History[ edit ] Proctor's fascination with geotechnical engineering began when taking his undergraduate studies at University of California, Berkeley. He was interested in the publications of Sir Alec Skempton and his ideas on in situ behavior of natural clays.
Nur-Ranji Jajurie Lab Report 3: Standard Proctor Test for Soils Abstract Soil Compaction is the process in which stress is applied to a soil which causes densification as the voids are filled with solids.
This plays a vital part in construction for soils are mainly used as supports for a lot of infrastructures. Compaction is greatly affected by soil type, moisture content, and compaction effort and is Soil moisture content laboratory test test using ASTM D Nur-Ranji Jajurie Group Mates: April 11, Date Submitted: April 29, 1 I.
Methodology 3 4 IV.
Data and Results Table 1 shows the recorded mass and dimensions of the cylindrical mold that was used for the computation for its volume as shown in Equation 1: Recorded masses and dimension of the mold used The initial mass of the air dried soil sample that was used in the experiment was 5.
Table 2 presents the data on the masses of the mold after the addition and compaction of the soil Soil moisture content laboratory test indicated in Section III. Note that the mass of the empty mold is 3.
Mass of the Soil Sample inside the mold in each trial The moisture content of the soil sample in each of the trials is determined using Equation 2: Table 3 presents the data used in order to determine the moisture content of each trial using Equation 2.
Moisture content of the compacted soil in each trial Next is to present the moist total and dry density, and dry unit weight of the compacted soil in each trial.
First to calculate the total density, Equation 3 is used: Using trial 1 as a sample computation: Moist Density of the Compacted Soils The dry density of the compacted soil sample can be computed using Equation 4: Using trial 1 for sample computation we then have: Dry Density of the Compacted Soils Finally, the dry unit weight of the compacted soil sample can now be acquired using Equation 5: Table 6 contains all the computed values for the computed dry unit weight of all the trials.
Dry Unit Weight of the Compacted Soil The compaction curve is then generated by plotting the dry unit weight versus the moisture content graph as shown in Table 7.
Points used in the Compaction Curve Compaction Curve of the Soil Sample The optimum water content and the maximum dry unit weight of the soil sample are acquired through analyzing the curve and getting the coordinate values of the maximum point, which is: Analysis and Discussion The main purpose of compacting soils is to reduce subsequent settlement under working loads.
Compaction also increases the shear strength of the soil, reduces voids ratio making it more difficult for water to flow through soil and prevent the buildup of large water pressures that cause soil to liquefy during earthquakes. Thus it is essential to identify the maximum unit weight of the soil in order to maximize the usages mentioned above through identifying the quantities or qualities of the factors that 8 affect compaction such as water content, the type of soil being compacted, and the amount of compactive energy that was used.
To assess the degree of compaction, the dry unit weight is greatly attributed because we are more interested on the weight of solid soil particles in a given volume than the amount of solid, air, and water in a volume in which is the bulk density.
Rearranging this equation, we yield: Moisture content acts as the driving force in controlling the dry unit density such that if water is added to a soil at low moisture content it becomes easier for the particles to move past one another during the application of the compacting forces.
As the soil compacts the voids are reduced and this causes the dry unit weight to increase. Initially then, as the moisture content increases so does the dry unit weight as what can be seen in Graph 1.
However, the increase cannot occur indefinitely because the soil state approaches its saturation point which indicates that the voids are filled with water and prohibits the solids to compact with each other. Varying compactive effort also affects the compactibility of the soil such that increasing it causes greater dry unit weights to be achieved.
This is because of the solid particles being forced to interlock with one another. Although that it should be noted that for moisture contents greater than the optimum the use of heavier compaction machinery will have only a small effect on increasing dry unit weights.
Thus, it is really important especially in construction sites to be able to control the moisture content of the soil at its optimal value in order to ensure that the dry unit weight is at its greatest.
Table 8 presents the typical values of maximum dry unit weight and optimum moisture content for some common types of soils. Typical Values of Dry unit Weight and Moisture Content for Common Soils Although Table 8 only presents only typical values which must not be used in design because soils exhibits great variability, we can still compare the computed values of maximum dry unit weight of Looking back on the previous laboratory report, the soil sample was described to be clay with low plasticity which gives reliability to the results of the experiment and some typical values.
The values attained can be of great use in construction using the test sample if maximum compaction is wanted in order to support the maximum load possible. There was no way in order to compute the error of the experiment and thus it is recommended to perform the experiment more than once in order to provide more precise and accurate data.
American Society for Testing and Materials. Principles of Geotechnical Engineering. Essentials of Soil Mechanics and Foundations.Moisture-Density Relationships by Use of the Proctor Test dried soil to bring it up to the initial moisture content for the test.
Weigh a clean, empty moisture tin and record the weight. water content. Add the water needed to bring the soil to the first moisture content. Mix the soil well in the pan with the spoon.
First. Solutions for Chapter 5 Problem 9P.
Problem 9P: Laboratory compaction test results on a clayey soil are listed in the table. Moisture content (%)Dry unit weight (kN/m3)Following are the results of a field unit weight determination test on the same soil with the sand cone method:• Calibrated dry density of Ottawa . The Proctor compaction test is a laboratory method of experimentally determining the optimal moisture content at which a given soil type will become most dense and achieve its maximum dry density.
The test is named in honor of Ralph R. Proctor, who in. Moisture content ; Liquid Limit / Plastic Limit (Atterberg Limits Test) Density by Linear Measurement ; Particle Density (Specific Gravity) Particle Size Distribution (Wet Sieving & Hydrometer).
Soil Moisture Content Testing Methods By Sarah Metzker Erdemir; Updated September 21, Whatever soil moisture test you use, the best time to do it is a day after you've watered.
This makes the soil soft enough to dig into, and you will get a better idea of how the soil holds moisture. If the soil is too wet or too dry, you won't be. The compaction curve and associated characteristics, namely maximum dry unit weight and optimum moisture content, should be determined in the laboratory by using Proctor test procedures.