1. GRAIN SIZE ANALYSIS THE LABORATORY TEST: ΤΜΗΜΑ ΕΚΠΑΙΔΕΥΤΙΚΩΝ
ΠΟΛΙΤΙΚΩΝ ΔΟΜΙΚΩΝ ΕΡΓΩΝ
THE LABORATORY TEST:
GRAIN SIZE ANALYSIS
Ακαδημαϊκός Υπεύθυνος:
Εργαστηριακός Υπεύθυνος:
Εργαστηριακοί Συνεργάτες:
Π.Κ. Πελέκης, Αν. Καθηγητής
Π. Καλαντζάκης , Καθηγητής Εφαρμογών
Δ. Καββαδία, Γεωλόγος Msc
Β. Ξενάκη, Δρ. Πολιτικός Μηχανικός

2. 1. GRAIN SIZE ANALYSIS PURPOSE:
To determine the proportion of material of each grain size present in a given soil (grain-size distribution)

3. 1. GRAIN SIZE ANALYSIS USES: Soil Classification according to USCS.
The distibution of different grain sizes affects the engineering properties of soil.
Assesment of hydraulic permeability (Understanding of the movement of the water through soil gaps).

4. 1. GRAIN SIZE ANALYSIS
SIEVE ANALYSIS (coarse- grained soils) (sands-gravels)
HYDROMETER ANALYSIS (fine- grained soils) (mud and clay)
COMBINED ANALYSES

5. 1. GRAIN SIZE ANALYSIS SIEVE ANALYSIS COVER PLATE STACK OF SIEVES
BOTTOM PAN
SEIVE SHAKER

6. 1. GRAIN SIZE ANALYSIS HYDROMETER ANALYSYS DISTILLED HYDROMETER
THERMOMETER
HYDROMETER
VOLUMETRIC TUBE
DISTILLED
WATER
SOIL WATER SUSPENSION

7. 1. GRAIN SIZE ANALYSIS SIEVE ANALYSIS SIEVE
STANDARD SEIVE SIZES (ASTM)
SIEVE NUMBER
OPENNINGS (mm)
SOIL DESCRIPTION
SIEVE
3’’ 75
PEBBLES
11/2’’
37,5
GRAVELS
COARSE
3/4’’ 19
Νο 4
4.75
FINE
Νο 10
2.0
SAND
Νο 40
0.425
MEDIUM
Νο 200
0.075

8. 1. GRAIN SIZE ANALYSIS SIEVE ANALYSIS Apparatus:
Splitter or riffle for dividing samples.
A series of U. S standard sieves including a cover plate, a bottom pan and the Sieve shaker
Balances
Oven (stable temperature 110 ο C)
Paintbrush, 1 in., or soft wire brush, for cleaning sieves.
Mortar and rubber-covered pestle for breaking up agreggations of soil particles

9. 1. GRAIN SIZE ANALYSIS SEIVE ANALYSIS Sieving Procedure
(επιλογή κοσκίνων – ASTM D 421 – 85)
(επιλογή κοσκίνων – ASTM D 421 – 85)
(επιλογή κοσκίνων – ASTM D 421 – 85)
Sieving Procedure
Select a series of sieves with openings ranging from 3 in. to mm (No. 200). The number and sizes of sieves used for testing a given soil will depend on the range of soil sizes in the material. Weight them empty.
The size of the sample to be used will depend on the maximum particle size in the sample and the requirement that the sample be representative of the material to be tested. The sample should be limited in weight so that no sieve in the series will be overloaded.
Oven-dry the sample at ii0 f 5 C, allow to cool, and weigh..
Place the nest of sieves in the shaking machine and shake them for 3 to 5 min, more or less.

10. 1. GRAIN SIZE ANALYSIS SIEVE ANALYSIS Sieving Procedure
(επιλογή κοσκίνων – ASTM D 421 – 85)
Sieving Procedure
Weight each sieve along with the remaing sample and record it to the laboratory sheet.
Clean the material used.

11. 1. GRAIN SIZE ANALYSIS
SIEVE ANALYSIS
CALCULATIONS

12. SUM RETAINED SOIL WEIGHT PERCENTAGE SUM RETAINED SOIL
1. GRAIN SIZE ANALYSIS
SIEVE ANALYSIS
Ε , Κεφ. 7
ASTM D421 D422
SIEVE NUMBER
RETAINED SOIL WEIGHT
[1] W1
[2]
W2 
[3]
W3  …
[n]
Wn 
SUM RETAINED SOIL WEIGHT W1
W1+W2
W1+W2+W3 …
W1+W2+W3+…Wn
PERCENTAGE SUM RETAINED SOIL
WEIGHT, %
W1/ Wtotal
[W1+W2] / Wtotal
[W1+W2+W3] / Wtotal …
[W1+W2+W3+…Wn] /Wtotal
PERCENT PASSING, %
100 – [W1/ Wtotal]
100 - [W1+W2] /Wtotal
100 – [W1+W2+W3] /Wtotal …
100–[W1+W2+W3+…Wn] /Wtotal
Total soil weight(gr) : Wtotal = W1 + W2 + W3 + … + Wn + Wbottom pan
ΦΥΛΛΟ
ΔΟΚΙΜΩΝ

13. 1. GRAIN SIZE ANALYSIS

14. Operational principle
1. GRAIN SIZE ANALYSIS
HYDROMETER ANALYSIS
Operational principle
The hydrometer method of analysis is based on Stokes’ law, which relates the terminal velocity of a sphere falling freely through a fluid to the diameter.
The hydrometer determines the percentage of dispersed soil particles remaining in suspension at a given time.
It consists of a cylindrical stem and a bulb weighted with mercury or lead shot to make it float upright.
Hydrometer, calibrated at 20/20 C (68/68 F), graduated in specific gravity or grams per liter

15. 1. GRAIN SIZE ANALYSIS HYDROMETER ANALYSIS Apparatus: Distilled water
Balance
Beaker 500 ml
Calgon Dispersing Agent
Mechanical stirrer
Sedimentation cylinder of glass(volume 1 lt)
Hydrometer
Centigrade thermometer
Stop clock

16. 1. GRAIN SIZE ANALYSIS HYDROMETER ANALYSIS Procedure
(ASTM D 421 – 85)
Procedure
Collect the dried soil from 50gr up to 100gr. ( Material is taken from the bottom pan ).
Put the soil in a beaker containing a solution of 125 ml with distilled water and dispersing agent .
Transfer the soil-water slurry to the mechanical stirrer and stir for 15 min. If necessary add water.
Transfer the suspension into a 1000-ml sedimentation cylinder and add distilled or demineralized water until the volume of the suspension equals 1000 ml.
Observe and record the hydrometer readings on the data sheet after 1 and 2 min have elapsed from the time the cylinder is placed on the table

17. 1. GRAIN SIZE ANALYSIS HYDROMETER ANALYSIS COMPUTATIONS
Meniscus Correction.
(Ractual)
Hydrometers are calibrated to read correctly at the surface of the liquid.
Soil suspensions are not transparent and a reading at the surface is not possible; therefore, the hydrometer reading must be made at the upper rim of the meniscus.

18. 1. GRAIN SIZE ANALYSIS HYDROMETER ANALYSIS COMPUTATIONS
Reading Correction (R): table 1.1(it also evolves corrections for dispersing agent influence, specific gravity of water, meniscus fault, temperature correction factor)
Corrected hydrometer reading (Rc):
Rc = Ractual - R

19. 1. GRAIN SIZE ANALYSIS HYDROMETER ANALYSIS COMPUTATIONS
Particle diameter (d) in mm:
where d : particle diameter, mm
nw : viscosity of water
Gw: specific gravity of water
Gs : specific gravity of soils
L : effective height (distance between the solution surface and the depth of the measurements), cm
t :time from the beginning, min

20. 1. GRAIN SIZE ANALYSIS HYDROMETER ANALYSIS COMPUTATIONS
For the152 Η hydrometer type the calculation of percent finer is done:
where, Ps : Percent finer
α : ratio between Gs and 2,65
Rc : corrected hydrometer reading
Ws : oven-dried weight of soil, gr

21. 1. GRAIN SIZE ANALYSIS HYDROMETER ANALYSIS COMPUTATIONS
Particle diameter (d) in mm:
Percent finer %:

22. 1. GRAIN SIZE ANALYSIS

23. 1. GRAIN SIZE ANALYSIS COMBINED ANALYSIS
Includes sieve analysis and hydrometer analysis.
When a combination of the results is done we must take into account the proportions of the grains both in sieves and in hydrometer.
We adapt the hydrometer percent finer to the total
Passing from sieve Νr 200

24. 1. GRAIN SIZE ANALYSIS hydrometer Sieves D10 (ενεργός διάμετρος) D50

25. Characteristic values
1. GRAIN SIZE ANALYSIS
Characteristic values
Diameter D50 : corresponds to 50% of the passing soil. It informs us about the middle grain size that characterizes our sample
Diameter D10 : corresponds to 10% of the passing soil. It is connected to the permeability of the soil.
Uniformity coefficient (Cu)
Cu=D60 / D10
If Cu< 5 the soil is uniform.
If Cu> 15 the soil is well gradated

26. THE END

27. SPLITTER FOR DIVIDING SAMPLES
1. GRAIN SIZE ANALYSIS
SIEVE ANALYSIS
Apparatus
SPLITTER FOR DIVIDING SAMPLES

28. 1. GRAIN SIZE ANALYSIS
SIEVE ANALYSIS
Apparatus
BALANCES

29. 1. GRAIN SIZE ANALYSIS
SIEVE ANALYSIS
Apparatus:
OVEN

30. 1. GRAIN SIZE ANALYSIS
SIEVE ANALYSIS
Apparatus:
BRUSHES
PESTLE

31. SENDIMENTATION CYLINDER
1. GRAIN SIZE ANALYSIS
HYDROMETER ANALYSIS
Apparatus:
HYDROMETER
THERMOMETER
SENDIMENTATION CYLINDER
SOIL WATER SUSPENSION
DISTILLED WATER

32. 1. GRAIN SIZE ANALYSIS
HYDROMETER ANALYSIS
Apparatus:
BEAKERS

33. 1. GRAIN SIZE ANALYSIS
HYDROMETER ANALYSIS
Apparatus:
STOP CLOCKS

34. SENDIMENTATION CYLINDER
1. GRAIN SIZE ANALYSIS
HYDROMETER ANALYSIS
Apparatus:
THERMOMETER
SENDIMENTATION CYLINDER
HYDROMETER
MECHANICAL STIRRER

35. 1. GRAIN SIZE ANALYSIS
HYDROMETER ANALYSIS
Apparatus:
HYDROMETER

37. Sodium tripolyphosphate
1. GRAIN SIZE ANALYSIS
HYDROMETER ANALYSIS
Apparatus:
Dispersing Agents
Stock solution per liter
Chemical type
Sodium Hexametaphosphate
(sometimes called sodium
metaphosphate (calgon) 41
NaPO3
Sodium polyphosphate 36
Na12P10O31
Sodium tripolyphosphate 29
Na5P3O10
Sodium tetraphosphate 31
Na6P4O13

38. Maximum grain diameter (mm)
1. GRAIN SIZE ANALYSIS
HYDROMETER ANALYSIS
Time (min)
Maximum grain diameter (mm) 2
0,041 5
0,026 15
0,015 30
0,011 60
0,0074
250
0,0037
1440
0,0015