The ultimate shear strength of the fly ash-improved sands

Abstract

The mechanical properties improvement of sands using industrial waste such as FA has been used extensively to mitigate shearing failure. The shear strength of FA-improved sand holds an essential role in this thing. This technique’s efficacy is determined not only from the shear strength at peak state but also at an ultimate circumstance. In that case, a series of direct shear strength tests were performed on both FA-improved sand and pure sand. The testing parameters were FA amount, sizes of the sand grain, and organic content. Ultimate shear strengths on those parameters are observed systematically and compared to each other. The test results show that the ultimate shear strength increases with FA amount in the specimen, grain sizes of the sand, and diminishing organic content. A bigger size of the grains, resulting from the FA bond, generates a higher internal friction angle directly associated with ultimate shear strength gain. On the other hand, the existence of organic content in the FA-improved sands impedes the refinement of the ultimate shear strength. At the ultimate state, FA-improved sands behave as ordinary sands purely frictional.