Building Materials, Third Edition

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flow has been reached and the out flow is considered as average of all the out flows measured
during this period of 100 hours.
The quantity of water percolating through it during a given interval of time is measured and
the coefficient of permeability (k) is calculated.

k = (/)

Q

ATH L

where, Q is the quantity of water (ml) percolating over the entire period of the test after the
steady state has been reached; A is the area of specimen face in cm^2 ; T is the time in seconds over
which Q is measured; and H/L is the ratio of pressure head to thickness of specimen.