Soil in general - IS 1498

Boulders - above 300 mm, Cobble- 300 to 80 mm, Gravels - 80 mm to 4.75 mm, Sand - 4.75 mm to 75 micron, Silts- 75 micron to 2 micron , Clay below 2 microns
if more than 50 % of soil (whole retain on 75 micron IS sieve) is retaining on 4.75 mm IS sieve is called Gravels and denoted by G, and if more than 50 % of soil (whole retain on 75 IS sieve) is retaining on 75 micron IS sieve is called Sandy soil and denoted by S

Clay - CL,Silts - ML,Gravel - G,Well graded gravels - GW,Gravel Clays - GC etc

As per IS 1498 -  'A' line representing high liquid limit more than 50 - H, modrate liquid limit between 35 to 50 - M, Low liquid limit below 35 - L
Soil particles passing 75 micron IS sieve between 5% to 12 % need to detailed studied for their behavior
Normally soils having particles more than 12% passing 75 micron IS sieve behaves like cohessive soils, e.g. clay
Coarse grained soils having particles less than 5% passing 75 micron IS sieve are cohesion less soils, e.g sands, gravel

Sulphates in soils - should be less than 0.2 % in use of Ordinary portlald, portland slag, Portland pozzolona cement, may be above than 2 %  for sulphate resistant portland , super sulphate cement with protective coatings over concrete.

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