Direct shear tests on sand treated with xanthan gum

Abstract

The present study aimed to discuss the applicability of biotechnologies in geotechnical engineering. For this purpose, a laboratory investigation was performed to investigate the effect of introducing a biomaterial, xanthan gum, on the behaviour of a sand using a direct shear testing apparatus. The factors addressed included the xanthan gum content and time of curing. The experimental data showed that the shear strength of the sand increased as the biological material content increased beyond 1% xanthan gum content. Increases in maximum shear stress of around 14–166% occurred in specimens with 3% xanthan gum content, and around 93–288% occurred in specimens with 5% xanthan gum content. A decrease in maximum shear stress of around of 7–60% occurred in specimens with 1% xanthan gum content. Within the range of parameters covered by the investigation, the principal factors governing the rate of this increase/decrease in maximum shear stress was the xanthan gum content. The impact of curing time was not significant. This report is intended to serve as an additional discussion and comments on the significance of collaboration between biologists and geotechnical engineers.