Abstract:

Fly ash is a byproduct dumped out of thermal power plants which use coal as one kind of fuel. It is urgent to consider how the vast quantity of harmful fly ash resources can be utilized. There are a large number of potential solutions to this problem; an effective disposal method is to use it as a fill material for dam construction or filled ground. Fly ash is a uncompacted lightweight material with a lot of pores. On one hand, it has a superior engineering capability in many aspects; On the other hand, pure fly ash lacks any necessary cohesion so that it has a very sensitive reaction with water which is an undesirable effect on the safe operation of the project which employs pure fly ash. Based on above considered, the engineering performance of the fly ash can potentially be enhanced by mixing different quantities of clay into fly ash, therefore the study of mechanical properties of fly ash mixed with different quantities of clay could help to promote the engineering application of fly ash. The fly ash taking from the Xianyang Weihe Thermal Power Plant as the object of study, and different quantities of loess are used to obtain the mixed-soil fly ash, then the engineering characteristics of fly ash with different quantities of soil mixed are studied via compaction test, compression test, and direct shear test as well as triaxial compression test. Furthermore, the trends of influence of different quantities of soil mixed on deformation and strength characteristics of fly ash are also obtained. The research results will offer the basis for both the effective utilization of fly ash and the improvement of its engineering property.

Key words: fly ash, mixtures, engineering property, experiment study