ABSTRACT
Cost efficient and robust transport systems are of critical importance to future economic prosperity as well as for the society’s social and environmental well-being. However, current performance shortcomings in the transport infrastructure formations induced by extreme climatic events associated with climate change cause excessive maintenance requirements with increased costs and disruptions to commuters and loss of productivity in the freight services.
Bio-mediated soil stabilisation is an innovative technology that improves the physical characteristics of soil using biological systems (e.g. microorganisms). This technique has substantial advantages compared to traditional chemical stabilizers (e.g. cement, lime) in terms of environmental sustainability while showing comparable performance.
In this paper, particular attention is given to the use of biopolymers and its potential application to subgrade soil. Biopolymers have high specific surfaces with electrical charges, which enable direct interactions between the finer soil particles, thereby providing biopolymer-soil matrices with higher strength. A series of unconfined compression tests were conducted to assess the potential use for subgrade stabilisation. Results indicate that small amounts of biopolymer in the order of 1% by weight are sufficient to obtain comparable strength to more established chemical stabilisers.
