APPLICABILITY OF MIXTURE GEOMATERIAL OF LIGHTWEIGHT EMBANKMENT MATERIAL AND SILICA SAND TO SUBBASE COURSE

Abstract

 As roads often have a residual settlement on soft foundations, reducing the weight of the subbase course is an alternative way to solve this problem. In this study, the applicability of lightweight geo-materials made from expansive shale and sewage sludge to pavement subbase was investigated by conducting CBR tests, and triaxial tests under two types of confining pressure and with or without 10,000 cycles of cyclic loading on three samples that were simply adjusted in particle size by mixing with silica sand.

 The test results showed that there was a clear trend between the mixing ratio and CBR, and that under all conditions, the strength did not decrease, showing a similar trend to crushed stone, and by applying cyclic loading, the deformation modulus increased from the same level to about 20% at the maximum load equivalent axial strain level. In addition, an appropriate particle size with both stiffness and lightness was proposed.