.4931.6351.867

Dry density, d1.3621.6501.3041.3991.529

GraphGraph of dry density against water content

DiscussionThe Proctor test is carried out to determine the relationship between the moisture content and the dry density of a soil sample. From the graph plotted above, we can see that the maximum dry density, 1.65 g/cm3, occurred when the water content is 11.64%. One can also see that the assumed water content is almost the same the theoretical one. This slight difference has occurred due to some small errors. For example, due to the presence of fans or because when pouring the water, some of it was splashed.Furthermore, we can conclude from the shape of the graph that experiment for the 15% and 21% are not correct. The actual result should be like the red graph below.

Some errors that might have occurred during the experiment:1. Parallax error when taking the measurement of the mould or when reading the measuring cylinder.2. The presence of fan which can make the soil become dry more quickly.3. The water and the soil were not mixed properly and uniformly.4. Loss of water due to splashing of water.5. The soil was not rammered uniformly which can result for some areas not being well compacted.6. The mould was not completely filled due to presence of air voids. So, the volume of soil will not be correct.ConclusionThe proctor test is very important in the construction field. It helps to lower the permeability of the soil and to increase its shear stress. From the results obtained above we can conclude that the dry density of soil is dependent of its water content. But the relationship is not a linear one. We can also conclude that the optimum water content is found at the maximum dry density of the soil.

Referenceshttp://www.uic.edu/classes/cemm/cemmlab/Experiment%209-Compaction.pdfAppendix Figure 1. Sample soil Figure 2. Weighing moisture can Figure 3. Rammering the soil Figure 4. Levelling the soil

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