Aasho developed a modified test to give a higher standard of compaction and is known as modified proctor test. 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. It uses the same cylindrical mold as the standard proctors 4 in. Relatively higher energy is applied in modified proctor tests compared to standard, thus yielding higher unit weight of the soil. Proctor test astm d155791 the proctor, or modified proctor test, determines the maximum density of a soil needed for a specific job site. The modified proctor uses a 10 lb rammer falling 18, also in a standard mold. Dry density ratio versus field moisture content, dry of optimum, for increasing compactive effort at site b.
The standard proctor test astm d698, aashto t99, and the modified proctor test astm d1557 and aashto t180. What is the difference in the maximum dry density achieved in standard and modified proctor test. What is the difference between standard proctor test and modified proctor test. Add water to the specimen and compact it in accordance to standard proctor test or modified proctor test. Comparison of reduced modified proctor vs modified proctor. It is then up to the contractor to select machinery, the thickness of each lift layer of soil. Modified proctor aashto t180astm d1557 testing procedures more closely approximate the compaction effort of modern equipment. The difference between the tests is the amount of energy used. Conclusions and recommendations correlations were developed between relative density, coefficient of uniformity, and maximum dry density tested in standard and modified proctor test. The use of the standard proctor or modified proctor should be used at the discretion of the. Since reduced modified proctor requires less time and 40% less compaction energy as compared to modified proctor test, it can be considered as. Secondly, it tests the effects of moisture on soil density. However, standard proctor density criteria is typically utilized in the eastern us where. Pdf use of proctor compaction testing for deep fill.
Objective to obtain the graphical relationship of the dry density to moisture content in the form of compaction curve, for determining the values of optimum moisture content omc and maximum dry density mdd. For the same type of soil, the modified proctor yields a higher maximum dry density and lower optimum moisture content. Objective to determine the required amount of water to be used when compacting the soil in the field and the resulting degree of denseness, which can be expected from compaction at optimum moisture content. Apparatus cylindrical metal mould shall be either of 100mm diameter and cm3 volume. Astm d698 12e2 standard test methods for laboratory. Determine the weight of the soil sample as well as the weight of the compaction mold with its base without the collar. Standard proctor vs modified proctor modified proctor test.
The main difference in the two tests are that the standard proctor test uses a 5. The details included in this test method are for use with the standard proctor test. Methods a, b, c, and d this test method applies to soil mixtures having 40 percent or less retained on the 4. In modified proctor test whole soil sample is compacted in 5 layers with 25 evenly distributed blows on each layer from 4.
Liquid limit and plastic limit tests are conducted on soils to determine the atterberg limits international symposium nondestructive testing in civil engineering ndtce. Standard and modified proctor test calculations civil. In geotechnical engineering, soil compactionis the process in which a stress applied to a soilcauses densification as air is displaced from the pores between the soil grains. May 14, 2009 modified proctor this is the same as the standard, except you use a 10 pound hammer dropped from a height of 18 inches. Do subscribe and be a part of the community for more such lessons here. Proctor test are used for determining the optimum moisture where a soil type will give more density and can achieve maximum dry density. Indian institute of technology gandhinagar department of. Modified proctor testing typically requires a lower optimum moisture content for achieving maximum density which is desirable for keystone retaining wall construction and performance especially with silts and silty soils. Enjoy the videos and music you love, upload original content, and share it all with friends, family, and the world on youtube. Standard proctordensity except for fine grained soils ie. Compaction test light weight standard proctor compaction is 2720part vii1980 reaffirmed2011 theory. The test is named in honor of ralph roscoe proctor, who in 1933 showed that the dry density of a soil for a given compactive effort depends on the amount of water the soil contains during soil. Standard vs modified proctor test procedures are similar, but the laboratory compactive effort of the modified method is higher.
Standard proctor compaction test take approximately 10lb of soil sample. Major difference i saw in both test is that modified proctor test is more precise compared to std. It may be prudent to utilize 90% of modified proctor density and optimum moisture content when working with fine grained soils such as clays. Materials used in this study are classified according to aashto and. In the standard compaction test, the maximum dry density is achieved on greater moisture content as compared to in modified proctor test and vice versa. Why do we use a modified proctor rather than a standard proctor. The compaction energy provided by the standard proctor test is not sufficient, hence a modified proctor test or aashto proctor test was developed.
Get a copy of each standard astm d698 for standard proctor and astm d1557 for modified proctor and read it. So this read explains in depth, the significance, background, apparatus and procedure of the standard proctor test. The modified proctor test was altered and practised by aashto and astm. Problem 4 a what is the difference between standard proctor test.
They are valid for clean sands with subangular particle size distribution and cu less than 6. Standard proctor and modified proctor are tests designed to emulate soil compaction. This typically leads to variances between 8% and 11%, as shown above. Some of the compaction tests used in the laboratory is. Maximum dry density of soil and optimum moisture content test. Doc sand replacement, standard proctor test and california. Astm d1557 12e1 standard test methods for laboratory. Each of these tests can be performed by three different methods as outlined in the attached table.
Difference between standard proctor test and modified. In the standard proctor test, the soil is compacted by a 5. Two types of compaction tests are routinely performed. The modified proctor test has a larger compaction capabilityenergy. The test first determines the maximum density achievable for the materials and uses this figure as a reference. What is the difference between standard proctor test and modified. Jan 27, 2019 maximum dry density of soil is determined in the laboratory with the help of standard proctor test standardized by astm d698 and aashto t99. The modified proctor basis of 1946 was developed by the us army corps of engineers waterways experiment station in vicksburg. Proctor 1933 was the first to develop a method of assessing compacted fill that has since become a universal standard and the test is known as standard proctor test. Difference between standard proctor test and modified proctor test. Proctor 1933 for the construction of earthfill dams in the state of california. Comparison of dcp, cbr, and rlt test results for granular.
After compaction, remove the collar and level the surface using cutting edge. Compaction tests results vary with the input compactive. The mould used in modified proctor test has a internal diameter of 100mm and height of 127. Research has been done showing the relationship between standard and modified proctor densi ty testing for different soils type. The differences between standard and modified proctor test. Summary of method the test consists of the following steps which are explained in the test procedure. What is the difference between standard proctor test and. Proctor test conducted on subgrade soils and modified proctor compaction test conducted on base materials according to astm d698 and astm d1557, respectively. Research has been done showing the relationship between standard and modified proctor densi ty testing for different soils types as indicated below. Standard proctor test an overview sciencedirect topics.
Standard proctor test procedure apparatus calculation. The density difference between modified proctor and standard proctor. Why do we use a modified proctor rather than a standard. Based on the specifications of the project, the firm testing the soil would run either of the test. It is an instantaneous process and always takes place in. Since reduced modified proctor requires less time and 40% less compaction energy as compared to modified proctor test, it can be considered as a suitable alternative to the modified proctor test. Standard proctor density except for fine grained soils ie. The density difference between modified proctor and standard proctor density testing appears to increase with the percentage of fines in the soil matrix while the optimum moisture content decreases. Basics of soil compaction it is worth mentioning, that densification or compaction of soil continue reading standard proctor test. The standard proctor test astm d698 employs 12,400 ftlbsft. Modified proctor standard proctor will be used in undertaking the experiment where the standard data are recorded as the following. May 03, 2020 standard proctor compaction test is to establish a relationship between dry density and moisture content for a soil under controlled conditions. Modified proctor test an overview sciencedirect topics. The modified proctor test, astm d1557 aashto t180, uses same mould, but uses a 10 lb.
The bulk density in gml of each compacted specimen shall be calculated from the equation. For example we could specify that field densities must be greater than 98% of the maximum dry unit weight as determined from the standard compaction test. Algorithms were subsequently developed to compare the difference between standard and modified proctors, as well as to create conversion formulas between the two proctors for each soil type. Soil density standard vs modified proctor keystone retaining walls. The modified proctor test is identical to the standard proctor test except it employs a 4. To provide the increased compactive effort energy supplied 2072 kjm3 a heavier hammer and a greater drop height for the hammer are used. Modified proctor test is used to determine the compaction of different types of soil and the properties of soil with a change in moisture. Standard proctor test whole soil sample is compacted in 3 layers with 25 evenly distributed blows on each layer with 2.
The test is conducted in accordance with the standard rationalization and automation for civil engineering, hydraulic engineering and road engineering raw provision. The test can be conducted as a normal proctor test or, with more stringent requirements, a more arduous test. Modified proctortesting typically requires a lower. All these results have been obtained using the standard proctor and modified proctor test methods. Sep 23, 2020 details title standard and modified proctor test calculations duration 10 mins language english format mp4 size 37 mb download method direct download. Twenty different samples of fayoum sandy soil were tested and studied.
Converting modified to standard proctor soil testing. Comparison of standard and modified proctor test results for site b. This proctor test is usually specified for fill material placed under buildings, sidewalks, utility trenches, and landscape areas. Comparisons between modified proctor, standard proctor, 15blow. This results in higher maximum soil densities at lower optimum moisture contents. Density determination proctor and cbr mos grondmechanica. The procedure and equipment is essentially the same as that used for the standard test except that 5 layers of soil must be used. The corresponding figure with the modified proctor test for the mean omc for cs is 6%, which is lower than the typical value for sand at 9% oflaherty, 2012.
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