DETERMINATION OF % SILT CONTENT IN FINE AGGREGATES-Silt content test describe below is field test to find out volumetric percentage of silt in fine aggregates. More detail and accurate test is describe in IS 2386 – Part 2. However generally field test procedure describe below is used as this is quick and simple method which gives fairly accurate results.
Silt content
Material and Apparatus
1.Fine aggregate
2.Potable water
3.Common salt
4.Measuring cylinder of 50 ml capacity.
Test Procedure:
Fill potable water in measuring cylinder up to 50 ml mark. Add pinch of common salt and stir it till salt completely dissolve in the water. Salt is added to quick settlement of silt which reduces testing time.
Gradually add fine aggregate into salty water till the mark of 30 ml.(Record height of fine aggregate as V1)
Shake the mixture of sand and salt solution well and keep it undisturbed for about 15-20 minutes.
Fine aggregates particles settle down quickly. Silt, being finer material settle down at the end.
Measure the height of silt content layer and record (V2).