Multi-functional performance of biopolymers and biocement in stabilisation of road bases

Abstract

To achieve the sustainability goals, Australia must dramatically reduce use of cement for stabilisation of soil used in road bases. Bio-based binders for soil stabilization are potential alternatives. Biocementation through Microbially Induced Calcite Precipitation (MICP) is well researched. Some research on biopolymeric stabilization is also available. This paper explores the synergistic effect of combined biopolymer and biocement for the stabilization of sandy soil and road bases. The soil has been stabilised using both biopolymer xanthan gum and MICP. The synergy between biopolymer and MICP has been evaluated by giving a few samples a combined treatment. The performance has been evaluated by compressive strength tests, micrographic analysis and water absorption. Although biopolymer treatment improved the compressive strength it degraded significantly in presence of water. Relatively high water absorption of xanthan gum could be mitigated by MICP. The study demonstrates that MICP surface coating is a sustainable solution to overcome this limitation of biopolymer. Likewise, the addition of biopolymers reduces the release of ammonia from MICP. The present study unravels the potential of a composite bio-treatment for stabilisation of road bases.

Increased Microbially Induced Calcium Carbonate Precipitation (MICP) Efficiency in Multiple Treatment Sand Biocementation Processes by Augmentation of Cementation Medium with Ammonium Chloride

“…Findings would give further insights into improving resource use efficiency in MICP treatments. Furthermore, a reduction in the use of Portland cement for the stabilisation of soil, for applications such as road bases [30], will contribute to achieving the UN Sustainable Development Goals.…”

Experimental Study on Enhancing the Mechanical Properties of Sandy Soil by Combining Microbial Mineralization Technology with Silty Soil

“…For instance, Kumar et al [26] observed a significant increase in the strength under the unconfined strength compression (USC) test when the soil contained substantial clay contents. Ramachandran et al [27] noted that incorporating xanthan gum into soil improves roadbed stability. Nikseresht et al [28] demonstrated that the addition of sugar cane molasses and vinasse enhances calcium carbonate production.…”