Emissions assessment related to the use of vibro-stone columns

This paper investigates a number of issues significant to the evaluation of the sustainability of vibro stone columns and, in so doing, discusses how a carbon dioxide emissions estimation tool could be developed for this area of ground improvement. It involves consideration of the use of recycled/secondary aggregates and how this choice affects the column design process, in terms of the durability of constructed works and the amounts of aggregates required. The paper concludes that assessing the sustainability of vibro stone column construction, in carbon dioxide emissions terms, is a complex process not based simply on whether recycled/secondary aggregates themselves are more ‘environmentally friendly' than primary aggregates. Instead, it requires care on the part of ground improvement engineers, who must balance geographical variation of aggregate sources against the amount of aggregate used in the vibro stone column construction. However, it is noted that the use of carbon dioxide provides a limited view of sustainable performance, and that the continued development of emerging assessment tools could help capture some of the true complexity of the decision-making process.