Sustainable utilization of biopolymers and biocement in aggregation of granular materials

Abstract

Soil stabilisation through materials such as lime or cement have considerable environmental penalty due to high embodied energy of the cementitious material. Bio-geotechnology allows cement formation with dramatically reduced carbon footprint and promises a sustainable soil improvement method. In the current study, investigations were performed to evaluate the effect of biopolymer Xanthan gum and Microbially Induced Calcite Precipitation (MICP) on cementation of sands as well as sand-clay mixtures individually as well as in combination. The unconfined compressive strength tests and micrographic analysis through scanning electron microscope and energy dispersive X-ray spectroscopy results revealed that synergistic effect of biopolymer and MICP resulted in superior performance. Water absorption test indicated that the Xanthan gum was susceptible to water attack and incorporation of MICP helped in addressing the concern. Therefore, the present study was successful in overcoming the individual limitations of biopolymer and MICP as a sustainable soil stabilisation technology.