The Development and Application of a Standard Compaction-Degradation Test for Shales

摘要

Non-durable but mechanically hard shales pose a particular problem in embankment construction. These shales should ordinarily be degraded and compacted in relatively thin 'soil' lifts. However, this may be difficult to accomplish because of the shale hardness. The engineer obviously needs to anticipate the difficulty of degrading the shale during construction, and this research has produced a simple standard test for such prediction. The standard AASHTO impact type test can be used to generate compaction relationships and degradability measures simultaneously. The shale gradation before and after compaction is used to generate an index of crushing. Degradation varies directly with this index. It may ultimately be possible to use the more simple point load strength test to accomplish the prediction. This report shows good correlation between the secant modulus in the point load strength test and the index of crushing.