I want you to paraphrase this discussion Discussion: This test is performed for

Question

I want you to paraphrase this discussion

Discussion:

               This test is performed for a variety of reasons. Firstly, in this report, the sieve analysis was performed to see if a soil is suitable for use in concrete as outlined in MTO standards. This test may also be performed for a relatively simple indication as to the performance of a soil as an engineering material in a variety of different functions. Knowing the grade of a soil may allow an engineer to predict how the soil will perform as a drainage material, how a soil will respond to the load of a foundation upon it, the susceptibility of a soil to deform from the action of frost, its potential to swell with the introduction of water, and even its ability to passively filter water that passes through it.

               Although this test used a large stack of sieves to give a rather fine approximation of the grade of the soil as it passed through many incrementally finer openings, certain properties of a soil may be determined with a much smaller stack of sieves. Under the Unified Soil Classification system, for instance, only two sieves (the No. 4 and the No. 200 sieves) are required to differentiate a soil between gravels, sands, and silts or clays. Immediately, a field engineer would have some insight into the soils drainage capacity and ability to provide filtration. The stack of sieves employed in this test is required, however, to fully classify since both the Coefficient of Uniformity and the Coefficient of Concavity require an insight into intermediate particle sizes between these the No. 4 and No. 200 sieves and the rate of change in particle sizes between them.

               Several sources of error are associated with this test. Firstly, some amount of soil may be lost as the test is conducted. This could be a result of fine particles not settling after the agitation portion of the test, fine particles being lost as the sample is transferred to the weighing dish from the sieve, or particles of any size being lodged in the mesh of the sieve. It is impossible to predict what size of particles would have been lost in these ways, but it is likely that finer particles would have been lost. As such, there would be a higher content of silts in the actual soil than what is indicated by these results. Furthermore, the sieves used in this particular test were damaged by improper handling before this test was conducted. The soil was not washed during the sieve analysis, this too would contribute to a higher content of silts in the soil than what is indicated by the results in this report. Finally, there is an inherent error with the accuracy of the balance, likely a loss of sensitivity, which would become apparent as the sample is divided into smaller portions after the sieve analysis compared to what was initially weighed before the test was performed. Fortunately, however, only 0.6% of the mass is unaccounted for. Aside from the decision not to wash the sample, whatever errors associated with this test do not significantly impact the validity of the results obtained.

Explanation / Answer

A test is performed to know the grain size. The Sieve analysis is done to know the size, nature of the grain. This test determines the relative proportion of different grain size as they are distributed among different size range.

This test is widely used to understand the classification of the soil, whether the soils is suitable for the function or not for its use as a concrete building material. The soils suitability is test on the basis of the MTO standards.

This test is also used to know the nature of the soil, by doing this analysis, the soils can be identified as to what purpose of engineering material the soil can be used, what are the specific functions of the soil. By knowing the grade (variety) of the soil, an engineer can identify if the soil is suitable for drainage material, what will happen to soils in case of fluctuation of load on the foundation soil. The nature of the soil is predicted based on the conditions like frost, if the water level on the soil is increased then whether the soil will swell or not or can it filter the water passively or not. Information obtained from the analysis can be used to predict soil water movement.

This test is performed using the nested column of sieves which includes wire mashed cloth or Stack of Sieves including pan and cover. While performing the test the grains passes through minute openings which helps in understanding the approximate size of the grains, certain other properties of soils is determined by using a smaller stack of sieves. By using the analysis, soil can also be classified and an engineer can identify the difference in the soil. Under the Unified Soil Classification system, for instance, only two sieves (the No. 4 and the No. 200 sieves) are required to differentiate a soil between gravels, sands, and silts or clays. By using this test, an engineer can identify the soils drainage capacity and can also know to what extend the filtration can be done by the soil. The stack of sieves employed in this test is required, however, to fully classify since both the Coefficient of Uniformity and the Coefficient of Concavity require an insight into intermediate particle sizes between these the No. 4 and No. 200 sieves and the rate of change in particle sizes between them.

Although Sieve test is widely used to identify the properties of the grain, there are several limitations to this test as well.

Since it is not possible to tell what size of particles are lost during the process, however it is very obvious that higher the particle, more chances of it is there to get lost during the process. This concludes that due to improper handling of the material, the sieve analysis will not give exact nature of soil.

Since after performing the test whatever error is resulted by the test will not impact the validity of the results.

Related Questions

Navigate

• Browse (All)
• Browse I
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.