Some factors affecting deformation and strength of coal ash

The deformation and strength of coal ash when compacted at the state of maximum dry density, p(dmax) was observed in triaxial apparatus. Developments of both stiffness and strength with aging were examined using coal ashes showing various composition of the chemical substances. The test results have been interpreted as the growth of cementation that is responsible for the time-dependent behaviour induced by pozzolan reaction of fly ash. Some factors to govern the time- and stress-dependent properties, such as the contents of carbon and calcium oxide, and the current confining pressure, together with its history are each investigated. A practical scheme is proposed how we possibly improve the properties of coal ash in use for geotechnical engineering works.