Lab Report Sieve Analysis

A H M 531

Sieve analysis

By: Ahmed Essam Mansour

Objectives: 1. To determine the grading or the size distribution of the aggregates using the sieve analysis. 2. To determine the fineness modulus. 3. To draw the grading curve of pile of aggregate.

Standards: ¾ B.S. 882 ¾ ASTM C – 136

A H M 531 The Civil Engineering Center General Discussion:

¾ ASTM E – 11 for the general specification of sieves.

Sieve analysis is the process of dividing a sample of aggregate into fraction of the same size. The purpose of doing this analysis is to determine the grading or size distribution of the aggregate which is important to find out whether the aggregate pile we are studying is good for the mix or not. The grading of the aggregate usually affects on the workability of the fresh concrete. The aggregate of interest is thrown into a series of sieves nested in order with the smallest at the bottom, and after shaking the mass of retained aggregate in each sieve is calculated. The aggregate we use in our experiment should be representative to the pile we obtained it from, so we can’t just take the mass we need for the experiment arbitrary because this arbitrary specimen might not contain a certain size of the aggregate. For that reason the Quartering Method is used, this method involves taking a big amount of aggregate from the pile of interest (more than the amount we need) and then divide them into quarters or halves till we gain the amount we need for the experiment. The Civil Engineering Center

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A H M 531

Sieve analysis

By: Ahmed Essam Mansour

A sieve have square opening and are usually constructed of wire mesh. In this analysis certain sizes of sieves should be used to get a desired and accepted results, these sieves are determined by ASTM E – 11 as mentioned in the specifications. The nested sieves we use every next sieve (starting from the smallest) is twice the size of sieve preceding it. After sieving the specimen, we calculate the retained mass in each sieve and a table is made and the grade curve is drawn. The table should contain the following columns: Sieve size, Mass retained, Percentage retained, Cumulative percentage passing and Cumulative percentage retained. The percentage retained can be gained by the following formula: mass retained \ total mass x 100% The grading curve is drawn by using the information of the table. The grading curve represents the relationship between the Sieve size (the abscissa) and the Cumulative percentage passing (the ordinates), we use the logarithmic scale to plot the graph. The standards usually give an Upper limit graph and a lower limit graph so that our graph should be between these 2 graph to be usable in mixes. The graph is drawn be drawing line segments between the points.

A H M 531 The Civil Engineering Center

Fineness Modulus is a measure to the grading of an aggregate pile, and it is used to compare aggregate that are gained from the same source. It can be defined as the sum of the Cumulative percentage retained on the sieves of the standard series divided by 100. The sieve analysis can be done in two methods, a wet method and a dry method, but as the wet method takes more time we have done the dry method.

Apparatus and Materials: 1. 2. 3. 4. 5. 6.

Set of sieves. A dried specimen of aggregate. Trays. Electronic weighting machine. Mechanical shaker. Riffle box.

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A H M 531

Sieve analysis

By: Ahmed Essam Mansour

Procedures: 1. We put the dried aggregate specimen into the sample splitter and reduce the amount till we get 2 kg of the specimen. 2. After nesting the sieves in order (starting from the smaller at the bottom) the aggregate specimen is thrown into the sieves. 3. The nested sieves are then moved to the mechanical shaker and left there for 15 minutes. 4. Then the weight of the retained aggregate in each sieve is calculated using the Electronic weighting machine. 5. Table of the results is established and the Grading curve is drawn.

Results and Calculations: A H M 531 The obtained results are tabulated in the following table: The Civil Engineering Center Sieve no # ------------#4 #8 # 16 # 30 # 50 # 100 # 200 ----Total

Sieve Size 19 mm 12.5 mm 9.5 mm 4.75 mm 2.36 mm 1.18 mm 0.6 mm 0.3 mm 0.15 mm 0.025 mm PAN

Mass Retained g

Percent Retained

88 542 391 515 321 83 18 8 5 7 26 2004

4.4 27.0 19.5 25.7 16.0 4.1 0.9 0.4 0.2 0.3 1.3

Cumulative Percentage Passing 96 69 49 24 7.4 3.3 2.4 2 1.8 1.5 -----

Cumulative Percentage Retained 4.4 31 51 76 92 96 97 98 98.2 98.5 -----742.1

Fineness modulus = 7.421

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A H M 531

Sieve analysis

By: Ahmed Essam Mansour

The following table shows the upper limit and the lower limit of the aggregate we studied as specified in standards:

Sieve Size 19 mm 9.5 mm 4.75 mm 2.36 mm 1.18 mm 0.6 mm 0.3 mm 0.15 mm 0.025 mm

Cumulative Passing Percentage Lower Limit Upper Limit 70 100 50 75 35 60 27 45 20 35 12 25 5 15 1 5 0 5

Conclusion: A H M 531 The Civil Engineering Center The aggregate we studied consists of coarse aggregate mainly; I noted that from the fineness modulus. From the Grading graph we note that the aggregate we have tested are not good for using in mixes, as the graph doesn’t lie between the upper limit and the lower limit.

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