CONTENTS

J. Duhok Univ., Vol.14, No.1 (Pure and Eng. Sciences), Pp 39-51, 2011
Each of these 14 samples were tested and
subjected to two cycles of slaking, the slake
durability index (Id2 % ) of the second-cycle was
calculated as:
Weight of shale remaining inside drum
Original weight of sample .
Fig. (9): Slake durability test.
x 100
The soil-like shale (rocks that disintegrated
through slaking) with slake durability indexes of
less than 80% were then further characterized by
measuring the plasticity index of fragments
passing through the slake drum mesh, Lama and
Vutukuri, (1978). While the rocks-like shale
with slake durability indexes greater than 80%
Table (2): Two cycles slake-durability (Id2) classification,
ASTM. (1992) and others.
Slake Durability, (Id2) % Classification
00 -30
30-60
60- 85
85- 95
95- 98
98-100
The second-cycle was considered for the
classification purposes. The results were firstly,
classified qualitatively using the following
classification method, adopted by the Geological
Society, (1977); ISRM, (1979b), Franklin J.A.
(1981) , ASTM, D-4644-87. (1992), Table (2).
Very low
Low
Medium
Medium to high
High
Very high
were tested to determine their strength using
point load strength index ( Is50) test, the result
data are shown in table (3). The test was
conducted on shale at natural water content and
the load applied perpendicular to the bedding
when tested for its strength.
04