A Laboratory Measurement of The Hydraulic Conductivity of Fragmented Gravels

Resumé

Due to severe environmental conditions and the action of different type of loading forces, granular materials that form the base of a road pavement may be subjected to crushing and fragmentation. The effect of the small fragments that move into the voids as a result of crushing is that they may have increased the bearing capacity of the base material. However, when the volume of the voids is decreased due to the migration, the flow ability of the material is said to reduce. This change in the engineering property of the material may lead to an undesirable drainage pattern within the pavement. A number of laboratory tests were conducted and repeated whereby small gravels were gradually fragmented and the hydraulic conductivity of the materials were measured. In this study, the pattern of fragmentation of different gravels was analyzed using fractal theory and the hydraulic conductivity of the gravels before and after different stages of fragmentation were measured. From the measurement of fractal dimension number in the fragmented rock it was found that as the fractal dimension is increased the hydraulic conductivity of the material is decreased.