improving behavioral properties of dispersive clay by addition of incinerated sewage sludge ash and hydrated lime

One of the methods to improve the quality of dispersive clays to reduce its washout tendency is to add lime with a proportion of 4% in construction projects. besides, adding lime will lead to the stabilization of the soil furthermore. therefore, if the stability of soil is of concern, some portion of soil may be replaced by lime. in this paper, the incinerated sewage sludge ash (issa), mixed with hydrated lime by appropriate proportions and about the duration of the curing process, was used to improve specifications and parameters of dispersive clay. afterward, the effect of this mixture on unconfined compressive strength relying on the dispersive properties of soil and the curing process of the combination was investigated at different periods. this research aims is to investigate the cementation process of dispersive clay with the addition of issa and i.l mixturet to curing durations. both mixtures were added to dispersive clay in 2, 4, 8, and 16 percent by weight. also, the proportion of issa to hydrated lime is 4: 1 in weight.  results of the tests showed that the unconfined compressive strength of the test specimens was increased by more than three times compared to the pure clay by adding hydrated lime and issa, indicating numerous potential applications of the mixture for soil improvement and administrative affairs in geotechnical engineering as well as practical applications in environmental engineering.