STANDARDIZED TESTS FOR COMPACTED SHALE HIGHWAY EMBANKMENTS

Economic considerations often dictate the use of shales in embankments. However, due to the nature of some shales, the embankment may deteriorate with time. Research that defined a series of laboratory tests and a numerical classification system (after Franklin) to be used to predict the performance of shales as embankment materials is described. The criteria for the tests are simplicity, economic and rapid evaluation, use of existing standard testing equipment, clear distinction between suitable and nonsuitable shales, and sufficient range to test most shales. Many tests, therefore, are simply standard tests modified for soft rock. The tests selected are Atterberg limits, five-cycle slake resistance, slake durability, point load strength, impact compaction-degradation, compaction moisture density, one-dimensional consolidation, and triaxial shear. Summarized procedures and discussions of each of these tests are presented. (Author)