Test For Clay Lumps And Friable Particles

Objective of Clay Lumps And Friable Particles

At times, in natural aggregates, friable and clay particles are present in the form of lumps. And, if they are close to surface, then lumps can result in dent under the impact of traffic. Thus, these particles can be made limited specifically to approx 1%.

Equipment And Materials
Weighing device as accurate to 0.1%
Flat pans to spread the specimens of test in a thin layer
Sieves for the Testing Procedure
Drying oven
Proper amount of test samples

Test Procedure For Clay Lumps And Friable Particles Prepare test samples as per the ASTM Designation. The sample should contain fine aggregates consist of particles retained on a 1.18-mm (No. 16) sieve and weigh at sieve and weight of approx 25 grams.
Clay Lanps and Friable Particles Making Up Test Sample Minimum Weight of Test Sample
4.75 to 9.5 mm (No. 4 to 3/8 inch sieves) 1000 Grams
9.5 to 19.0 mm (3/8 to .3/4inch sieves) 2000 Grams
19.0 to 37.5 mm (3/4 to 1.5 inch sieves) 3000 Grams
Retained on 37.5 mm (1.5 inch sieve) 5000 Grams


Se-Test sample consists of both fine and coarse aggregates, the material is separated on a 4.75-mm (No. 4) sieve. The fine and coarse fractions are then handled as above.

Now the weighed specimen should be made to spread in a thin layer on the surface of the container which remains shielded for approx 24 hours with the distilled water.

Make sure to turn and squeeze the particles that are there between the forefinger and the thumb. Such particles which can be classified in this manner, are then sorted into friable particle and clay lumps.

Now separate the detritus from the remaining of the sample through the help of wet sieving or by following the given process.
Clay Lamps and Friable Particles Making Up Test Sample Minimum Weight of Test Sample
Fine Aggregate 850 μm (No. 20)
4.75 to 9.5 mm (No. 4 to 3/8 inch) 2.36 mm (No. 8)
9.5 to 19.0 mm (3/8 to 3/4 inch) 4.75 mm (No. 4)
19.0 to 37.5 mm (3/4 to 1.5 inches) 4.75 mm (No. 4)
Over Fine Aggregate 37.5 mm (1.5 inches) 4.75 mm (No. 4)


Get rid of the retained particles and try doing a proper weight at 110°±5°C (230°±9°F). temperature in the oven. Let the aggregates cool and then weigh the same to the nearest 0.1%.

Calculations For Clay Lumps And Friable Particles

P = (W − R)/W × 100
P = % of based upon the weighted average of the clay lumps and friable particles
W = weight for test sample
R = weight of particles maintained on the designated sieve in wet sieving


For coarse aggregates, P shall be based upon the weighted average of the clay lumps and friable particles in each sieve size fraction. Any coarse aggregate fraction that is less than 5% of the total gradation shall not be tested separately. Se-Test India aggregate fraction shall be assumed to contain the same percent of clay lumps and friable particles as that to the larger or smaller coarse aggregate fraction.
Written by:- civillabequipment for Cement