(a)    Coarse aggregates (retained on 4.76 mm sieve)

I     Flakiness index- max. 20%

      Elongation index- max 35%

II   Los Angeles abrasion test- max 25%

III  Water Absorption for each fraction- max 3.0%

      Average- max 2.5%

IV  Density gr/cm³- min 2.5

V    Clay particles - max 0.5% 

(b)   Fine aggregates (passing sieve 4.76 mm)

NOTE: The tests must be conducted on the raw material before entering  the dryer drum. 

I Liquid limit     max 25

II Plasticity index max 3%

III Sand equivalent min 50%

IV Clay praticles max 0.5%

For many years we have never encounterd any problem related to the plasticity requirements of fine aggraegates. However , in one of our dolomite quarries in which clean rocks are crushed - all the requirements are met but for the sand equivalent value which is about 35-40.

I would appreciate any comment on the engineering implications of this case

Thanks