Particle Size Distribution Analysis
The gradation of the soil in our online Particle Size Analysis introduction can be used for classification in line with Practice D2487. The particle size analysis by sieving (particle size distribution analysis) curve is used to compute the coefficient of uniformity as well as the coefficient of curvature.
Choice and approval of fill materials are usually based on gradation. For instance, highway embankments, backfills, and earthen dams may have gradation requirements.
Particle Size Analysis Selections
Selection of choices for dynamic compaction and grouting is related to gradation of the soil.
The gradation of a land is an indicator of technology properties. But, engineering behaviour depends upon many variables (for instance, effective stress, anxiety background, mineral type, structure, plasticity, and geologic origins) and cannot be based solely upon gradation.
NOTE 1: The quality of the outcome produced by these evaluation methods is dependent on the competence of their employees performing it, and also the suitability of their facilities and equipment utilized. Agencies that meet the criteria of Practice D3740 are generally considered capable of capable and objective testing/sampling/inspection/etc.. Users of these evaluation methods are cautioned that compliance with Exercise D3740 doesn’t in itself guarantee reliable results. Reliable results are dependent on many factors; Practice D3740 provides a means of assessing a few of those variables.
Soils consist of particles with several shapes and sizes. This test system is used to separate particles into size ranges and also to determine quantitatively the bulk of particles in each range. These statistics are combined to determine the particle-size distribution (gradation). This test method uses a square opening sieve criterion in determining the gradation of dirt between the 3-in. (75-mm) and No. 200 (75-µm) sieves.
In scenarios where the gradation of particles bigger than 3 . (75 mm) sieve is needed, Test Method D5519 may be used.
In the end, in the event the maximum particle dimension is equivalent to or higher than 19.0 mm (3/4-in sieve), composite sieving is appropriate. For special conditions see 10.3.
Online Particle Size Analysis Introduction
Two test methods are provided in this standard. The methods differ in the significant digits recorded and also the size of the noun (mass) required. The method to be used may be given by the requesting authority; otherwise Method A shall be performed.
Method A–The percentage (by mass) passing each sieve size is recorded to the nearest 1 percent. This method must be used when performing composite sieving.
Method B–The percentage (by mass) passing each sieve size is recorded to the nearest 0.1 percent.
This test method doesn’t cover, in any detail, procurement of this sample. It is assumed that the sample is obtained using proper methods and is agent.
Soil Sample Processing
Three processes (moist, air dry, and oven dry) are supplied to process the sample to obtain a specimen. The process chosen will be based on the kind of sample, the maximum particle-size from the sample, the assortment of particle sizes, the first conditions of the material, the plasticity of the substance, the efficiency, and the demand for other testing on the sample. The procedure may be given by the requesting authority; differently the guidance given in Section 10 shall be followed.
This evaluation method typically requires two or three times to complete, depending on the type and size of this soil and sample type.
This test method Isn’t applicable for the following lands:
Soils containing fibrous peat which will change in particle size through the drying, washing, or sieving process.
Soils containing extraneous matter, such as organic solvents, oil, asphalt, wood fragments, or comparable items. Such extraneous issue can affect the washing and sieving procedures.
Issues with test method
This test method may not produce consistent evaluation results within and between laboratories for the subsequent soils and the accuracy statement doesn’t apply to them.
Friable lands in which the sieving procedures change the gradation of the ground. Common examples of these soils are several residual lands, most weathered shales and some weakly cemented soils like hardpan, caliche or coquina.
Soils that won’t readily disperse for example glauconitic clays or some dried plastic clays.
To test these lands, this evaluation method has to be adapted, or modified, and such alterations documented. Depending on the design factors, a technical gradation-testing program could be performed. The alterations could necessitate the washing and sieving procedures to be standardized such that each specimen would be processed in an identical manner.
Some substances which aren’t soils, but are composed of particles may be examined using this technique. On the other hand, the important sections above should be used in applying this standard.
Calculations – Particle Size Analysis
All calculated and observed values shall conform to the guidelines for significant digits and rounding established in Practice D6026, unless superseded by this test method.
The processes used to specify how information are collected/recorded and calculated within this standard are considered as the industry norm. In addition, they are representative of the significant digits that normally should be retained. The procedures used don’t consider material variation, purpose for obtaining the data, special function studies, or some other considerations for the user’s objectives; and it’s common practice to raise or decrease significant digits of documented information to be commensurate with those factors. It is beyond the range of these evaluation methods to consider substantial digits used in analysis methods for technology design.
Units
The dimensional values stated in either SI units or inch-pound components must be considered standard, like 200-mm or even 8-in. diameter sieve. But the sieve designations are generally identified using the “option” system in accordance with Practice E11, such as 3 in. And No. 200, instead of the “standard” method of 75 mm and 75 µm, respectively. Just the SI units are used for mass determinations, calculations, and reported outcomes. On the other hand, the use of balances or scales recording pounds of mass (lbm) will not be regarded as nonconformance with this standard.