3. OBJECTIVE : To determine a particular soil grain size distribution(GSD)
THEORY : The experiment is carried out to determine a good distribution of aggregate by
using sieve and comparing the result obtained with BS 410. The plotted distribution curve
can give a clear picture of the quality of different sizes of aggregates. A good distribution
curve must be an ’Ideal Fuller Curve’ .
7. PROCEDURE :
1.Perform a visual classification on the soil provided.
2.Inspect your sieve stack. Check for any loose screens, holes in the screens or tears at the seams. Clean the sieve if
necessary. Use a course wire brush for larger sieve sizes, but use a soft nylon brush with smaller sieve sizes
8. 3. Collect ½ pail of fine aggregate with a division box, size 25.5mm and course aggregate with division box
size 44.445mm.
4. Divide the sample of fine aggregate with a division box, size 25.4mm and course aggregate with division
box size 44.45mm
5. Weigh accurately 500g of fine aggregate and 2000g of course aggregate.
6. Use a sieve with diameter 20.32mm to 2.4mm for fine aggregate and 30.48mm to 7.76mm for coarse
aggregate.
9. 7. Place your sieves in a stack of increasing sieve number- this corresponds to decreasing opening size. The largest
sieve opening should be on top, and the pan at the bottom.
8. Pour the prepared aggregate sample into the top if the sieve and place the cover tightly on top.
10. 9. Place the sieve stacked into the sieve shaker and secure the top clamp.
10. Set the timer attached to the shaker for 10 minutes. The shaker will now start.
11. When the sieve shaker has stopped, remove the sieve stack.
11. 12. Carefully disassemble the sieve stack the sieves will tend to be stuck to one another quiet tightly. If you force
them apart, you may end up scattering the aggregate inside all over the laboratory. Try to use a twisting motion to
separate the sieves. If all else fails, use a wedge which should be located by the sieve rack.
13. Now, record the mass of each sieve (and the pan) with it’s contents. Since you’ve already obtained the sieve’s
masses, you can now determine the amount of soil retained on each sieve.
12.
13. ANALYSIS
Percentage retained : weight retained
( % ) (Rn) weight of sample
Weight passing through : weight of sample – weight retained
Percentage passing through: weight passing through
weight of sample
x 100 %
14. Sample of aggregate : Sand
Weight of sample : 500g
Sieve no. Weight
Retained (g)
Percentage
Retained
(%)
Weight
Passing
Through(g)
Percentage
Passing
Through(%)
Cumulative
% Retained
Cumulative
% Passing
Through
2.36 8 1.6 491 98.4 1.6 98.4
1.18 102 20.44 397 79.56 22.04 77.96
0.60 166 33.27 333 66.73 55.31 44.69
0.25 144 28.86 355 71.14 84.17 15.83
0.212 37 7.41 462 92.6 91.58 8.42
pan 42 8.42 457 91.6 100 0
∑=499 g ∑=100 %
RESULTS :
1. Analyse the result obtained, by drawing the distribution curve in the graph given. Determine the
various zone of aggregate with the analysed result and compare it with Grading Standard MS 7.4.
Discuss the differences.